Linkages of acute care and emergency medical services to state and local public health programs: the role of interactive information systems for responding to events resulting in mass injury()


Proposal for vaccination against SARS coronavirus using avian infectious bronchitis virus strain H from The Netherlands


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docid: ljqrxjvv

title: 04 – Apport des explorations microbiologiques au diagnostic des infections des voies respiratoires basses

text: The diagnosis of community-acquired pneumonia is usually based on clinical and radiological criteria. The identification of a causative organism is not required for the diagnosis. Although numerous microbiological techniques are available, their sensitivity and specificity are not high enough to guide first-line antimicrobial therapy. Consequently, this treatment remains most often empiric. If the causative organism is identified, the antimicrobial treatment is adapted. Sputum analysis may be proposed as a diagnostic tool for patients with an acute exacerbation of chronic obstructive pulmonary disease, in specific cases (prior antibiotherapy, hospitalization, failure of the empiric antimicrobial treatment).


title: Experimental infection of piglets with Cryptosporidium

text: Piglets from five litters were dosed orally with Cryptosporidium originally derived from diarrhoeic calves. The piglets were either nursed by the sow, artificially reared after sucking colostrum, or weaned on to creep feed. Colostrum-fed, artificially reared piglets obtained from two litters and exposed in the first week of life developed clinical signs of inappetence, vomiting and diarrhoea and shed oocysts in the faeces. Histologically the parasite was observed throughout the small and large intestine attached to epithelial cell surfaces and its presence was associated with extensive mucosal damage, particularly in the posterior small intestine, stunting and fusion of villi, immaturity of villous epithelial cells and oedema with increased cellularity of the lamina propria. Piglets from two other litters, both sucking and colostrum-fed artificially reared, exhibited similar but milder clinical signs. Histological lesions were less severe and Cryptosporidium infection less extensive. When weaned piglets were exposed they remained clinically healthy although histologically there was evidence of Cryptosporidium attachment in the small intestine and minor mucosal damage. There appears to be a good correlation between the extent of intestinal infection, the degree of mucosal damage and the severity of clinical disease induced by Cryptosporidium in piglets.


title: Template for documenting and reporting data in physician-staffed pre-hospital services: a consensus-based update

text: BACKGROUND: Physician-staffed emergency medical services (p-EMS) are resource demanding, and research is needed to evaluate any potential effects of p-EMS. Templates, designed through expert agreement, are valuable and feasible, but they need to be updated on a regular basis due to developments in available equipment and treatment options. In 2011, a consensus-based template documenting and reporting data in p-EMS was published. We aimed to revise and update the template for documenting and reporting in p-EMS. METHODS: A Delphi method was applied to achieve a consensus from a panel of selected European experts. The experts were blinded to each other until a consensus was reached, and all responses were anonymized. The experts were asked to propose variables within five predefined sections. There was also an optional sixth section for variables that did not fit into the pre-defined sections. Experts were asked to review and rate all variables from 1 (totally disagree) to 5 (totally agree) based on relevance, and consensus was defined as variables rated ≥4 by more than 70% of the experts. RESULTS: Eleven experts participated. The experts generated 194 unique variables in the first round. After five rounds, a consensus was reached. The updated dataset was an expanded version of the original dataset and the template was expanded from 45 to 73 main variables. The experts approved the final version of the template. CONCLUSIONS: Using a Delphi method, we have updated the template for documenting and reporting in p-EMS. We recommend implementing the dataset for standard reporting in p-EMS.


Responding to the severe acute respiratory syndrome (SARS) outbreak: Lessons learned in a Toronto emergency department()


Severe Childhood Respiratory Viral Infections


Nurse Participation in Continuing Education in Disaster Nursing in Taiwan


title: Health Guidelines for Travel Abroad

text: Most travel medical care is provided by patients’ primary care physicians; only 10% of international travelers visit a travel clinic. The main purposes for travel include vacationing, visiting friends and family, business, and for educational purposes. The purposes of the pretravel consultation are to estimate risk and provide recommendations to mitigate risk.


Are You Covered? Safe Practices for the use of Personal Protective Equipment


title: INFRAGLOTTIC AND BRONCHIAL INFECTIONS

text: The Yankees are rapidly finding out the benefits of the telephone. A newly made grandmamma, we are told, was recently awakened by the bell at midnight, and told by her inexperienced daughter, “Baby has the croup. What shall I do with it?” Grandmamma replied she would call the family doctor, and would be there in a minute. Grandmamma woke the doctor, and told him the terrible news. He in turn asked to be put in telephone communication with the anxious mamma. “Lift the child to the telephone, and let me hear it cough,” he commands. The child is lifted, and it coughs. “That's not the croup,” he declares, and declines to leave his house on such small matters. He advises grandmamma also to stay in bed; and, all anxiety quieted, the trio settle down happy for the night.(138) Concerns over infraglottic and bronchial infections have been a source of anxiety and lost sleep for many children, parents, and physicians long before the advent of the telephone. The annual incidence of lower respiratory tract infections in children younger than 6 years old exceeds 5 million in the United States.(83) Despite the frequency of these infections, the often common and nonspecific clinical symptomatology, variable severity, and changing epidemiology over time all have contributed to our understanding and misunderstanding of these disorders. The anxiety of the relatives described in the opening passage is a poignant reminder that the diagnosis of diphtheritic croup at that time carried a mortality of around 25%.(62) By simple definition, laryngitis, tracheitis, bronchitis, and any combination of terms (e.g., laryngotracheitis, laryngotracheobronchitis [LTB], tracheobronchitis) represent inflammatory conditions of part or parts of the airway.42, 155 In this basic form, no specific causes, infectious or noninfectious, are implied by these terms.


EVALUATION OF PERSISTENT COUGH IN CHILDREN


Teaching “One Medicine, One Health”


title: Southwestern Internal Medicine Conference: Pneumonias in Adults Due to Mycoplasma, Chlamydiae, and Viruses

text: Pneumonias in adults due to mycoplasma, chlamydiae, and viruses are a common clinical problem. These microorganisms contribute to the etiologies in 6–35% of all cases of pneumonia and are the sole pathogens in 1–17% of hospitalized cases. Important trends and developments in the field include (1) the emergence of a Chlamydia psittaci strain (TWAR) that is passaged from human to human, causes a mycoplasma-like illness, and that is relatively resistant to erythromycin, (2) the recognition of respiratory syncytial virus as a pathogen in nursing home outbreaks and in immunosuppressed adults, the continuing high lethality of fully developed influenza pneumonia, (4) the efficacy of acyclovir and adenine arabinoside in limiting the complications of varicella-zoster virus infections, and (5) the increasing frequency of pneumonia caused by cytomegalovirus and the severity of this disorder in highly immunosuppressed patients. Developments in the rapid diagnosis and therapy of respiratory syncytial virus infections with an aerosolized antiviral drug in children may pave the way for comparable advances in difficult pneumonias in adult patients.


Risk of SARS transmission to persons in close contact with discharged patients


Hepatitis-associated antigen


Cigarette smoking and coronary heart disease: new evidence and old reactions


Retrospective analysis of liver function derangement in severe acute respiratory syndrome


Clinical and Immunologic Responses in Patients with Viral Keratoconjunctivitis


Rhabdomyolysis associated with probable SARS


Prognostic importance of lymphopenia in West Nile encephalitis


docid: owxcokge

title: Emerging and re-emerging infectious diseases: Be prepared


Ocular Pathogens for the Twenty-First Century


title: Acute bronchitis: Results of U.S. and European trials of antibiotic therapy

text: Acute bronchitis, an illness frequently encountered by primary-care physicians, is an inflammation of the tracheobronchial tree that results from a respiratory tract infection. It is characterized by persistent cough and sputum production and is occasionally accompanied by fever and/or chest pain. Acute bronchitis may have a viral or bacterial origin and is often treated with antibiotics. Four clinical trials were conducted to compare high and low doses of loracarbef, a new oral β-lactam antibiotic, with three agents commonly used to treat acute bronchitis: amoxicillin/clavulanate, cefaclor, and amoxicillin. Results of these studies indicated that loracarbef, 400 and 200 mg twice daily, had clinical and bacteriologic efficacy against the common respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella (Branhamella) catarrhalis that was comparable with that of the comparative agents. Loracabef was as well tolerated as cefaclor and amoxicillin; moreover, it produced a significantly lower incidence of diarrhea than did amoxicillin/clavulanate. Loracarbef may be considered a safe and effective alternative agent for the treatment of patients with acute bronchitis.


When pigs fly: Confronting the new era of disease transmission


It's Always Something: Another four-letter-word disease


Travel Bugs


title: Case Report: Presumed Respiratory Syncytial Virus Pneumonia in Three Immunocompromised Adults

text: Three cases of presumed respiratory syncytial virus (RSV) pneumonia in immunocompromised adults are described. Two patients had symptoms of cough, fever, and malaise, following completion of a course of combination chemotherapy for the treatment of acute lymphoblastic leukemia. The third patient, a juvenile onset diabetic, developed similar symptoms while hospitalized for severe hyperglycemia. Chest roentgenograms showed lower lobe infiltrates in both leukemic patients and a bilateral non-confluent bronchopneumonia in the diabetic patient. All patients had a marked rise in complement-fixing antibody titres to RSV, suggesting a concurrent infection with the virus. Extensive microbiological investigations failed to reveal any other etiologic agent. Nosocomial infection was considered possible. RSV is not considered a cause of pneumonia in compromised adults. Our three cases suggest that there may be a higher incidence of RSV pneumonia in compromised patients, than previously recognized.


Marked decline in serum digoxin concentrations during an episode of severe diarrhea()


Viruses in Balkan nephritis


Ophthalmologists Are More Than Eye Doctors—In Memoriam Li Wenliang


title: Analysis of Ia induction on Lewis rat astrocytes in vitro by virus particles and bacterial adjuvants

text: Viral particles of a neurotropic murine hepatitis virus (JHM) and various substances known to have immunoregulatory effects, including bacterial lipopolysaccharide (LPS) and synthetic adjuvant peptide (muramyl dipeptide) (AP), were tested for their ability to induce Ia antigen expression on Lewis rat astrocytes in vitro. JHM virus, LPS and AP are all capable of inducing Ia molecules on astrocytes, however, in a pattern and kinetics distinct from recombinant rat gamma interferon (γ-IFN). Whereas γ-IFN induced Ia expression on astrocytes and all macrophages after 48 h treatment, JHM virus, LPS and AP required 4–7 days for maximal induction of Ia on astrocytes, but had little to no effect on the macrophage population. This indicates that astrocytes are uniquely reactive to components derived from infectious agents and that these components are immunoregulatory with respect to Ia expression on astrocytes. We have also attempted to determine possible mechanisms by which these agents induce astrocyte Ia and show that phorbol myristate acetate and Ca(2+) ionophore A23187 have similar effects. These findings suggest that infectious agents may directly stimulate antigen presenting functions of astrocytes in the brain through γ-IFN-independent mechanisms.


title: Chronic Theiler's virus infection in mice: appearance of myelin basic protein in the cerebrospinal fluid and serum antibody directed against MBP

text: Myelin basic protein (MBP) appears frequently in the cerebrospinal fluid (CSF) of mice with chronic demyelination following intracerebral infection with Theiler's murine encephalomyelitis virus (TMEV); antibody to MBP can frequently be found in the sera. The peaks of the immune responses to both MBP and TMEV coincide with the time course of the clinical signs of disease. Adsorption of mouse sera with TMEV or MBP indicate the non-identity of the antigens and the specificity of the antisera as measured by ELISA. Immunoblot analysis of sera confirmed the ELISA findings. The mechanism of induction of antibody directed against MBP and its role in TMEV-associated demyelination remain to be determined.


title: Differential suppression of interferon-γ-induced Ia antigen expression on cultured rat astroglia and microglia by second messengers()

text: The roles of intracellular second messengers in interferon-γ (IFN-γ)-induced Ia antigen (Ag) expression by astroglia and microglia were examined. Ia Ag on both glia types was induced by IFN-γ. Reagents known to increase intracellular cAMP or activate intracellular protein kinase C (PKC) reduced IFN-γ-induced Ia Ag expression by astroglia. In contrast, increasing intracellular cAMP had no suppressive effect on Ia Ag expression by microglia. These results indicate (1) cAMP and PKC negatively regulate IFN-γ-induced Ia expression on astroglia, and (2) Ia expression is regulated differentially in astroglia vs. microglia. These findings may explain the frequent observation of Ia(+) microglia (or macrophages) but not astroglia in various neurodegenerative diseases.


title: Construction of a bovine-murine heteromyeloma cell line; Production of bovine monoclonal antibodies against rotavirus and pregnant mare serum gonadotrophin

text: Bovine-murine heteromyeloma cell lines were prepared by fusing lymphoid cells from a bovine leukemia virus (BLV)-infected cow with mouse myeloma cells. Selection of hybrid cell colonies was based on the ratio of bovine and murine chromosomes, the presence of cell-surface immunoglobulins and growth characteristics. First-generation fusion partners were compared for fusion efficiency and the number of antigen-specific antibody-producing clones generated. Hybrid cell colonies that initially secreted antibodies were selected from first-generation heteromyelomas to function as second-generation fusion partners. Although fusion efficiencies for both generations did not differ, the second-generation heteromyelomas yielded a higher number of specific antibody-producing clones. Fusion of heteromyelomas with either lymph node cells or splenocytes indicated that fusion with lymph node cells results in a higher number of specific antibody-producing clones, whereas fusion efficiency was found to be higher with splenocytes. The optimal time intervals between the final booster injection and fusion were found to be 4 days for splenocytes and 7 days for lymph node cells. Finally, the characterization of bovine monoclonal antibodies against bovine rotavirus and pregnant mare serum gonadotrophin and their neutralizing capacities in vitro are described.


title: Trafficking of activated cytotoxic T lymphocytes into the central nervous system: Use of a transgenic model

text: We have used cell or tissue-specific promoters to express lymphocytic choriomeningitis virus (LCMV) proteins in selected cells in independent lines of transgenic mice. Upon adoptive transfers into these mice, MHC-restricted LCMV-specific cytotoxic T lymphocytes homed specifically to either the choroid plexus (SV40 promoter) or β cells of the islets of Langerhans (rat insulin promoter). The availability of promoters specific for neurons, oligodendrocytes and astrocytes makes this approach compelling for evaluating T cell trafficking into the CNS and for analyzing antigen presentation in vivo in the CNS.


title: Characterization of measles virus-induced cellular autoimmune reactions against myelin basic protein in Lewis rats

text: Subacute encephalomyelitis (SAME) in Lewis rats following infection with a neurotropic measles virus (MV) is associated with a cell-mediated autoimmune response (CMAI) to myelin badic protein (MBP). MBP-selected CD4(4+) T cell lines both from measles-infected animals as well as from rats challenged with guinea pig MBP (Gp-MBP) had a similar pattern of response in the presence of synthetic peptides to Gp-MBP and specifically responded in vitro only to the encephalitogenic and not the non-encephalitogenic or other control peptides. In primary splenic lymphocyte cultures from SAME animals, however, a low but significant T-cell response was obtained against the non-encephalitogenic peptide S67 (residues 69–81) of the Gp-MBP. Moreover, immunization of MV-infected rats with this peptide induced clinical and histological experimental allergic encephalomyelitis (EAE) in 38% of the animals. The results of the study show that the non-encephalitogenic peptide S67 can be rendered encephalitogenic in rats when an additional stimulus is given in the form of MV infection. The data indicate further that MV infection of the central nervous system (CNS) enhances the susceptibility of the CNS to autoimmune T cell aggression.


title: Interleukin-1β decreases HLA class II expression on a glioblastoma multiforme cell line

text: Antigens encoded within the major histocompatibility complex (MHC) are not normally expressed in the central nervous system (CNS), but can be induced by treatment with interferon-γ (IFN-γ). Other cytokines released during an inflammatory process can potentially influence MHC expression as well. One cytokine of interest is interleukin-1 (IL-1), an immunoregulatory polypeptide that is produced by macrophages and also by cells in the CNS. In this study, the effedt of IL-1β on MHC expression in a human glioblastoma multiforme cell line, U-105 MG, has been examined. Treatment of U-105 MG with 10 U IL-1β/ml for a period of 5 days resulted in a decrease in constitutive cell surface HLA class II expression and limited the induction of class II by IFN-γ. This effect was also observed on steady-state levels of class II RNA and could be neutralized with antibodies to IL-1β. All class II transcripts examined (HLA-DR, -DQ, and -DP α and β) were affected. Class I expression was only marginally changed by IL-1β treatment. A minimal concentration of 1 U IL-1β/ml was required to reduce class II expression and a kinetics experiment indicated that U-105MG must be treated for at least 4 days with IL-1β for a decrease in class II expression to be observed. This study suggests that IL-1 may play a role in limiting immunoreactivity in the CNS by limiting class II induction.


title: Natural killer (NK) activity of porcine blood lymphocytes against allogeneic melanoma target cells

text: Allogeneic PM/86 melanoma cells of Munich Troll® miniature swine have been used for the demonstration of porcine peripheral blood NK cell activity. Compared with the specific lysis of xenogeneic K562-, U937- and Vero-target cells, NK cell-mediated cytotoxicity (NK-CMC) against PM/86 melanoma tumor cells was significantly lower in a 16 h chromium release assay. The target cell susceptibility to pheriperal blood NK-CMC of both adult Troll® miniature swine and German Landrace sows was very similar. Cold target inhibition assays revealed the allogeneic PM/86 melanoma cells to be the most powerful inhibitors of NK-CMC. Nylon wool non-adherent lymphocytes produced interferon (IFN)-alpha in different quantities upon contact with NK susceptible target cells. The NK effector cells could lytic activity against all susceptible targets by a moderate dose of natural human inteleukin-2 (nhuIL-2). The role of NK-CMC in melanoma tumor rejection and/or prevention of metastases is yet unknown in swine although porcine melanoma serves as a good model for the disease in man.


Erratum: Vol. 69, No. 11


title: Multiple sclerosis patients have reduced HLA class II-restricted cytotoxic responses specific for both measles and herpes virus

text: It has been previously demonstrated that the generation of measles virus (MV)-specific cytotoxicity (CTL) is reduced in patients with multiple sclerosis (MS). By contrast, CTL specific for influenza virus (FLU) and mumps virus is normal. It is uncertain if reduced CTL is limited to MV in MS patients, or if reduced CTL may be found to other viruses as well. Since MV-specific CTL is predominantly restricted by HLA class II molecules, while FLU-specific and mumps-specific CTL have large HLA class I-restricted components, reduced MV-specific CTL may reflect a broader reduction in HLA class II-restricted CTL in patients with MS. To examine this question we studied the generation of CTL specific for herpes simplex virus type I (HSV). HSV-specific CTL, like MV-specific CTL is predominantly restricted by HLA class II molecules. We found that patients with MS had reduced generation of CTL to both MV and HSV. Most, but not all patients who had reduced generation of CTL to one virus also had a similar impairment with respect to the second virus. Some patients, however, had a reduction in the generation of CTL only to MV or to HSV. These findings extend our earlier observations regarding reduced MV-specific CTL in patients with MS to a second HLA class II-restricted virus, HSV. Such a reduction may reflect discrete impairments in immune function to separate viruses, possibly those that are associated with viral persistence, or may reflect a more generalized defect in HLA class II-restricted CTL.


title: Alteration of intracerebral cytokine production in mice infected with herpes simplex virus types 1 and 2

text: Previously we reported that a lethal strain of herpes simplex virus type 2 (HSV-2) infects the brain following ocular inoculation of mice. We now demonstrate that HSV-2 mediates an unusual intracellular sequestering of class II major histocompatibility complex (MHC) antigens. With use of an RNase protection assay, we observed a selective inhibition of IFN-γ and IL-6 gene transcription in brains of mice infected with HSV-2. It is likely that the inhibition of cytokine gene expression was mediated through a failure to activate CD4(+) lymphocytes. These data suggest that the infecting herpesvirus can influence the profile of intracerebrally produced cytokines, which in turn may determine the outcome of the infection.


title: A transgenic mouse model to assess the interaction of cytotoxic T lymphocytes with virally infected, class I MHC-expressing astrocytes

text: Astrocytes provide crucial support for neurons and their impairment by viruses or their interactions with anti-viral or autoimmune responses could contribute to neurological disease. We have developed a transgenic mouse model to assess lymphocyte-astrocyte interactions. The major histocompatibility complex (MHC) class I molecule, D(b), was expressed in astrocytes under the transcriptional control of regulatory sequences from the glial fibrillary acidic protein (GFAP) gene. Baseline cerebral MHC class I mRNA levels from transgenic mice were elevated over those of non-transgenic controls, and a prominent increase in cerebral MHC class I expression occurred following focal, injury-induced astroglial activation within transgenic brains but not in non-transgenic controls. FACS analysis of explant astrocyte cultures from established transgenic lines demonstrated astroglial expression of the GFAP-D(b) fusion gene at the protein level. Functional antigen-presenting capacity was conferred by the D(b) transgene, as virus-infected primary astrocytes obtained from transgenic BALB/c mice (K(d)I(d)D(d)L(d)) expressing the D(b) molecule were lysed by D(b)-restricted anti-viral CTL.


title: Number and distribution of T lymphocytes in the small intestinal mucosa of calves inoculated with rotavirus

text: An understanding of the immune response to rotavirus is needed to develop effective prophylaxis. There is evidence that cell-mediated responses may be involved and to extend these observations, rotavirus antigen and the three major T cell subsets, BoCD4(+), BoCD8(+), and BoWC1(+)γ/δ lymphocytes were immunostained in tissue sections from calves killed at 2, 4, 6, 8 and 10 days post inoculation and quantified by image analysis. It was established that in control calves, BoCD4(+) lymphocytes were predominantly in the lamina propria, while the majority of BoCD8(+) and BoWC1(+)γ/δ lymphocytes were in the epithelium. Rotavirus infection was seen throughout the small intestine with the greatest amount of viral antigen detected at 4 days post inoculation in the mid and distal small intestine. Increased numbers of all subsets were detected; small increases in intraepithelial BoCD4(+) and BoWC1(+)γ/δ T lymphocytes were observed especially in the distal small intestine, while larger increases in BoCD8(+) cells were detected in the epithelium and lamina propria of the proximal, mid and distal small intestine. The timing and location of these increases in T lymphocyte subsets is indicative of a specific immune response involving BoCD8(+) and BoWC1(+)γ/δ T lymphocytes.


title: Isolation and functional studies on feline bone marrow derived macrophages

text: In this report, we describe an in vitro culture method for feline bone marrow cells, which yields large numbers of quiescent macrophages after 14 days of culture. The bulk of the cultured cell population consists of macrophages as assessed by morphology, macrophage specific cytochemistry, and phagocytosis. The remaining cells were lymphocytes, bone marrow stromal cells, fibroblasts and occasional polymorphonuclear leukocytes. While resting cells produced no detectable interleukin 1, stimulation with lipopolysaccharide (LPS) induced the production of biologically active interleukin 1. After 6 h LPS stimulation, mRNA for tumor necrosis factor α and interleukin 1β was detectable. The absence of mRNA in unstimulated cells indicates cultured macrophages were not activated until stimulated by LPS or plastic adherence. This approach provides a useful means to measure potential modulatory effects by virus infections or other agents upon feline macrophage gene expression.


title: Endogenous gamma interferon produced in central nervous system by systemic infection infection with Theiler's virus in mice

text: Theiler's virus GD VII strain causes acute encephalomyelitis by intracerebral inoculation. We established acute encephalomyelitis in mice by the intravenous (i.v.) inoculation of Theiler's virus GD VII strain. Replication of Theiler's virus injected i.v. could be observed in both the brain and spinal cord of mice, and interferon (IFN)-γ could be detected in the extracts of brain and spinal cord in parallel with viral replication. Furthermore, by the injection of anti-IFN-γ monoclonal antibody (mAb) on Day 1 post-infection (p.i.), mortality and virus titres in the spinal cord increased compared with the control mice treated with normal rat globulin. The histological exacerbation of inflammation was observed in spinal cord of anti-IFN-γ mAb-treated mice. These results indicate that endogenous IFN-γ, produced locally in the brain and spinal cord of mice through both antiviral action and anti-inflammatory action of IFN-γ in central nervous system, plays an important role in Theiler's virus infection.


title: Recombinant porcine interferon-gamma activates in vitro porcine adherent mononuclear cells to produce interleukin 1

text: The effect of recombinant porcine interferon-gamma (rPoIFNγ) on in vitro production of interleukin 1 (IL-1) by porcine blood monocytes was studied. Three-day-old cultures of porcine adherent blood mononuclear cells were treated by doses of rPoIFNγ for 3 or 6 days before lipopolysaccharide (LPS)-induction. While rPoIFNγ alone had no effect, a combined treatment by rPoIFNγ and LPS enhanced the IL-1 secretory potential of adherent mononuclear cells and, to a lesser extent, the level of cell-associated IL-1. The IL-1 activity was neutralized by anti porcine IL-1 α and β antisera. These results demonstrate that rPoIFNγ has immunomodulatory effects in vitro on porcine monokine production.


title: Swine leukocyte antigen and macrophage marker expression on both African swine fever virus-infected and non-infected primary porcine macrophage cultures()

text: Swine leukocyte antigens (SLA) and a macrophage specific marker were monitored on porcine macrophages cultured with or without macrophage colony stimulatory factor (M-CSF) and on cells infected with African swine fever virus (ASFV). SLA expression was maximal either in the total cell extract or on the cell surface at 3–4 days of culture; after 4 days these values began to decrease. Fluorescence analyses of immunostained macrophages cultured with or without M-CSF indicated a major upward shift in the number of SLA Class I molecules on individual macrophages whereas for SLA Class II both a novel expression of Class II and an upward shift in the number of molecules per cell were evident. Infection of 3-day-old macrophage cultures with three different isolates of ASFV resulted in minor changes in surface expression of SLA Class I, SLA Class II, and macrophage markers. No differences in infection with ASFV was observed whether macrophages were SLA Class II positive or negative, nor was there blocking by anti-SLA Class I or Class II monoclonal antibodies of ASFV infection of cultured macrophages.


title: Influence of experimentally induced endogenous production of cortisol on the immune capacity in swine

text: Field studies have suggested that ‘stressors’, such as transportation and mixing, might interfere with the immune competence of pigs. Therefore, an experimental model was established to study the influence of elevated concentrations of circulating cortisol on the immune capacity in swine. Three experimental groups, with six pigs in each, were immunized twice, 4 weeks apart, with Mycoplasma hyopneumoniae antigen. Endogenous production of cortisol was induced by intramuscular injection of adrenocorticotropic hormone (ACTH) twice daily. One group received ACTH during the week before and after the second immunization, one group during the week after the second immunization only, while one group served as untreated controls. The treatment with ACTH induced high, but physiological, concentrations of cortisol in plasma. Simultaneously, the number of lymphocytes per milliliter blood decreased while the neutrophil number increased. The elevated concentrations of cortisol also coincided with reduced proliferation and interleukin-2 production by blood lymphocytes stimulated with the mitogens concanavalin A and phytohemagglutinin in vitro, while the responses to pokeweed mitogen were less affected. The suppression of mitogen responses was more pronounced in cultures of whole blood than in cultures of purified peripheral blood mononuclear cells (PBMC). Antibody production, induced by M. hyopneumoniae in cultures of purified PBMC was also inhibited by ACTH treatment. Both the rate of increase and the magnitude of the antibody production induced by the primary immunization were reduced. In contrast, no effects of ACTH treatment were recorded for the response to the second immunization or on the serum levels of antibodies to M. hyopneumoniae. The ability of blood leukocytes to produce interferon-α (IFN-α) at exposure in vitro to fixed pseudorabies virus adsorbed to porcine kidney cells increased in all animals shortly after the second immunization with M. hyopneumoniae. The influence of cortisol on the IFN-α-producing capacity was dependent on whether the test was carried out in whole blood cultures or in cultures with purified PBMC. This finding further emphasizes that the relevance of in vitro assays for measuring in vivo phenomena must be carefully scrutinized.


title: Synergistic interaction between measles virus infection and myelin basic protein peptide-specific T cells in the induction of experimental allergic encephalomyelitis in Lewis rats

text: The questions how a viral infection induces cellular autoimmune reactions (CMAI) and which components of both virus and auto-antigen play part in this process were addressed in our animal model of measles virus (MV)-induced CMAI against myelin basic protein (MBP) during subacute measles encephalitis (SAME). In an attempt to define whether cellular or humoral immune responses are involved in the occurrence of the autoimmune based disease process, Lewis rats were treated with different combinations of antibodies and T cells reactive with either MV and its structural proteins or MBP and MBP-peptides. The only treatment combination after which experimental allergic encephalomyelitis (EAE)-like disease and pathology developed was when non-encephalitogenic T cells reactive against residues 69–81 of MBP were adoptively transferred into MV-infected Lewis rats. The results of the study show that T cells which are non-encephalitogenic in the normal central nervous tissue are capable of inducing an allergic encephalomyelitis in animals with a viral infection involving the brain.


title: Genic amplification of the entire coding region of the HEF RNA segment of influenza C virus

text: In order to provide an easy and powerful analysis of influenza C viral HEF RNA segment of a recent strain, a combination of reverse transcription and the polymerase chain reaction was used. We amplified the entire coding region of the HEF gene of a laboratory strain of virus called C/Johannesburg/1/66, widely used for binding and esterase activity studies as well as that of a strain isolated in 1991 (C/Paris/145/91) from a patient suffering from severe flu syndrome. The sequences we amplified were about 2 kilobases long. In this work, we show that the forward ‘universal primer’ Unil, which has been used for influenza A and B viruses cDNA syntheses can also be used for influenza C virus. The PCR primers were designed to contain restriction sites to make the PCR products ready to be used for further purposes. A restriction analysis of the PCR products combined with analyses of all the human influenza C virus HEF gene sequences published so far permitted the design of sets of oligonucleotides which can prime PCR on cDNA of unknown influenza C virus for cloning.


title: Clinical and pathological findings in feline immunodeficiency virus experimental infection

text: A study is described of the clinical and pathological findings in 20 specific pathogen free cats infected when 1 year old with feline immunodeficiency virus and monitored over 12 months. Cats were divided into two groups (A and B). The clinical and clinicopathological features were studied in Group A. In Group B, at 1, 2, 4, 9 and 12 months post infection two cats were necropsied. Clinically all cats developed generalised lymphadenopathy, six cats were neutropenic and five cats lymphopenic. Three cats became febrile with conjunctivitis and anterior uveitis and one of these cats ultimately developed jaundice. Postmortem examinations confirmed a generalised lymphadenopathy involving peripheral and visceral lymph nodes with concurrent stimulation of splenic white matter and mucosal lymphoid tissue of the digestive tract and conjunctiva. Within the lymph nodes there was a reactive follicular hyperplasia accompanied by a paracortical hyperplasia with an increased paracortical vascularity. Unusual features were the presence of lymphoid follicles in the bone marrow, thymus and parathyroid tissue. In addition, aggregates of lymphoid cells were found within salivary glands, kidneys, sclera and choroid of the eye. One cat developed a lymphosarcoma affecting the liver and kidneys at 36 weeks post infection. The cat with jaundice had a cholangitis with marked biliary epithelial hyperplasia.


title: Cloning, expression and characterization of biologically active feline tumour necrosis factor-α

text: We report the cloning, expression and characterization of biologically active feline tumour necrosis factor-α (fTNF-α). Messenger RNA was extracted from feline peritoneal macrophage cultures and used to synthesize cDNA for polymerase chain reaction (PCR) amplification. The PCR products were cloned into the plasmid vector pCRII and sequenced, showing 99.3% homology with a published fTNF-α gene sequence. Subcloning into the vector pGEX-2T and subsequent expression resulted in a 43 kDa fusion protein of fTNF-α and glutathione S-transferase (GST). Thrombin cleavage of the fusion protein yielded a 17 kDa protein. This protein cross-reacted with a monoclonal anti-human TNF-α antibody in Western blotting, but not with a polyclonal anti-murine TNF-α serum. Recombinant fTNF-α (rfTNF-α) and rfTNF-α-GST had a CD(50) of 15 ng ml(−1) and 230 ng ml(−1), respectively, in the L929 cytotoxicity assay. Cats given rfTNF-α-GST intravenously manifested the typical biological effects of TNF-α, including fever, depression, and piloerection. The rfTNF-α-GST upregulated IL-2 receptor and MHC-II antigen expression on peripheral blood mononuclear cells stimulated in vitro, but had no effect on TNF-α receptor and MHC-I antigen expression.


docid: krzbkryz

title: Recombinant FeLV vaccine: long-term protection and effect on course and outcome of FIV infection

text: The efficacy and the long-term protection of a recombinant feline leukemia virus (FeLV) vaccine were determined in 30 specified pathogen free cats for over 3 years. At the same time, in order to specify the effects of feline immunodeficiency virus (FIV) on the immune system, one half of the cats (n = 15) were previously infected with the Swiss isolate FIV Zurich 2. The second half of the animals (n = 15) served as non-infected controls. Eighteen (nine FIV-negative, nine FIV-positive) vaccinated and 12 (six FIV-negative, six FIV-positive) non-vaccinated cats were intraperitoneally challenged with FeLV A. Seventeen of 18 vaccinated cats were protected against persistent viremia, while ten of 12 non-vaccinated controls became infected. An increase of antibodies against FeLV SU was found in all protected cats after the challenge exposure. No difference in vaccine efficacy was found between FIV-negative and FIV-positive animals. The whole group of cats was observed for over 3 years. There were no further vaccinations during this period. CD4(+) and CD8(+) cell subsets, clinical outcome and time of survival of the cats were recorded. FIV-negative and FIV-positive animals were kept in two different rooms. However, FeLV-negative and FeLV viremic cats were housed together in both rooms in order to imitate a natural FeLV exposure situation. Anti-recombinant FeLV SU antibodies were measured by enzyme-linked immunosorbent assay. Although a continuous decline of antibodies was found in FeLV vaccinated cats, they remained protected against constant FeLV challenge for over 3 years. FIV infection had a stronger effect on the depression of the CD4(+):CD8(+) ratio than FeLV infection. Within the group of FIV-positive cats, the FeLV-vaccinated animals had significantly better survival rates as well as better clinical and laboratory parameters. FIV- and FeLV-coinfected cats showed the lowest CD4(+):CD8(+) ratio, mainly caused by decreased CD4(+) lymphocyte counts. CD8(+) lymphocytes with strong fluorescence (CD8(high)) disappeared and cells with weak fluorescence (CD8(low)) appeared instead. Prevention of coinfection by immunizing FIV-positive cats against FeLV infection improved the clinical outcome and prolonged the cat's life expectancy.


title: Recognition of major histocompatibility complexantigens on murine glial cells()

text: Recognition of autologous major histocompatibility complex (MHC) antigens by T cells is an essential step in the induction of an immunologic reaction to either endogenous or exogenous antigens. We investigated the ability of murine glial cells of different ages to stimulate clones of allospecific T lymphocytes. We also investigated the effects of supernatants from cultures of activated T cells on the immunologic recognition of MHC antigens on murine glial cells. Lymphocyte clones specific for Class I, Class II and non-MHC, background antigens were obtained from C57B1/6J-anti-DBA/2 mixed lymphocyte cultures. Glial cell cultures were prepared from newborn syngeneic (C57B1/6J) and allogeneic (DBA/2) mouse brains. Glial cultures 1–4 weeks of age were able to stimulate α-Class I-specific clones. No stimulation of α-Class II or α-background clones was noted. Incubation of glial cells with supernatants from cultures of alloantigen-activated spleen cells (C57131/0-anti-DBA/2) resulted in a decreased ability of glial cells to stimulate a-Class I responses. In contrast supernatant-treated cultures acquired the capacity to stimulate a-Class II-specific clones. No responses were noted in clones responsive to non-MHC antigens. The ability to stimulate α-Class II-specific clones was most prominent with one-week-old glial cultures and was lost by four weeks of culture. The increased susceptibility of younger glial cultures to the modulatory effects of lymphokines from activated T cells may be a factor in the increased susceptibility of the immature central nervous system to persistent viral infections and the development of autoimmune phenomena.


docid: btnwopac

title: The effect of dexamethasone-induced immunosuppression on the development of faecal antibody and recovery from and resistance to rotavirus infection

text: Rotavirus-naive and rotavirus-immune gnotobiotic calves were treated with high doses of dexamethasone (DX) to suppress the immune system. Calves were then infected with a virulent rotavirus inoculum, J-160, to investigate the role of immune responses both in recovery from primary rotavirus infection and in resistance to secondary rotavirus infection. Treatment of calves with DX markedly suppressed in vitro responsiveness of peripheral blood lymphocytes to mitogens within 48 h of the start of DX treatment. Suppression was similar in rotavirus-naive and rotavirus-immune calves. In contrast, the effect of DX treatment on specific antibody responses differed depending on when DX treatment started in relation to rotavirus infection. When DX treatment commenced prior to primary rotavirus infection both systemic and local specific antibody responses were inhibited. These calves, in which mitogen and antibody responses were suppressed, exhibited greater clinical signs than did control calves after infection with virulent rotavirus, but virus excretion was affected in only one of the two calves. When DX treatment was started after primary rotavirus infection but before secondary infection, systemic and local antibody responses to the primary infection and to the challenge infection were not affected. These calves resisted challenge with virulent virus as did DX-untreated rotavirus-immune calves, even though mitogen responses were suppressed. We conclude that in a primary rotavirus infection, virus excretion ceased when both antibody and mitogen responses were suppressed. Resistance to secondary rotavirus infection occurred when mitogen responsiveness was suppressed, but when antibody levels were normal. Thus, no evidence was obtained that fully functional cell-mediated immune mechanisms are essential for resistance to rotavirus infection. Evidence was provided for the ability of parenteral treatment with DX to suppress mucosal as well as systemic antibody responses.


title: Interleukin-4 induces proliferation and activation of microglia but suppresses their induction of class II major histocompatibility complex antigen expression

text: We recently found that microglia, brain macrophages, express interleukin-4 (IL-4) receptor mRNA in vitro. Since IL-4 exhibits a variety of functions on the cells of monocyte-macrophage lineage, we examined the effects of IL-4on the functions of microglia. Recombinant IL-4 induced the proliferation of microglia in a dose- and time-dependent manner as determined by MTT colorimetric assay, [(3)H]thymidine uptake and bromodeoxyuridine (BrdU) incorporation. IL-4 also synergistically enhanced the proliferation of microglia with such colony-stimulating factors as IL-3, granulocyte-macrophage colony-stimulating factor (GM-CSF) and macrophage colony-stimulating factor (M-CSF). It also increased acid phosphatase activity and superoxide anion formation by these cells. Despite these positive effects on proliferation and activation, IL-4 suppressed the IFN γ-induced class II MHC antigen expression in these cells. Since these effects of recombinant IL-4 inhibited by the addition of monoclonal antibody against IL-4 receptors, the effects of IL-4 on microglia appear to be a specific function via IL-4 receptors. Although microglia and astrocytes produce a variety of immunoregulatory cytokines, neither cell produced IL-4 as determined by bioassay or detection of IL-4 mRNA by RT-PCR method. Thus, the exogenous IL-4 may contribute to the accumulation of microglia in or around inflammatory lesions in the central nervous system, and may be involved in the regulatory mechanisms of microglia.


Vaccines and adjuvants


title: Facilitation of experimental allergic encephalomyelitis by irradiation and virus infection: role of inflammatory cells

text: Infection with an avirulent strain of Semliki Forest virus (SFV-A7) facilitates the development of experimental allergic encephalomyelitis (EAE) in a genetically resistant BALB/c mouse strain. Irradiation which is necessary for EAE induction caused a decrease in the total number of lymphocytes and an increase in CD4(+)/CD8(+) T cell ratio in the spleen of BALB/c mice. EAE induction increased the ratio further until clinical and histological signs of EAE appeared. Entry of perivascular CD4(+) and CD8(+) cells preceded the onset of clinical signs and the appearance of MAC-1(+) cells in the central nervous system (CNS). In the acute phase of EAE, cellular infiltrates, which were sparse, consisted mainly of MAC-1(+) cells and a few CD4(+) and CD8(+) cells. Inflammatory cells gradually disappeared during the recovery phase. SFV-A7 infection after irradiation and EAE induction did not significantly change the CD4(+)/CD8(+) ratio in the spleen or in the CNS infiltrates but enhanced the entry of inflammatory cells into the CNS. Similar perivascular cell influx was also seen in untreated mice infected with SFV-A7. We conclude that observed rapid reduction of splenic mononuclear cells and increase of the CD4(+)/CD8(+) T cell ratio caused by irradiation prior EAE induction are early crucial events in disease induction in this resistant strain of mice. SFV-A7 infection, which further facilitates the development of EAE, does not induce immunoregulatory changes but provides its effect by enhancing the entry of inflammatory cells into the CNS. The combination of these two mechanisms thus effectively breaks the natural resistance against EAE in this genetically resistant mouse strain.


The immunobiology of the feline leukemia virus


docid: rapinodd

title: Induction and regulation of class II major histocompatibility complex mRNA expression in astrocytes by interferon-γ and tumor necrosis factor-α

text: Astrocytes can function as antigen-presenting cells (APC) upon expression of class II major histocompatibility complex (MHC) antigens, which are induced by interferon-γ (IFN-γ). Previous data from this laboratory had shown that the cytokine tumor necrosis factor-α (TNF-α) enhances IFN-γ-mediated class II antigen expression on astrocytes. We have now investigated the effect of IFN-γ and TNF-α on class II MHC mRNA expression in astrocytes using Northern blot analysis. Astrocytes do not constitutively express mRNA for class II MHC. Kinetic analysis of class II MHC mRNA expression in IFN-γ-treated cells demonstrated an 8 h time lag, which was followed by an increase over the next 16 h. Optimal expression of class II mRNA was detected after a 24 h incubation with IFN-γ. This level of expression was further enhanced by the simultaneous addition of IFN-γ and TNF-α to the astrocytes, while TNF-α alone had no effect on class II mRNA expression. TNF-α does not act by increasing the stability of IFN-γ-induced class II mRNA, indicating its action is not at that specific level of post-transcriptional control. Furthermore, astrocyte class II mRNA expression was inhibited when cycloheximide (CHX) was added together with IFN-γ or IFN-γ/TNF-α, and when CHX was added up to 4 h after treatment with IFN-γ or IFN-γ/TNF-α. These results indicate that astrocyte class II mRNA expression is mediated by newly synthesized proteins induced by IFN-γ and/or IFN-γ/TNF-α. The expression of class II antigens on astrocytes, and cytokine modulation of their expression, may be important in the initiation and perpetuation of intracerebral immune responses.


Author index : Veterinary Immunology and Immunopathology, volumes 26–50, 1990–1996


title: Expression of major histocompatibility complex (MHC) class I genes in astrocytes correlates with the presence of nuclear factors that bind to constitutive and inducible enahcers

text: The molecular basis of constitutive and inducible major histocompatibility complex (MHC) class I gene expression was studied in murine astrocytes in primary culture. Astrocytes constitutively expressed MHC class I molecules and treatment of these cells with interferon-γ (IFN-γ) further induced expression. The conserved region containing the upstream MHC class I regulatory element (MHC-CRE) and juxtaposed interferon consensus sequence (ICS) enhanced consttutive MHC class I promoter activity. As seen with cell surface expression of MHC molecules, treatment of astrocytes with IFN-γ increased MHC class I promoter activity. Inducible expression required the presence of the MHC-CRE/ICS enhancer region. Nuclear factors that bind to the MHC-CRE and ICS were constitutively expressed in cultured astrocytes and IFN-γ treatment further induced binding activity both to the MHC-CRE and ICS and correlated with induction of MHC class I gene expression. This study identifies the MHC-CRE and ICS as the major cis elements in controlling MHC class I promoter activity and suggests that the expression of nuclear factor binding activities to these enhancer elements is a basic transactivating mechanism for the expression of MHC class I genes in astrocytes.


title: Application of radioimmunological methods for checking the quality of class-specific antibodies against bovine and porcine immunoglobulins

text: Class-specific antibodies against bovine IgG1, IgG2, IgM and IgA and porcine IgG, IgM and IgA immunoglobulins were prepared. Their class specificity was assessed by two radioimmunological methods, namely, radioimmunoelectrophoresis and double antibody sandwich radioimmunoassay. The methods are highly specific and sensitive and do not require the use of purified immunoglobulins, but can be performed with normal serum or colostrum. It was confirmed that antibodies found satisfactory in these tests were suitable for a wide range of use including radioimmunoassay and enzyme linked immunosorbent assay.


title: Human oligodendrocytes are susceptible to cytolysis by major histocompatibility complex class I-restricted lymphocytes()

text: The majority of human oligodendrocytes in enriched glial cell cultures expresses class I major histocompatibility complex (MHC) antigens. We used a (51)Cr release assay to study the susceptibility of oligodendrocyte-enriched glial cells to MHC-restricted and non-restricted immune-mediated cytolysis. Mitogen-activated mononuclear cells induced significant lysis in a lectin-dependent cytotoxicity assay. Mononuclear cells allo-activated in a one-way mixed lymphocyte culture with E(−) cells from the glial cell donor induced a significantly higher degree of oligodendrocyte cytolysis than mononuclear cells activated with E(−) cells bearing MHC-class I antigens discordant with the glia. Cytolysis by alloactivated unfractionated lymphocytes and by purified CD8(+) lymphocytes was reduced by an anti-class I antibody (W6/32). Our findings suggest that human oligodendrocytes can be susceptible targets for MHC class I-restricted lysis.


title: Adult human glial cells can present target antigens to HLA-restricted cytotoxic T-cells

text: T-lymphocyte recognition of antigen either on antigen-presenting cells (APC) necessary for the generation of an immune response or on target cells during the effector phase of a cellular immune response requires expression of HLA molecules. Although immune mechanisms operate in many disease processes of the central nervous system (CNS), cells of the CNS generally express low levels of HLA molecules. In this study, the potential for upregulation of HLA molecules on adult human glial cells was examined. Moreover, the functional implication of this upregulation was assessed by the capacity of glial cells to process and present target antigens to HLA class I-restricted influenza-specific and class II-restrict myelin basic protein (MBP)-specific CTL lines. Glial cells cultured from adult human surgical brain specimens or cells from established glioblastoma multiforme cell lines were studied. Lysis by antigen-specific CTLs was dependent on treatment of the target cell with interferon-γ. The lysis was HLA restricted and antigen specific. The results indicate that adult human glial cells can process and present antigen to HLA-restricted CTLs but require the upregulation of HLA molecules. These findings have implications for infectious and autoimmune diseases of the CNS.


title: Comparison of the blastogenic response of peripheral blood lymphocytes from canine parvovirus-positive and -negative outbred dogs

text: Lymphocyte blast transformation assays (LBT) were performed on canine parvovirus (CPV) -positive and -negative mongrel dogs randomly selected from a humane facility. Concanavalin A as well as Phytohemagglutinin P stimulation was depressed (p<0.001) in the group of animals shedding CPV compared to CPV-negative dogs.


title: Expression of aminopeptidase N/CD13 in tumour-infiltrating lymphocytes from human renal cell carcinoma

text: We have previously demonstrated the expression of aminopeptidase N (APN, CD13) on synovial T cells from patients with different forms of arthritis. T cells of peripheral blood and serous body fluids are CD13-negative but can be stimulated to express CD13 after activation, e.g., with Con A. In the present report, double-labelling and flow cytometry analyses were performed to characterize the phenotype of tumour-infiltrating lymphocytes (TIL). A large panel of antibodies specific for different activation-associated molecules on T cells was used. In contrast to TIL of lung cancer, TIL of renal cell carcinoma (RCC) consisted of significantly higher percentages of T cells expressing CD13, dipeptidylpeptidase N (DPIV, CD26) and HLA-DR, whereas T cells of lung cancer expressed more CD25, CD69 and CD54/ICAM1. No differences could be found in the expression of CD45RO, CD49a/VLA-1 and CD62L/L-selectin. Our results demonstrate that T cells in RCC and lung cancer differ in their phenotype, especially with respect to surface aminopeptidases. Investigations into the function of APN on T cells could be of help in gaining deeper insight into tumour defence as well as into general mechanisms of T cell functions.


title: Tumor necrosis factor-α enhances interferon-γ-mediated class II antigen expression on astrocytes

text: Astrocytes can function as antigen-presenting cells (APC) upon expression of class II antigens, which are induced by interferon-γ (IFN-γ). Tumor necrosis factor-α (TNF-α) can act synergistically with IFN-γ with respect to class II expression on a variety of cells. As brain cells themselves can secrete TNF-like factors upon stimulation, we examined the effect of TNF-α on IFN-γ-mediated class II induction on astrocytes. TNF-α alone had no effect on class II expression, but did synergize with IFN-γ for enhanced expression of class II antigens. The specificity of TNF-α activity was demonstrated by blocking the amplifying effect of TNF-α with a polyclonal anti-TNF-α antibody. Kinetic analysis of the synergistic effect indicated that optimal TNF-α enhancement of class II expression was observed when astrocytes were pretreated with IFN-γ 12–24 h prior to TNF-α addition. A possible mechanism for the synergistic action between IFN-γ and TNF-α may be increased TNF-α receptor expression by IFN-γ. Astrocytes treated with IFN-γ for 24 h express more TNF-α receptors (3900/cell) than do untreated astrocytes (2483/cell), with no significant change in the binding affinity (K(d)). These results suggest that the synergistic activity of TNF-α requires an inductive signal from IFN-γ, which in part may be increased TNF-α receptor expression. Altogether, our observations indicate that TNF-α enhances ongoing class II major histocompatibility complex gene expression in rat astrocytes, which in this system is initially induced by IFN-γ. TNF-α exerts its effect by binding to high affinity TNF-α receptors on astrocytes, whose expression is also enhanced by IFN-γ. These two cytokines work in concert to elevate class II expression on astrocytes, an event which can contribute to initiation and/or perpetuation of intracerebral immune responses.


title: Tissue chambers — a useful model for in vivo studies of cytokine production in the pig

text: An in vivo tissue chamber model was developed to enable studies of local cytokine production and cellular events during inflammatory and immune reactions in the pig. Tissue chambers made of sialistic rubber tubing were surgically implanted in the subcutaneous tissue and samples of tissue chamber fluid (TCF) and inflammatory cells were collected by aspiration with a syringe. To evaluate the model for local cytokine production, two cytokine inducers, polyribinosinic-polyribocytidylic acid (poly I:C) and fixed Aujeszky's disease virus infected PK15 cells (ADV-PK15), were injected into the tissue chambers and samples of TCF were collected 0, 4, 8, 12, 24 and 48 h post injection. Poly I:C injections induced local production of interferon-α (IFN-α) as well as tumor necrosis factor (TNF) in the TCF but kinetic differences in the production of the cytokines were noted. Poly I:C also induced an increase in cell numbers in the TCF, mainly due to increased neutrophil numbers. Injections of ADV-PK15 induced local IFN-α production in the TCF as long as the pigs were serologically negative to ADV. Immunofluorescence and in situ hybridization techniques could be applied for characterization of TCF cells. Moreover, cells recovered from the tissue chambers were viable and could be used in functional in vitro tests. Taken together, this tissue chamber model could prove very useful in in vivo studies of inflammatory/immune responses and cytokine production in the pig.


title: IgM, IgA, IgG1 and IgG2 specific responses in blood and gut secretion of calves fed soyabean products

text: Calves fed soya proteins may develop severe gastrointestinal disorders. Whether these are predominantly associated with particular Ig subclasses and (or) dietary proteins remains unclear. Therefore, antibody responses to soyabean protein were analysed by dot- and blot-immunobinding in plasma and intestinal mucous secretions. One-month-old calves were fed for 2.5 months liquid diets based on skim milk powder (SMP) or a mixture (2:3, protein basis) of whey and soyabean products including a low antigenic hydrolysed soya protein isolate (HSPI) and a highly antigenic heated soya flour (HSF). Specific antibodies (Abs) of the main isotypes (IgM, IgA, IgG1, IgG2) were characterised by immunostaining of samples which had been previously incubated with nitrocellulose sheets coated with SMP, HSPI or HSF extracts. Plasma collected before feeding experimental diets showed very little specific Abs. By contrast, 2.5 month later, a three-fold increase (P < 0.05) in IgG1 and IgA titres against HSF antigens was observed in calves fed HSF compared with those fed the control or HSPI diet. IgG1 immunoblotting revealed many protein bands from soya in the molecular range of 22–32 and 38–42 kDa. Immunorecognition of specific proteins from SMP and HSPI remained low and similar among animal groups. Specific IgM, IgA and IgG1 titres against HSF, and to a lesser extent HSPI, were significantly higher (P < 0.05) in jejunal mucous secretion of calves fed HSF compared with other groups. Secretions from calves fed HSF bound to many soyabean proteins in the range of 17–23 and 26–38 kDa, with similar patterns for IgA and IgG1. By contrast, only weak bands were found for IgM and IgG2 in all groups of calves. Thus, calves fed antigenic HSF do present specific Abs including IgG1 and IgA isotypes, both systemically and locally. Therefore, IgG1 and (or) IgA rather than IgM and IgG2 Abs may be preferred for assessing the immunogenicity of soyabean products in calves. Interestingly, soyabean immunogenicity was drastically reduced by adequate proteolysis.


title: Serum haptoglobin as an indicator of the acute phase response in bovine respiratory disease

text: The early stages of the host response to infectious agents include a number of physiologic changes, collectively known as the acute phase response. The acute phase response is comprised of reactions localized at the site of infection, as well as the initiation of systemic responses, which include a rapid increase in the serum concentration of some proteins, known as acute phase proteins (APP). Using polyacrylamide gel electrophoresis, we detected two APP of approximately 22 and 37 kDa molecular weight in sera obtained from cattle with bovine respiratory disease (BRD). Based on their presence in the sera of sick, but not normal animals, the molecular weights, N-terminal amino acid sequence analysis, and the ability to bind hemoglobin, we identified these proteins as the α and β subunits of haptoglobin. The haptoglobin molecule and the α subunit were isolated from serum, purified, and used to produce monoclonal and polyclonal antibodies. With these reagents, an enzyme linked immunosorbent assay was developed to measure the concentration of haptoglobin in bovine serum. Using an experimental model of BRD induced by a sequential challenge of calves with bovine herpesvirus type-1 and Pasteurella haemolytica, we observed a temporal relationship between the increase in haptoglobin concentration in serum and the onset of bacterial infection. The haptoglobin concentration ranged from undetectable in the serum of most calves prior to challenge, to greater than 1 mgml(−1) in over one-third of the calves at the height of disease. Furthermore, the concentration of haptoglobin was associated significantly with other measures of the severity of disease. Together, these results indicate that quantification of acute phase proteins in animals with BRD could be a valuable diagnostic and prognostic aid.


title: Humoral immune response to Salmonella abortusovis in sheep: in vitro induction of an antibody synthesis from either sensitized or unprimed lymph node cells

text: In vitro culture conditions were determined to induce an anti-Salmonella abortusovis antibody synthesis from lymph node leucocytes of three immunized sheep and two unprimed lambs maintained in culture in the presence of heat-inactivated bacteria for 2 weeks. Humoral immune responses were assessed by enumerating specific antibody-secreting cells using ELISASPOT and by titrating immunoglobulins secreted into culture supernatants using ELISA techniques. Optimal secondary antibody response was observed from cultures performed with fetal calf serum (compared with horse serum) and with an antigen concentration of one to ten bacteria per cell. This kind of antigenic stimulation allowed induction of numerous antibody-secreting cells without adsorption of the secreted antibodies. Maximal numbers of antibody-secreting cells could reach a rate of 1% of the sheep leucocytes initially put into culture. Kinetic profiles of antibody production from boosted lymph node cells were characterized by an ascending phase from the sixth to the twelfth day of culture and then showed a plateau phase until Day 14. Most of the responses were composed of IgM and IgG1 antibodies, traces of IgG2 being detected at the end of experiments. From the twelfth day of antigenic stimulation, the IgM isotype was preferentially expressed with high antigen concentration (100 bacteria per cell), whereas the highest amounts of IgG1 were detected at lower concentration (one to ten bacteria per cell). While anti-Salmonella IgM appeared to be mainly specific for the lipopolysaccharide (LPS) cell wall fraction, some IgG1 recognized other bacterial antigens. Kinetic profiles and magnitudes of primary antibody responses induced in vitro from lamb lymph node cells did not differ from those defined in cultures of sheep boosted leucocytes. But these immune reactions were mainly made up of anti-LPS IgM. Few anti-Salmonella IgG1 were detected from the tenth day of culture. So these in vitro assays allowed induction of an antibody synthesis from either in vivo sensitized or unprimed sheep lymph node leucocytes. This methodology would permit achievement of more detailed studies on interactions between Salmonella and lymph node leucocytes, leading to a better understanding of the mechanisms controlling bacterial dissemination through the lymphoid tissue.


title: Gamma interferon expression and major histocompatibility complex induction during measles and vesicular stomatitis virus infections of the brain

text: Lymphocytic interferon gamma (IFN-γ) production and major histocompatibility complex (MHC) antigen induction were studied in experimental measles and vesicular stomatitis virus infections in the brain. Fifteen-day-old Sprague-Dawley rats injected intracerebrally with the HNT strain of measles virus showed already within 1 day after infection an increased number of cells producing IFN-γ in the spleen, cervical lymph nodes and leptomeninges. These rats recovered after a transient neuronal infection in the brain. Rats infected intracerebrally with vesicular stomatitis virus, on the other hand, all succumbed after 2 days and showed no IFN-γ production in lymphoid cells. Immunohistochemically MHC class I antigen appeared in infected and uninfected cells in the brain during replication of both viruses. A role for the recently discovered nerve fibres with IFN-γ-like immunoreactivity, which are normally present in the brain, in the MHC antigen induction is discussed.


title: In vitro responses of cheetah mononuclear cells to feline herpesvirus-1 and Cryptococcus neoformans

text: In vitro T cell function by domestic cats and cheetahs to two common pathogens, feline herpesvirus-1 (FHV-1) and Cryptococcus neoformans, was assessed. Peripheral blood mononuclear cells (PBM) were stimulated with two strains of UV-inactivated FHV-1, whole heat-killed organisms or capsular antigen of Cryptococcus neoformans, and proliferative responses measured. As a group, cheetah PBM responded significantly poorer than domestic cat PBM when cultured with FHV-1. However, individual cheetah responses varied widely. Supplementation of cultures with exogenous interleukin 2 (IL-2) significantly increased the level of response of individual cheetahs to both strains of FHV-1. Cheetah sera contained slightly higher neutralizing antibody titers to FHV-1 than did domestic cat sera, suggesting that B cells function adequately in cheetahs. When stimulated with Cryptococcus neoformans, both species had similar incidences of positive proliferative responses. These data demonstrate that cheetahs exhibit heterogeneous responses to specific antigens, similar to domestic cats. However, a lower group response to FHV-1 in cheetahs suggests species differences occur. In addition, level of variability in major histocompatibility complex (MHC) class I-like genes, as determined by Southern blot hybridization, does not appear to correlate with a uniform response in in vitro functional assays. Therefore, additional mechanisms influence the final outcome of the immune response.


title: The effects of irradiation on major histocampatibility complex expression and lymphocytic infiltration in the normal rat brain and the 9L gliosarcoma brain tumor model

text: The effects of irradiation on major histocompatibility complex (MHC) expression and lymphocytic infiltration in the normal rat brain and the 9L gliosarcoma brain tumor model were examined. Doses of irradiation administered were biologically equivalent to that used in the treatment of patients with malignant gliomas. No significant change in immune parameters was observed following irradiation in the normal rat brain. In the 9L gliosarcoma model irradiation did not suppress MHC expression or lymphocytic infiltration. These findings suggest that prior exposure to therapeutic irradiation need not adversely affect subsequent immunotherapies, and provide a foundation for future studies of immunomodulation in the irradiated brain.


title: Host genetic regulation of acute MHV-4 viral encephalomyelitis and acute experimental autoimmune encephalomyelitis in (BALB/cKe × SJL/J) recombinant-inbred mice()

text: In the present report we provide the strain distribution patterns of susceptibility to acute mouse hepatitis virus type-4 (MHV-4) encephalomyelitis, acute experimental allergic encephalomyelitis (EAE) and vasoactive amine sensitivity (VAAS) for 9 (CXJ) recombinant-inbred strains between BALB/cKe (C) and SJL/J (J) mice. We confirm that susceptibility to MHV-4 is not linked to the H-2 complex, and that all strains susceptible to acute EAE have both a responder H-2 haplotype (H-2(s) or H-2(d)) and induced (B. pertussis) VAAS. In addition, we provide evidence that susceptibility to acute EAE induction is controlled by an additional presently unmapped locus and that an EAE-like histopathological disease does not usually follow MHV-4 infection intracerebrally in animals susceptible to MHV-4, acute EAE and induced VAAS.


title: Characteristics of in vitro cytotoxic effects of myelin basic protein-reactive T cell lines on syngeneic oligodendrocytes()

text: We have previously found that Lewis rat myelin basic protein (MBP)-reactive lymphocytes (Lc) were cytotoxic in vitro to cultured syngeneic oligodendrocytes (oligos). We report here additional studies to characterize this reaction. The effector lymphocytes in the cytotoxic reaction are also encephalitogenic as evidenced by the capacity of other aliquots of these cells to transfer experimental allergic encephalomyelitis (EAE). We confirmed that the presence of both MBP and antigen-presenting cells (APC) are required for this in vitro cytotoxic effect. This reaction (measured by (51)Cr release from labeled oligos) is dose-dependent on the effector/target ratio with marked (51)Cr release at a 20/1 ratio. Effector/target cell contact is required since: (a) (51)Cr release is not significantly increased when effector Lc and oligo are separated by a micropore membrane (28% vs. 24% spontaneous release); (b) no cytotoxic activity is present in the supernatant fluid of a toxic reaction. The adhesion of (51)Cr-labeled effector Lc to unlabeled oligo is increased in the presence of both MBP and APC (21 ± 1.0% of cell adhering) as compared with effector Lc + APC (12 ± 2.7%), or effector Lc alone (14 ± 2.8%). Surface expression of class I major histocompatibility complex (MHC) antigens was expressed on the surface of the target oligos during this in vitro cytotoxic reaction. This may explain our previously observed MHC restriction in this reaction. The findings described here may explain some of the in vivo pathogenic events in EAE.


docid: bpuifdqd

title: VIth International Congress of Neuroimmunology(): Edinburgh, Scotland, September 3–7, 2001


title: Characterization of brain-infiltrating mononuclear cells during infection with mouse hepatitis virus strain JHM()

text: The eradication of infectious virus from the central nervous system (CNS) following infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV) is thought to be immune-mediated. Furthermore, a significant decrease of infectious virus coincides with the appearance of prominent inflammatory infiltrates in the brain and spinal cord. In the present study, mononuclear cells infiltrating the brain during JHMV infection were isolated and characterized. While all subsets of immune cells were present, there appeared to be a temporal relationship between the peak incidence of CD8(+) T cells (40% of total isolated cells) and reduction of virus at day 7 post-infection. Cells with the natural killer (NK) phenotype (at least 30%) were also present throughout infection. These data suggest that CD8(+) T cells and NK cells are prominent among cells which infiltrate the brain during JHM virus infection and may have important roles in reduction of virus within the CNS.


title: Virus specificity and isotype expression of intraparenchymal antibody-secreting cells during Sindbis virus encephalitis in mice

text: To study the generation of specific antibody responses within the central nervous system (CNS), we have utilized a murine model of acute viral encephalitis. When Sindbis virus (SV) is injected intracerebrally into weanling mice it causes an acute non-fatal encephalitis and recovery is primarily dependent on the development of antiviral antibody. We used a modified enzyme-linked immunoassay to determine the number of antibody-secreting cells (ASC) specific for SV and their Ig isotype in brain, spleen and cervical lymph nodes over the course of the acute encephalitis. The numbers of SV-specific ASC peak early in spleen and lymph nodes and then begin to increase in brain, suggesting that initial stimulation of B cells occurs primarily in peripheral lymphoid tissue followed by B cell entry into the circulation and appearance in the brain. The pattern for each individual isotype was similar with peak numbers of SV-specific cells present in the spleen 5–7 days after infection, while numbers in the brain continue to rise through day 20 when most ASC were secreting IgG2a or IgA SV-specific antibody. The data suggest therefore that most isotype switching from IgM to IgG and IgA occurs in peripheral lymphoid tissue. An exception to this pattern is IgG1, where numbers of ASC producing IgG1 do not show a peak in spleen and continue to rise in brain through the course of acute encephalitis. The data also indicate that early in infection a large proportion of ASC in the brain are not specific for SV and demonstrate that recruitment of ASC into the CNS is non-specific. However, the percentage of ASC that are specific for SV structural proteins rises steadi throughout the course of encephalitis suggesting that retention of ASC in the CNS is specific or that some portion of the SV-specific antibody response is generated within the CNS.


title: Natural killer cell activity of chicken intraepithelial leukocytes against rotavirus-infected target cells

text: Intraepithelial leukocytes (IEL) and splenocytes collected from uninfected and rotavirus-infected chickens were evaluated for cytotoxic activity against a natural killer (NK) cell-susceptible lymphoblastoid cell line (LSCC-RP9) and against rotavirus-infected chick kidney cells in 4-h chromium-release assays. Both splenocytes and IELs from uninfected and rotavirus-infected chickens were cytotoxic for LSCC-RP9, and the levels of this NK cell activity were not altered by infection of the host with rotavirus. IELs but not splenocytes from uninfected and rotavirus-infected chickens were cytotoxic for rotavirus-infected but not for uninfected chick kidney cell targets. Because this cytotoxic activity was not induced nor altered by rotavirus infection of the host, and was not major histocompatibility complex-restricted, it was considered to be due to NK cell activity. The cytotoxicity of IELs against rotavirus-infected target cells was dose-dependent; however, there was some suppression of cytotoxic activity at high effector to target cell ratios. There were no differences in the cytotoxic activities of IELs collected from the duodenum versus the jejunum. The in vitro cytotoxic activity of IELs against rotavirus-infected target cells suggested that NK cell activity may be an important immune response to rotavirus infections in vivo. The absence of cytotoxic activity by splenocytes against rotavirus-infected target cells indicated that there may be different subpopulations of NK cells in the spleen and intestinal epithelium of chickens.


title: A novel candidate autoantigen in a multiplex family with multiple sclerosis: prevalence of T-lymphocytes specific for an MBP epitope unique to myelination

text: Although the major isoform of myelin basic protein (MBP) in the healthy adult CNS is the 18.5-kDa protein, other isoforms containing exon 2 encoded protein (21.5 kDa and 20.2 kDa) exist and are expressed primarily during myelin formation. Since remyelination is a prominent feature in MS lesions, we examined the frequencies of T cell lines (TCLs) specific for epitopes within exon 2 encoded MBP (X2MBP), and also within 18.5-kDa MBP, in members of a multiplex family with MS. TCLs specific for X2MBP were as prevalent as TCLs specific for immunodominant epitopes within 18.5-kDa MBP. In addition, while frequencies of TCLs specific for 18.5-kDa MBP were no different between the affected and unaffected, the frequency of X2MBP-specific TCLs correlated with disease.


title: Development and evaluation of an ELISA using recombinant fusion protein to detect the presence of host antibody to equine arteritis virus

text: A recombinant glutathione-S-transferase fusion protein expressing amino acids 55–98 of equine arteritis virus (EAV) G(L) (rG(L)55–98) was tested in an ELISA for its ability to detect serum antibodies to EAV. Host antibodies induced following EAV infection bound the recombinant antigen by ELISA. The ELISA specificity and sensitivity were determined with a panel of equine sera including postinfection and postvaccination samples. A good correlation existed between EAV neutralizing antibody titers and ELISA absorbance values (r = 0.827). The sensitivity and specificity of the ELISA were 99.6 and 90.1%, respectively, compared with the EAV neutralization test and the recombinant antigen did not crossreact in ELISA with equine sera directed against other common equine respiratory viruses. Three post-EAV infection equine sera raised against different EAV isolates reacted strongly in the ELISA, as did two equine sera raised against EAV vaccines, indicating that the viral epitope was conserved between the viruses tested. Following vaccination with an inactivated whole virus vaccine, antibody detected with the recombinant antigen ELISA preceded the development of a virus-neutralizing response. The study demonstrates the potential application of rG(L)55–98 as a diagnostic antigen.


title: Suppression of bovine lymphocyte responses to mitogens following in vivo and in vitro treatment with dexamethasone

text: Gnotobiotic calves given intramuscular injections of dexamethasone (DM, 0.5 mg kg(−1) day(−1)) showed marked changes in haematological parameters including a neutrophilia and a lymphopaenia. Not only was there a reduction in the numbers of circulating mononuclear cells, but there was also a significant (P<0.01) decrease in the in vitro responsiveness of the remaining circulating peripheral blood lymphocytes to the mitogens, phytohaemagglutinin (PHA), concanavalin A (ConA) and poke-weed mitogen (PWM). Responses to all three mitogens were suppressed to a similar degree. Analysis of the circulating mononuclear cell sub-populations before and during DM treatment demonstrated a selective depletion of B cells; the T lymphocyte sub-population that expresses the gamma/delta form of T cell receptor, are CD2(−), CD5(+), CD8(−), CD4(−) and constitute a major population in peripheral blood of calves. In vitro studies in gnotobiotic and conventional calves confirmed that DM was highly inhibitory for PHA responses but, in contrast to the in vivo findings, showed little effect of DM on ConA responses. Expression of surface antigens after 72 h in vitro culture in the presence of DM were little affected with the exception of BoCD8 and MHC II, which showed increased and decreased expression, respectively. These observations would suggest that distinct mechanisms are involved in glucocorticosteroid suppression of the responses to these two mitogens.


title: Effect of recombinant human interferon-alpha in vitro and in vivo on mitogen-induced lymphocyte blastogenesis in cats()

text: The effect of recombinant human interferon-alpha (rHuIFN-α) in vitro and in vivo on mitogen-induced lymphocyte blastogenesis was evaluated in specific-pathogen-free cats. Pre-incubation of isolated feline peripheral blood lymphocytes (PBL) in vitro with either 10(4) or 10(3) International Units (U) of rHuIFN-α for 24 h significantly suppressed (P<0.001 and 0.01, respectively) blastogenic responses to the phytomitogens concanavalin A (Con A) and pokeweed mitogen (PWM). Lower doses of IFN (range, 10–10(−3) U/ml) neither suppressed nor enhanced mitogenesis. In the absence of phytomitogens, incubation of PBL with 10(4)–10(2) U (P<0.001) or 10 U (P<0.05) of rHuIFN-α/ml resulted in a significant decrease in incorporation of [methyl-(3)H] thymidine into newly synthesized cellular DNA. Cultures of PBL exposed continuously for 4 days to rHuIFN-α doses of 10(4) U/ml or less did not demonstrate specific reductions in cell viability, indicating that the observed antiproliferative actions of IFN apparently were independent of any direct cytotoxic effects. To investigate the dose-response effects of rHuIFN-α in vivo on lymphocyte blastogenesis, individual groups of cats were evaluated on 3 consecutive days before and then 24 h after each cat was inoculated intramuscularly with either a high dose (10(6) U/kg), moderate dose (10(4) U/kg), or a relatively low dose (10(2) U/kg) of rHuIFN-α. Cats inoculated with 10(6) U ofrHuIFN-α/kg had significantly reduced (P=0.037) blastogenic responses to Con a at 24 h postinoculation compared to preinoculation values; mean PWM responses were also decreased, but this effect was not statistically significant. In contrast, inoculation of cats with either 10(4) or 10(2) U of rHuIFN-α/kg significantly enhanced (P=0.05 or 0.008, respectively) Con A-induced blastogenesis and had no discernible effect on PWM responses. These findings suggest that very high doses of rHuIFN-α given parenterally may be associated with suppression of certain T-cell responses in cats; conversely, much lower doses may be immunoenhancing.


docid: bxfwykch

title: Enhancement of encephalomyeloradiculitis in mice sensitized with spinal cord tissue and infected with lactate dehydrogenase-elevating virus()

text: C57BR/cdJ mice develop encephalomyeloradiculitis following peripheral inoculation of the C strain of lactate dehydrogenase-elevating virus (LDV-C). We investigated the effect of subcutaneous administration of syngeneic spinal cord homogenate mixed with phosphate buffered saline or emulsified in complete or incomplete Freund's adjuvant 1 week before or after inoculation of LDV-C on the incidence and severity of central nervous system lesions. C57BR/cdJ mice developed an acute histological allergic encephalomyelitis when given 2 weekly sensitizing injections of homogenate in complete Freund's adjuvant. When peripheral inoculation of LDV-C was substituted for one of the two sensitizing injections, a higher percentage of mice developed lesions, and the lesions were more severe and persisted for much longer periods of time. This same lesion-enhancing effect was not observed if the mice were sensitized with homogenate suspended in buffer or emulsified in incomplete Freund's adjuvant. Interestingly, mice sensitized with complete Freund's adjuvant alone before or after infection with LDV-C also developed intense central nervous system lesions, suggesting that the mycobacterial component of the adjuvant was the critical element in enhancing the lesions.


title: Envelope proteins of avian infectious bronchitis virus: Purification and biological properties

text: Immunoadsorbents, made with monoclonal antibodies, were used to purify the spike and membrane proteins of infectious bronchitis virus (IBV). The purified proteins were inoculated into rabbits to produce antisera. The rabbit anti-spike sera neutralized the infectivity of the virus whereas the anti-membrane sera did not. IBV-infected chickens produced antibodies to both the spike and membrane proteins. Both these antibodies were at their highest concentration about 9–11 days after inoculation, whereas neutralizing antibodies were present only at very low concentrations at that time. Neutralizing antibodies were at their highest concentration 21 days after inoculation. A second inoculation of virus at 42 days induced an anamnestic antibody response to the spike and membrane proteins and also for the neutralizing antibodies. The neutralizing, anti-spike and anti-membrane antibodies all reached highest concentrations 7–11 days after this inoculation. The advantages of purifying viral proteins using affinity chromatography with monoclonal antibodies are discussed.


title: Comparison of the “ProDect BCS RV CHIP” assay with the combination of shell vial cell culture and immunofluorescence antibody test for the detection of respiratory viruses

text: In the present study, a multiplex reverse transcriptase polymerase chain reaction combined with a chip hybridization assay (ProDect BCS RV CHIP) was evaluated as an alternative to the combination of immunofluorescent antibody test and shell vial cell culture considered as gold standard for the detection of respiratory viruses. Among 100 specimens, 40 were positive using the combination of immunofluorescent antibody test and shell vial cell culture assay in which 9 of them were infected by two different viruses (27 parainfluenza virus type 3, 10 adenovirus, 9 respiratory syncytial virus, 2 influenza type B, and 1 influenza type A). ProDect BCS RV CHIP detected only 10 positive specimens in which one of them was infected by two different viruses (5 respiratory syncytial virus, 3 parainfluenza virus type 3, 2 adenovirus, and 1 influenza virus type B). The sensitivity, specificity, PPV, NPV, and diagnostic accuracy of ProDect BCS RV CHIP were 25.0%, 100%, 100%, 66.6%, and 70.0%, respectively, compared to the combination of shell vial cell culture and immunofluorescent antibody test. As a result, the specificity of ProDect BCS RV CHIP is high, however, the sensitivity (25%) of the assay is not sufficient for routine laboratory use.


title: Theiler's virus is eliminated by a gamma-interferon-independent mechanism in the brain

text: The intravenous infection of Theiler's virus GD VII strain causes acute encephalomyelitis in infected mice. To determine the cellular mechanism of resistance and interferon (IFN)-γ-producing cell populations, mononuclear cells isolated from tissues of the brain were analyzed by the flow cytometry method. Antibodies specific for CD3, CD4, CD8, T cell receptor (TCR)-αβ, and Asialo GM1 were used to deplete the corresponding cell populations in Theiler's virus-infected mice. CD4(+) lymphocytes and CD8(+) lymphocytes infiltrated in the brains of infected mice from 5 days postinfection (p.i.). The number of CD3(+)/TCR-γδ(+) lymphocytes increased in the brains on Day 6 p.i. The elimination of CD3(+) lymphocytes or CD4(+) lymphocytes augmented viral replication and suppressed the production of IFN-γ. The suppression of IFN-γ production by anti-CD3 monoclonal antibody (mAb) persisted, although the suppression by anti-CD4 mAb was observed only on Day 6 p.i. The depletion of CD8(+) lymphocytes as well as TCR-αβ(+) lymphocytes also augmented the viral replication; however, it did not alter the production of IFN-γ. Anti-Asialo GM1 antibody had no effect on viral replication and IFN-γ production. These results indicate that T lymphocytes are important for eliminating Theiler's virus from the brain, CD3(+)/CD4(+)/CD8(−) lymphocytes and CD3(+)/TCRαβ(−)/CD4(−)/CD8(−) lymphocytes would produce IFN-γ in brain. However, from the result on the experiment of the depletion of TCR-αβ(+) lymphocytes, the defence mechanisms by T lymphocytes against Theiler's virus would be independent of endogenous IFN-γ production.


title: The expression of major histocompatibility complex (MHC) class I antigens in the brain differs markedly in acute and persistent infections with lymphocytic choriomeningitis virus (LCMV)

text: Intracranial inoculation of immunocompetent mice with lymphocytic choriomeningitis virus (LCMV) induces a fatal neurologic illness. In this disease a marked increase in MHC class I expression was found, closely associated with viral antigens and inflammatory infiltrates, in meninges, choroid plexus and ventricular ependyma but not within the brain parenchyma. Immunosuppression prevented MHC induction. Mice inoculated at birth had persistent infections, with LCMV antigens found primarily in neurons, but no inflammatory cells or focal increase in MHC class I. Failure of infected neurons to express MHC class I allow them to escape destruction by cytotoxic T cells (CTL) but may increase their susceptibility to be persistently infected by non-lytic viruses.


title: Class II-restricted T cell responses in Theiler's murine encephalomyelitis virus (TMEV)-induced demyelinating disease(): III. Failure of neuroantigen-specific immune tolerance to affect the clinical course of demyelination

text: Intracerebral inoculation of Theiler's murine encephalomyelitis virus (TMEV) into susceptible mouse strains produces a chronic demyelinating disease in which mononuclear cell-rich infiltrates in the central nervous system (CNS) are prominent. Current evidence strongly supports an immune-mediated basis for myelin breakdown, with an effector role proposed for TMEV-specific, major histocompatibility complex (MHC) class II-restricted delayed-type hypersensitivity (DTH) responses in which lymphokine-activated macrophages mediate bystander demyelination. The present study examined the possibility that concomitant or later-appearing neuroantigen-specific autoimmune T cell responses, such as those demonstrated in chronic-relapsing experimental allergic encephalomyelitis (R-EAE), may contribute to the demyelinating process following TMEV infection. T cell responses against intact, purified major myelin proteins (myelin basic protein (MBP) and proteolipid protein (PLP), and against altered myelin constituents were readily demonstrable in SJL/J mice with R-EAE, but were not detectable in SJL/J mice with TMEV-induced demyelinating disease. TMEV-infected mice also did not display T cell responses against the peptide fragments of MBP(91–104) and PLP(139–151) recently shown to be encephalitogenic in SJL/J mice. In addition, induction of neuroantigen-specific tolerance to a heterogeneous mixture of CNS antigens, via the i.v. injection of syngeneic SJL/J splenocytes covalently coupled with mouse spinal cord homogenate, resulted in significant suppression of clinical and histologic signs of R-EAE and the accompanying MBP- and PLP-specific DTH responses. In contrast, neuroantigen-specific tolerance failed to alter the development of clinical and histologic signs of TMEV-induced demyelinating disease or the accompanying virus-specific DTH and humoral immune responses. These findings demonstrate that TMEV-induced demyelinating disease can occur in the apparent absence of neuroantigen-specific autoimmune responses. The relationship of the present results to the immunopathology of multiple sclerosis is discussed.


The immune response to virus infections


title: Flavivirus infection up-regulates the expression of class I and class II major histocompatibility antigens on and enhances T cell recognition of astrocytes in vitro

text: West Nile virus (WNV) infection of astrocytes can up-regulate their expression of both class I and class II major histocompatibility complex (MHC) antigens as determined by flow cytometry with monoclonal antibodies specific for class I and class II MHC antigens. The up-regulation of class I MHC antigen expression could be partly caused by interferon secreted after WNV infection because the synthetic interferon inducer polyinosinic-polycytidylic acid (poly I : C) has similar effects. In contrast the up-regulation of class II MHC antigen expression was not induced by poly I : C. The increased MHC antigen expression by WNV infection had significant effects on T cell recognition. Thus, WNV and influenza virus A/WSN double-infected astrocytes but not astrocytes infected by A/WSN alone were lysed by influenza virus-immune cytotoxic T cells. Similarly, WNV-infected astrocytes were better stimulators than normal astrocytes for a class II MHC-reactive T cell line, both in terms of T cell proliferation and interleukin release.


title: Immunohistochemical studies of adult human glial cells

text: Using immunohistochemical techniques, we examined major histocompatibility complex (MHC) antigen expression on astrocytes, oligodendrocytes, and macrophages-microglia derived from surgically resected tissue from young adults and maintained in dissociated cell cultures supplemented with either fetal calf or human AB serum. The majority of these cells in culture expressed class I MHC antigens. MHC class II expression was observed on only a restricted proportion of astrocytes either under basal or induction conditions (γ-interferon, activated lymphocyte supernatants), on the majority of macrophages-microglia under inducing conditions, and not on oligodendrocytes. MHC class II expression on astrocytes in culture did not correlate with the extent of in situ gliosis or with in vitro cell morphology. MHC antigen expression was not detected in situ immunohistochemically. These data extend observations on the dissociation of in vivo and in vitro expression of MHC antigens on glial cells. The apparent greater expression of MHC class II antigens on macrophages-microglia compared to astrocytes raises the issue of the relative roles of each of these cell types in promoting immune reactivity under pathologic conditions.


title: Cytotoxic effect of myelin basic protein-reactive T cells on cultured oligodendrocytes

text: To help clarify effector mechanisms in experimental allergic encephalitis (EAE), the cytotoxic effects of myelin basic protein (MBP)-reactive lymphocytes on oligodendrocytes were studied using a (51)Cr release assay. MBP-reactive encephalitogenic T cell lines were cytotoxic to (51)Cr-labeled oligodendrocyte target cells derived from Lewis rat fetal brain-dissociated culture, when incubated for 6 h in the presence of antigen-presenting cells (APC) and MBP (percent51Cr release = 65±3% vs. spontaneous release = 22±3% vs. normal lymph node cells + APC and MBP = 20 ± 3%). This reaction is time dependent, likely MHC restricted, and is not just a nonspecific toxic effect against any Lewis target cells since neither fibroblasts nor astrocytes were affected. Other (tetanus toxoid-reactive) lymphoblasts stimulated by specific antigen were not cytotoxic to the oligodendrocytes. These findings suggest that oligodendrocytes might be target cells for MBP-reactive lymphocytes in EAE if antigen presentation is appropriate.


Is serum in childhood naturally protective against SARS-coronavirus?


title: Early major histocompatibility complex (MHC) class I antigen induction in hypothalamic supraoptic and paraventricular nuclei in trypanosome-infected rats

text: Sprague-Dawley rats were injected intraperitoneally with a suspension of Trypanosoma brucei. An early induction of major histocompatibility complex (MHC) class I antigens as well as an infiltration of macrophage-like and cytotoxic T-cells was detected with immunohistochemical techniques in circumventricular organs, such as the median eminence, neurohypophosis, subformical organ, pineal gland and area postrema. These areas, which lack a blood-brain barrier, correspond to those showing early invasion of trypanosomes. In addition, there was a marked induction of MHC class I in neurons in two hypothalamic nuclei, The paraventricular and supraoptic nuclei. Neurons in these two nuclei are located behind the blood-brain, but project to the neurohypophysis and to the medain eminence, thereby exposing their axon terminals to factors circulating in the blod or released locally from invading trypanosomes or from macrophages or cytotoxic T-cells. It is suggested that the alteration in the nerve cell bodies in the hypothalamic nuclei is caused by retrograde axonal signals from these target areas. Sleeping sickness; Trypanosomes; Paraventricular nucleus; Major histocompatibility complex classI


title: Genetic regulation of class I major histocompatibility complex (MHC) antigen induction on astrocytes

text: Neural cells, indluding astrocytes, normally do not express detectable levels of class I major histocompatibility complex (MHC) molecules, unlike cells of most tissues. However, upon cultivation in vitro, astrocytes begin to express class I molecules, increasing with time after plating. This spontaneous expression was examined in the present study to characterize inducible expression on astrocytes among various strains of mice. Inducible expression, either as a consequence of cultivation or standard γ-interferon treatment, differed markedly among the strains examined. Analysis of congenic strains on a C57BL/10 (B10) background showed that expression was controlled by genes within the MHC locus. Examination of additional congeneic animals with various recombinations within the MHC showed that high or low expression of MHC molecules correlates with the presence of particular MHC class I genes. In general, H-2(a) and H-2(d) class I products are expressed much higher on astrocytes than H-2(b) and H-2(s) products. This difference in expression is not seen on spleen cells indicating tissue specificity. Moreover, levels of expression at the cell surface are reflected by the steady-state level of RNA message within astrocytes of the different strains.