bluuebunny/crossref_metadata_2025 huggingface dataset:
Cytokine production in a whole-blood assay after Epstein-Barr virus infection in vivo
Authors: Hornef M W , Wagner H J , Kruse A , Kirchner H
Published: January 2020

Epstein-Barr virus (EBV) has a marked tropism for cells of the immune system, and infection can result in profound immunomodulatory effects. In order to examine the role of cytokines during the acute phase of infectious mononucleosis, we studied the levels of different interleukins (ILs), interferons (IFNs), and the soluble IL-2 receptor (sIL-2R) in serum samples of 20 patients. We found elevated levels of IL-2, IL-6, sIL-2R, and IFN-gamma. Whereas the peak of IL-2 and IL-6 concentration occurred during the first week (P < 0.01), the largest amounts of sIL-2R were measured during the second week (P < 0.01). IFN-gamma levels were only enhanced during the first week. In addition, we investigated the ability to produce cytokines in response to mitogenic stimulation in a whole-blood assay of 11 patients compared with healthy blood donors. In the whole-blood assay of patients compared with controls after stimulation with lipopolysaccharide, we measured more than 10-fold elevated levels of tumor necrosis factor alpha (P < 0.01), 3-fold elevated levels of IL-1 beta (P < 0.01), and about 2-fold increased amounts of IL-6 (P < 0.01). A significant enhancement in sIL-2R and IFN-gamma concentration was found in the assay after stimulation with phytohemagglutinin after 24 h of incubation (P < 0.01). Collectively, our data seem to indicate that monocytes are strongly activated during infectious mononucleosis. Monocytes and monocyte-derived factors may play an important role in the pathogenesis of infectious mononucleosis and, together with T lymphocytes, may be partly responsible for clinical symptoms.
Utility of various commercially available human immunodeficiency virus (HIV) antibody diagnostic kits for use in conjunction with efficacy trials of HIV-1 vaccines
Authors: Schwartz D H , Mazumdar A , Winston S , Harkonen S
Published: January 2020

There is a need for human immunodeficiency virus (HIV) screening assays which will distinguish uninfected HIV vaccine recipients from HIV-infected individuals. Commercial screening kits were used to test serum samples from low- and high-risk participants in clinical trials before and after immunization with various recombinant HIV type 1 (HIV-1) envelope glycoprotein 120 (gp120) candidate vaccines. All kits were 100% sensitive in detecting HIV infection. Both Murex Single Use Diagnostic System and United Biomedical, Inc., HIV type 1 or 2 (HIV-1/2) enzyme immunoassay (EIA) kits, which detect antibodies to HIV-1 gp41, were 98 to 100% specific when used to screen baseline or recombinant gp120-vaccinated populations as vaccine-induced antibodies to gp120 were nonreactive in these tests. The Abbott HIVAB HIV-1 EIA (lysate of whole infected cells, reactive with anti-gp120 antibodies) gave high levels of reactivity due to vaccine-induced antibodies and a high baseline rate of false positives (12 of 83) among nonvaccinated high-risk volunteers. Assays containing only gp41 and p24 solid-phase components are compatible with gp120-based vaccines but are unlikely to be useful in a similar role for vaccines containing gp160, gp41, or gp120 plus p24 antigens. Efficacy trials must be designed in concert with available diagnostic screening assays to avoid problems caused by vaccine-induced seroconversion in high-risk populations.
Role of histamine in natural killer cell-dependent protection against herpes simplex virus type 2 infection in mice
Authors: Hellstrand K , Asea A , Hermodsson S
Published: January 2020

Depletion of natural killer (NK) cells in vivo with anti-NK1.1 monoclonal antibody or anti-asialo-GM1 antiserum drastically reduced survival time in Swiss albino mice infected intravenously (i.v.) with herpes simplex virus type 2 (HSV-2). In contrast, depletion of NK cells did not affect the survival time of mice inoculated with HSV-2 by the intraperitoneal route. A single dose of histamine prolonged survival time in animals inoculated with HSV-2 i.v. but not in animals infected intraperitoneally. Treatment with the histamine H2 receptor antagonist ranitidine alone reduced survival time in i.v.-infected animals and blocked the protective effect of histamine. Histamine or ranitidine did not affect survival time in anti-NK1.1- or anti-asialo-GM1-treated animals. Our data suggest a role for histaminergic mechanisms in NK cell-mediated protection against HSV-2.
Lymphocytic 2',5'-oligoadenylate synthetase activity increases prior to the appearance of neutralizing antibodies and immunoglobulin M and immunoglobulin G antibodies after primary and secondary immunization with yellow fever vaccine
Authors: Bonnevie-Nielsen V , Heron I , Monath T P , Calisher C H
Published: January 2020

Primary and secondary immunizations with live, attenuated yellow fever virus vaccine (17D strain) were performed in order to study the course of appearance of virus-neutralizing antibodies and immunoglobulin M (IgM) and IgG antibodies directed against the virus and the interferon-dependent enzyme 2',5'-oligoadenylate synthetase (2',5'AS) activity, determined in homogenates of peripheral B and T lymphocytes. From cellular ATP, this enzyme generates 2',5'-oligoadenylates which mediate degradation of viral mRNA by stimulation of a latent RNase. By day 4 after the first immunization, the earliest and highest 2',5'AS activity was present in the T-lymphocyte fraction. By day 7, the enzyme activity was highest in the B-lymphocyte fraction. Virus-neutralizing antibodies appeared on day 7, and IgM antibodies were present on day 12. After the second immunization, performed 2 years +/- 2 months later, the only significant increase in 2',5'AS activity was observed in the T-lymphocyte fraction. Virus-neutralizing antibodies were present from day 1, whereas no IgM antibodies were detected. By day 12, 80% of the vaccines were IgG positive. In the primary and secondary (memory) immune responses, 2',5'AS activity is expressed in the T-lymphocyte fraction prior to the appearance of antibodies directed against the virus and may serve as an early and sensitive marker of an ongoing virus infection which is otherwise difficult to detect. No change in conventional laboratory analysis parameters, such as in differential blood cell counts or total IgA, IgG, and IgM, disclosed the immune activity in either the primary or the secondary immunization.
Interaction of human immunodeficiency virus type 1, human T-cell leukemia/lymphoma virus type I (HTLV-I), and HTLV-II with in vitro-generated dendritic cells
Authors: Zucker-Franklin D , Fraig M , Grusky G
Published: January 2020

Although it is known that impairment of dendritic cells (DC) plays a role in the pathogenesis and immunosuppression of retrovirus-associated diseases, it is not clear whether, or to what extent, these antigen-presenting cells themselves become infected. The realization that the cells can be generated in vitro in larger numbers than can be isolated from circulating blood or bone marrow raised the possibility that they could be used for therapeutic purposes. Therefore, we investigated whether DC generated in vitro from CD34 precursors are susceptible to infection when cocultured with human immunodeficiency virus type 1- or human T-cell leukemia/lymphoma virus-infected cell lines. While there appears to be a remarkable affinity of the viruses for the plasma membranes of the DC, interiorization or budding was not observed in 30 experiments carried out under a variety of conditions.
Measurement of sputum antibodies in the diagnosis of acute and chronic respiratory infections associated with Chlamydia pneumoniae
Authors: von Hertzen L , Leinonen M , Surcel H M , Karjalainen J , Saikku P
Published: January 2020

The aim of this study was to develop methods for the measurement of sputum antibodies in the laboratory diagnosis of acute and chronic lower respiratory tract infections caused by Chlamydia pneumoniae. Paired serum specimens, sputum specimens, and pharyngeal or nasopharyngeal swabs were obtained from 97 patients; 51 of them had community-acquired pneumonia, and 46 had chronic obstructive pulmonary disease (COPD). C. pneumoniae-specific serum immunoglobulin G (IgG), IgA, and IgM antibodies were measured by the microimmunofluorescence (micro-IF) test. For sputa, specific IgA and IgG antibodies were measured by the micro-IF test and secretory IgA (sIgA) was measured by enzyme immune assay (EIA) with C. pneumoniae elementary bodies as the antigen. Sputum IgA and sIgA antibodies to C. pneumoniae were found, respectively, in 52 and 51% of the COPD patients. Elevated levels of stable serum IgG and IgA antibodies (IgG titer of > or = 128 and IgA titer of > or = 40), suggesting chronic infection, were found in 54% of the COPD patients. The sensitivity for the sputum IgA micro-IF test compared with elevated serum antibody levels was 87.5%, and that for the sputum sIgA EIA was 88%; the respective specificities were 90 and 95%. Acute C. pneumoniae infection was diagnosed in seven pneumonia patients, and two (29%) of these patients were positive by sputum EIA antibody measurements. Two pneumonia patients without acute infection had stable elevated IgG and IgA levels in their sera, and both of them were sputum antibody positive. We conclude that the measurement of IgA antibodies to C. pneumonia in sputum is a useful additional diagnostic tool for chronic C. pneumoniae infections.
Pattern of cytokines and pharmacomodulation in sepsis induced by cecal ligation and puncture compared with that induced by endotoxin
Authors: Villa P , Sartor G , Angelini M , Sironi M , Conni M , Gnocchi P , Isetta A M , Grau G , Buurman W , van Tits L J
Published: January 2020

The production of tumor necrosis factor alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and IL-6 and their pharmacomodulation were evaluated in a model of polymicrobial sepsis induced in mice by cecal ligation and puncture (CLP) and were compared with the effects of endotoxin (lipopolysaccharide [LPS]) treatment. LPS levels rose as early as 1 h after CLP and increased further after 2 and 21 h. TNF-alpha was detectable in serum, spleen, liver, and lungs during the first 4 h, with a peak 2 h after CLP. IL-1 beta was measurable in serum after 24 h, and levels increased significantly in spleen and liver 4 and 8 h after CLP. IL-6 levels increased significantly in serum throughout the first 16 h after CLP. These cytokines were detectable after LPS injection, with kinetics similar to those after CLP but at a significantly higher level. To cast more light on the differences between these two animal models of septic shock, we studied the effects of different reference drugs. Pretreatment with dexamethasone (DEX); ibuprofen (IBU), an inhibitor of cyclooxygenase; and NG-nitro-L-arginine, an inhibitor of nitric oxide synthase, significantly reduced survival, while chlorpromazine (CPZ) and TNF did not affect it. Only the antibiotics and pentoxifylline significantly increased survival in mice with CLP. However, CPZ and DEX protected the mice from LPS mortality. On inhibiting TNF-alpha with DEX, CPZ, or pentoxifylline, survival was reduced, unchanged, and increased, respectively, and on increasing TNF-alpha with IBU and TNF, survival was decreased or unchanged, respectively, suggesting that the modulation of this cytokine does not play a significant role in sepsis induced by CLP, unlike treatment with LPS. The negative effects of IBU and N(G)-nitro-L-arginine suggest a protective role by prostaglandins and nitric oxide in sepsis induced by CLP.
Comparison of the vibriocidal antibody response in cholera due to Vibrio cholerae O139 Bengal with the response in cholera due to Vibrio cholerae O1
Authors: Qadri F , Mohi G , Hossain J , Azim T , Khan A M , Salam M A , Sack R B , Albert M J , Svennerholm A M
Published: January 2020

Vibrio cholerae serogroup O139, now considered to be the second organism capable of causing epidemic severe dehydrating cholera, contains a capsular polysaccharide which makes it difficult for it to be used in the conventional vibriocidal antibody assay optimized for V. cholerae O1. After modification of the procedure, which involved the use of specific bacterial strains, a lower bacterial inoculum, and increased amounts of complement, the vibriocidal antibody responses to V. cholerae O139 were measured in acute- and convalescent-phase sera from 33 V. cholerae O139-infected and 18 V. cholerae O1-infected patients and in single serum samples from 20 healthy control subjects. The responses in these individuals to V. cholerae O1 strains were also determined. Significant elevations in the homologous antibody response were found only in the convalescent-phase sera from both groups of patients with cholera. These findings may explain the basis for the lack of heterologous protection between the two serogroups of V. cholerae. Healthy controls had higher background levels of vibriocidal antibody to V. cholerae O1 than to V. cholerae O139.
Dysregulated production of interleukin-10 (IL-10) and IL-12 by peripheral blood lymphocytes from human immunodeficiency virus-infected individuals is associated with altered proliferative responses to recall antigens
Authors: Daftarian M P , Diaz-Mitoma F , Creery W D , Cameron W , Kumar A
Published: January 2020

The loss of immune function following infection with human immunodeficiency virus (HIV) may result from altered production of immunoregulatory cytokines such as interleukin-10 (IL-10) and IL-12. In this study, we analyzed IL-10 and IL-12 production by mitogen-stimulated peripheral blood mononuclear cells (PBMC) from HIV+ individuals and correlated their levels with proliferative responses to the recall antigens HIV p25 and influenza virus. We report two distinct groups of HIV+ patients. One group produced small amounts of IL-10, had PBMC that proliferated in response to recall antigens, and demonstrated enhanced recall antigen-induced proliferation upon addition of anti-IL-10 antibodies and/or IL-12. Conversely, the second group produced high levels of IL-10, had PBMC that failed to proliferate to recall antigens, and did not demonstrate enhanced proliferation upon addition of anti-IL-10 antibodies and/or IL-12. Mitogen-stimulated PBMC from both groups produced significantly lower levels of IL-12 than did those from HIV- controls. Analysis of the source of the IL-10-producing cell subset in PBMC demonstrated that in HIV+ individuals, IL-10 is produced by monocytes, while in HIV- controls, it is produced by both T cells and monocytes. Taken together, our results suggest that monocytes from HIV+ individuals secrete decreased amounts of IL-12, a Th1-type cytokine, which may lead to the development of Th2-type responses characterized by high IL-10 secretion and immune dysfunction.
Characterization of preparations enriched for Streptococcus mutans fimbriae: salivary immunoglobulin A antibodies in caries-free and caries-active subjects
Authors: Fontana M , Gfell L E , Gregory R L
Published: January 2020

The ability of bacteria to adhere to salivary pellicle-coated enamel tooth surfaces is a critical step in oral bacterial colonization. Oral bacteria adhere to receptors of host origin in salivary pellicle. Streptococcus mutans has been identified as the major etiological agent of human dental caries and composes a significant proportion of the oral streptococci in carious lesions. Bacterial fimbriae are small (100 to 300 nm) hairlike appendages emanating from the cell surface. Preparations enriched for S. mutans fimbriae were isolated by a shearing technique and alternating high- and low-speed centrifugations. A representative fimbrial preparation had two distinct double bands comprising four proteins of approximately 100 to 200 kDa and one faint band at 40 kDa on reducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis/immunoblots and had demonstrable glucosyltransferase activity. Rabbit antisera raised against the preparation specifically stained the fuzzy coat of S. mutans, demonstrating short fimbria-like structures protruding 100 to 200 nm from the cell surface. Controls without antifimbria antibody did not exhibit this staining. There were significantly higher (P < or = 0.05) levels of salivary immunoglobulin A, but not serum immunoglobulin G, antibodies to the enriched S. mutans fimbria preparation by enzyme-linked immunosorbent assay from caries-free subjects than from caries-active subjects. The results suggest that S. mutans fimbriae may be an important adherence factor to which caries-free subjects mount a protective salivary immune response.
Expression of recombinant feline tumor necrosis factor is toxic to Escherichia coli
Authors: Otto C M , Niagro F , Su X , Rawlings C A
Published: January 2020

The tumor necrosis factor (TNF) genes from cats, horses, and pigs have all been cloned into the pFLAG-1 fusion protein expression vector (International Biotechnologies, Inc., Kodak, New Haven, Conn.). Growth curves for Escherichia coli containing the pFLAG-1 vector alone and the pFLAG-1 vector containing the TNF gene from each species were determined by visible light spectrophotometry (at 600 nm). Porcine TNF, equine TNF, and feline TNF cultures had slower doubling rates than cultures containing the pFLAG-1 vector alone. Cultures of cells transformed with feline TNF reached peak densities at 3 to 4 h and then decreased to near initial densities prior to the recovery of growth. The induction of expression with isopropyl-beta-D-thiogalactopyranoside (IPTG) arrested the growth of fresh feline TNF cultures for 6 h, which was followed by complete recovery. This inhibition occurred in two strains of E. coli (LL308 and JM101). Induced feline TNF cultures expressed the TNF-FLAG fusion protein for the first 6.5 h. Uninduced cultures expressed low levels of fusion protein. The feline TNF-pFLAG-1 vector was purified from cells expressing fusion protein and from cells with recovered growth curves. Sequencing the vector demonstrated the complete feline TNF gene and tac promoter in cells expressing the fusion protein and a deletional mutation of the tac promoter site in recovered cells. In contrast to equine and porcine TNF, the expression of recombinant feline TNF is toxic to E. coli. Alterations in protein folding and the prevention of secretion of the feline protein may explain the toxic effect.
Bereavement is associated with time-dependent decrements in cellular immune function in asymptomatic human immunodeficiency virus type 1-seropositive homosexual men
Authors: Goodkin K , Feaster D J , Tuttle R , Blaney N T , Kumar M , Baum M K , Shapshak P , Fletcher M A
Published: January 2020

Seventy-nine human immunodeficiency virus type 1 (HIV-1)-seropositive homosexual men participating in a longitudinal study of HIV-1 infection were assessed twice, 6 months apart, to investigate associations between bereavement and cellular immune function. Subjects were assessed by using a theory-driven model comprising life stressors, social support and coping style, and control variables. Natural killer cell cytotoxicity was decreased among the bereaved at both times. Lymphocyte proliferative response to phytohemagglutinin was decreased among the bereaved at the second time point but not at the first. These functional immune decrements are associated with increased neuroendocrine responses of the sympathetic adrenomeduallary system as well as the limbic-hypothalamic-pituitary-adrenal axis. Implications for differential neuroendocrine responses over time are discussed. Active coping style was independently and positively related to both immune measures. The results imply that a bereavement support group intervention merits investigation for an effect on immunological measures and clinical progression of HIV-1 infection as well as grief resolution.
Effect of malnutrition on serum and milk antibodies in Zairian women
Authors: Brüssow H , Barclay D , Sidoti J , Rey S , Blondel A , Dirren H , Verwilghen A M , Van Geert C
Published: January 2020

Serum and human milk antimicrobial antibody titers were measured longitudinally in 17 malnourished and 14 control Zairian women during 6 to 18 months of lactation to test whether malnutrition is specifically associated with an impaired secretory antibody response. No decreases in total serum and human milk immunoglobulin concentrations, neutralizing antibody titers against rotavirus, or specific enzyme-linked immunosorbent assay antibody titers against rotavirus, respiratory syncytial virus, Escherichia coli, Streptococcus pneumoniae, and Haemophilus influenzae were detected when malnourished women were compared with control women. Malnutrition had no effect on circulating and secretory antibody concentrations in Zairian women. Daily human milk outputs, however, were about 30% lower in malnourished than in control women, resulting in a correspondingly lower ingestion of immunoglobulins by the children of malnourished women.
Immunoglobulin G subclass responses of children during infection with Onchocerca volvulus
Authors: Gbakima A A , Nutman T B , Bradley J E , McReynolds L A , Winget M D , Hong Y , Scott A L
Published: January 2020

To characterize the patterns of immunoglobulin G (IgG) subclass and IgE reactivity during the early stages of onchocerciasis, sera were collected from 224 children (age groups, 2 to 5, 6 to 10, and 11 to 15 years) residing in a region of Sierra Leone where Onchocerca volvulus is endemic, and these samples were tested by enzyme-linked immunosorbent assay for their reactivity to adult antigens (OvAg) and against four recombinant proteins (OV11, OV27, OV29, and OV16). Over 88% of the samples contained detectable levels of anti-OvAg IgG. In samples from microfilaria (MF)-positive children, IgG4 responses were significantly elevated and constituted on average 39, 35 and 28% of the total IgG responses for the age groups of 2 to 5, 6 to 10, and 11 to 15 years, respectively. For MF-negative individuals, the mean contributions of IgG4 to the total IgG response were 11% (2 to 5 years), 27% (6 to 10 years), and 56% (11 to 15 years). OvAg-specific IgE was detectable in the sera from both MF-negative and MF-positive individuals. To increase the specificity of the response, recombinant antigens OV11, OV27, and OV29 were tested individually or as a cocktail. Nearly 50% of the MF-negative children and 85% of the MF-positive children had detectable levels of IgG against at least one of the recombinant antigens. Only a small portion of the IgG against the recombinant peptides was IgG4. The prevalence of IgG against OV16 in samples from MF-negative children was 51%, and that for MF-positive children was 75%. The general profile of the humoral immune responses mounted by both MF-positive and a large percentage of the MF-negative children during the initial phases of infection with O. volvulus is similar to the profile reported for adults harboring chronic O. volvulus infections. These results suggest that very quickly after infection, the interactions between parasite and host result in an immunological environment that may contribute to the maintenance of a long-term, chronic infection.
Immunoglobulin G avidity testing in serum and cerebrospinal fluid for analysis of measles virus infection
Authors: Narita M , Yamada S , Matsuzono Y , Itakura O , Togashi T , Kikuta H
Published: January 2020

We studied a variety of patients with measles virus infection by using avidity testing for measles virus-specific immunoglobulin G (IgG) in serum and cerebrospinal fluid samples. For the avidity testing, an Enzygnost measles IgG enzyme-linked immunosorbent assay kit was used with an 8 M urea denaturing method. With this method, low-avidity IgG (acute primary infection, avidity of < 30% within 15 days of the onset of rash) and high-avidity IgG (subacute sclerosing panencephalitis, avidity of > 75%) could be clearly distinguished by using serum samples. One patient, who developed a typical course of measles despite a previous vaccination, showed a positive IgM response with an initial low titer of measles virus-specific IgG of low avidity, but a later sample revealed a high titer of IgG of intermediate (40%) avidity, suggesting previous immunological priming. Two patients with breakthrough infection (secondary vaccine failure), both having central nervous system involvement, showed a positive IgM response with initial high titers of serum IgG of high avidity. In addition, one of the patients had a detectable level of measles-specific IgG in cerebrospinal fluid. In this patient, the avidity of both serum and cerebrospinal fluid IgG decreased during the short follow-up period. This phenomenon has never before been reported. In subacute sclerosing panencephalitis patients, the avidity of cerebrospinal fluid IgG was consistently lower than that of serum IgG. The difference in avidity between cerebrospinal fluid and serum IgG may be used as a direct indicator of intrathecal production of IgG. In conclusion, the avidity testing is simple to perform, reliable, and highly informative in the analysis of measles virus infection.
Specific antibody response to oligomannosidic epitopes in Crohn's disease
Authors: Sendid B , Colombel J F , Jacquinot P M , Faille C , Fruit J , Cortot A , Lucidarme D , Camus D , Poulain D
Published: January 2020

Elevated antibody levels against the yeast Saccharomyces cerevisiae have been reported in sera from patients with Crohn's disease and not with ulcerative colitis. The aim of the study was to identify the nature of the epitopes supporting this antibody response. Whole cells from different S. cerevisiae strains were selected in immunofluorescence assay for their ability to differentiate the antibody responses of patients with Crohn's disease and ulcerative colitis. Their cell wall phosphopeptidomannans were then tested as antigen in enzyme-linked immunosorbent assay (ELISA) against sera from 42 patients with Crohn's disease, 20 patients with ulcerative colitis, and 34 healthy controls. Graded chemical degradations were performed on the most reactive strain phosphopeptidomannan. The discriminating epitope was determined through gas-liquid chromatography-mass spectrometry. The greatest discrimination among patients with Crohn's disease, ulcerative colitis, and controls was obtained with Su1, a S. cerevisiae strain used in brewing of beer. ELISA directed against phosphopeptidomannan of this strain was 64% sensitive and 77% specific for discriminating Crohn's disease versus ulcerative colitis and 71% sensitive and 89% specific for Crohn's disease versus controls. Periodate oxidation and selective degradation demonstrated that the most important polysaccharide epitope was shared by both the acid-stable and the alkali-labile domains of the phosphopeptidomannan. The determination of oligomannose sequences of S. cerevisiae Su1 phosphopeptidomannans suggested that a mannotetraose, Man (1 --> 3)Man(1 --> 2)Man(1 --> 2)Man, supported the serological response seen in Crohn's disease. Further identification of the immunogen eliciting this antibody response as a marker of the disease may help to understand its etiology.
Antibody response to human parvovirus B19 in patients with primary infection by immunoblot assay with recombinant proteins
Authors: Palmer P , Pallier C , Leruez-Ville M , Deplanche M , Morinet F
Published: January 2020

Human parvovirus B19 recombinant VP1 and VP2 capsid proteins were produced by a procaryotic pGEX expression plasmid to evaluate the humoral response by immunoblot assay in 14 patients with primary infection. The same concentrations of VP1 and VP2 recombinant proteins were used. This demonstrates that VP1 immunoglobulin M detection and/or VP1 immunoglobulin G seroconversion is a reliable marker of primary infections. Consequently, detection of antibodies to B19 VP1 might be helpful for identifying patients at risk for chronic B19 infection or patients who are susceptible to viral reinfection.
Antibody response of monkeys to invasion plasmid antigen D after infection with Shigella spp
Authors: Oaks E V , Picking W D , Picking W L
Published: January 2020

The antigen preparation most often used for determining the levels of antibodies to virulence-associated proteins of Shigella spp. consists of a mixture of proteins (including IpaB, IpaC, IpaD, and VirG*) extracted from virulent shigellae with water (water extract). To overcome the lack of specificity for individual antigens in the water-extract enzyme-linked immunosorbent assay (ELISA), the ipaD gene from S. flexneri has been cloned, expressed to a high level, and purified for use in a new ELISA for the determination of the levels of antibody against IpaD in monkeys and humans challenged with shigellae. The IpaD ELISA for serum immunoglobulins G and A correlated well with the water-extract ELISA in that monkeys infected with S. flexneri or S. sonnei responded with high serum antibody titers in both assays. The IpaD assay required less antigen per well, had much lower background levels, and did not require correction with antigens from an avirulent organism. In conjunction with the water-extract ELISA, it was possible to identify infected animals that did not respond to IpaD but did produce antibodies that reacted in the water-extract ELISA. This indicates that even though IpaB, IpaC, and IpaD are essential for the invasiveness phenotype, the infected host does not always produce antibodies against all components of the invasiveness apparatus.
Sensitivity and specificity of the borreliacidal-antibody test during early Lyme disease: a "gold standard"?
Authors: Callister S M , Jobe D A , Schell R F , Pavia C S , Lovrich S D
Published: January 2020

The serodiagnosis of early Lyme disease has been plagued with problems of sensitivity and specificity. We found that the flow-cytometric borreliacidal-antibody test had a sensitivity of 72% for the detection of patients with early Lyme disease. By contrast, the sensitivity of the enzyme immunofluorescence assay was 28%. The enhanced sensitivity of the borreliacidal-antibody test was due to the use of Borrelia burgdorferi 50772, which lacks OspA and OspB. When B. burgdorferi 297, which expresses both OspA and OspB, was used, the sensitivity of the borreliacidal-antibody test was 15%. Our results also showed that the borreliacidal-antibody test was specific. No borreliacidal activity was detected in normal sera or in sera from patients with mononucleosis, rheumatoid factor, or syphilis. These results demonstrate that the flow-cytometric borreliacidal-antibody test may be the laboratory "gold standard" for the serodiagnosis of Lyme disease.
Serological responses to human papillomavirus type 6 and 16 virus-like particles in patients with cervical neoplastic lesions
Authors: Sasagawa T , Inoue M , Lehtinen M , Zhang W , Gschmeissner S E , Hajibagheri M A , Finch J , Crawford L
Published: January 2020

Serum samples from 36 cervical carcinoma patients, 33 patients with high-grade squamous intraepithelial lesions, and 31 cytologically normal women were tested by enzyme-linked immunosorbent assay (ELISA) using human papilloma virus type 6 (HPV 6) and HPV 16 virus-like particles as antigens. Forty serum specimens from 1-year-old children were used to assign cutoff points. When serum samples from the subjects infected with HPV 16 were tested in an HPV 16 ELISA detecting immunoglobulin A (IgA), IgG, and IgM binding, 61% showed IgA, 44% showed IgG, and 39% showed IgM reactivity. Of HPV 6- or 11- or HPV 18-infected subjects. fewer than 17% showed IgA or IgG responses and 33% showed IgM reactivity. In contrast, 13% showed IgA, 10% showed IgG, and 16% showed IgM reactivity in the HPV DNA-negative controls. The results suggest that the IgA and IgG responses are HPV 16 specific and the IgM response is cross-reactive to different HPV types. On the other hand, the serological responses to HPV 6 did not differ in the patient and control groups. The percentages of patients positive for both IgA and IgG antibodies were significantly higher in the groups with high-grade squamous intraepithelial lesions (12% [4 of 33]; P = 0.04) and cancer (17% [6 of 36]; P = 0.02) than in the healty women (0% [0 of 31]), and the percentages for either IgA or IgG were higher for the cancer group (47% [17 of 36]; P = 0.01) than in the normal group (19% [6 of 31]). Most sera positive for IgA and IgG in the patient groups showed higher titers than those in the normal group. All these results suggest that high IgA and IgG responses are good indicators for estimating HPV 16 infection.
Detection of antibodies to Shigella lipopolysaccharide in urine after natural Shigella infection or vaccination
Authors: Cohen D , Orr N , Robin G , Slepon R , Ashkenazi S , Ashkenazi I , Shemer J
Published: January 2020

The purpose of the present study was to explore the possibility of detecting antibodies to Shigella sonnei lipopolysaccharide (LPS) in urine after infection or vaccination. Urinary immunoglobulin A (IgA) and IgG antibodies and specific IgA secretory protein against S. sonnei LPS were measured by enzyme-linked immunosorbent assay (ELISA), after adjustment for urine concentration. A significant antibody level was defined as one above a cutoff value calculated from the geometric mean + 2 standard deviations of urinary anti-S. sonnei LPS levels in 43 healthy hepatitis B vaccinees (controls). Of 11 culture-proven cases of S. sonnei shigellosis, at convalescence 9 (82%) had significantly elevated levels of urinary antibodies to the homologous LPS. The S. sonnei conjugate vaccine, composed of S. sonnei O-specific polysaccharide covalently bound to recombinant exoprotein A of Pseudomonas aeruginosa, elicited a significant urine IgA or IgG anti-LPS response in 60% (6 of 10), 56% (9 of 16) 43% (16 of 37), and 14% (3 of 21) of the volunteers at 2 weeks, 6 weeks, 6 months, and 12 months after vaccination, respectively. The specificity of the urine antibody response to S. sonnei LPS was documented by the total lack of response in subjects who received parenteral Shigella flexneri 2a-recombinant exoprotein A conjugate (69 urine samples) or meningoccal tetravalent control vaccines (4 urine samples). All the volunteers who lacked a significant response to S. sonnei LPS in serum also lacked such response in urine samples. Seventy-four percent of the volunteers with a significant IgA or IgG anti-LPS response in serum at convalescence or 14 days after vaccination showed a similar response in urine. The ratio of the titer of secretory protein bound to IgA anti-S. sonnei LPS in urine to that in serum was 303 times higher than the ratio of anti-S. sonnei LPS total IgA titer in urine to that in serum, indicating that the urine IgA is of secretory origin. These findings suggest the possible use of urinary Shigella LPS antibodies as markers of systemic and secretory immune responses after natural infection or vaccination. At this stage, because of its limited sensitivity, the detection by ELISA of Shigella LPS antibodies in urine cannot replace the same assay in serum as a definitive test in an individual with a negative result.
Type 1 and type 2 cytokine profiles in children exposed to or infected with vertically transmitted human immunodeficiency virus
Authors: Lee B N , Lu J G , Kline M W , Paul M , Doyle M , Kozinetz C , Shearer W T , Reuben J M
Published: January 2020

In human immunodeficiency virus (HIV)-infected adults, cytokine production profiles switch from predominantly type 1 (interleukin-2 [IL-2] and gamma interferon [IFN-gamma]) to type 2 (IL-4 and IL-10) cytokines with disease progression. To test this hypothesis in vertically HIV-infected children, we measured cytokine transcription and production in rapid progressors (RPs), seroreverters (SRs), and those children exposed to HIV in utero (P0s). Production of type 1 and type 2 cytokines was measured in peripheral blood mononuclear cell cultures of 8 SR, 25 P0, and 11 RP children. Unstimulated cultures, irrespective of infection and stage of disease, produced similar levels of IL-2, IFN-gamma, IL-4, and IL-10. Upon stimulation with phytohemagglutinin (PHA) plus phorbol-12-myristate-13-acetate (PMA), RP children produced less IL-2 (P < 0.01) and IFN-gamma (P < 0.02) than SR children and also expressed significantly less IFN-gamma mRNA (P < 0.01) than SR children. RP children expressed significantly higher levels of IL-4 mRNA than P0 children (P < 0.03). There were no differences in the production of IL-10 by PHA-PMA-stimulated peripheral blood mononuclear cell cultures among the three groups of children. Our data with these pediatric patients suggest that a deficiency in mitogen-stimulated type 1 cytokine production and excess type 2 cytokine (IL-4) transcription correlate with disease progression. Additional studies with larger sample sizes are needed to test further the hypothesis of the type 1-to-type 2 cytokine switch in children infected with HIV.
Antibody responses against the G and F proteins of bovine respiratory syncytial virus after experimental and natural infections
Authors: Schrijver R S , Langedijk J P , van der Poel W H , Middel W G , Kramps J A , van Oirschot J T
Published: January 2020

Antibodies against the two major surface glycoproteins of bovine respiratory syncytial virus (BRSV), G and F, play a role in protection against BRSV-associated disease, but only the antibody response against the F protein has been well described. Therefore, we used a novel peptide-based enzyme-linked immunosorbent assay (G peptide-ELISA) to compare immunoglobulin G (IgG) and IgG subclass antibody responses against the G protein with the antibody response against the F protein, as measured by a conventional BRSV ELISA (F-ELISA). Experimental infection of cattle induced significantly lower antibody titers than did natural infection. After natural primary infection, G peptide-specific antibodies declined more rapidly and to lower levels than the F protein-specific antibodies. As a consequence, the G peptide-ELISA detected more reinfections than did the F-ELISA. Ratios of G- and F-specific IgG1/IgG2 antibody titers did not differ markedly after infection or vaccination. Interestingly, after natural infection calves did not develop an IgG2 response to the complete G protein. In contrast, adult cattle had high IgG2 titers against this protein. Vaccination with a live vaccine induced low antibody titers, similar to the titers after experimental infection, whereas vaccination with an inactivated vaccine induced high titers. The results indicate that the kinetics of the G- and F-specific antibody responses differ. Furthermore, the IgG subclass response against the unglycosylated central region of the G protein is similar to the IgG subclass response to the F protein, but the IgG subclass response differs from the response to the complete G protein.
Increasing doses of purified influenza virus hemagglutinin and subvirion vaccines enhance antibody responses in the elderly
Authors: Keitel W A , Cate T R , Atmar R L , Turner C S , Nino D , Dukes C M , Six H R , Couch R B
Published: January 2020

The reactogenicities and immunogenicities of two influenza virus vaccines were compared in a placebo-controlled clinical trial among healthy ambulatory persons > or = 65 years old (mean age, 72 years). Volunteers were assigned randomly to receive 15-, 45-, or 135-micrograms doses of monovalent influenza A/Taiwan (H1N1) hemagglutinin (HA) or subvirion (SV) vaccine intramuscularly or a placebo. Increasing doses of SV vaccine were associated with a higher rate of injection site discomfort (P < 0.05; chi-square test for linear trend), but all doses of both vaccines were well tolerated. Increasing the dose of the HA or the SV vaccine resulted in increasingly higher postimmunization levels of serum hemagglutination inhibition and neutralizing antibody levels (P < 0.001; multiple linear regression). Mean serum antibody titers at 1 month increased two- to threefold with a ninefold increase in dose; the frequencies of fourfold or greater rises in titer likewise increased. An increase in the dose of the HA or the SV vaccine also resulted in increased frequencies of rises in immunoglobulin A or G antibody titers in nasal wash specimens. The frequencies increased approximately twofold for each vaccine with a ninefold increase in the dose. These data suggest that increasing the HA vaccine dose is a promising approach to the development of improved influenza virus vaccines for use in elderly people.
Purification of Mycobacterium bovis BCG Tokyo antigens by chromatofocusing, lectin-affinity chromatography, and hydrophobic interaction chromatography
Authors: Sugden E A , Stilwell K , Watson D C , Rohonczy E B , Martineau P
Published: January 2020

A combination of chromatofocusing, lectin-affinity chromatography, and hydrophobic interaction chromatography resulted in a simple purification of protein antigens of Mycobacterium bovis BCG Tokyo culture filtrate. Identification was established on the basis of chromatographic separation, sodium dodecyl sulfate-polyacrylamide gel electrophoresis determination of molecular weights, and N-terminal amino acid determination. Chromatofocusing on PBE 94 accomplished the separation of BCG85B from other BCG85 complex antigens and partial separation of MPB64 and MPB70 antigens. Subsequently, MPB64 and MPB70 were completely separated on a high-performance liquid chromatography TSK Phenyl 5PW hydrophobic interaction chromatography column. This column also separated BCG85B from a 17-kDa protein with an N-terminal amino acid sequence of A-V-P-I-T-G-K-L-G-S-E-L-T-M-T-D-( )-V-G-Q, which is similar to the sequence of MPT63. Concanavalin A-Sepharose-affinity chromatography separated MPB64 from a 43- and 47-kDa doublet with an amino acid sequence of D-P-E-P-A-P-P-V-P-P-V-P-A-( )-A-A-S-P, which is similar to the sequence of MPT32 and which appears to be glycosylated.
Effect of Clostridium difficile toxin A on CD11/CD18 expression in vitro
Authors: Warny M , Chatelain B , Delmée M
Published: January 2020

Clostridium difficile toxin A is chemotactic for neutrophils and induces their emigration into the colonic mucosae of rodents. We found that toxin A did not upregulate neutrophil beta 2 integrins on isolated human neutrophils. These data support the hypothesis that in C. difficile colitis, these adhesion molecules are upregulated by endogenous mediators.
Collaborative study for the evaluation of enzyme-linked immunosorbent assays used to measure human antibodies to Bordetella pertussis antigens
Authors: Lynn F , Reed G F , Meade B D
Published: January 2020

Acellular pertussis vaccines are being evaluated in multiple clinical studies, and human immunogenicity data will likely be pivotal in the appraisal of vaccine responses between populations and the responses to different vaccine combinations. Antibody response to pertussis antigens is also used in the diagnosis of pertussis. An international study was designed to assess the comparability of data generated in different laboratories by enzyme-linked immunosorbent assays (ELISAs). Thirty-three participating laboratories were asked to quantitate specific antibody to pertussis toxin (PT), filamentous hemagglutinin (FHA), pertactin (PRN), or fimbrial proteins (FIM) in 21 samples. Samples were to be assayed in triplicate in five independent assays by each ELISA routinely performed in the laboratory to assess intra-assay, interassay, and population variability. The mean sample values were used to compare quantitative results among the laboratories. Thirteen of the 32 laboratories which submitted evaluable data for an assay to measure antibodies to PT, 12 of 30 laboratories with assays for FHA, 10 of 17 laboratories with assays for PRN, and 6 of 13 laboratories with assays for FIM maintained a coefficient of variation below 20% for 75% of the samples tested. Assays that measure antibodies to FIM appear to be less precise than the other assays. Precision varied among laboratories that used similar methods. The relative values of intra- and interassay variabilities were not consistent for a given assay within a laboratory, indicating that the sources of these variability components may be unrelated. Precision and agreement appeared less reliable for samples with low antibody levels. Ranking and regression analyses suggest that some laboratories generated comparable quantitative results, although direct comparison or combination of results from different laboratories remains difficult to support. Calibration to the U.S. Reference Pertussis Antisera appears to have been successful at standardizing the results in some laboratories. Statistical analyses are affected by assay precision and are not necessarily reliable sole predictors of biologically relevant differences in quantitative results. If results from different laboratories must be compared, appropriate studies of precision and quantitative agreement should be conducted to support the specific comparisons.
A new procedure for the purification of streptococcal pyrogenic exotoxin A from Streptococcus pyogenes supernatant
Authors: Mascini E M , Hazenberg M A , Verhage L A , Holm S E , Verhoef J , van Dijk H
Published: January 2020

An important role in the pathogenesis of invasive group A streptococcal disease has been ascribed to the production of streptococcal pyrogenic exotoxin A. We present a new technique for the purification of streptococcal pyrogenic exotoxin A from Streptococcus pyogenes NY-5 supernate, which is highly efficient with respect to yield (35%), purity (> or = 99%), and time.
In vitro immunologic and virologic effects of interleukin 15 on peripheral blood mononuclear cells from normal donors and human immunodeficiency virus type 1-infected patients
Authors: Lucey D R , Pinto L A , Bethke F R , Rusnak J , Melcher G P , Hashemi F N , Landay A L , Kessler H A , Paxton R J , Grabstein K , Shearer G M
Published: January 2020

Interleukin 15 (IL-15) is a cytokine that shares receptor subunits and functional activity, such as T-cell and B-cell stimulation, with IL-2. The effect of IL-2 on immune function and human immunodeficiency virus (HIV) viral load in HIV-infected patients is being actively studied. Thus, we examined how IL-15 compares with IL-2 in several in vitro immunologic and virologic assays in order to explore whether a rationale exists for pursuing initial clinical therapeutic trials with IL-15. The effects of IL-15 on induction of lymphokine-activated killer (LAK) cells, gamma interferon (IFN-gamma) production from HIV-positive peripheral blood mononuclear cells (PBMCs), and HIV production from PBMCs were studied. Induction of LAK cells by IL-15 was found in eight of eight HIV-positive donors. Incubation of PBMCs from some donors with IL-15 (1, 10, 50, and 100 ng/ml) induced production of IFN-gamma. The effect of IL-15 was compared with that of IL-2 on HIV replication in PBMCs from five HIV-positive patients and four HIV-negative donors whose PBMCs were infected in vitro with HIV. Levels of HIV p24 antigen were moderately lower in the presence of 10 ng of IL-15 per ml than with 10 ng of IL-2 per ml, but they were similar for 100 and 500 ng of each cytokine per ml. In summary, IL-15 can induce LAK cell activity in HIV-seropositive patients and can stimulate IFN-gamma production from PBMCs of some donors. IL-15 stimulates levels of HIV production from PBMCs which are similar to or moderately lower than those obtained with IL-2, depending on cytokine concentration.