bluuebunny/crossref_metadata_2025 huggingface dataset:
Lupus anticoagulant and history of thrombosis are not associated with persistent endothelial cell activation in systemic lupus erythematosus
Authors: Frijns C J M , Derksen R H W M , De Groot P H G , Algra A , Fijnheer R
Published: March 2003

Antiphospholipid antibodies (aPL), especially lupus anticoagulant (LAC), characterize systemic lupus erythematosus (SLE) patients at increased risk for arterial and venous thromboembolic complications. It has been reported that purified human anti-phospholipid antibodies cause endothelial cell activation in in vitro experiments. In order to investigate whether increased endothelial cell activation is associated with thromboembolic events in SLE patients with LAC, we measured plasma levels of thrombomodulin (TM), von Willebrand factor (vWf), sP-selectin, vascular cell adhesion molecule-1 (sVCAM-1) and ED1-fibronectin in a study of 76 patients with SLE. Patients were subdivided on the basis of: no history of thrombosis and LAC-negative (n = 22) or LAC-positive (n = 17); positive history of thrombosis and LAC-negative (n = 16) or LAC-positive (n = 21). The median SLE disease activity index (SLEDAI) was 4. Although concentrations of sTM, vWf, sP-selectin and sVCAM-1 were significantly elevated in SLE compared with values in healthy controls, they did not differ between the four groups, between patients with or without history of thrombosis, and between patients with or without LAC. Presence of anticardiolipin antibodies could not explain these negative findings. Adjustment of the concentrations for significantly associated variables, such as age, hypertension, smoking, immunosuppressive treatment and concentrations of creatinine, cholesterol and homocysteine, did not change the main results of the study. Only sTM was significantly lower in patients with both LAC and thrombosis than in patients without both these features after adjustment for serum creatinine concentrations. In conclusion, we did not find an association between endothelial cell activation and presence of LAC or history of thrombosis in SLE.
Regulation of LPS induced IL-12 production by IFN-γand IL-4 through intracellular glutathione status in human alveolar macrophages
Authors: Dobashi K , Aihara M , Araki T , Shimizu Y , Utsugi M , Iizuka K , Murata Y , Hamuro J , Nakazawa T , Mori M
Published: March 2003

Interleukin-12 (IL-12) is secreted from monocytes and macrophages; it exerts pleiotropic effects on T cells and natural killer (NK) cells, and stimulates interferon-γ (IFN-γ) secretion. Glutathione tripeptide regulates the intracellular redox status and other aspects of cell physiology. We examined whether IFN-γ and IL-4 affect the balance between intracellular reduced glutathione (GSH) and oxidized (GSSG) glutathione, as this may affect IL-12 production in human alveolar macrophages (AM). We used both AM from healthy non-smokers obtained by bronchoalveolar lavage and the monocytic THP-1 cell line in this study. Incubation of AM for 2 h with the GSH precursor N-acetylcysteine (NAC) increased the intracellular GSH/GSSG ratio, and enhanced lipopolysaccharide (LPS)-induced IL-12 secretion by AM. In THP-1 cells, NAC increased the GSH/GSSG ratio and the expression of LPS-induced IL-12 mRNA, whereas L-buthionine-[S,R]-sulphoximine (BSO) decreased these. NAC and BSO offset their own effects on the intracellular GSH/GSSG ratio and the expression of LPS-induced IL-12 mRNA. Furthermore, exposure of AM to the helper T cell type 1 (Th1) cytokine IFN-γ or the helper T cell type 2 (Th2) cytokine IL-4 for 72 h increased and decreased the GSH/GSSG ratio, respectively. Lipopolysaccharide (LPS)-induced secretion of IL-12 in AM was enhanced by IFN-γ but inhibited by IL-4. These results suggest that IFN-γ and IL-4 oppositely affect the GSH/GSSG balance, which may regulate IL-12 secretion from AM in response to LPS.
Identification of antigenic domains on the human sodium-iodide symporter which are recognized by autoantibodies from patients with autoimmune thyroid disease
Authors: Kemp E H , Waterman E A , Ajjan R A , Smith K A , Watson P F , Ludgate M E , Weetman A P
Published: March 2003

The sodium-iodide symporter (NIS) is a novel autoantigen in autoimmune thyroid disease. In the present study we have characterized the antigenic domains on the human symporter which are recognized by autoantibodies from patients with either Graves' disease (GD) or autoimmune hypothyroidism (AH). Deletion derivatives of complementary DNA (cDNA) encoding the Na+/I− symporter were constructed using polymerase chain reaction (PCR) amplification. These deletion constructs were translated in vitro with the concomitant incorporation of [35S]methionine into the protein products. The reactivity of seven GD and six AH sera, which were known to contain symporter-binding antibodies, to each of the radiolabelled modified symporters was then determined in immunoprecipitation experiments. Analyses of the results obtained in the radiobinding assays suggest the existence of multiple antibody binding sites on human NIS (hNIS), including regions between amino acids (aa) 1–134, 191–286, 290–411, 411–520 and 520–588. Computer prediction of the potential B cell epitopes on the symporter revealed that, apart from aa 134–191, all the epitope domains identified overlapped, at least in part, with areas predicted to be highly antigenic. Interestingly, the antigenic domains represented by aa 191–286, 290–411 and 411–520 include regions of the polypeptide which form putative extracellular domains in the secondary structure model of the rat symporter. No correlation between the recognition of specific epitopes on the human symporter and the type of autoimmune thyroid disease was demonstrated.
Heterogeneity of human Ro ribonucleoproteins (RNPS): nuclear retention of Ro RNPS containing the human hY5 RNA in human and mouse cells
Authors: Gendron M , Roberge D , Boire G
Published: March 2003

Ro ribonucleoproteins (RNPs) are autoantigens that result from the association of a 60-kDa protein (Ro60) with a small RNA (hY1, hY3, hY4 or hY5 in humans, mY1 or mY3 in mice). Previous studies localized Ro RNPs to the cytoplasm. Because Ro RNPs containing hY5 RNA (RohY5 RNPs) have unique biochemical and immunological properties, their intracellular localization was reassessed. Subcellular distribution of mouse and human Ro RNPs in intact and hY-RNA transfected cells was assessed by immunoprecipitation and Northern hybridization. Human RohY1−4 RNPs as well as murine RomY1, mY3 RNPs are exclusively cytoplasmic. Ro RNPs containing an intact hY5 RNA, but not those containing a mutated form of hY5 RNA, are found in the nuclear fractions of human and mouse cells. RohY5 RNPs are stably associated with transcriptionally active La protein and are known to associate with RoBPI, a nuclear autoantigen. Our results demonstrate that RohY5 RNPs are specifically present in the nucleus of cultured human and murine cells. The signal for nuclear localization of RohY5 RNPs appears to reside within the hY5 sequence itself. In conclusion, we suggest that the unique localization and interactions of primate-specific RohY5 RNPs reflect functions that are distinct from the predicted cytoplasmic function(s) of more conserved Ro RNPs.
Antiphosphatidylserine antibodies are elevated in normal tension glaucoma
Authors: Kremmer S , Kreuzfelder E , Klein R , Bontke N , Henneberg-Quester K B , Steuhl K P , Grosse-Wilde H
Published: March 2003

The two main entities of open-angle glaucoma are primary open-angle glaucoma (POAG) and normal tension glaucoma (NTG). Both diseases may be associated with autoimmune processes. Therefore, IgG and IgM antibodies to phospholipids (APL) and their subspecies cardiolipin (ACL), phosphatidylserine (APS) and β2-glycoprotein (β2GP) were determined in 43 NTG patients, 40 POAG patients and 40 healthy controls in a prospective study. The most prominent observation was the increase in APS concentrations in NTG patients (IgG 20·6 ± 2·7 U/ml, IgM 24·4 ± 3·4 U/ml) compared with POAG patients (IgG 8·8 ± 1·2 U/ml, IgM 11·0 ± 1·7), and controls (IgG 7·7 ± 1·3 U/ml, IgM 12·8 ± 1·5 U/ml). APS may be important due to their binding specificity to phosphatidylserine molecules which become accessible during apoptosis; this in turn may lead to local thrombosis.
Deregulated cytokine network and defective Th1 immune response in multiple myeloma
Authors: Frassanito M A , Cusmai A , Dammacco F
Published: March 2003

Intracellular cytokine production by peripheral blood mononuclear cells (PBMC) was analysed in 51 patients with multiple myeloma (MM), 22 with monoclonal gammopathy of undetermined significance (MGUS) and 20 healthy subjects, as a parameter of immunological dysfunction in MM. An increased proportion of T cells and HLA-DR+ cells producing IL-6 was observed in MM patients with active disease (at diagnosis and relapsing) compared with patients in remission and with MGUS, whereas no difference of IFN-γ+, IL-2+ PBMC between patients and controls was evident. Determination of serum cytokine levels demonstrated that the imbalanced IL-6 production by T cells and the defective anti-tumour Th1 cell activity were related to elevated levels of IL-6 and IL-12. In vitro studies of PHA- and anti-CD3/anti-CD28 MoAbs stimulation of PBMC demonstrated the ability of lymphocytes from MM patients to differentiate towards the Th1 subset in the presence of rIL-12. By contrast, addition of exogenous rIL-6 impaired IFN-γ production by rIL-12-prompted T cells. Inhibition of Th1 polarization of the immune response by IL-6 was direct on T cells and not mediated by dendritic cells (DC). Evaluation of the ability of MM-derived DC to stimulate cell proliferation of allogenic T lymphocytes and produce IL-12 in vitro, in fact, suggested that MM-derived DC were functionally active. Taken as a whole, these results indicate that a deregulated cytokine network occurs in active MM. They also suggest that increased IL-6 production by peripheral T lymphocytes contributes to the immune dysfunction observed in MM, and enables tumour cells to escape immune surveillance by preventing the anti-tumour Th1 immune response.
NF-κB is involved in the regulation of CD154 (CD40 ligand) expression in primary human T cells
Authors: Srahna M , Remacle J E , Annamalai K , Pype S , Huylebroeck D , Boogaerts M A , Vandenberghe P
Published: March 2003

Cognate interactions between CD154 (CD40 ligand, CD40L) on activated T cells and its receptor CD40 on various antigen-presenting cells are involved in thymus-dependent humoral immune responses and multiple other cell-mediated immune responses. We have studied the regulation of CD154 expression in human T cells after activation with anti-CD3 and anti-CD28 antibodies or after pharmacological activation of protein kinase C with phorbol 12-myristate 13-acetate, and the calcium ionophore ionomycin. Under these conditions, transcription of the CD154 gene was rapidly induced without requiring de novo protein synthesis. Pharmacological inhibitors of NF-κB activation down-regulated CD154 mRNA and protein levels. Cyclosporin A, an inhibitor of NF-AT activation, acted similarly, and the effects of both inhibitors were additive. A potential NF-κB binding site is present within the CD154 promoter at positions −1190 to − 1181. In electrophoretic mobility shift assays, this sequence was specifically bound by NF-κB present in nuclear extracts from activated T cells. Furthermore, in transient co-transfection of Jurkat T cells, p65 activated the transcription of a reporter construct containing a multimer of this NF-κB binding site. These observations demonstrate a role of NF-κB transcription factors in the regulation of CD40L expression in activated primary human T cells.
HLA-A and HLA-B transcription decrease with ageing in peripheral blood leucocytes
Authors: Le Morvan C , Cogné M , Drouet M
Published: March 2003

Immunosenescence involves modifications of humoral and cellular immunity. In a previous study, we have shown a locus-dependent reduction of HLA class-I cell surface expression on peripheral lymphocytes and monocytes with advancing age. Here we report the quantitative analysis of HLA-A and -B transcripts from PBL of 54 healthy subjects aged 21–90 years. Using a competitive RT-PCR method, we observed a significant decrease of HLA-A (P < 0·0001) and -B (P = 0·0025) mRNA contents with increasing age. Secondly, to investigate this locus-dependent alteration of HLA class-I transcription, we performed EMSA using nuclear extracts from PBL of five young (24–31-year-old) and 5 elderly (58–69 years old) donors with locus A and B sequences of the Enh-A as probes. No qualitative variation of EMSA profiles appeared between the two groups of donors with 6 and 4 bandshift for the locus A and B, respectively. Quantitatively, we observed a significant increase of B4 intensity in the elderly group compared to the young group (P < 0·05). These results suggest that the variation of DNA binding protein could contribute to the lower transcription of HLA-A and -B with ageing. These alterations of HLA class-I expression at the transcriptional level could lead to the unresponsiveness of CD8 T cells due to default of antigen presentation with ageing.
The proportion of Th1 cells, which prevail in gut mucosa, is decreased in inflammatory bowel syndrome
Authors: Van Damme N , De Keyser F , Demetter P , Baeten D , Mielants H , Verbruggen G , Cuvelier C , Veys E M , De Vos M
Published: March 2003

T lymphocytes and their cytokines have an important role in the regulation of immune responses in the gut and in the pathogenesis of intestinal inflammation such as in Crohn's disease. The aim of this study was to analyse the Th1/Th2 cytokine profile (IFN-γ, IL-2, IL-4 and IL-10) in intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL) in Crohn's disease (CD) and ulcerative colitis (UC) in relation to healthy controls (C). Colonic and ileal biopsy specimens were obtained from controls (n = 13) and patients with CD (n = 32). Colonic biopsies were obtained from patients with UC (n = 11). Intracytoplasmic IFN-γ, IL-2, IL-4 and IL-10 were determined by flow cytometry after PMA–ionomycin stimulation in IEL and LPL. In colonic LPL, a significant proportional decrease of IFN-γ and IL-2 producing CD3+ cells was observed in patients with CD and UC compared to controls. In ileal LPL, a similar tendency was found although differences were not significant. In IEL no differences in cytokine profiles could be observed. Flow cytometric analysis of intracytoplasmic cytokines at single cell level showed a proportional decrease of IFN-γ and IL-2 producing T cells in colonic lamina propria in patients with inflammatory bowel disease.
Expansion of CD4+ T cells with a cytotoxic phenotype in patients with B-chronic lymphocytic leukaemia (B-CLL)
Authors: Porakishvili N , Roschupkina T , Kalber T , Jewell A P , Patterson K , Yong K , Lydyard P M
Published: March 2003

Abnormal CD4/CD8 ratios and T-cell function have previously been shown in patients with B-chronic lymphocytic leukaemia (B-CLL). We have demonstrated that CD4+ T cells containing both serine esterase and perforin (PF) are increased in the blood of these patients. Using flow cytometry, we have shown that the CD4+ PF+ cells were CD57+ but lacked expression of CD28, suggesting a mature population. The same phenotype in CD8+ T cells is characteristic of mature cytotoxic T cells. However, in contrast to the CD8+ T cells, the CD4+ T cells were more frequently CD45RO positive than CD45RA positive, indicating prior antigen experience. In contrast, this population lacked expression of either CD69 or HLA-DR, arguing that they were not activated or that they are an abnormal population of T cells. Their constitutive cytokine levels showed them mainly to contain IL4 and not IFNγ, suggesting a Th2 phenotype. The role of the CD4+ PF+ T-cell population is at present uncertain. However, this potentially cytotoxic T-cell population could contribute both to enhancing survival of the B-CLL tumour cells through production of IL4, and to the immunodeficient state frequently seen in patients with this tumour, independent of drug treatment.
Differential effect of phosphodiesterase inhibitors on IL-13 release from peripheral blood mononuclear cells
Authors: Yoshida N , Shimizu Y , Kitaichi K , Hiramatsu K , Takeuchi M , Ito Y , Kume H , Yamaki K , Suzuki R , Shibata E , Hasegawa T , Takagi K
Published: March 2003

Increased cyclic AMP (cAMP)-phosphodiesterase (PDE) activity in peripheral blood leucocytes is associated with the immunological inflammation that characterizes allergic diseases, such as atopic dermatitis and allergic rhinitis. Recently, it has been found that IL-13 has similar biological functions to IL-4. The aim of this study was to investigate the possible involvement of cAMP-PDE activity on IL-13 release from peripheral blood mononuclears cells (PBMC) from atopic asthma patients. Phytohaemagglutinin (PHA)-induced IL-13 release from PBMC was concentration-dependently inhibited by rolipram, a type 4 PDE inhibitor, as well as by dibutyryl cAMP, a membrane-permeant cAMP analogue. However, theophylline, a non-specific PDE inhibitor, and cilostazol, a type 3 PDE inhibitor, failed to inhibit IL-13 release. The inhibitory effect of rolipram was enhanced by the addition of forskolin (10−4m), an adenylyl cyclase stimulator. PHA itself did not alter the intracellular cAMP level. Rolipram concentration-dependently increased cAMP level in PHA-stimulated PBMC, and this increase was synergistically facilitated by the addition of forskolin (10−4m). These results suggest that type 4 PDE inhibitors, alone or synergistically in combination with forskolin, inhibit PHA-induced IL-13 release from PBMC of atopic asthma patients by elevating intracellular cAMP concentrations. These inhibitors have the potential to exert an anti-inflammatory effect by inhibiting IL-13 production in allergic diseases such as atopic asthma.
Lack of age-associated LFA-1 up-regulation and impaired ICAM-1 binding in lymphocytes from patients with Down syndrome
Authors: Lin S-J , Wang J-Y , Klickstein L B , Chuang K-P , Chen J-Y , Lee J-F , Shieh C-C
Published: March 2003

To investigate the role of LFA-1 in the immune defects in DS patients, we analysed lymphocytes from DS patients in LFA-1 expression and LFA-1 mediated cell adhesion. DS patients less than 2 years of age expressed a higher level of LFA-1 when compared with age-matched controls. The difference in LFA-1 expression was much less significant in older DS patients when compared with age-matched children. Although older children (2–15-year-old groups) without DS tend to increase their expression of lymphocyte LFA-1 when compared with younger normal children (0–2 years old), DS patients showed no age-associated increase in lymphocyte LFA-1 expression. Two-colour analysis with CD4/CD8 and LFA-1 in patients and controls showed that proportions of CD4 + lymphocytes were comparable in DS patients and controls, while the proportion of CD8 + lymphocytes was higher in older DS patients. Expression levels of LFA-1 on both CD4 + and CD8 + lymphocytes in younger DS patients were higher when compared with age-matched controls and close to the expression levels in the older DS group. Proportions of memory lymphocytes expressing the CD45RO isoform were higher in both younger and older DS patients when compared with age-matched control groups. Noticeably, the LFA-1 expression levels on CD45RO lymphocytes from younger DS patients were higher than the levels of the controls and declined in the older DS group. We tested lymphocytes (EBV transformed B cells, resting and anti-CD3 stimulated T cells) for cellular adhesion to recombinant ICAM-1 and found that lymphocytes from DS patients were less adhesive, even though their β2 integrin expression was comparable with that of normal controls. These results suggest that more generalized pathological processes, such as early senescence of the immune system or ineffective lymphocyte activation, and subsequent integrin dysfunction may underlie the immune defects in DS patients.
Interferon-γsecretion of peripheral blood CD8+ T lymphocytes in patients with bronchial asthma:In vitrostimulus determines cytokine production
Authors: Biller H , Bade B , Matthys H , Luttmann W , Virchow J C
Published: March 2003

It has been postulated that T lymphocytes orchestrate the chronic inflammation in bronchial asthma. In animal models, infiltration of CD8+ T lymphocytes into the bronchial mucosa prevented bronchial hyperresponsiveness and decreased early and late phase reaction. IFN-γ antagonizes IL-4-dependent IgE production as well as IL-5-induced proliferation and activation of eosinophils. We therefore investigated the secretion of IFN-γ of isolated CD8+ T lymphocytes from peripheral blood of patients with allergic asthma (n = 6) and from healthy controls (n = 7) in vitro. In this setting we compared the effect of stimulation with anti-CD3 antibodies with that of phorbol myristate acetate (PMA) and calcium-ionophore. As expected, CD8+ T lymphocytes from peripheral blood of healthy volunteers produced significantly more IFN-γ in the presence of PMA and calcium-ionophore than after stimulation with anti-CD3 antibodies. However, in subjects with allergic asthma, IFN-γ secretion of CD8+ T cells was significantly higher when incubated with anti-CD3 antibodies than after activation with PMA and calcium-ionophore. While IFN-γ secretion of CD8+ T lymphocytes of patients with allergic asthma was lower than that of healthy controls in the presence of PMA/calcium-ionophore, it was significantly elevated when compared with normal controls after stimulation with anti-CD3 antibodies. Thus, potent activators of cytokine secretion, such as PMA and calcium-ionophore, induce a cytokine profile different from that induced by weaker stimulants, such as anti-CD3 antibodies. These findings have implications for further studies investigating cytokine production of inflammatory cells in vitro.
Characterization ofHerpesvirus saimiri-transformed T lymphocytes from common variable immunodeficiency patients
Authors: CABANILLAS J A , CAMBRONERO R , PACHECO-CASTRO A , GARCÍA-RODRÍGUEZ M C , MARTÍN-FERNÁNDEZ J M , FONTÁN G , REGUEIRO J R
Published: March 2003

Common variable immunodeficiency (CVID) is a very frequent but heterogeneous syndrome of antibody formation. The primary defect remains unknown, but many reports describe peripheral blood T lymphocyte dysfunctions in a substantial proportion of CVID patients, which may impair T–B cell collaboration. In order to investigate whether such putative defects were intrinsic to T cells or, rather, secondary to quantitative differences in T cell subset distribution, or to other described disorders, we have used Herpesvirus saimiri (HVS) for the targeted transformation of CVID CD4+ and CD8+ T cells and subsequent functional evaluation by flow cytometry of their capacity to generate cell surface (CD154, CD69) or soluble (IL-2, TNF-α, IFN-γ) help after CD3 engagement. Unexpectedly, the results showed that 40 different CVID blood samples exposed to HVS gave rise with a significantly increased frequency to transformed CD4+ T cell lines, compared to 40 age-matched controls (27%versus 3%, P≤ 0·00002) suggesting the existence of a CVID-specific signalling difference which affects CD4+ cell transformation efficiency. The functional analysis of 10 CD4+ and 15 CD8+ pure transformed T cell lines from CVID patients did not reveal any statistically significant difference as compared to controls. However, half of the CD4+ transformed cell lines showed CD154 (but not CD69) induction (mean value of 46·8%) under the lower limit of the normal controls (mean value of 82·4%, P≤ 0·0001). Exactly the same five cell lines showed, in addition, a significantly low induction of IL-2 (P≤ 0·04), but not of TNF-α or IFN-γ. None of these differences were observed in the remaining CD4+ cell lines or in any of the transformed CD8+ cell lines. We conclude that certain CVID patients show selective and intrinsic impairments for the generation of cell surface and soluble help by CD4+ T cells, which may be relevant for B lymphocyte function. The transformed T cell lines will be useful to establish the biochemical mechanisms responsible for the described impairments.
Smoking and disease severity are independent determinants of serum adhesion molecule levels in Graves’ ophthalmopathy
Authors: WAKELKAMP I M M J , GERDING M N , MEER J W C VAN DER , PRUMMEL M F , WIERSINGA W M
Published: March 2003

Adhesion molecules play a key role in autoimmune disorders, and serum concentrations of soluble adhesion molecules are increased in Graves’ ophthalmopathy (GO). Whether this is due to the strong association with smoking is unknown. It is also not known if the severity or activity of GO determine the serum levels of adhesion molecules. We measured serum concentrations of sICAM-1, sVCAM-1 and sELAM-1 in 62 euthyroid Graves’ patients with untreated GO, in 62 healthy controls matched for sex, age and smoking habits, and in 26 euthyroid Graves’ patients without GO. GO severity was assessed by the Total Eye Score and the activity by the Clinical Activity Score. Adhesion molecules were measured by highly sensitive ELISAs. GO patients had higher levels than controls (median values in ng/ml with range): sICAM-1 300 [171–575] versus 244 [119–674], P < 0·001; sVCAM-1 457 [317–1060] versus 410 [238–562], P < 0·001; and sELAM-1 61 [19–174] versus 53 [23–118], P = 0·021. Euthyroid Graves’ disease patients without GO had levels similar to controls: sICAM-1 273 138–453), sVCAM-1 386 [260–1041] and sELAM-1 46 [22–118]. Smoking had an independent effect and was associated with higher levels of sICAM-1 and lower levels of sVCAM-1 in both GO patients and controls; sELAM-1 levels were comparable. In the 62 GO patients, sICAM-1 correlated significantly with severity of eye disease (r = 0·40, P = 0·002). No correlation was found with the duration of GO, the Clinical Activity Score or TBII levels. Multivariate analysis of all 150 subjects showed that the presence of GO and smoking are independent determinants of sICAM-1 and sVCAM-1 concentrations. In GO patients, the Total Eye Score was a stronger determinant than smoking. It is concluded that (i) smoking is associated with increased sICAM-1 and decreased sVCAM-1 levels; (ii) independent from smoking, euthyroid GO patients have higher levels of sICAM-1, sVCAM-1 and sELAM-1 than patients with euthyroid Graves’ disease or healthy controls; (iii) the major determinant of sICAM-1 in GO patients is the severity of their eye disease.
The CD28/HLA-DR expressions on CD4+T but not CD8+T cells are significant predictors for progression to AIDS
Authors: Choi B-S. , Park Y-K , Lee J-S
Published: March 2003

To investigate the changes of CD28 and HLA-DR molecules on CD4+ and CD8+ T cells during HIV infection, we classified 130 HIV-infected Koreans into four groups by the CD4 level as follows: group I (≥500 cells/mm3), group II (201–499 cells/mm3), group III (51–200 cells/mm3), and group IV (≤50 cells/mm3). In CD4+ T cells, the proportion of CD28 expression decreased significantly with the CD4 level while the proportion of HLA-DR expression increased gradually. In particular, the changes of HLA-DR expressions on CD4+ T cells were parallel to the loss of CD28 molecules from stage III to IV. However, the CD28 expression on CD8+ T cells decreased dramatically in the early stage of HIV infection, and the sum and pattern of CD28 and HLA-DR expressions on CD8+ T cells was stable after the first stage. Even though CD28 down-regulation on CD8+ T cells was very severe from the early stage of HIV infection, it might not influence the survival time of HIV-infected Koreans. The sum of the CD28+ subsets and HLA-DR subsets in each T cell was stable in all stages of disease progression. The sums of the CD28+ subsets and HLA-DR+ subsets in CD4+ T and CD8+ T cells were constant as approximately 100% and 55–60% of each T cell. These results suggested that the changes of CD28/HLA-DR expressions on CD4+ T cells were more predictable than those on CD8+ T cells in the evaluation of the disease progression during HIV-infected periods. However, we need further studies to understand why the sum of two molecules in each T cell are constant.
Complement activation in infective endocarditis: correlation with extracardiac manifestations and prognosis
Authors: MESSIAS-REASON I J , HAYASHI S Y , NISIHARA R M , KIRSCHFINK M
Published: March 2003

In an infectious process complement activation is necessary for a proper immune and inflammatory response, but when exacerbated may cause tissue injuries. In infective endocarditis (IE) patients tend to develop high titres of circulating immune complexes (CIC) that activate complement. The aim of this study was to evaluate for the first time complement activation in IE for possible correlation with extracardiac manifestations and clinical prognosis. Twenty patients with IE, 14 healthy controls and 15 patients presenting mitral and aortic valve lesions (with no signs of either infection or other associated diseases), were studied. Plasma levels of C3adesArg, SC5b-9, C1rs-C1Inh and C3b(Bb)P were determined by ELISA and C3d by double decker immunoelectrophoresis. C3 and C4 levels were assayed by turbidimetry and CIC by ELISA. Elevation of plasma levels of all complement activation products, with the exception of C3b(Bb)P, indicated a significant classical pathway activation in IE patients when compared to controls (C3d: P < 0·00004; C3adesArg: P < 0·03, SC5b-9: P < 0·01, C1rs-C1Inh: P < 0·00007). CIC levels were significantly increased (P < 0·005) and C3 reduced in IE patients (P < 0·05). Elevated C3d (P < 0·02) and C3adesArg (P < 0·03) levels were associated with pulmonary manifestations. In addition, C3d was significantly elevated in the patients who died when compared to those who had a good recovery (P < 0·02). Our data demonstrate the activation of the complement classical pathway, most probably mediated by CIC, in IE and suggests C3d and C3adesArg as possible markers for extracardiac lesion and severity of the disease.
Induction of apoptosis and modulation of activation and effector function in T cells by immunosuppressive drugs
Authors: STRAUSS G , OSEN W , DEBATIN K-M
Published: March 2003

Immunosuppressive drugs (ISD) are used for the prevention and treatment of graft rejection, graft-versus-host-disease (GVHD) and autoimmune disorders. The precise mechanisms by which ISD interfere with T cell activation and effector function or delete antigen-specific T cells are defined only partially. We analysed commonly used ISD such as dexamethasone (DEX), mycophenolic acid (MPA), FK506, cyclosporin A (CsA), rapamycin (RAP), methotrexate (MTX) and cyclophosphamide (CP) for apoptosis-induction and modulation of activation and effector function in human peripheral T cells, cytotoxic T cell lines (CTL) and Jurkat T cells. Of all drugs tested only CP and MTX prevented antigen-specific proliferation of T cells and decreased cytotoxicity of alloantigen specific CTL lines by direct induction of apoptosis. MTX and CP also slightly increased activation-induced cell death (AICD) and CD95-sensitivity. In contrast, all other drugs tested did not induce T cell apoptosis, increase CD95-sensitivity or AICD. CsA and FK506 even prevented AICD by down-modulation of CD95L. DEX, MPA, CsA, FK506 and RAP inhibited activation of naive T cells, but were not able to block proliferation of activated T cells nor decrease cytotoxic capacity of CTL lines. These results show that ISD can be classified according to their action on apoptosis-induction and inhibition of proliferation and would favour a rational combination therapy to delete existing reactive T cells and prevent further T cell activation.
Immunophenotypic characterization of peripheral T lymphocytes inMycobacterium tuberculosisinfection and disease
Authors: RODRIGUES D S S , MEDEIROS E A S , WECKX L Y , BONNEZ W , SALOMÃO R , KALLAS E G
Published: March 2003

The cellular immune response probably plays a pivotal role in determining the clinical outcome after exposure to Mycobacterium tuberculosis. We used multi-parameter flow-cytometry to evaluate the distribution of T-lymphocyte subsets during infection and disease caused by M. tuberculosis. Samples were obtained from 71 volunteers to identify the T CD4+ and CD8+ lymphocyte numbers, and the activation plus memory/naïve phenotypes, as defined by CD38, HLA-DR, CD45RA and CD27 markers. Subjects were divided into 18 healthy volunteers without detectable reaction to purified protein derivative (PPD−), 18 health care workers with a recent conversion to PPD, 20 patients with active pulmonary tuberculosis (TBC) and 15 patients with treated TBC at 6 months of therapy. By multiple-comparison analyses, the T CD4+ lymphocyte number of the TBC group was lower than the PPD– group (P < 0·05). This difference was apparently lost after treatment. The higher and the lower number of naïve T CD4+ cells was observed in the PPD– and TBC group, respectively. CD8+ T lymphocytes were also statistically different among the four groups (P = 0·0002), lower in the TBC group (P < 0·05). CD8+ T lymphocyte activation was evaluated by the CD38 and HLA-DR surface expression. The percentage distribution of these markers was statistically different between the four groups (P = 0·0055). TBC patients had a higher percentage of CD38+ cells and mean fluorescence index, suggesting an overall increase of cell activation. These results suggest that peripheral T lymphocytes reflect cellular activation during TBC, along with possible redistribution of naïve, memory/effector and late differentiated memory/effector phenotypes in the peripheral blood after infection and disease caused by M. tuberculosis.
Defective expression and tyrosine phosphorylation of the T cell receptor zeta chain in peripheral blood T cells from systemic lupus erythematosus patients
Authors: PANG M , SETOYAMA Y , TSUZAKA K , YOSHIMOTO K , AMANO K , ABE T , TAKEUCHI T
Published: March 2003

We have reported that tyrosine phosphorylation and expression of the T cell receptor zeta chain (TCR ζ) was decreased in two systemic lupus erythematosus (SLE) patients with an abnormal TCR ζ lacking exon-7. To examine further the TCR ζ defect and any possible relationship with specific clinical features, we studied the expression of TCR ζ in peripheral blood T cells from 44 patients with SLE, 53 with other rheumatic diseases (30 rheumatoid arthritis (RA), 11 systemic sclerosis (SSc) and 12 primary Sjögren's syndrome(SjS)) and 39 healthy individuals. Flow cytometric analysis demonstrated a significant decrease in the expression of TCR ζ in SLE (P < 0·001), but not in the other rheumatic diseases. Immunoprecipitation experiments confirmed that the expression of TCR ζ in SLE T cells was decreased dramatically (normal: 111·4 ± 22·6%, SLE: 51·6 ± 37·4%, P < 0·0001). The decrease in TCR ζ did not correlate with disease activity, or with the dose of prednisolone (PSL). There were, however, three SLE patients in whom the level of TCR ζ expression normalized after treatment, suggesting that mechanisms responsible for the TCR ζ defect appear to be heterogeneous. These results confirm the defective expression and altered tyrosine phosphorylation of TCR ζ in a large proportion of SLE patients, suggesting that it may play an important role in T cell dysfunction in SLE.
Kinetics of changes in lymphocyte sub-populations in mouse lungs after intrapulmonary infection withM. bovis(Bacillus Calmette-Guerin) and identity of cells responsible for IFNγ responses
Authors: SAXENA R K , WEISSMAN D , SAXENA Q B , SIMPSON J , LEWIS D M
Published: March 2003

Gamma interferon (IFNγ) plays a key role in host defense against pulmonary mycobacterial infections. A variety of lymphocyte subsets may participate in producing pulmonary IFNγ responses, but their relative contributions after mycobacterial infection have not been clearly elucidated. To address this question, C57Bl/6 female mice were infected by intrapulmonary instillation of 2·5 × 104 BCG (Mycobacterium bovis Bacillus Calmette-Guerin). Lymphocyte populations in lung interstitium were examined at different time points after the infection. BCG load in lungs peaked between 4 and 6 weeks post-infection and declined to very low levels by the 12th week of infection. Recovery of lung interstitial lymphocytes doubled by 4–6 weeks after infection and declined thereafter. Flow cytometric analysis of the lung-derived lymphocytes revealed that about 5% of the these cells made IFNγ in control mice, and this baseline IFNγ production involved T (CD3+NK1.1−), NK (CD3−NK1.1+) and NKT (CD3+NK1.1+) cells. As the BCG lung infection peaked, the total number of CD3+ T cells in the lungs increased threefold at 5–6 weeks post-infection. There was a marked increase (sixfold) in the number of T cells secreting IFNγ 5–6 weeks post-infection. Some increase was also noted in the NKT cells making IFNγ, but the numbers of NK cells making IFNγ in BCG-infected lungs remained unaltered. Our results suggest that whereas NK and NKT cells contribute to baseline IFNγ secretion in control lungs, expansion in the IFNγ-producing T-cell population was essentially responsible for the augmented response seen in lungs of BCG-infected mice.
C-ANCA-positive IgG fraction from patients with Wegener's granulomatosis induces lung vasculitis in rats
Authors: WEIDEBACH W , VIANA V S T , LEON E P , BUENO C , LEME A S , ARANTES-COSTA F M , MARTINS M A , SALDIVA P H N , BONFA E
Published: March 2003

The aim of the present study was to analyse in rats the ability of C-ANCA-positive IgG fraction in triggering inflammatory response on pulmonary tissue. Wistar rats (n = 18) were injected via the the internal jugular vein with 20 mg of total C-ANCA-positive IgG fraction isolated from serum of three different Wegener's granulomatosis patients obtained before therapy. Similarly, control rats were treated with IgG fraction from two rheumatoid arthritis patients (n = 7), IgG from six normal human sera (n = 15) or saline (n = 18), respectively. Animals were sacrificed after 24h of injection for histological analysis of the lungs. Vasculitis and inflammatory infiltrate were consistently absent in rats injected with rheumatoid arthritis IgG or saline and in 14/15 of normal IgG treated animals. In contrast, marked vasculitis was observed in all 18 animals injected with C-ANCA-positive IgG fraction. The histological features were characterized by the presence of a perivascular pleomorphic cellular sheath, particularly around small vessels, endothelial adherence and diapedesis of polymorphonuclear leucocytes and presence of granuloma-like lesions. A dose–response relationship was observed between protein concentration of C-ANCA IgG sample and the intensity of the inflammatory response in the animals. In addition, IgG fraction with undetectable C-ANCA, obtained from one patient in remission after treatment, was not able to reproduce the pulmonary tissue alterations induced by its paired IgG that was positive for C-ANCA taken before therapy. The experimental model described herein may be useful to characterize more effectively the pathogenic mechanism of C-ANCA in Wegener's disease.
Metallothionein suppresses collagen-induced arthritis via induction of TGF-βand down-regulation of proinflammatory mediators
Authors: YOUN J , HWANG S-H , RYOO Z-Y , LYNES M A , PAIK D-J , CHUNG H-S , KIM H-Y
Published: March 2003

Metallothionein is a low molecular weight, cysteine-rich, stress response protein that can act as an antioxidant and as an immunosuppressive agent in instances of antigen-dependent adaptive immunity. In this context, we assessed the therapeutic potential and mechanisms of action of metallothionein in a collagen-induced arthritis model. Repeated administration of metallothionein-I + II during the course of disease dramatically reduced the incidence and severity of the disease. Joint tissues isolated from boostered paws of metallothionein-I + II-treated mice expressed significantly reduced levels of proinflammatory mediators, such as tumour necrosis factor (TNF)-α and cyclooxygenase-2, when compared with those of control-treated mice. Lymph node cells obtained from metallothionein-I + II -injected mice exhibited a significant decrease in the proliferative response and a remarkable increase in tumour growth factor (TGF)-β production in response to type II collagen. Taken together, these results suggest that metallothionein-I + II promote the development of type II collagen-specific, TGF-β-producing cells to antagonize the expansion of arthritogenic cells. This could lead to local suppression of inflammatory responses by inhibiting the expression of proinflammatory molecules. Thus, this study demonstrates the suppressive effects of metallothionein on collagen-induced arthritis, and indicates that there may be a potential therapeutic application for manipulation of metallothionein during the treatment of autoimmune disorders.
Immunogenicity ofMycobacterium tuberculosisRD1 region gene products in infected cattle
Authors: MUSTAFA A S , COCKLE P J , SHABAN F , HEWINSON R G , VORDERMEIER H M
Published: March 2003

Current immuno-diagnostic tests for the detection of Mycobacterium bovis infection in cattle rely on the use of tuberculin PPD as antigens. However, the use of a cattle vaccine is effectively prohibited because BCG, the only potentially available cattle TB vaccine, compromises the current tuberculin test. The main objective of this study was to identify specific antigens, which could increase the test sensitivity to levels achieved with tuberculin. Our approach utilized the availability of the genome sequences of Mycobactereium tuberculosis and BCG by applying principles of comparative genomics to the identification of species-specific antigens. Eight open-reading frames (Rv3871 to Rv3878) encoding for putative antigens in the RD1 region of the M. tuberculosis genome, which is deleted in all strains of BCG, were selected and screened in the form of pools of synthetic peptides for immunological reactivity (antigen induced proliferation and IFN-γ secretion) with peripheral blood mononuclear cells from cattle experimentally infected with M. bovis. Our results confirm the immunodominant role of two RD1 region products, CFP-10 (Rv3874) and ESAT-6 (Rv3875). In addition, we were able to identify 3 more antigens (Rv3871, Rv3872 and Rv3873), which induced immunological reactivity in PBMC from more than 50%M. bovis of infected cattle.
Fcγreceptor-mediated phagocytosis ofPlasmodium falciparum-infected erythrocytesin vitro
Authors: TEBO A E , KREMSNER P G , LUTY A J F
Published: March 2003

Although convincing evidence exists for the role of immunoglobulin G (IgG) antibodies in immunity to malaria, antibody titres do not usually predict protection. In this study we have assessed the interaction between Plasmodium falciparum-infected erythrocytes (PE), opsonized with immune serum containing different amounts of IgG antibody isotypes, with either THP-1 cells, ex-vivo human monocytes or IIAI.6 transfectant cells expressing FcγRIIa-Arg/Arg131 or –His/His131 allotypes. Our results show that PMA-treated THP-1 cells were capable of phagocytosing serum-opsonized PE by FcγRI (CD64) and FcγRIIa (CD32), acting synergistically. The known FcγRIIa polymorphism motivated us to examine its influence  on  IgG  isotype-mediated  phagocytosis  of  opsonized  PE  with  human  monocytes  and  the IIAI.6 transfectant cells expressing either allelic forms. Regardless of the cell type, PE phagocytosis with FcγRIIa-His/His131 was highest following opsonization with a predominantly IgG3-containing immune serum pool. In contrast, PE phagocytosis with FcγRIIa-Arg/Arg131 tended to be higher with an IgG1-containing pool. These results suggest a genetically determined influence of effector cell phenotype on IgG antibody–pathogen interaction in P. falciparum malaria.
Risk factors in HIV-1-infected patients developing repetitive bacterial infections: toxicological, clinical, specific antibody class responses, opsonophagocytosis and Fcγ  RIIa polymorphism characteristics
Authors: PAYERAS A , MARTINEZ P , MILà J , RIERA M , PAREJA A , CASAL J , MATAMOROS N
Published: March 2003

The aim of the study was to determine possible factors related to the risk of developing recurrent bacterial respiratory tract infections in HIV-1-infected patients, regardless of the degree of immune cellular impairment. Thirty-three HIV-1 seropositive patients with previous repetitive bacterial respiratory tract infections (case group), 33 HIV-1 seropositive controls (matched by CD4-cell counts) without these antecedents and 27 healthy controls were studied before and after administration of pneumococcal and Haemophilus influenzae type b vaccines. Clinical or toxicological variables, cutaneous tests, complement factors, beta2-microglobulin, serum IgM, IgA, IgG and subclasses, specific antibodies (IgG, IgG2, IgA) against pneumococcal vaccine and polyribosylribitol phosphate (PRP), their avidity, opsonophagocytosis and IgG2m and FcγRIIa allotypes were determined. A history of drug abuse (P = 0·001), less likelihood of receiving high activity antiretroviral treatment high activity antiretroviral treatment (HAART) (P = 0·01), higher levels of HIV-1 viral load (P < 0·05), serum IgG (P < 0·01) and beta2-microglobulin (P < 0·01) were observed in the case group. Also, a lower increase in specific antibodies to pneumococcal vaccine and PRP was demonstrated in the cases in comparison with the two control groups. No differences were observed in the avidity of antibodies, opsonophagocytic capacity or IgG2m and FcγRIIa allotypes between the three groups. These data indicate that vaccination strategies against encapsulated bacteria can be unsuccessful in the HIV-1-infected patients presenting repetitive bacterial respiratory tract infections if behavioural aspects or measures to improve adherence to HAART therapies are not considered.
Gangliosides inhibit the development from monocytes to dendritic cells
Authors: WöLFL M , BATTEN W Y , POSOVSZKY C , BERNHARD H , BERTHOLD F
Published: March 2003

Dendritic cell (DC) development and function is critical in the initiation phase of any antigen-specific immune response against tumours. Impaired function of DC is one explanation as to how tumours escape immunosurveillance. In the presence of various soluble tumour-related factors DC precursors lose their ability to differentiate into mature DC and to activate T cells. Gangliosides are glycosphingolipids shed by tumours of neuroectodermal origin such as melanoma and neuroblastoma. In this investigation we address the question of whether gangliosides suppress the development and function of monocyte-derived DC in vitro. In the presence of gangliosides, the monocytic DC precursors showed increased adherence, cell spreading and a reduced number of dendrites. The expression of MHC class II molecules, co-stimulatory molecules and the GM-CSF receptor (CD116) on the ganglioside-treated DC was significantly reduced. Furthermore, the function of ganglioside-treated DC was impaired as observed in endocytosis, chemotactic and T cell proliferation assays. In contrast to monocytic DC precursors, mature DC were unaffected even when higher doses of gangliosides were added to the culture. With regard to their carbohydrate structure, five different gangliosides (GM2, GM3, GD2, GD3, GT1b), which are typically shed by melanoma and neuroblastoma, were tested for their ability to suppress DC development and function. Suppression was induced by GM2, but not by the other gangliosides. These data suggest that certain gangliosides impair DC precursors, implying a possible mechanism for tumour escape.