bluuebunny/crossref_metadata_2025 huggingface dataset:
Parasite-mediated down-regulation of collagen-induced arthritis (CIA) in DA rats
Authors: Mattsson L , Larsson P , Erlandsson-Harris H , Klareskog L , Harris R A
Published: March 2003

Microbial infection can impact on the course of autoimmune disease, both in disease-inducing and disease-protecting capacities. Here we investigated if infection with Trypanosoma brucei brucei (Tbb), the protozoan causative agent of African Sleeping Sickness, could ameliorate the course of CIA in the Dark Agouti rat, an experimental model which shares many features with human rheumatoid arthritis. Infection of animals with living, but not inoculation with dead Tbb resulted in complete or significant reduction of clinical arthritic symptoms. Infection prior to collagen immunization was more effective than a later treatment, and this effect was related to the level of parasitaemia. Using reverse transcriptase-polymerase chain reaction we detected an increase in interferon-gamma mRNA in the draining lymph nodes of Tbb-treated animals relative to controls at day 28 after disease induction. Transforming growth factor-beta could be detected in the lymph nodes in four out of six animals that had received Tbb. In the joints, immunohistochemistry revealed reduced production of tumour necrosis factor-alpha in Tbb-treated animals relative to controls. The most striking difference between Tbb-infected and control groups, as measured by ELISA, was the down-regulation of anti-collagen II IgG antibody responses in parasite-infected animals. We conclude that live parasites can exert an immunomodulatory and protective effect in CIA in which several mechanisms may work in parallel, although the almost complete down-regulation of the anti-collagen antibody response may alone explain the protective effect in CIA. The described model may be useful in further attempts to use the mechanisms involved in parasite immune defence to prevent and treat certain autoimmune conditions.
T cell activation, apoptosis and cytokine dysregulation in the (co)pathogenesis of HIV and pulmonary tuberculosis (TB)
Authors: Hertoghe T , Wajja A , Ntambi L , Okwera A , Aziz M A , Hirsch C , Johnson J , Toossi Z , Mugerwa R , Mugyenyi P , Colebunders R , Ellner J , Vanham G
Published: March 2003

Immune parameters were compared in four groups of Ugandan subjects: HIV−and HIV+ adult patients with active pulmonary TB (HIV− PTB n = 38; HIV+ PTB n = 28), patients with HIV infection only (n = 26) and PPD+ healthy controls (n = 25). Compared with healthy controls, CD4 and CD8 T cells from patients with HIV and/or PTB expressed more activation markers (HLA-DR, CD38); their CD8 T cells expressed more CD95 (pre-apoptosis) and less CD28 (co-stimulatory receptor). Peripheral blood mononuclear cells (PBMC) of patients with either HIV or PTB were impaired in interferon-gamma (IFN-γ) production upon antigenic stimulation. PTB (with or without HIV) was characterized by monocytosis, granulocytosis, increased transforming growth factor-beta 1 production and PPD-induced apoptosis. In vivo CD4 T cell depletion, in vitro increased spontaneous CD4 T cell apoptosis and defects in IFN-γ responses upon mitogenic stimulation were restricted to HIV+ subjects (with or without PTB). Overlapping and distinctive immune alterations, associated with PTB and HIV, might explain mutual unfavourable influences of both diseases.
Autoantibodies to early endosome antigen (EEA1) produce a staining pattern resembling cytoplasmic anti-neutrophil cytoplasmic antibodies (C-ANCA)
Authors: Selak S , Woodman R C , Fritzler M J
Published: March 2003

Autoantibodies to EEA1 have been described in patients with neurological diseases, subacute cutaneous lupus and a variety of other conditions, including a patient with Wegener's granulomatosis (WG). EEA1 is a hydrophilic peripheral membrane protein transiently associated with the cytoplasmic face of early endosomes. Antibodies to EEA1 produce a staining pattern that resembles the C-ANCA pattern produced by anti-proteinase 3 (PR3) antibodies in WG sera. Co-localization studies show incomplete overlap of the staining produced by anti-EEA1 with anti-PR3. We showed that 0/40 unselected sera, from a cohort of WG patients and antibodies to PR3, reacted with EEA1. In addition, 1/15 sera that have a C-ANCA staining pattern but do not react with PR3 in an ELISA, immunoprecipitated the recombinant EEA1 protein. We conclude that although antibodies to EEA1 produce a staining pattern that resembles anti-PR3 and C-ANCA, antibodies to EEA1 in WG are rare. However, some C-ANCA+ sera that do not react with PR3 may contain EEA1 autoantibodies.
Role of macrophage migration inhibitory factor (MIF) in murine antigen-induced arthritis: interaction with glucocorticoids
Authors: Santos L , Hall P , Metz C , Bucala R , Morand E F
Published: March 2003

(MIF) is a broad-spectrum proinflammatory cytokine implicated in human rheumatoid arthritis. The synthesis of MIF by synovial cells is stimulated by glucocorticoids, and previous studies suggest that MIF antagonizes the anti-inflammatory effects of glucocorticoids. This has not been established in a model of arthritis. We wished to test the hypothesis that MIF can act to reverse the anti-inflammatory effects of glucocorticoids in murine antigen-induced arthritis (AIA). Cutaneous DTH reactions and AIA were induced by intradermal injection and intra-articular injection, respectively, of methylated bovine serum albumin in presensitized mice. Animals were treated with anti-MIF MoAbs, recombinant MIF, and/or dexamethasone (DEX). Skin thickness of DTH reactions was measured with callipers and arthritis severity was measured by blinded quantitative histological assessment of synovial cellularity. Cutaneous DTH to the disease-initiating antigen was significantly inhibited by anti-MIF MoAb treatment (P < 0·001). AIA was also significantly inhibited by anti-MIF MoAb (P < 0·02). DEX treatment induced a dose-dependent inhibition of AIA, which was significant at 0·2 mg/kg (P < 0·05). MIF treatment reversed the effect of therapeutic DEX on AIA (P < 0·001). DEX also significantly inhibited DTH reactions (P < 0·05) but rMIF had no effect on this effect of DEX. DTH and AIA are MIF-dependent models of inflammation and arthritis. The reversal of glucocorticoid suppression of AIA by MIF supports the concept that MIF is a counter-regulator of glucocorticoid control of synovial inflammation. Although DTH was observed to be MIF-dependent and glucocorticoid-sensitive, rMIF had no reversing effect on the suppression of DTH by glucocorticoids. This suggests that inflammatory processes in specific tissues may respond differently to MIF in the presence of glucocorticoids.
Epitope focus, clonal composition and Th1 phenotype of the human CD4 response to the secretory mycobacterial antigen Ag85
Authors: Valle M T , Megiovanni A M , Merlo A , Li Pira G , Bottone L , Angelini G , Bracci L , Lozzi L , Huygen K , Manca F
Published: March 2003

Lymphoproliferation of healthy donors was tested against mycobacterial antigens (PPD, Ag85, Ag85 peptides). All PPD responders recognized the secretory antigen Ag85 and the peptide specificity for Ag85B was defined. Peptide 91–108 was recognized by 85% of donors. In addition, all CD4 T cell lines generated from 12 donors against PPD or Ag85 responded to 91–108. When this peptide was used to generate T cell lines, the cells responded also to tuberculins from atypical mycobacterial species. Thus the cross-reactive peptide behaved as quasi-universal. The analysis of TCR-BV gene usage by cell lines showed that most Ag85-specific T cells correspond to 91–108-specific clonotypes. Intracytoplasmic staining of cell lines after phorbol myristate acetate stimulation resulted in dominance of interferon-gamma (IFN-γ)-IL-4 double-positive cells, whereas antigen stimulation resulted in production of IFN-γ only. The data show that peptide 91–108 is the major focus of the CD4 response to mycobacterial antigens in peripheral blood mononuclear cells and in T cell lines from PPD responders.
Age-related autoantibody production in a nonhuman primate model
Authors: Attanasio R , Brasky K M , Robbins S H , Jayashankar L , Nash R J , Butler T M
Published: March 2003

Autoantibody production increases with ageing. However, the pathological significance of this increase as well as the corresponding underlying mechanisms are poorly understood. To further our understanding of the role that ageing plays in the development of autoantibody responses, we used a novel nonhuman primate model consisting of healthy baboons of ages representing the entire lifespan of this animal species. Results from this study indicate that production of antinuclear antibodies, anticell extract antibodies and natural autoantibodies gradually and significantly increases from young age to old age without a corresponding increase in neither serum immunoglobulin concentration nor in levels of selected markers of immune dysregulation (sTNF-RI, sTNF-RII, IL-2 sRα and IFN-γ). Therefore, in the baboon model, autoantibodies may be produced in absence of recognizable pathological conditions of the ageing immune system.
Reduced HIV-stimulated T-helper cell reactivity in cord blood with short-course antiretroviral treatment for prevention of maternal–infant transmission
Authors: Kuhn L , Meddows-Taylor S , Gray G , Trabattoni D , Clerici M , Shearer G M , Tiemessen C
Published: March 2003

T-helper cell responses to HIV have been associated with protection against maternal-infant HIV transmission in the absence of antiretroviral treatment, but the effects of antiretroviral treatment, now widely used for prevention, on development of these cell-mediated responses is unknown. We tested whether development of T-helper cell responses to HIV and other antigens would be affected by exposure to short-course regimens of zidovudine-lamivudine (ZDV-3TC) given to prevent maternal-infant HIV transmission. Cord blood samples were collected from 41 infants of HIV-infected mothers enrolled in a clinical trial in which they were treated with regimens of ZDV-3TC and from 29 infants whose HIV-infected mothers were not treated with any antiretroviral drugs. T-helper cell reactivity to HIV envelope peptides and other antigens was measured in vitro using a sensitive culture supernatant titration assay based on IL-2-dependent proliferation. Infants in the clinical trial were followed to 18 months to determine their HIV infection status, and venous blood samples were re-tested at 4·5 and 9 months for T-cell reactivity to HIV. HIV-stimulated T-helper cell reactivity in cord blood was detected 10-fold less frequently among those exposed to antiretroviral prophylaxis (2·4%) than among those unexposed (24·1%) (P = 0·007). Reductions in HIV-stimulated responses in cord blood occurred despite detectable HIV RNA (mean 3·38 standard deviation 0·76 log10 copies per ml) at delivery among treated women and occurred independent of treatment duration. Our results suggest that short-course antiretroviral treatment given to prevent maternal-infant HIV transmission may attenuate HIV-stimulated T-cell memory responses in the neonate.
Differential requirements for induction of total immunoglobulin and physiological rheumatoid factor production by human peripheral blood B cells
Authors: Van esch W J E , Reparon-Schuijt C C , Levarht E W N , Van kooten C , BreedveLd F C , Verweij C L
Published: March 2003

Rheumatoid factors (RFs) are autoantibodies directed against the Fc part of IgG. Considerable evidence exists that there are two classes of RFs, pathological and physiological. Whereas pathological RFs are associated with disease, physiological RFs are considered to be a normal component of the immune response. RF+ precursor B cells present as part of the B cell repertoire of healthy individuals are held responsible for the production of physiological RFs, which is a transient phenomenon with a clear correlation with an initiating stimulus such as immunization or exposure to an infection. Here we demonstrate a difference in the regulatory control of total Ig and RF production by peripheral blood (PB) B cells of both healthy controls (HC) and patients with rheumatoid arthritis (RA). Highly purified B cells from HC and patients with RA were cocultured with T cells stimulated with immobilized anti-CD3 mAb. Similar to IgM production, IgM-RF production was shown to be dependent on CD40 cross-linking. However, activation of PB B cells in the CD40 system in the presence of IL-2, IL-4, IL-10, combinations of these cytokines or supernatant of anti-CD3-stimulated T cells failed to induce detectable IgM-RF, whereas total IgM production was considerable. From these results we conclude that conditions to activate physiological RF+ B cells require additional contact besides CD40–CD40L interactions between T and B cells. Since the requirements for RF production were similar using PB B cells from HC and patients with RA it is suggested that the regulatory properties of RF+ precursors in the PB B cell compartment is equal among these groups. Together, these results indicate that conditions for the induction of total Ig and physiological RFs are different.
Determination of the frequency of HLA antibody secreting B-lymphocytes in alloantigen sensitized individuals
Authors: Mulder A , Kardol M J , Kamp J , Uit Het Broek C , Schreuder G M T , Doxiadis I I N , Claas F H J
Published: March 2003

Sera from prospective transplant patients are usually screened for HLA antibodies prior to transplantation, but presently available tests do not permit quantification of the humoral alloantigen directed response. We adapted a culture system for isolated human B-lymphocytes to assay the secretion of HLA-antibodies on a single cell basis. B-cell supernatants were screened for HLA antibodies by complement dependent cytotoxicity. The assay assigns precursor frequencies for HLA-alloantibody secreting B-lymphocytes (BCPFs), and simultaneously allows for dissection of the humoral alloantigen directed response into its monoclonal components. The lymphocytes of 15 HLA-seropositive multiparous women that were used to validate the assay, were found to contain HLA-BCPFs ranging from 0 to 123 per 106 B-lymphocytes (mean: 43 ± 45 per 106 B-lymphocytes). The HLA-specificities of antibodies in the B-cell supernatants were in agreement with serum specificities. Genuine HLA reactivity of B-cell supernatants was confirmed using an ELISA with purified HLA class I antigens. When applied to lymphocytes of patients on transplant waiting lists, the present assay may enable the unraveling of serum specificities in their components, thus supplementing HLA antibody serum screening data.
Intravenous immunoglobulin prevents experimental autoimmune myositis in SJL mice by reducing anti-myosin antibody and by blocking complement deposition
Authors: Wada J , Shintani N , Kikutani K , Nakae T , Yamauchi T , Takechi K
Published: March 2003

High-dose intravenous immunoglobulin (IVIG) therapy has been effective in many autoimmune and systemic inflammatory diseases including polymyositis (PM) and dermatomyositis (DM). In the present study we evaluated the efficacy of IVIG using experimental models of PM and DM. An experimental autoimmune myositis (EAM) model was produced in SJL/J mice by an immunization with rabbit myosin B (MB) fraction. In this model, the plasma level of anti-MB antibody was elevated, and mouse IgG and complement C3 were deposited in the muscle fibres. Administration of IVIG dose-dependently reduced the incidences of necrotic and inflammatory changes in the skeletal muscle. IVIG treatment also decreased the elevation of anti-MB antibody level, as well as the deposition of IgG and C3. We next evaluated the effect of IVIG in adoptive EAM mice made by an intravenous injection of lymph node cells previously stimulated with MB. Adoptive EAM mice showed similar lesions in skeletal muscle as EAM mice and IVIG inhibited the lesion development. In vitro experiments demonstrated that IVIG inhibited complement-mediated lysis of human erythrocytes sensitized with anti-human erythrocyte antibodies. The binding of C1q, C4 and C3 to the same cells was also inhibited by IVIG. Taken together these findings suggest that IVIG prevents the development of myositis in EAM and adoptive EAM models by several mechanisms, such as reducing anti-myosin antibody and by blocking complement activation. Our present findings might account for the clinical efficacy of IVIG in PM and DM patients.
Anti-galectin-1 autoantibodies in humanTrypanosoma cruziinfection: differential expression of thisβ-galactoside-binding protein in cardiac Chagas' disease
Authors: Giordanengo L , Gea S , Barbieri G , Rabinovich G A
Published: March 2003

The pathogenesis of Chagas' disease has been subject of active research and still remains to be ascertained. Galectin-1 (Gal-1), a member of a conserved family of animal β-galactoside-binding proteins, localized in human heart tissue, has been suggested to play key roles in immunological and inflammatory processes. In the present study we demonstrated the occurrence of anti-Gal-1 autoAb in sera from patients in the acute and chronic stages of Chagas' disease (ACD and CCD) by means of ELISA and Western blot analysis. We found a marked increase in the level and frequency of Ig E anti-Gal-1 antibodies in sera from patients with ACD, but a low frequency of Ig M anti-Gal-1 immunoreactivity. Moreover, Ig G immunoreactivity to this β-galactoside-binding protein was found to be correlated with the severity of cardiac damage in CCD, but was absent in nonrelated cardiomyopathies. We could not detect immunoreactivity with Trypanosoma cruzi antigens using a polyclonal antibody raised to human Gal-1 and no hemagglutinating activity could be specifically eluted from a lactosyl-agarose matrix from parasite lysates. Moreover, despite sequence homology between Gal-1 and shed acute phase antigen (SAPA) of T. cruzi, anti-Gal-1 antibodies eluted from human sera failed to cross-react with SAPA. In an attempt to explore whether Gal-1 immunoreactivity was originated from endogenous human Gal-1, we finally investigated its expression levels in cardiac tissue (the main target of Chagas' disease). This protein was found to be markedly upregulated in cardiac tissue from patients with severe CCD, compared to cardiac tissue from normal individuals.
The role of C5a in the development of thrombotic glomerulonephritis in rats
Authors: Kondo C , Mizuno M , Nishikawa K , Yuzawa Y , Hotta N , Matsuo S
Published: March 2003

Thrombus formation is the important pathologic finding observed in glomerulonephritis induced by antiglomerular basement membrane (GBM) antibodies. Although strong deposition of C3 and membrane attack complex (MAC) is observed in this disease, the role of complement has not been fully elucidated. The aim of this work was to investigate the role of complement, especially an anaphylatoxin C5a, in a rat model of thrombotic glomerulonephritis. Rats were first pretreated with subclinical dose of lipopolysaccharide (LPS). Thrombotic glomerulonephritis was then induced by intravenous injection with rabbit antirat GBM (RbAGBM) (Group I). For the evaluation of the role of complement, the soluble complement receptor type 1 (sCR1) (Group II) or the C5a receptor antagonist peptide (C5aR-AP) (Group III) was intravenously administered 30 min before RbAGBM injection. For exploring the role of neutrophils, rats were pretreated with cyclophosphamide before induction of disease (Group IV). All rats were sacrificed at 6 h, and histological examination was performed.

Rats in Group I developed severe glomerular thrombosis. Leucocyte accumulation and strong binding of C3 and MAC were observed in the glomeruli. In rats treated with sCR1 (Group II) and C5aR-AP (Group III), both leucocyte accumulation and thrombus formation in the glomeruli were significantly inhibited. C3 and MAC were negative in the glomeruli in Group II rats, while they were strongly observed in Group III. In neutrophil depleted rats (Group IV), there was also deposition of C3 and MAC in the glomeruli but thrombus formation was not observed. These findings indicated that glomerular thrombosis is dependent on the leucocytes, and mediated in part by the anaphylatoxin C5a but not MAC in the present model.
Induction and abrogation of LACK reactive cells in the evolution of human leishmaniasis
Authors: Maasho K , Wolday D , Edjigu M , Söderström K , Britton S , Akuffo H
Published: March 2003

Peripheral blood mononuclear cells (PBMC) from cutaneous leishmaniasis patients with ongoing Leishmania aethiopica infection and individuals cured/under treatment from L. infantum or L. donovani infection were stimulated in vitro with LACK, the Leishmania homologue of receptors for activated C kinase. The LACK protein is conserved in related leishmanial species and is expressed both in the promastigote and amastigote stages of Leishmania. Our results show that LACK induced marked NK and some CD8+ cell proliferation in PBMC from cutaneous leishmaniasis patients with active disease. These responses were coupled with high levels of IFN-γ and IL-10 production. At the concentration tested, the proliferative responses to freeze-thawed Leishmania antigen (Ft-Leish) were higher, while the levels of IFN-γ were consistently lower than that of LACK. Although cells from individuals cured of leishmaniasis could respond to whole Leishmania lysate by proliferation and IFN-γ production, there was no evident response to LACK. Ethiopian controls tested at the same time also showed LACK induced proliferation with IFN-γ and IL-10 responses. Thus LACK reactivity in terms of proliferation and cytokine induction were present in cells from some healthy donors and most of the patients with active lesions, while this response was absent in individuals cured of L. infantum or L. donovani leishmaniasis. Since cure from leishmaniasis often results in life-long protection, and active but not cured patients showed in vitro responses to LACK stimulation, questions arose as to how this highly immunodominant molecule functions during human leishmanisasis. Some possible mechanisms are discussed.
Cytomegalovirus infection and proinflammatory cytokine activation modulate the surface immune determinant expression and immunogenicity of cultured murine extrahepatic bile duct epithelial cells
Authors: Hsu H-Y , Chang M-H , Ni Y-H , Huang S-F
Published: March 2003

Murine extrahepatic bile duct epithelial cells (MEBEC) were isolated from extrahepatic bile ducts of BALB/c mice and established in primary culture. The epithelial origin was confirmed by positive cytokeratin 19 staining for these cells and the presence of microvilli and tight junctions under electron microscopy. By immunofluorescent staining with monoclonal antibodies and flow-cytometric analysis, MEBEC in culture constitutively express low levels of intercellular adhesion molecule (ICAM)-1, class I and class II major histocompatibility (MHC) antigens. The expression of ICAM-1 was significantly increased by interferon gamma (INF-γ) or tumour necrosis factor alpha (TNF-α) stimulation. Class I and class II antigen expression were significantly enhanced by INF-γ and in vitro murine cytomegalovirus (MCMV) infection. MEBEC infected with MCMV revealed a progressive cytopathic effect. MEBEC activated by INF-γ or infected by MCMV induced a low but significant proliferation of allogeneic T cells and displayed a significant decrease in the absorbance at O.D. 550 nm in a microtitre tetrazolium assay after these treated cells were co-cultured with allogeneic T cells. These results suggest that following the up-regulation of surface MHC antigen and adhesion molecule expression with cytokines or MCMV, the MEBEC can function as antigen-presenting cells and initiate T-cell proliferation, which in turn trigger the recognition of MEBEC by effector T-cell-mediated cytotoxic responses. These findings may be implicated in the pathogenesis of virally induced, immune-mediated extrahepatic bile duct damage disorders.
Impaired T cell proliferation, increased soluble death-inducing receptors and activation-induced T cell death in patients undergoing haemodialysis
Authors: Ankersmit H J , Deicher R , Moser B , Teufel I , Roth G , Gerlitz S , Itescu S , Wolner E , Boltz-Nitulescu G , Kovarik J
Published: March 2003

Haemodialysis is a widespread option for end-stage renal disease (ESRD). Long-term success of dialysis is, however, limited by a high rate of serious bacterial and viral infections. We compared T cell functions in ESRD patients undergoing haemodialysis (n = 20), or were not dialysed and received conventional medical treatment (n = 20). Healthy volunteers (n = 15) served as controls. The T cell phenotype was examined by immunofluorescence using fluorochrome-labelled monoclonal antibodies and FACS analysis. The concentration of soluble CD95/Fas and of tumour necrosis factor-α receptor type 1 (sTNFR1) in the sera was quantified by ELISA. Activation-induced programmed T cell death was triggered by anti-CD3/CD28 antibodies and measured by 7-AAD staining. All immunological tests were performed at least 1 month after dialysis initiation. T cell proliferation in response to phytohaemagglutinin or anti-CD3 monoclonal antibodies was moderately diminished in non-dialysed patients and markedly reduced in haemodialysis patients compared to healthy controls (P < 0·01 and P < 0·001, respectively). In a mixed lymphocyte culture the proliferative response of T cells from dialysed patients was significantly diminished (P < 0·001). T cells of both non-dialysed and dialysed patients have augmented CD95/Fas and CD45RO expression, increased sCD95/Fas and sTNFR1 release and spontaneously undergo apoptosis. Culture of T cells from haemodialysis patients with anti-CD3/CD28 antibodies increased the proportion of CD4+ T cells committing activation-induced cell death by a mean 7·5-fold compared to T-helper cells from non-dialysed patients (P < 0·001). Renal failure and initiation of haemodialysis results in a reduced proliferative T cell response, an aberrant state of T cell activation and heightened susceptibility of CD4+ T cells to activation-induced cell death.
Increased distribution and expression of CD64 on blood polymorphonuclear cells from patients with the systemic inflammatory response syndrome (SIRS)
Authors: Qureshi S S , Lewis S M , Gant V A , Treacher D , Davis B H , Brown K A
Published: March 2003

Evidence is growing to suggest that the multiple organ damage of the systemic inflammatory response syndrome (SIRS) arises from the untoward activity of blood polymorphonuclear cells (PMNs), which upon activation acquire the IgG high affinity receptor, CD64. In the current study, flow cytometry was used to assess the prevalence of CD64-bearing PMNs and the intensity of expression of CD64 in whole blood samples from 32 SIRS patients, 11 healthy normal subjects and from eight non-SIRS patients in the intensive care unit (ICU). The percentage of PMNs expressing CD64 was higher in SIRS patients (mean 65%) than in non-SIRS patients (mean 42%; P < 0·02) and in healthy controls (mean 19%; P < 0·001) and was particularly evident in patients with SIRS and sepsis (mean 71%; P < 0·02) as opposed to SIRS alone (mean 55%). There were more CD64 molecules expressed on PMNs from patients with SIRS (median 1331 molecules/cell) in comparison with PMNs from healthy subjects (median 678 molecules/cell; P < 0·01). The highest intensity of CD64 expression was associated with PMNs from patients with both SIRS and sepsis. Functional studies revealed that the supranormal binding of PMNs from patients with SIRS to endothelial monolayers treated with TNFα was impeded by anti-CD64 antibodies (mean 24% inhibition; P < 0·01). Monitoring the distribution of CD64+ PMNs and their level of CD64 expression could be of assistance in the rapid discrimination of patients with SIRS from other ICU patients and in the identification of PMNs which are likely to participate in the pathological manifestations of the disease.
In vitrogeneration of human CD86+ dendritic cells from CD34+ haematopoietic progenitors by PMA and in serum-free medium
Authors: Ramadan G , Schmidt R E , Schubert J
Published: March 2003

The cytokine requirements to differentiate CD34+ progenitor cells from different origins either cord blood (CB) or peripheral blood (PB) into dendritic cells (DC) are known to be different. In addition to DC, macrophages and neutrophils are generated. On the other hand, phorbol esters such as PMA induce primary human CD34+ bone marrow (BM) progenitor cells to differentiate into functional DC and no other lineages are generated. In addition, FCS is used as culture supplement in most of the protocols described which contains additional foreign antigens potentially skewing the resulting immune response. Therefore, we evaluated the ability to differentiate CB- and PB-CD34+ progenitor cells into DC with PMA and under serum-free conditions. In this study, we delineate the maturation of cultured human blood DC by analysis of expression co-stimulatory molecule B7–2 (CD86). Human mature DC with typical morphology and surface antigen phenotype (CD1a−, CD83+ and CD86+) were obtained from CB- and PB-CD34+ progenitor cells after 1 week of culture in serum-free medium upon stimulation with PMA alone. The same result was obtained from ex vivo-expanded BM-CD34+ cells. CD86+ yield was increased by PMA compared to cytokine cocktails (28·0% ± 7·0 versus 15·3% ± 5·6 for CB and 44·6% ± 7·5 versus 28·1% ± 7·5 for PB, respectively). CD86 was most up-regulated in the presence of the calcium ionophore ionomycin. However, the number of viable cells after differentiation was decreased by PMA plus ionomycin (P < 0·05) or plus TNF-alpha (P > 0·05) as compared with that in PMA alone. We conclude that PMA is a potent activator to differentiate human CD34+ cells into mature DC in serum-free medium. This may be used for in vitro studies of primed or genetically modified DC against infectious and tumour-associated antigens.
Alveolar macrophages of allergic resistant and susceptible strains of rats show distinct cytokine profiles
Authors: Sirois J , Bissonnette E Y
Published: March 2003

Brown Norway rats are widely used as a model of asthma, whereas Sprague Dawley rats do not develop allergic reactions under the same conditions. Given the importance of alveolar macrophages (AM) in down-regulating cellular immune responses in the lung, we postulated that the different susceptibilities in the development of airway allergic reactions in these rat strains may be related to functional differences in their AM. We investigated the production of important mediators in asthma, namely tumour necrosis factor (TNF), interleukin-10 (IL-10), IL-12, IL-13, nitric oxide (NO) and macrophage inflammatory protein-1α (MIP-1α), by AM of unsensitized Sprague Dawley and Brown Norway rats. AM were purified by adherence and stimulated with OX8 (anti-CD8 antibody) or LPS. OX8 stimulation significantly increased the release of TNF, IL-10 and NO in both strains of rats, whereas MIP-1α and IL-12 release were increased in Brown Norway rats only. Interestingly, stimulated AM from Sprague Dawley rats released significantly more TNF and less IL-10, IL-12, IL-13, MIP-1α and NO compared with AM from Brown Norway rats. These differences were also observed at the mRNA level, except for TNF. Thus, AM from Brown Norway and Sprague Dawley rats are functionally different. Furthermore, LPS- and OX8-stimulated AM from Brown Norway rats produce more Th2 type cytokines (IL-10 and IL-13) than AM from Sprague Dawley rats, suggesting that these cells may play an important role in creating a cytokine milieu that may favour the development of allergic reactions.
An evaluation of serum soluble CD30 levels and serum CD26 (DPPIV) enzyme activity as markers of type 2 and type 1 cytokines in HIV patients receiving highly active antiretroviral therapy
Authors: Keane N M , Price P , Lee S , Stone S F , French M A
Published: March 2003

This study evaluates serum CD26 (dipeptidyl peptidase IV, DPPIV) enzyme activity and serum levels of soluble CD30 as markers of T1 and T2 cytokine environments in HIV patients who achieved immune reconstitution after highly active antiretroviral therapy (HAART). Patients who had experienced inflammatory disease associated with pre-existent opportunistic infections after HAART (immune restoration diseases, IRD) were considered separately. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were compared with IFN-γ production by PBMC cultured with cytomegalovirus (CMV) antigen in controls and patient groups. High sCD30 levels were associated with low IFN-γ production after antigenic stimulation in control subjects and, to a lesser extent, in immune reconstituted HIV patients. There was no association between serum CD26 (DPPIV) enzyme activity and IFN-γ production or sCD30 levels. Serum sCD30 levels and CD26 (DPPIV) enzyme activity were significantly increased in immune reconstituted patients with high HIV viral loads. Patients who had experienced CMV retinitis as an IRD had significantly higher sCD30 levels than all other patient groups. Hence, high sCD30 levels may be a marker of a T2 cytokine environment in HIV patients with immune reconstitution and are associated with higher HIV viral loads and a history of CMV associated IRD.
Dexamethasone impairs pulmonary defence againstPseudomonas aeruginosathrough suppressing iNOS gene expression and peroxynitrite production in mice
Authors: Satoh S , Oishi K , Iwagaki A , Senba M , Akaike T , Akiyama M , Mukaida N , Atsushima K M , Nagatake T
Published: March 2003

To elucidate the in vivo mechanisms involved in the impairment in pulmonary defence as the result of treatment with glucocorticoids, we established fatal pneumonia with bacteraemia in dexamethasone (DEX)-treated mice by means of an intratracheal challenge of Pseudomonas aeruginosa. An increased neutrophil influx was observed in bronchoalveolar lavage (BAL) fluids from both untreated and DEX-treated mice. The complete suppression of an inducible isoform of nitric oxide synthase (iNOS) mRNA expression and tumour necrosis factor alpha (TNF-α) production during the early phase of pneumonia, but not CXC chemokine production, were found in the case of the DEX-treated mice. An immunohistochemical study with a specific antibody also revealed negative staining for nitrotyrosine in the lung tissue of DEX-treated mice, while the formation of nitrotyrosine, which indirectly indicates the generation of peroxynitrite with a potent bactericidal activity, was detected clearly in the bronchial epithelium as well as alveolar phagocytic cells of lung tissue from untreated mice. Furthermore, an intraperitoneal administration of S-methyl-isothiourea (SMT), a potent inhibitor of NOS, significantly decreased the survival and increased bacterial density in the case of untreated mice. In contrast, no significant effects on the survival and bacterial density in the lung and blood were found as the result of treatment with SMT in DEX-treated mice.

Collectively, a complete repression of iNOS gene expression and a lack of the generation of peroxynitrite as well as an inhibition of TNF-α production in the lung appeared to be responsible for the progression of the fatal pneumonia due to P. aeruginosa in DEX-treated mice.
Characterization of four CD18 mutants in leucocyte adhesion deficient (LAD) patients with differential capacities to support expression and function of the CD11/CD18 integrins LFA-1, Mac-1 and p150,95
Authors: Shaw J M , Al-Shamkhani A , Boxer L A , Buckley C D , Dodds A W , Klein N , Nolan S M , Roberts I , Roos D , Scarth S L , Simmons D L , Tan S M , Law S K A
Published: March 2003

Leucocyte adhesion deficiency (LAD) is a hereditary disorder caused by mutations in the CD18 (β2 integrin) gene. Four missense mutations have been identified in three patients. CD18(A270V) supports, at a diminished level, CD11b/CD18 (Mac-1, αMβ2 integrin) and CD11c/CD18 (p150,95, αXβ2 integrin) expression and function but not CD11a/CD18 (LFA-1, αLβ2 integrin) expression. Conversely, CD18(A341P) supports a limited level of expression and function of CD11a/CD18, but not of the other two CD11/CD18 antigens. CD18(C590R) and CD18(R593C) show a decreasing capacity to associate with the CD11a, CD11c and CD11b subunits. Transfectants expressing the CD11a/CD18 with the C590R and R593C mutations are more adhesive than transfectants expressing wild-type LFA-1, and express the reporter epitope of the monoclonal antibody 24 constitutively. Thus, the four mutations affect CD18 differently in its capacities to support CD11/CD18 expression and adhesion. These results not only provide a biochemical account for the clinical diversity of patients with leucocyte adhesion deficiency, but also offer novel insights into the structural basis of interaction between the α and β subunits, which is an integral component in our understanding of integrin-mediated adhesion and its regulation.
Beta-cell, thyroid, gastric, adrenal and coeliac autoimmunity and HLA-DQ types in type 1 diabetes
Authors: De Block C E M , De Leeuw I H , Vertommen J J F , Rooman R P A , Du Caju M V L , Van Campenhout C M , Weyler J J , Winnock F , Van Autreve J , Gorus F K
Published: March 2003

The autoimmune attack in type 1 diabetes is not only targeted to β cells. We assessed the prevalence of thyroid peroxidase (aTPO), parietal cell (PCA), antiadrenal (AAA) and endomysial antibodies (EmA-IgA), and of overt autoimmune disease in type 1 diabetes, in relation to gender, age, duration of disease, age at onset, β-cell antibody status (ICA, GADA, IA2A) and HLA-DQ type. Sera from 399 type 1 diabetic patients (M/F: 188/211; mean age: 26 ± 16 years; duration: 9 ± 8 years) were tested for ICA, PCA, AAA and EmA-IgA by indirect immunofluorescence, and for IA2A (tyrosine phosphatase antibodies), GADA (glutamic acid decarboxylase-65 antibodies) and aTPO by radiobinding assays. The prevalence rates were: GADA 70%; IA2A, 44%; ICA, 39%; aTPO, 22%; PCA, 18%; EmA-IgA, 2%; and AAA, 1%. aTPO status was determined by female gender (β = − 1·15, P = 0·002), age (β = 0·02, P = 0·01) and GADA + (β = 1·06, P = 0·02), but not by HLA-DQ type or IA2A status. Dysthyroidism (P < 0·0001) was more frequent in aTPO + subjects. PCA status was determined by age (β = 0·03, P = 0·002). We also observed an association between PCA + and GADA + (OR = 1·9, P = 0·049), aTPO + (OR = 1·9, P = 0·04) and HLA DQA1*0501-DQB1*0301 status (OR = 2·4, P = 0·045). Iron deficiency anaemia (OR = 3·0, P = 0·003) and pernicious anaemia (OR = 40, P < 0·0001) were more frequent in PCA + subjects. EmA-IgA + was linked to HLA DQA1*0501-DQB1*0201 + (OR = 7·5, P = 0·039), and coeliac disease was found in three patients. No patient had Addison's disease. In conclusion, GADA but not IA2A indicate the presence of thyrogastric autoimmunity in type 1 diabetes. aTPO have a female preponderance, PCA are weakly associated with HLA DQA1*0501-DQB1*0301 and EmA-IgA + with HLA DQA1*0501-DQB1*0201.
Antibodies against glutathione S-transferase T1 (GSTT1) in patients withde novoimmune hepatitis following liver transplantation
Authors: Aguilera I , Wichmann I , Sousa J M , Bernardos A , Franco E , García-Lozano J R , Núñez-Roldán A
Published: March 2003

Four patients of 283 liver-transplant recipients (1·4%) developed de novo immune-mediated hepatitis approximately 2 years after transplantation. Antibodies showing an unusual liver/kidney cytoplasmic staining pattern were detected in the sera of all four patients and one of them was used to screen a human liver cDNA expression library with the aim of identifying the antigenic target of these newly developed antibodies. After cloning and sequencing the gene, it was identified as the gene encoding the glutathion-S-transferase T1 (GSTT1), a 29-kD molecular weight protein, expressed abundantly in liver and kidney. Sera from the other three patients also contained anti-GSTT1 antibodies, two of them demonstrated by immunoblot analysis against the recombinant antigen and the other, which was negative by immunoblot, gave a positive reaction when used directly to screen the same library, suggesting it to be directed to a conformational epitope. The GSTT1 enzyme is the product of a single polymorphic gene that is absent from 20% of the Caucasian population. When we analysed the GSTT1 genotype of the four patients described above, we found that this gene is absent from all of them. Three donor paraffin embedded DNA samples were available and were shown to be positive for GSSTT1 genotype. In accordance with these results, we suggest that this form of post-transplant de novo immune hepatitis, that has been reported as autoimmune hepatitis by others, could be the result of an antigraft reaction in individuals lacking the GSTT1 phenotype, in which the immune system recognizes the GSTT1 protein as a non-self antigen, being the graft dysfunction not the result of an autoimmune reaction, but the consequence of an alo-reactive immune response.
Epstein–Barr virus primes human polymorphonuclear leucocytes for the biosynthesis of leukotriene B4
Authors: Gosselin J , Savard M , Tardif M , Flamand L , Borgeat P
Published: March 2003

In the present study, we have investigated the effect of the short-term incubation of polymorphonuclear leucocytes (PMN) with infectious Epstein–Barr virus (EBV) on leukotriene B4 (LTB4) biosynthesis. Pre-exposure of PMN to EBV led to an increased production of LTB4 upon stimulation with either the ionophore A23187, the chemotactic peptide fMLP, or phagocytic particles (zymosan). Experiments performed with viral particles pretreated with a neutralizing antibody raised against the gp350 of the viral envelope revealed that a specific interaction between the PMN surface and the viral glycoprotein gp350 is required for the priming effect of EBV. Preincubation of PMN with EBV resulted in an increased release of arachidonic acid upon stimulation with a second agonist. Moreover, LTB4 biosynthesis in EBV/A23187-treated PMN was greatly diminished in the presence of an inhibitor of the cytosolic phospholipase A2 (cPLA2), suggesting that cPLA2 plays a critical role in the priming effect of EBV. Accordingly, EBV by itself promoted Ser-505 phosphorylation of cPLA2 and strongly enhanced fMLP-induced phosphorylation of p38 MAP kinase, an enzyme known to phosphorylate cPLA2 in human PMN. Furthermore, fMLP-induced translocation of cPLA2 was strongly enhanced when PMN were previously exposed to EBV. These data indicate that binding of EBV to human PMN results in the activation of intracellular events involved in the release of pro-inflammatory lipid mediators.
The effects of chromium and copper supplementation on mitogen-stimulated T cell proliferation in hypercholesterolaemic postmenopausal women
Authors: Rhee Y S , Hermann J R , Burnham K , Arquitt A B , Stoecker B J
Published: March 2003

The purpose of this study was to analyse effects of chromium and/or copper supplementation on immune function in hypercholesterolaemic postmenopausal women. A 2 × 2 factorial research design was used and 40 subjects were supplemented with 0·394 g lactose, 200 μg Cr, 3·0 mg Cu, or 200 μg Cr and 3·0 mg Cu/d for 12 weeks. A significant interactive effect of Cr and Cu supplementation on lymphocyte proliferation was observed with ConA 50 μg/ml stimulation. After 12 weeks of supplementation, ConA-stimulated (50 μg/ml) lymphocyte proliferation was significantly lower when Cu was added to the Cr supplementation group. Moreover, ConA-stimulated (100 μg/ml) lymphocyte proliferation was significantly lower in the Cu supplementation group compared to the Cr supplementation group after 12 weeks of supplementation. These results suggest that Cu blocks enhancement of lymphocyte proliferation by Cr supplementation and that Cu supplementation has potential suppressive effects on the immune function in these subjects.
Intracellular cytokine production by Th1/Th2 lymphocytes and monocytes of children with symptomatic transient hypogammaglobulinaemia of infancy (THI) and selective IgA deficiency (SIgAD)
Authors: Kowalczyk D , Baran J , Webster A D B , Zembala M
Published: March 2003

Intracellular expression of several cytokines was assessed in lymphocytes and monocytes of children with transient hypogammaglobulinaemia of infancy (THI) and selective IgA deficiency (SIgAD). THI was characterized by an increased frequency of CD3+/CD4+ lymphocytes expressing tumour necrosis factor α (TNF-α), TNF-β and interleukin 10 (IL-10), while in SIgAD elevated numbers of these cells containing TNF-α and interferon γ (IFN-γ) were observed. No changes in the number of CD4+ T cells expressing IL-4 in both diseases were noted. The proportion of CD33+ monocytes containing TNF-α both in THI and SIgAD was unchanged. The secretion of IL-12 by peripheral blood mononuclear cells (PBMCs) of patients with THI and SIgAD was significantly elevated and associated with an increased frequency of IL-12 expressing monocytes in THI but not in SIgAD. IL-18 secretion was slightly, but not significantly, elevated in both diseases. Intracellular Th1 and Th2 type cytokines within CD3+/CD4+ lymphocytes were also determined in the normal blood donors that showed high or low production of IgG and IgA in vitro. In low producers of IgG an increased proportion of CD3+/CD4+ cells expressing TNF-α and IFN-γ was found, while in low IgA responders only elevated TNF-α positive CD3+/CD4+ cells were observed. These results suggest that THI and SIgAD may represent diseases with an excessive Th1 type response that is associated with an up-regulation of IL-12 secretion and, at least in THI, elevated numbers of monocytes expressing intracellular IL-12. Up-regulation of IL-12 may be the essential factor in the patomechanism(s) of these diseases as already described in common variable immunodeficiency (CVID).
Regulation of primary HIV-1 isolate replication in dendritic cells
Authors: MacDougall T H J , Shattock R J , Madsen C , Chain B M , Katz D R
Published: March 2003

The potential role of dendritic cells (DC) in the immunopathology of human immunodeficiency virus 1 (HIV-1) disease remains controversial. This study examines replication of a panel of HIV-1 strains (both laboratory adapted and primary) within DC, in the context of the well-established monocyte–DC and monocyte–macrophage transition. Viral replication was assessed by p24 ELISA assay. All strains of HIV-1 tested replicated in DC. Only CCR5-tropic virus replicated in macrophages. Lipopolysaccharide (LPS) induced DC maturation (as reflected in altered cell phenotype) and at the same time diminished the ability of DC to support HIV-1 replication. In contrast the presence of activated T cells, which had been fixed to prevent them acting as a site for viral replication, enhanced the ability of the DC to support viral replication, as has been reported previously for macrophages. Thus cells that are DC by phenotype, but are not activated, act as the optimum reservoir for HIV-1 replication. If this form of DC is present in peripheral tissues, this will be permissive for amplification of the in vivo viral load at sites where there are few responder cells available, and hence contribute to the persistent immunopathology.