bluuebunny/crossref_metadata_2025 huggingface dataset:
Percutaneous exposure of adjuvant oil causes arthritis in DA rats
Authors: KLEINAU S , ERLANDSSON H , KLARESKOG L
Published: July 2010

The arthritogenic properties of adjuvant oil upon percutaneous administration in DA rats was investigated. Groups of rats were administered single or repeated percutaneous applications of Freund's incomplete adjuvant (FIA) or olive oil on shaved skin with or without prior abrasion of the skin. Control rats were shaved and abrased only. A transient arthritis developed in 8/16 animals after repeated applications of FIA on abrased skin. The incidence of arthritis increased to 7/8 animals when FIA was repeatedly administered via filter paper on abrased skin and covered with a bandage. Histological examination of the arthritic joints showed proliferation of the synovial lining layer, infiltration of mononuclear cells and polymorphonuclear cells in the subsynovial tissue. Some bone and cartilage destruction was also seen. Repeated treatment with olive oil on abrased skin induced joint swelling in 3/15 animals, which did not, however, correspond to any microscopically observable signs of inflammation. Also, a single application of FIA on abrased skin or repeated applications of FIA without abrasion induced arthritis, although with low penetration, whereas control animals had no clinical signs of joint involvement. These findings demonstrate that percutaneous administration of adjuvant oil can cause arthritis in genetically susceptible animals.
Profiles of immunoregulatory cytokine productionin vitroin patients with IgA nephropathy and their kindred
Authors: SCIVITTARO V , GESUALDO L , RANIERI E , MARFELLA C , SCHEWN S A , EMANCIPATOR S N , SCHENA F P
Published: July 2010

We hypothesized that the altered immunoglobulin synthesis and/or lymphocyte function apparent in patients with IgA nephropathy (IgAN) is due to a primary defect in lymphokine regulation. In addition, we reasoned that such changes in lymphokine production might be, at least partially, genetically determined. To assess the extent of lymphocyte abnormalities, we investigated the profile of cytokine production from peripheral blood mononuclear cells (PBMC) in 34IgAN patients and 44 of their first degree relatives, 10 of whom had persistent microhaematuria. Compared with healthy volunteers (n=34), PBMC from patients showed increased IL-2 production both spontaneously or after phytohaemagglutinin (PHA) (20 μ/ml) stimulation, whereas IL-4 and interferon-gamma (IFN-γ) production were significantly higher only after stimulation. Microhaematuric relatives had a similar pattern of cytokine production, whereas non-microhaematuric relatives showed no significant difference versus normals. The altered pattern of cytokine production appeared to be quite specific to IgAN patients and their microhaematuric relatives, because patients with other forms of primary glomerulonephritis (n= 17) did not differ from normal individuals. Patients and relatives that hyperproduced IL-4 were also hyperproducers of IL-2. No such congruence was seen in any other group or with any other pairing of cytokines. We propose that a subpopulation of IgAN patients bear lymphocytes intrinsically hyper responsive. Among those individuals such hyperresponsiveness may be causally related to the pathogenesis and/or character of IgAN.
Autoantibodies from mixed cryoglobulinaemia patients bind glomerular antigens
Authors: DOLCHER M P , MARCHINI B , SABBATINI A , LONGOMBARDO G , FERRI C , RIENTE L , BOMBARDIERI S , MIGLIORINI P
Published: July 2010

Mixed cryoglobulinaemia (MC) is a disorder characterized by the presence of large amounts of cryoprecipitating IgM-IgG complexes. An immune complex glomerulonephritis develops in one third of all patients, but its occurrence docs not seem related to the amount of cryoglobulins in the sera, nor to their complement-fixing ability. In this study we investigated the presence of IgG antibodies reactive with kidney antigens in 33 MC patients (11 with glomerulonephritis, 22 without renal involvement). A total glomerular extract was run on a 10% acrylamide gel, blotted to nitrocellulose and probed with the patients'sera. Sera from half of the patients without renal involvement reacted with several glomerular antigens whose molecular weight ranged between 200 and 29 kD. In the group with renal involvement, sera from 7/11 patients reacted with an antigen of 50 kD, which is also expressed in thymus, but not in the heart or liver. In a follow-up study of four patients with renal involvement, the amount of serum antibody specific for the 50-kD antigen fluctuated, either spontaneously or in response to therapy. These results show that antibodies specific for glomerular antigens are detectable in MC sera. The immune response against a 50-kD antigen expressed in the kidney and thymus seems to be restricted to a subset of MC patients with renal involvement. Circulating autoantibodies specific for glomerular antigens might contribute to the induction of glomerulonephritis in MC forming immune complexes in situ.
Modulation of immune response toLol pI by pretreatment with anti-idiotypic antibody is not restricted to the idiotypic expression
Authors: BOUTIN Y , HÉBERT J
Published: July 2010

To study the role of anti-idiotypic antibodies in the regulation of the immune response to Lol p I (the major allergenic component of rye grass pollen), we have recently generated a panel of three MoAbs directed against distinct epitopes of Lol p I and an anti-idiotypic MoAb directed against the idiotype borne by one of the anti-Lol p I MoAbs (290A-167). The effects of pretreatment with this anti-idiotypic MoAb in BALB/c mice before immunization with the antigen have been examined. The anti-idiotypic MoAb or unrelated MoAb were given weekly for 8 weeks intraperitoneally. Mice then received the antigen (2 μg) adsorbed with alum (2 mg) at weeks 9, 11 and 13. Serum anti-Lol p I antibodies (IgG or IgE) and specific idiotypic responses were measured. Anti-Lol pI IgG antibodies could be detected before immunization with Lol p I only in mice pretreated with anti-idiotypic MoAb. Immunization with Lol p I induced an anti-Lol p I IgG response in both groups, but this response was higher in mice that received anti-idiotypic MoAb. Similar profiles were seen for specific IgE antibodies and idiotypic responses. Surprisingly, idiotypes borne by other anti-Lol p I MoAbs (539A-6 and 348A-6) had also been enhanced after pretreatment with the anti-290A-167 MoAb. These observations suggested that the pretreatment with this anti-idiotypic MoAb modulates not only the expression of the respective idiotype, but also affects other idiotype responses.
Biological and clinical significance of neutralizing and binding antibodies to interferon-alpha (IFN–α) during therapy for chronic hepatitis C
Authors: GIANNELLI G , ANTONELLI G , FERA G , DEL VECCHIO S , RIVA E , BROCCIA C , SCHIRALDI O , DIANZANI F
Published: July 2010

It is known that IFN therapy can induce the development of anti-IFN antibodies. In order to evaluate the biological and clinical significance of both neutralizing (NA) and non-neutralizing (binding) antibodies, 123 patients with chronic hepatitis C treated with recombinant IFN-α were examined. Among them, 15 were positive for NA and 24 for binding antibodies. The kinetics of NA appearance show that, in general, they develop early during the first 3 months of treatment. Moreover, NA seem to be clinically relevant, since they may be responsible for non-responsiveness to treatment in 53% of patients who develop them. The evaluation of the clinical significance of binding antibodies is more difficult. They appear significantly earlier in non-responders than in responders, but no differences were observed in the overall percentage of seroconversion between responders and non-responders. Thus, it is not possible at the moment to establish their possible role in inducing non-responsiveness.
Co-expression of the CD45RA and CD45RO antigens on T lymphocytes in chronic arthritis
Authors: SUMMERS K L , O'DONNELL J L , HART D N J
Published: July 2010

The site of T lymphocyte activation in chronic arthritis is unknown. Peripheral blood (PB) lymphocytes from chronic arthritis patients are in a ‘naïve’ or non-activated state, as defined by expression of the CD45RA antigen and lack of HLA class II expression. In contrast, most synovial fluid (SF) T lymphocytes express a ‘memory’ or activated phenotype, as defined by the CD45RO antigen and high HLA class II expression. Following stimulation, naive cells lose CD45RA and gain CD45RO expression to become memory cells with a transitional stage of dual CD45RA, CD45RO antigen expression. To localize where this change in phenotype occurs we used dual colour immunofluorescence labelling to compare the percentage of dual CD45RA, CD45ROpositive T lymphocytes in PB and SF from chronic arthritic patients and from normal PB, assuming this population would be increased at the primary site of T lymphocyte activation. Expression of the intermediate and late activation marker. HLA-DR, was also analysed using dual colour immunofluorescence labelling. The percentage of dual positive T lymphocytes was similar between arthritic PB, SF. and normal PB, as was the density of both CD45RA and CD45RO antigens. Thus, CD45 isoform expression did not indicate where T lymphocytes were activated. However, we identified a previously unreported population of CD45RA+ CD45RO+ HLA-DR- T lymphocytes in arthritic and normal PB. In SF, this population was absent, but a substantial number of dual CD45RA, CD45RO-positive HLA-DR+ T lymphocytes were identified. This population would not be predicted by the current model of T lymphocyte activation. Division of T lymphocytes into functional groups on the basis of CD45 isoform expression is likely to be more complicated than previously thought. Based on our findings we propose an alternative model of T lymphocyte differentiation.
Nitric oxide synthesis in patients with advanced HIV infection
Authors: EVANS T G , RASMUSSEN K , WIEBKE G , HIBBS J B
Published: July 2010

The discovery that humans produce nitric oxide and that this molecule plays an important role in cell communication, host resistance to infection, and perhaps in host defence to neoplastic disease, has created much interest in further research on its function in the body. A cytokine-inducible high output L-arginine/nitric oxide pathway was recently detected in patients with advanced malignancy treated with IL-2. The production of nitric oxide was thus examined in patients with advanced HIV infection and in intensive care unit control patients. Extrinsic nitrate and nitrite consumption were carefully controlled in the diet or through the use of total parenteral nutrition. Seven of eight HIV+ patients were placed into positive nitrogen balance. Nitric oxide synthesis was found to be within the normal human range. In contrast, nitric oxide synthesis in extremely ill intensive care unit patients was low normal to depressed.
Assessment of the correlation between nitrite concentration and Listericidal activity in cultures of resident and elicited murine macrophages
Authors: HIGGINBOTHAM J N , PRUETT S B
Published: July 2010

Reactive nitrogen intermediates (RNI) derived from L-arginine have been implicated as important anti-bacterial agents in the control of Listeria monocytogenes by murine macrophages. However, not all evidence is consistent with this conclusion. In the present study, this issue was examined using a simple experimental system to assess the correlation between macrophage Listericidal activity and production of nitrite (a stable end product of RNI) in culture. Various levels of nitrite production were achieved by activating macrophages with interferon-gamma (IFN-γ) (20 or 500 U/ml) with or without lipopolysaccharide (LPS) (10 ng/ml) for 20 h before the Listericidal assay, and by using normal and arginine-free culture medium during the Listericidal assay. Nitrite concentration was measured for the same wells used to assess Listericidal activity. There was essentially no correlation between initial or final nitrite concentration and Listericidal activity in resident peritoneal macrophages. Significant correlations were noted between initial and final nitrite concentration and Listericidal activity in proteose peptone-elicited peritoneal macrophages. However, the correlation coefficients (0·34 and 0·52) suggested marginal biological relevance. In addition, no correlation was noted when LPS-activated macrophages were omitted from analysis. A previous study suggested that the enhanced Listericidal activity of LPS-treated macrophages could be accounted for by an enhanced rate of phagocytosis during the initial phase of the assay. These results suggest RNI are probably not the predominant bactericidal agents used by macrophages from female CD-I mice to kill L. monocytogenes. However, it remains possible that RNI are important anti-bacterial agents in highly activated (LPS-treated) macrophages, and that there are other mechanisms whereby RNI contribute to host resistance to L. monocytogenes.
Adoptive transfer of an autoimmunological labyrinthitis in the guinea pig; animal model for a sympathetic cochleolabyrinthitis
Authors: GLODDEK B , ROGOWSKI M , ARNOLD W
Published: July 2010

Sensorineural hearing loss is a common problem in the otolaryngologist's practice, with autoimmune disease of the inner ear being one possible cause. The restoration of auditory function in some patients following immunosuppressive therapy has created a desire to define and understand this disease better. Because of the lack of a well defined detection method to identify this entity clinically, this study was undertaken in order to provide an animal model for autoimmune disease of the inner ear. Previous studies with guinea pigs have demonstrated that sensitized lymphocytes from the systemic circulation migrate to the labyrinth during an immune response in the inner ear. The aim of this study was to prove the capacity of sensitized lymphocytes to transfer autoimmune inner ear disease, and to describe the resulting morphological and physiological changes. Therefore two groups of sensitized lymphocytes partially labelled with a radioactive marker from inbred guinea pigs with an immune response within the inner ear were injected into the bloodstream of naive recipient animals. Most of the labelled cells were observed in the apical turn of the experimental cochlea, while only few cells were detectable in the control cochleas. In addition, the absence of otoacoustic emissions and the loss of outer hair cells observed by electron microscopy were interpreted as a sign of damage caused by the provoked immunopathologic mechanism. The results are discussed as a possible model for a sympathetic cochleolabyrinthitis.
Neonatal injections of cyclosporin enhance autoimmune diabetes in non-obese diabetic mice
Authors: SAÏ P , SENECAT O , MARTIGNAT L , GOUIN E
Published: July 2010

Since the modulation of the immune system at birth may influence the course of insulin-dependent (type 1) diabetes, we investigated whether neonatal injections of cyclosporin (CsA) to newborn non-obese diabetic (NOD) mice influence diabetes during later life. Two groups of 90 mice (45 female, 45 male) were injected intraperitoneally for the first 6 days of life with CsA (l0mg/kg per day) or with vehicle. In female NOD mice, the onset of diabetes was earlier and cumulative incidence was higher after neonatal treatment with CsA (P < 0·01). The incidence of diabetes was also dramatically enhanced in male NOD mice (P < 0·01), which normally display a very low disease incidence. Concomitantly, the severity of lymphocytic infiltration of the pancreatic islets was higher in female NOD mice neonatally treated by CsA (P < 0·02), and to a lesser extent in males, than in control mice. After administration of CsA to newborn NOD mice, there was a reduction (P < 0·01) of both CD4+CD8+ and CD4+CD8+ thymocytes, whereas the number of double positive CD4+CD8+ thymocytes was increased. Concomitantly, Thy 1–2+ cells in spleen were decreased (P < 0·01), and spleen cells expressing either CD3 molecule or αβ TCR complex were diminished (P < 0·01). Both CD4+ and CD8+ spleen T cells were depleted. By contrast, the low percentage of γδ TCR-expressing splenocytes was not modified. Numbers of MHC class 1+ or MHC class 2+ spleen cells were also depressed (P < 0·01). After neonatal injections of CsA, spleen cells showed a reduced response to concanavalin A (Con A) (P < 0·01). On the contrary, stimulation indices of splenocytes incubated with xenogeneic insulin-producing cell extracts were enhanced (P < 0·03). Proliferation indices of splenocytes to self class 2 antigens, generating suppressor cell activity, during syngeneic mixed lymphocyte reaction (SMLR) were significantly reduced (P < 0·01). Irradiated NOD mice were used as recipients for spleen cells from CsA -neonatally treated NOD mice. They displayed enhanced insulitis 2 weeks after transfer, and diabetes was successfully produced by 1 month after transfer in 50% of the recipients. By contrast, NOD mice which received control syngeneic spleen cells remained normoglycaemic, with only moderate islet infiltration which would be expected of NOD mice of this age. Thus, neonatal injections of CsA markedly enhance diabetes in both female and male NOD mice. The mechanisms behind the clinical effect are at least related to arrest of thymocytopoiesis at the double positive stage and to attenuation of suppressor cell activity during the completion of immune selftolerance, leading to enhancement of autoreactive T lymphocytes directed against insulin-secreting cells. This could be a useful tool for gaining insight into both the mechanisms underlying the thymic generation of autoreactive T lymphocytes against islet cells and the peripheral immunoregulatory device that controls expansion of the disease already initiated.
Serological association of lupus autoantibodies to a limited functional domain of 28S ribosomal RNA and to the ribosomal proteins bound to the domain
Authors: SATO T , UCHIUMI T , ARAKAWA M , KOMINAMI R
Published: July 2010

Site-specific anti-RNA antibodies were sought in 120 sera of patients with autoimmune diseases by ribonuclease-protection assay using six fragments covering 28S ribosomal RNA (rRNA) as antigens. Fifteen of 90 sera from patients with systemic lupus erythematosus (SLE), but none of 30 sera of the other autoimmune diseases, provided a 60 nucleotide fragment within a region termed the ‘GTPase domain’ of 28S rRNA. These sera had potency to precipitate 0·42–69·3 nmol of the RNA domain per ml serum, which was higher than 15 control sera of healthy donors. No other specific antigenic site was detected in 28S rRNA under conditions used. All of the 15 sera having this anti-RNA antibody showed reactivity to ribosomal P proteins (anti-P), and two of them contained an additional antibody to ribosomal protein L12. These results suggested a strong association of the production of these three antibodies. Since P and L12 proteins form a stable complex with the GTPase domain, this serological association may result from an immune response to epitopes clustered on a single RNA-protein complex domain in ribosomes.
Evaluation of a model for post-partum arthritis and the role of oestrogen in prevention of MRL-lprassociated rheumatic conditions
Authors: RATKAY L G , ZHANG D , TONZETICH J , LEVY J G , WATERFIELD J D
Published: July 2010

Sixty-eight percent of female MRL-lpr- mice developed a post-partum exacerbation of their mild spontaneous arthritis within 30 days of parturition- The flare became evident between 5 and 15 days after delivery. Histologically it was characterized by a significant increase of subsynovial inflammation and synovial hyperplasia without changes in the level of cartilage and bone erosion. Immunohistologically, marked subsynovial and frequent synovial staining of MHC class II bearing cells was noted, along with the sporadic presence of CD3, CD4, and CD43 receptor-bearing cells in the subsynovium. Injection of physiological levels (0·08mg/kg) of estradiol on days 2, 3, 9, 15 and 20 post-partum delayed and reduced the flare to 23% of the animals. Administration of pharmacological amounts (0·4mg/kg per day for 2 weeks following Freund's complete adjuvant injection) prevented adjuvant-enhanced arthritis, reducing the incidence from 67% to the baseline 21% level- Deleterious changes in the underlying systemic lupus erythematosus (SLE), as demonstrated by proteinurea and mortality rate increases, were elicited only by the employed pharmacological amounts of estradiol. These results indicate that the MRL-lpr mice might serve as a model for post-partum flare of arthritis in SLE and rheumatoid arthritis by providing an approach to study the complexity of the effects of pregnancy on autoimmune diseases, and to obtain further evidence for the involvement of oestrogen in arthritis.
Use of methyl prednisolone and antioxidants in mercuric chloride-induced experimental vasculitis
Authors: QASIM F J , MATHIESON P W , THIRU S , OLIVEIRA D B G
Published: July 2010

The systemic vasculitides are characterized by necrotizing inflammation of blood vessels. Neutrophils are implicated in tissue damage by their presence at the site of injury. They can mediate injury by release of cellular contents including proteinases, cytokines and reactive oxygen species. Antioxidants such as vitamin E and N-acetyl cysteine (NAC) may therefore be predicted to ameliorate oxidative damage in vivo and could be a cheap and non-toxic form of therapy. We examined this hypothesis in an experimental model of vasculitis which has some similarities to human disease, and in which depletion of neutrophils ameliorates tissue injury. Mercuric chloride (HgCl2) treatment induces an autoimmune syndrome and necrotizing leucocytoclastic vasculitis in the Brown Norway (BN) rat; anti-myeloperoxidase (MPO) and anti-glomerular basement (GBM) antibodies are present, and vasculitis is reduced by antimicrobials. Methyl prednisolone given intravenously was effective in reducing tissue injury, demonstrating that the model was responsive to a treatment used in man. Vitamin E and NAC were given as daily injections intraperitoneally to BN rats either before, during or after HgCl2 administration. Serial blood samples were taken for anti-MPO and IgE antibodies, which were assayed by ELISA. Necropsies were performed on animals killed at peak disease. At doses of 50—200mg/kg per day vitamin E had no beneficial effect on tissue injury, regardless of timing of treatment, NAC at 100 or 200 mg/kg also had no significant protective effect on vasculitis. Autoantibody and IgE levels were not affected by either methyl prednisolone or the antioxidants. The lack of benefit of vitamin E and NAC suggests that oxidative damage, whether generated by neutrophils or other cells, does not play a major role in the pathogenesis of vasculitis, and that antioxidant therapy is unlikely to be of benefit in systemic vasculitis in man.
Predominance of T cell receptor Vδ3 in small bowel biopsies from celiac disease patients
Authors: FALK M C , NG G , ZHANG G Y , FANNING G C , KAMATH K R , KNIGHT J F
Published: July 2010

Increased numbers of T cells bearing the γδ antigen receptor (γδ T cells) have been reported in small bowel biopsies of patients with latent, active or treated coeliac disease. We have studied jejunal biopsies from seven children with coeliac disease and 10 children with normal gut histology to characterize γδ T cell receptor (TCR) variable region gene subfamily expression in resident γδ T cells and compared the results with the findings in peripheral blood mononuclear cells (PBMC) obtained on the same day as the gut biopsy. Molecular analysis of RNA extracted from PBMC and biopsies was performed by reverse transcription and amplification with the polymerase chain reaction using primers specific for six TCR Vδ families and four TCR Vγ families. We report, first, that a significantly increased number of γδ T cells expressing the TCR Vδ3 subfamily (P= 0·008) was observed in jejunal biopsies from children with coeliac disease, and second, that γδ T cell V region subfamily populations in gut differed from those seen in PBMC for both control and celiac patients. Significantly reduced numbers of TCR Vδ2, Vδ3, Vδ5 (P < 0·01) and Vγ2, Vγ4 (P < 0·01) T cells were found in gut compared with PBMC. The difference in γδ T cell repertoire observed between gut and blood may reflect differences in the nature of the antigens usually encountered in these two compartments. The over-representation of TCR Vδ3 in patients with coeliac disease suggests a specific role for these cells in the induction or maintenance of the jejunal abnormality associated with this disease.
Methotrexate treatment in murine experimental systemic lupus erythematosus (SLE); clinical benefits associated with cytokine manipulation
Authors: SEGAL R , DAYAN M , ZINGER H , MOZES E
Published: July 2010

The objective of this study was to determine the effects of Methotrexate (MTX) on the development and the course of experimental murine SLE, as well as on the cytokine profile involved in the disease. SLE was induced in naive BALB/c female mice by injection of the human anti-DNA MoAb bearing a common idiotype (16/6 Id). Six weeks following immunization, when high levels of autoantibodies were demonstrated, the mice were treated with MTX (2 mg/kg once a week) for a period of 10 months. MTX treatment had no effect on 16/6 Id-induced autoantibody production. However, MTX treatment had beneficial effects on the clinical manifestations of the experimental disease (i.e. leucocyte counts, levels of protein in the urine and immune complex deposits in the kidneys). Thus, only 20% of 16/6 Id-immunized BALB/c mice that were treated with MTX had immune complex deposits in their kidneys compared with 100% of SLE-afflicted BALB/c mice that were not treated. We have observed a significant elevation in IL-1, tumour necrosis factor (TNF) and IL-10 secretion in BALB/c mice afflicted with experimental SLE. IL-2, IL-4, IL-6 and interferon-gamma (INF-γ) levels were decreased in these mice compared with the levels detected in healthy controls. Treatment with MTX reversed the levels of all the above cytokines to normal levels observed in control mice. These studies demonstrate therapeutic effects of MTX on murine experimental SLE. The normal cytokine profile observed following treatment with MTX is suggested to play a role in the amelioration of the clinical manifestations of experimental SLE.
Decreased cervicovaginal production of both IgA1 and IgA2 subclasses in women with AIDS
Authors: BELEC L , MEILLET D , GAILLARD O , PRAZUCK T , MICHEL E , EKOME J NGONDI , PILLOT J
Published: July 2010

Paired sera and cervicovaginal secretions from 35 HIV-1-infected women representing different CDC stages of HIV infection were evaluated for total IgA, IgA1 and IgA2, for IgA, IgA1 and IgA2 to gp160, and for albumin. Age-matched healthy women (n= 45) served as controls. The secretion rates of total IgA, IgA1 and IgA2 were evaluated by calculating their relative coefficients of excretion by reference to albumin. In HIV-infected women, total IgA1 and IgA2 in sera and in cervicovaginal secretions increased proportionately as early as stages II + III and more markedly at stage IV. By contrast, the secretion rates of total IgA, IgA1 and IgA2 were markedly reduced in AIDS women, the IgA2 secretion rate decreasing significantly as early as stages II +III. This apparent discrepancy was probably the result of increased transudation of serum-borne immunoglobulins into the vaginal cavity, since albumin levels in cervicovaginal secretions increased significantly according to the stages of disease. HIV-reactive IgA antibodies in serum, as in cervicovaginal secretions, were principally found within the IgA 1 subclass. In women at stage IV, a high local production of IgA1 to gp160 occurred in spite of the impairment of cervicovaginal IgA synthesis, probably because of marked genital HIV replication at advanced stages.
Enhanced expression of MHC class I molecules on cultured human thyroid follicular cells infected with reovirus through induction of type 1 interferons
Authors: ATTA M S , IRVING W L , POWELL R J , TODD I
Published: July 2010

Certain viruses are known to modulate the cellular expression of MHC molecules. We have investigated whether reovirus types 1 or 3 can alter the normal MHC molecule expression on cultured human thyroid follicular cells (TFC). Primary TFC cultures were established from eight human thyroid donors and MHC class I and II expression was assessed by indirect immunofluorescence microscopy. Both types of reovirus enhanced MHC class I expression on TFC from all thyroid donors. Class II MHC protein was strongly induced by type 1 reovirus on TFC from one donor, while weak induction of expression, by either reo-1 or reo-3 virus, was noted on the TFC of five other donors. Studies on the mechanism(s) of MHC class I hyperexpression showed that mouse MoAb against the type 3 reovirus haemagglutinin (anti-HA3) reduced the ability of the virus to induce hyperexpression of class I MHC molecules on TFC. However, supernatant harvested from type 3 reovirus-infected TFC cultures maintained its ability to enhance class I expression after incubation with anti-HA3. Moreover, adding rabbit anti-sera lo interferon-alpha (IFN-α) or IFN-β inhibited the increased class I MHC expression on TFC by both types of reovirus. These data suggest that reoviruses (types 1 and 3) can enhance MHC class I on cultured TFC. The mechanism of MHC class I enhancement is most probably through the release of IFN-α and IFN-β.
Activation of the endothelium by IL-1α and glucocorticoids results in major increase of complement C3 and factor B production and generation of C3a
Authors: COULPIER M , ANDREEV S , LEMERCIER C , DAUCHEL H , LEES O , FONTAINE M , RIPOCHE J
Published: July 2010

Constitutive secretion of complement C3 and factor B by the endothelial cell (EC) is lowered by therapeutic concentrations of glucocorticoids such as hydrocortisone or dexamethasone, whereas regulatory protein factor H production is increased by these hormones. In contrast, the pro-inflammatory cytokine IL-1α has a stimulatory effect on C3 and factor B secretion by the endothelium and an inhibitory effect on factor H secretion. In this study, we examined the combined effect of IL-1α and glucocorticoids on C3 and factor B expression by the endothelial cell. When dexamethasone or hydrocortisone were added to IL-1α, significant potentialization of IL-1α-induced stimulation of C3 and factor B production was observed, occurring at various concentrations of either stimuli. Dose-response experiments indicate that, in vitro, optimal concentrations are in the range of 10−7 to 10−5m for dexamethasone and 50–200 U for IL-1α. In contrast, dexamethasone counteracts, in an additive way, the inhibitory effect of IL-1α on regulatory complement protein factor H production by EC. Such a potentialization between glucocorticoids and IL-1α was not observed for another marker of endothelial activation, IL-1α-induced stimulation of coagulation tissue factor expression. The association of glucocorticoids and IL-1α therefore appears to be a specific and major stimulus for the secretion of complement C3 and factor B, two acute-phase proteins, by the endothelium. As a result of the in vitro endothelium stimulation by glucocorticoids and IL-1α, C3a is generated in the vicinity of the endothelial cell. This study further suggests that complement activation, with its deleterious consequences, may result from the stimulation of endothelium in situations where high levels of IL-1α and endogenous glucocorticoids coexist, such as in septic shock.
Allergen-stimulated T lymphocytes from allergic patients induce vascular cell adhesion molecule-1 (VCAM-1) expression and IL-6 production by endothelial cells
Authors: DELNESTE Y , JEANNIN P , GOSSET P , LASSALLE P , CARDOT E , TILLIE-LEBLOND I , JOSEPH M , PESTEL J , TONNEL A-B
Published: July 2010

Adhesion of inflammatory cells to endothelium is a critical step for their transvascular migration to inflammatory sites. To evaluate the relationship between T lymphocytes (TL) and vascular endothelium, supernatants from allergen-stimulated TL obtained from patients sensitive to Dermatophagoides pteronyssinus (Dpt) versus healthy subjects were added to endothelial cell (EC) cultures. TL were stimulated by autologous-activated antigen-presenting cells (APC) previously fixed in paraformaldehyde to prevent monokine secretion. Two parameters were measured: the expression of adhesion molecule and the production of IL-6. Related allergen-stimulated TL supernatants from allergic patients induced an increase of VCAM-1 and inter-cellular adhesion molecule-1 (ICAM-1) expression when supernatants of the control groups (TL exposed to an unrelated allergen or not stimulated or TL obtained from healthy subjects) did not, E-selectin expression was not modulated whatever the supernatant added to EC culture. IL-6 production by EC was significantly enhanced after activation with related allergen-stimulated TL supernatants from allergies compared with control supernatants. Induction of VCAM-1 expression was inhibited by adding neutralizing antibodies against IL-4, whereas IL-6 production and ICAM-I expression were inhibited by anti-interferon-gamma (IFN-γ) antibodies. Enhanced production of IL-4 and IFN-γ was detected in related allergen-stimulated TL supernatants from allergic subjects compared with the different supernatants. These data suggest that allergen-specific TL present in the peripheral blood of allergic patients are of Th1 and Th2 subtypes. Their stimulation in allergic patients may lead to the activation of endothelial cells and thereby participate in leucocyte recruitment towards the inflammatory site.
Antimycobacterial hsp65 and rheumatoid factor titres in a population of normal twins: evidence of genetic control of rheumatoid factor
Authors: Birnie D , Mckay I C , Veitch J , Whaley K , Hood S , Hillis W S , Holme E R
Published: July 2010

Rheumatoid arthritis (RA) is an autoimmune disease and rheumatoid factor (RF), anti-IgG, has been implicated in the pathogenesis, but the exact etiology remains unclear. There are data to suggest an infectious trigger to the autoimmune process, and mycobacteria are considered a candidate. Immunization of various animals with mycobacterial heat shock protein 65 (mhsp65) protects against subsequent autoimmune arthritis in a number of experimental models. Elevated anti-mhsp65 titres have been demonstrated in RA patients, together with specific T cells isolated from inflamed synovium. Mycobacterial hsp65 has also been implicated in other autoimmune disease and in atherosclerosis. The anti-mhsp65 and RF (IgG, IgM and IgA isotypes) titres were assayed by ELISA in 123 pairs of normal twins (61 monozygotic and 62 dizygotic, age 14–79 years), to examine the population distribution and inter-relationship of these antibodies. In addition, we studied the effects of age, sex, genetics and environment on antibody titres, IgG-RF and IgM-RF were detectable in all subjects and IgA-RF in 41 subjects. None of the RF isotypes showed any significant dependence on age or sex. There was a statistically significant correlation between twins for the IgG-RF and IgM-RF, and a positive but not significant correlation for the IgA-RF. All three correlations were stronger for monozygotic than dizygotic twins, reaching statistical significance for IgM-RF (P < 0.001), and this indicates that there is a genetic influence on RF titres. Anti-mhsp65 titres were detectable in 90.5% of the study group with a range of 0.15–19.7 AU/ml. There were weak correlations between twins, stronger for dizygotic than monozygotic twins. This suggests that familial influences on anti-mhsp65 titres are very small, with no evidence of any genetic influence at all. There was no significant relationship of anti-mhsp65 titre with age, sex or RF titres.
Antigen-specific B cells present cartilage proteoglycan (aggrecan) to an autoreactive T cell hybridoma derived from a mouse with proteoglycan-induced arthritis
Authors: Brennan F R , Mikecz K , BuzÁS E I , Ragasa D , Cs-SzabÓ G , Negroiu G , Glant T T
Published: July 2010

Cartilage proteoglycan (aggrecan)-induced polyarthritis in BALB/c mice is characterized by chronic inflammation and destruction of joint tissues similar to that observed in human rheumatoid arthritis. The immunization of mice with fetal human proteoglycan (PG) elicits specific antibodies to the immunizing antigen of which a population cross-reacts with native mouse PG. This (auto)antibody production is immediately followed by an explosive proliferation of autoreactive T cells, suggesting that PG-specific B cells may participate in antigen presentation of PG to autoreactive T cells. We therefore isolated B cells from the spleens and lymph nodes of PG-immunized mice and examined their ability to present PG to a PG-specific T cell hybridoma. The antigen-specific T cell responses elicited by B cells from PG-immunized mice (both arthritic and clinically asymptomatic) were markedly higher that those of non-immune mice and keyhole limpet haemocyanin (KLH)-immunized mice, and these B cells could present low PG concentrations. Levels of B cell presentation corresponded with the serum levels of PG-specific antibodies, implying that these B cells were presenting the PG specifically via their surface immunoglobulin. This B cell T cell interaction was strongly dependent on MHC class II/T cell receptor (TCR), LFA-1/intercellular adhesion molecule-1 (ICAM-1) and CD28/B7 interactions, as antibodies to Ia, ICAM-1 and B7-2 (but not to B7-1) markedly reduced presentation. These data indicate that PG-specific B cells may play an essential role in governing the development of PG-induced arthritis.
The outer surface proteins of Lyme disease borrelia spirochetes stimulate T cells to secrete interferon-gamma (IFN-γ): diagnostic and pathogenic implications
Authors: Forsberg P , Ernerudh J , Ekerfelt C , Roberg M , Vrethem M , BergstrÖM S
Published: July 2010

Late stages of borrelia Lyme disease infections may be difficult to diagnose because of unspecific symptoms and unreliable laboratory tests, being too unspecific or insensitive. The T cell immune response was thus evaluated in these patients by using a sensitive ELISPOT T cell assay that detects the secretion of IFN-γ, i.e. a T helper 1 (Th1) response on the single-cell level. Three subcellular fractions of the Lyme borreliosis strain Borrelia afzelii were used for antigenic stimulation. The outer surface protein (Osp) fraction elicited the strongest response, discriminating between borrelia infections (n= 15) compared with other neurological diseases (n= 10) and normal controls (n= 12) (P= 0.0001). The more heterogeneous sonicated borrelia fraction also elicited a strong response, however, also in some of the controls. The flagellin fraction did not have a similar T cell-stimulating effect. When looking at subgroups of borrelia infections, central nervous system (CNS) infections (n= 7) revealed a lower T cell response in blood (P= 0.0128) compared with other borrelia manifestations (n= 8). Cerebrospinal fluid (CSF) lymphocytes were available from three patients with CNS borreliosis, and all showed a compartmentalization with higher responses to the Osp fraction in CSF compared with blood, also in the two patients without any intrathecal-specific antibody synthesis. The ELISPOT method is feasible for detecting a specific IFN-γ T cell response in borrelia infections. This Th1 response may well be of pathogenic relevance.
Reduced antigen-presenting function of human Epstein-Barr virus (EBV)-B cells and monocytes after UVB radiation is accompanied by decreased expression of B7, intercellular adhesion molecule-1 (ICAM-1) and LFA-3
Authors: Kremer I B , Bos J D , Teunissen M B M
Published: July 2010

In this study, the effect of ultraviolet-B (UVB) radiation on antigen-presenting function was studied, to investigate whether antigen-presenting cells (APC) are inhibited by UVB through a common mechanism. Two types of human APC were used: EBV-B cells and monocytes, and these were irradiated in vitro with single low doses of UVB (range 0–200 J/m2). Irradiation of EBV-B cells or monocytes resulted in similar dose-dependent reduction in APC function, when determined by the allogeneic mixed leucocyte reaction (MLR) or Candida albicans- or tetanus toxoid-specific T cell response. Our study shows that the reduced APC function was not likely to be caused by alterations in antigen processing or cytokine production. However, UVB-irradiated APC displayed marked changes in adhesion molecule expression. Irradiated EBV-B cells showed reduced expression of ICAM-1 (30%), LFA-3 (25%) and B7-1 (35%), white expression of HLA-DR, CD19 and LFA-1 was not affected. UVB irradiation of monocytes did result in reduction in the expression of HLA-DR (30%), LFA-3 (40%), ICAM-1 (65%) and B7-1 and B7-3 (90%), but had no effect on CD14, LFA-1 and ICAM-3 expression. Addition of non-irradiated cells (but not the supernatant of these cells) or CD28 antibodies partly restored T cell activation, indicating that UVB-induced reduction in APC function is at least partly mediated via impairment of co-stimulatory molecule expression.
Impaired cellular immune response in harbour seals (Phoca vitulina) feeding on environmentally contaminated herring
Authors: De Swart R L , Ross P S , Timmerman H H , Vos H W , Reijnders P J H , Vos J G , Osterhaus A D M E
Published: July 2010

In a 2.5-year immunotoxicological study, two groups of captive harbour seals (Phoca vitulina) were fed herring from the heavily polluted Baltic Sea or from the relatively uncontaminated Atlantic Ocean. Blood samples were collected at regular intervals, and functional immunological parameters were monitored. T cell mitogen and mixed lymphocyte-induced proliferative responses of peripheral blood mononuclear cells (PBMC) obtained from seals fed Baltic herring were significantly reduced over the course of the experiment. Upon immunization with rabies virus antigen (RV) and tetanus toxoid (TT), specific proliferative responses of PBMC from the seals fed Baltic herring were also significantly reduced. Impairment of T cell-mediated immune responses became especially apparent during the second year on the respective diets, and correlated significantly to 2,3,7,8-tetrachloro-dibenzo-p-dioxin toxic equivalent levels in blubber biopsies taken from the seals after 2 years on the respective diets. Humoral immune responses, including lipopolysaccharide (LPS)-induced lymphoproliferative responses, in vitro immunoglobulin production by PBMC, as well as RV-, TT- and poliovirus-specific serum antibody responses following immunization, remained largely unaffected. We conclude that suppression of the cellular immune response in the seals fed Baltic herring was induced by the chronic exposure to immunotoxic environmental contaminants accumulated through the food chain. Since cellular immune responses are known to be of crucial importance in the clearance of morbillivirus infections, these results suggest that environmental pollution-related immunosuppression may have contributed to the severity and extent of recent morbillivirus-related mass mortalities among marine mammals.
Cyclic AMP-elevating agents down-regulate the oxidative burst induced by granulocyte-macrophage colony-stimulating factor (GM-CSF) in adherent neutrophils
Authors: Ottonello L , Morone M P , Dapino P , Dallegri F
Published: July 2010

Human neutrophils, plated on fibronectin-precoated wells, were found to release large quantities of superoxide anion (O2−) in response to GM-CSF. O2− production was reduced by prostaglandin E2 (PGE2) and the phosphodiesterase type IV (PDE IV) inhibitor RO 20–1724. Both agents are known to increase intracellular cyclic AMP (cAMP) levels by inducing its production (PGE.) or blocking its catabolism (RO 20–1724). When added in combination, PGE2 and RO 20–1724 had a marked synergistic inhibitory effect, which was reproduced by replacing PGE2 with a direct activator of adenylate cyclase, i.e. forskolin (FK). Moreover, the neutrophil response to GM-CSF was inhibited by a membrane-permeable analogue of cAMP in a dose-dependent manner. As GM-CSF and PGE2 are known to be generated at tissue sites of inflammation, the results suggest the existence of a PGE2-dependent regulatory pathway potentially capable of controlling the neutrophil response to GM-CSF, in turn limiting the risk of local oxidative tissue injury. Moreover, owing to its susceptibility to amplification by RO 20–1724, the PGE2-dependent pathway and in particular PDE-IV may represent a pharmacological target to reduce the generation of histotoxic oxidants by GM-CSF-responding neutrophils.
Granulocyte-macrophage colony-stimulating factor (GM-CSF) counteracts the inhibiting effect of monocytes on natural killer (NK) cells
Authors: Van Den Bosch G , Preijers F , Vreugdenhil A , Hendriks J , Maas F , De Witte T
Published: July 2010

GM-CSF is known to accelerate haematopoietic recovery following allogeneic bone marrow transplantation (BMT). In addition, it may restore and enhance both granulocyte and monocyte functions. Stimulation of monocyte functions may induce a direct or an indirect anti-leukaemic activity due to an increase of cellular cytotoxicity and production of cytokines which may result in a reduction of the relapse rate after BMT. NK cells may play a crucial role in this activity. Therefore we studied the influence of monocytes on NK activity in combination with GM-CSF. Lymphocytes and monocytes were isolated from buffy coats of healthy individuals by counterflow centrifugation elutriation (CCE). NK activity was exerted by CD3−CD56+ cell populations and could be enhanced by IL-2 incubation overnight. Incubation of CD3−CD56+ cells with GM-CSF in the presence or absence of IL-2 hardly influenced NK activity of the lymphocyte population. Low amounts of monocytes enhanced NK activity. NK activity in lymphocyte population in the presence of equivalent numbers of monocytes with or without IL-2 was strongly decreased irrespective of the effector: target ratio (ETR). This appeared not to result from sterical hindrance effects (if the present number of cells. However, addition of GM-CSF abrogated the inhibition of NK activity by monocytes in the presence of IL-2. In monocyte fractions neither IL-2 nor GM-CSF yielded NK activity. Our findings indicate that GM-CSF can affect NK activity by counteracting the suppressing effects of monocytes, and hence may improve the outcome after BMT.
Defective functional response to membrane stimuli in lymphocytes from patients with benign prostatic hyperplasia
Authors: PÉRez-Blas M , MartÍNez-MartÍN B , Carballido J , Hontoria J , Salazar L I , Olivier C , Alvarez-Mon M
Published: July 2010

Benign prostatic hyperplasia (BHP) is a local disturbance in the prostate that may involve an inflammatory infiltrate predominantly composed of activated lymphocytes and macrophages. The activation and proliferative response of T lymphocytes to different mitogenic signals has been analysed in peripheral blood mononuclear cells (PMBC) from 45 patients with BHP and 55 healthy controls. The PBMC obtained from the patients showed a significant specific impairment in proliferation, CD25 expression and IL-2 production in response to stimulation with lectins (phytohaemagglutinin (PHA), concanavalin A (Con A)), that was not corrected by the addition of IL-2 or of phorbol esters (phorbol myristate acetate (PMA)). Also, the CD28 response was defective in patient PBMC. Activation with anti-CD3 or anti-CD2 MoAbs was normal, but the addition of PMA to these stimuli provoked a significant defective response. Only the use of transmembrane stimuli (PMA and ionomycin) elicited responses similar to those found in the control group. The results indicate that peripheral T lymphocytes from BPH patients show a functional impairment that is mainly explained by an alteration of membrane signals (PHA, CD28) and is distal to protein kinase C (PKC) activation.