bluuebunny/crossref_metadata_2025 huggingface dataset:
Chemokines produced by mesothelial cells: huGRO-α, IP-10, MCP-1 and RANTES
Authors: Visser C E , Tekstra J , Brouwer-Steenbergen J J E , Tuk C W , Boorsma D M , Sampat-Sardjoepersad S C , Meijer S , Krediet R T , Beelen R H J
Published: March 2003

Recently we showed the in vivo relevance of chemokines in cases of bacterial peritonitis in continuous ambulatory peritoneal dialysis (CAPD) patients. Mesothelial cells, the most numerous cells in the peritoneal cavity, are hypothesized to function as a main source of chemokine production. We investigated the time- and dose-dependent expression patterns of four chemokines by mesothelial cells at the mRNA and protein level in response to stimulation with physiological doses of proinflammatory mediators that are present at the site of bacterial inflammation. Besides the chemokines huGRO-α (attractant for neutrophils), MCP-1 and RANTES (monocyte attractants), the expression and production of IP-10 was analysed. Mesothelial cells were cultured and stimulated with either IL-1β, tumour necrosis factor-alpha (TNF-α) or IFN-γ or combinations of these. The time- and dose-dependent mRNA expression of the chemokines was determined by Northern blot analysis and the protein production by ELISA. It was concluded that mesothelial cells could indeed be triggered by the mentioned stimuli to induce mRNA and protein production (huGRO-α and IP-10) or to augment constitutive protein production (MCP-1). However, RANTES mRNA and protein production could only be induced in some cases and only in small amounts. The chemokine response of mesothelial cells was regulated differentially, depending on the stimulus and the chemokine measured. In distinct cases, combination of the stimuli led to synergy in mRNA expression and protein production. The presented in vitro data support our hypothesis that mesothelial cells in vivo are the main source of relevant chemokines in response to proinflammatory mediators, suggesting an important role for mesothelial cells in host defence.
Production of cytotoxic factor by peripheral blood mononuclear cells (PBMC) in patients with dengue haemorrhagic fever
Authors: Agarwal R , Chaturvedi U C , Misra A , Mukerjee R , Kapoor S , Nagar R , Tandon R , Mathur A
Published: March 2003

A unique cytokine, human cytotoxic factor (hCF), has been shown to occur in the sera of patients with dengue fever (DF) and dengue haemorrhagic fever (DHF). The present study was undertaken to investigate the ability of fresh PBMC of such patients to produce hCF. The PBMC were cultured for 24 h and the culture supernatants (CS) were analysed for the presence of hCF by cytotoxicity assay, competitive ELISA and dot blot tests. In 90% of 246 cases CS were positive for hCF by the three tests. CS were positive for hCF in PBMC collected from days 1–20 of illness but not at later periods. Higher cytotoxic activity was observed in CS of days 1–4 of illness and was highest in cases of DHF grade IV and lowest in cases of DF. Dot blot hybridization of RNA extracted from the PBMC of the patients showed the presence of mRNA for hCF in 94% of cases. A similar number of patients showed the presence of hCF in situ in the PBMC smears by fluorescent antibody technique. hCF was found only in CD4+ T cells. The findings thus present direct evidence of the production of hCF by CD4 T cells of cases of DF/DHF.
Iodination of human thyroglobulin (Tg) alters its immunoreactivity. I. Iodination alters multiple epitopes of human Tg
Authors: Saboori A M , Rose N R , Bresler H S , Vladut-Talor M , Burek C L
Published: March 2003

Human Tg, the site of synthesis of thyroid hormones, thyroxine (T4) and triiodothyronine (T3), is one of the major autoantigens in autoimmune thyroiditis. The degree of iodination of Tg may have a major impact on its immunological properties by changing its antigenicity with respect to antibody binding. We have previously prepared a panel of MoAbs that bind to different epitopes of the Tg molecule. In the present study, we show that iodination alters the conformation of Tg molecule in such a way that it is recognized differently by different MoAbs. Monoclonal antibody 137C1 recognizes Tg regardless of its iodine content. Monoclonal antibody 42C3 recognizes Tg only if the Tg is iodinated either in vitro or in vivo. Monoclonal antibody 133B1 recognizes both in vivo iodinated Tg and non-iodinated Tg, but this MoAb did not recognize Tg following in vitro iodination. Monoclonal antibody 41A5 recognizes intact Tg and tryptic peptides of normal (in vivo) iodinated and non-iodinated Tg, but did not bind the tryptic peptides of artificially (in vitro) iodinated Tg. From the results of these experiments, we conclude that iodination of Tg by either in vivo or in vitro methods changes its conformation in such a way that some natural epitopes are ‘lost’ and some ‘new’ epitopes are generated. The generation of new epitopes may be important in the generation of autoimmune responses leading to autoimmune disease.
Expression of lymphotactin mRNA in experimental crescentic glomerulonephritis
Authors: Natori Y U , Ou Z L , Yamamoto-Shuda Y , Natori Y
Published: March 2003

Lymphotactin (LTN) is the sole member of C chemokine, the third subfamily of chemokines. LTN has been shown to be a chemoattractant specific for CD8+ cells and/or natural killer (NK) cells, and to be produced by CD8+ T cells, NK cells, and mast cells. However, there have been no reports describing its expression in clinical or experimental models of diseases so far. Since glomerular infiltration of CD8+ cells is prominent in an animal model of crescentic glomerulonephritis induced in WKY rats by an injection of anti-glomerular basement membrane antibody, we investigated the gene expression of LTN in this model. LTN mRNA was not detected in normal glomeruli but was detected at 0.5 h after the antibody injection, which detection preceded the infiltration of CD8+ cells. The expression of LTN mRNA peaked on day 3 and decreased thereafter. We next studied the expression of LTN mRNA in cultured glomerular and vascular cells, and found that glomerular mesangial and vascular endothelial cells could express LTN mRNA when stimulated with IL-1β. These results indicate that the gene expression of LTN is enhanced in the animal model of glomerulonephritis and that intrinsic renal cells are the potential source of the gene expression of LTN in the kidney.
Pattern of expression of tetraspanin antigen genes in Burkitt lymphoma cell lines
Authors: Ferrer M , Yunta M , Lazo P A
Published: March 2003

Tetraspanin antigens are implicated in the prognosis of different types of tumours. In this study we determine by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) the level of 13 tetraspan messages in 21 Burkitt lymphoma (BL) cell lines. All tumour cell lines have a common pattern of tetraspanin gene expression. There are five antigens which are detected in 90% of cell lines at high levels, CD53, CD81, CD63, SAS and CD82. Another two, CD9 and CD37, were detected in 60% of cell lines, and have a very variable level of expression. The remaining antigens, A15, CoO29, KRAG, L6, TI-1 and il-TMP, are expressed at low levels in very few cell lines without any specific pattern. The level of gene expression corresponds with the level of cell surface antigen determined by flow cytometry. The average number of tetraspan proteins expressed per cell line is six. These proteins may form subunits of an oligomeric structure with 24 transmembrane domains. There are no major differences in tetraspan expression pattern among sporadic or endemic tumours, type of translocation or Epstein–Barr virus status, suggesting the original cell of these tumours is the same, probably a late pre-B cell, at the CD9 to CD37 transition point. Tetraspanin gene expression is consistent with BL being a single entity, despite variations in other parameters.
Expression of the activation antigen CD69 predicts functionality ofin vitroexpanded peripheral blood mononuclear cells (PBMC) from healthy donors and HIV-infected patients
Authors: Nielsen S D , Afzelius P , Ersbøll A K , Nielsen J O , Hansen J-E S
Published: March 2003

Gene therapy for AIDS necessitates harvest and expansion of PBMC from HIV-infected patients. We expanded PBMC from healthy blood donors and HIV-infected patients for up to 14 days using four expansion protocols: 3 days of phytohaemagglutinin (PHA) stimulation, continuous PHA stimulation, 3 days of stimulation with anti-CD3 and anti-CD28, and continuous stimulation with anti-CD3 and anti-CD28. Functionality of PBMC was evaluated prior to and after expansion using standard proliferation assay. Phenotype and lymphocyte subset activation defined by expression of CD69 and CD25 were determined using flow cytometry. PBMC from healthy donors and HIV-infected patients were readily expanded. The best expansion was obtained using stimulation for 3 days. After expansion, functionality of PBMC measured as proliferative response was partly conserved. PBMC expanded with stimulation for 3 days exhibited more preserved functionality than PBMC stimulated continuously (P < 0·03). The mean proliferative response in each of the four different expansion protocols correlated with the mean values of CD69 expression. The proliferative responses from patients and healthy donors expanded with PHA stimulation for 3 days correlated with CD69 expression on CD4 cells (r = 0·68, P < 0·01) and on CD8 cells (r = 0·59, P < 0·03). Furthermore, expression of CD69 reliably predicted which patients and donors had highly conserved functionality after in vitro expansion. Finally, PBMC expanded with PHA stimulation for 3 days were examined for apoptosis. Only a minor fraction was primed for apoptosis, and this fraction could be significantly reduced by addition of IL-2 to the culture medium (P < 0·05). In conclusion, the feasibility of expanding PBMC from HIV patients was demonstrated. Expanded PBMC had conserved functionality. Finally, after in vitro expansion, expression of the activation antigen CD69 reliably predicted functionality of PBMC.
Kinetics of eotaxin expression and its relationship to eosinophil accumulation and activation in bronchial biopsies and bronchoalveolar lavage (BAL) of asthmatic patients after allergen inhalation
Authors: Brown J R , Kleimberg J , Marini M , Sun G , Bellini A , Mattoli S
Published: March 2003

We investigated the kinetics of allergen-induced eotaxin expression and its relationship to eosinophil accumulation and activation in the airways of patients with allergic asthma. Twenty-four patients with allergic asthma and late asthmatic responses to allergen inhalation were randomly allocated into three groups of eight patients each, who received bronchoscopy with bronchial biopsies and BAL at 2, 4 and 24 h, respectively, after the inhalation of the diluent and the allergen. The expression of eotaxin mRNA and protein and eotaxin release were evaluated by in situ hybridization, immunohistochemistry, immunocytochemistry, and radioimmunoassay. Increased transcription from the eotaxin gene preceded the appearance of the late asthmatic response and the influx of activated eosinophils in bronchial tissue and BAL fluid (BALF). This was followed by increased cell expression of eotaxin protein (P < 0.001) and increased eotaxin release (P < 0.001), which correlated with the numbers of total and activated eosinophils and the level of airflow obstruction at 4 h after allergen exposure (P < 0.05 for all correlations). At 24 h after allergen inhalation, enhanced eotaxin expression declined without a similar reduction in the numbers of eosinophils in bronchial biopsies and when there was a further increase in the number of these cells in BALF (P < 0.05). These results indicate that eotaxin contributes to the early phase of allergen-induced recruitment of activated eosinophils into the airways of patients with allergic asthma and that other factors are implicated in the persistence of eosinophil infiltration.
Induction of cytokines and anti-cytokine autoantibodies in cerebrospinal fluid (CSF) during experimental bacterial meningitis
Authors: Bakhiet M , Mustafa M , Zhu J , Harris R , Lindquist L , Link H , Diab A
Published: March 2003

We have recently described the induction of anti-cytokine autoantibodies (Aabs) in the serum as a novel mechanism for cytokine regulation during bacterial infections. Here we use the infant rat-model of Haemophilus influenzae type b (Hib) meningitis to examine the induction of five potentially important cytokines and their autoantibody responses in the CSF. Protein levels of the cytokines interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), transforming growth factor-beta (TGF-β), IL-4 and IL-10 were detected at day 3 post-inoculation (p.i.) with maximum induction at day 8. Thereafter, these levels of cytokines had become undetectable. Increased Aab titres to these cytokines, except IL-4, were registered with peak levels between days 7 and 9. Upon re-inoculation with Hib at day 30, regeneration of Aabs was recorded 7 days later (i.e. at day 37). To control the specificity of these Aabs, preincubation of the CSF with a cytokine inhibited the binding effects of that particular cytokine, but not those of any other cytokine. Aabs dose-dependently inhibited IFN-γ-induced MHC expression by peritoneal macrophages and TNF-α-mediated L929 cytotoxicity. Our data demonstrate for the first time the existence of the anti-cytokine antibodies in the CSF of the meningitis Hib model. Furthermore, the data present a role for the Aabs in cytokine regulation, which is consistent with the previously demonstrated effects of the Aabs in the serum.
Abdominal surgery reduces the ability of rat spleen cells to synthesize and secrete active tumour necrosis factor-alpha (TNF-α) by a multilevel regulation
Authors: LAHAT N , RAHAT M A , BROD V , COHEN S , WEBER G , KINARTY A , BITTERMAN H
Published: March 2003

We have previously shown that abdominal surgery (explorative laparotomy) reduces the ability of lipopolysaccharide (LPS)-triggered spleen macrophages to secrete TNF-α. In this study we characterize possible mechanisms which could be responsible for the reduction in splenic production of TNF-α. Post-operative and control (unoperated) rat splenocytes or enriched splenic macrophages were cultured with LPS. Steady-state levels of TNF-α mRNA were determined by Northern and slot blot analyses, and validated by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). The amount of TNF-α protein was measured by Western blot analysis, and its biological activity was determined by the fibroblast L-929 cytotoxicity assay. Surgery induced a 12-fold inhibition in TNF-α activity (P < 0.02), caused up to two-fold reduction in the accumulation of TNF-α mRNA (P < 0.01), and suppressed TNF-α protein maturation into its 17-kD form in cellular extracts. Post-surgical spleen supernatants revealed mainly a band of a lower molecular weight (14 kD). Our data suggest a multilevel regulation of post-operative inhibition of TNF-α response to LPS, at the accumulation of mRNA, translational and secretory levels. We also suggest that the reduced bioactivity could be partially caused by a proteolytic cleavage of TNF-α. Since TNF-α is an important participant in immune responses, its reduced production and activity may be a central mechanism of post-operative immunosuppression.
Anti-cardiolipin antibodies and circulating immune complexes in type 1 diabetes mellitus: increased prevalence and relation to vascular complications
Authors: AHMED E , NITYANAND S , MUSTAFA A , BRISMAR K , LEFVERT A K
Published: March 2003

Anti-cardiolipin antibodies, oxidatively modified low-density lipoproteins (oxLDL) and circulating immune complexes are humoral factors that have been linked to vascular damage. To analyse their possible role in the vascular complications in type 1 diabetes mellitus, we investigated patients with and without vascular complications (retinopathy, nephropathy, polyneuropathy, foot ulcers). The patients were matched for age, sex and duration of diabetes. The patients were also compared with 102 healthy individuals. Anti-cardiolipin antibodies of IgG and IgA type were more common in patients compared with healthy individuals. There was no difference between patients with and without vascular complications. There was no increased prevalence of IgM anti-cardiolipin antibodies, but the levels of these antibodies were higher in patients with vascular complications compared with patients without complications and controls. Eighty-three percent of patients had circulating immune complexes in comparison with 5% of healthy individuals. Such complexes were more common in patients with complications. Both the prevalence and the levels of immune complexes were higher in patients with null alleles of complement factor C4. Patients with vascular complications had higher prevalence of C4A than of C4B null alleles. Anti-cardiolipin antibodies were present in higher relative concentrations in immune complex form than in serum in all six patients analysed. There was no increased prevalence of antibodies against oxidatively modified LDL in the patients. The higher prevalence and levels of anti-cardiolipin antibodies and circulating immune complexes in patients with vascular complications suggests that these humoral factors might be involved in the vascular complications of type 1 diabetes mellitus.
Reactivation of tuberculosis is associated with a shift from type 1 to type 2 cytokines
Authors: HOWARD A D , ZWILLING B S
Published: March 2003

The pattern of cytokines produced by T cells from mice with latent tuberculosis and during reactivation of tuberculosis was determined. A type 1 cytokine pattern was observed in T cells isolated from the lung of mice with latent disease. Reactivation of mycobacterial growth, by activation of the hypothalamic–pituitary–adrenal (HPA) axis, resulted in a shift from a type 1 to a type 2 cytokine pattern in both CD4 and CD8 T cells. Classification of the T cells based on their differential expression of CD45 and CD44 showed that the phenotypically different populations of CD4 and CD8 cells exhibited a type 1 cytokine pattern at latency and that reactivation of latent tuberculosis was associated with a shift in cytokines produced by these populations to a type 2 cytokine response. Control of mycobacterial growth resulted in a return to the type 1 cytokine pattern found during latent disease.
Macrophage inflammatory protein-1α (MIP-1α) expression plasmid enhances DNA vaccine-induced immune response against HIV-1
Authors: LU Y , XIN K-Q , HAMAJIMA K , TSUJI T , AOKI I , YANG J , SASAKI S , FUKUSHIMA J , YOSHIMURA T , TODA S , OKADA E , OKUDA K
Published: March 2003

CD8+ cell-secreted CC-chemokines, MIP-1α, and MIP-β have recently been identified as factors which suppress HIV. In this study we co-inoculated MIP-1α expression plasmid with a DNA vaccine constructed from HIV-1 pCMV160IIIB and pcREV, and evaluated the effect of the adjuvant on HIV-specific immune responses following intramuscular and intranasal immunization. The levels of both cytotoxic T lymphocyte (CTL) activity and DTH showed that HIV-specific cell-mediated immunity (CMI) was significantly enhanced by co-inoculation of the MIP-1α expression plasmid with the DNA vaccine compared with inoculation of the DNA vaccine alone. The HIV-specific serum IgG1/IgG2a ratio was significantly lowered when the plasmid was co-inoculated in both intramuscular and intranasal routes, suggesting a strong elicitation of the T helper (Th) 1-type response. When the MIP-1α expression plasmid was inoculated intramuscularly with the DNA vaccine, an infiltration of mononuclear cells was observed at the injection site. After intranasal administration, the level of mucosal secretory IgA antibody was markedly enhanced. These findings demonstrate that MIP-1α expression plasmid inoculated together with DNA vaccine acts as a strong adjuvant for eliciting Th1-derived immunity.
Detection of allergen-induced basophil activation by expression of CD63 antigen using a tricolour flow cytometric method
Authors: MONNERET G , GUTOWSKI M C , BIENVENU J
Published: March 2003

In the field of allergy diagnosis, most in vitro functional tests are focused on basophils. Nevertheless, the very small number of circulating basophils limits these experiments and their clinical benefit remains controversial. As flow cytometry is a valuable tool for identifying cell populations, even at low concentrations, we developed a tricolour flow cytometric method for the study of allergen-induced basophil activation. Identification of cells was based both on CD45 expression and on the presence of IgE on the cell surface, since basophils express high-affinity receptors for IgE (FcεRI). Cell activation upon allergen challenge was assessed by the expression of CD63 antigen on the plasma membrane. Basophil isolation and activation (with the chemotactic peptide formyl-methionyl-leucyl-phenylalanine) were validated in 32 non-allergic patients. In 12 allergic patients, basophil stimulation by a relevant allergen was in most cases positive (10/12). Furthermore a concentration-dependent hook effect was observed. Of the allergic and non-allergic patients, none showed non-specific activation with an irrelevant allergen (specificity 100%). Overall, our preliminary results, even in a small population, suggest that this is a reliable and valuable method for the diagnosis of allergies complementing specific allergen IgE and skin test results. Obviously, additional clinical studies are needed to validate these first results.
Up-regulation of intercellular adhesion molecule-1 (ICAM-1), endothelial leucocyte adhesion molecule-1 (ELAM-1) and class II MHC molecules on pulmonary artery endothelial cells by antibodies against U1-ribonucleoprotein
Authors: OKAWA-TAKATSUJI M , AOTSUKA S , FUJINAMI M , UWATOKO S , KINOSHITA M , SUMIYA M
Published: March 2003

In order to elucidate the pathogenic role(s) of autoantibodies in connective tissue disease (CTD), we examined whether autoantibodies against U1-ribonucleoprotein (RNP) and double-stranded (ds) DNA can up-regulate ICAM-1, ELAM-1 and class I and II MHC molecule expression on pulmonary artery endothelial cells (HPAEC). ICAM-1, ELAM-1 and class II MHC molecule expression on HPAEC cultured in the presence of anti-U1-RNP-containing and anti-dsDNA-containing IgG from CTD patients was up-regulated significantly in comparison with that on HPAEC cultured with IgG from normal healthy volunteers. Affinity chromatographic enrichment and depletion of the anti-U1-RNP antibody content of anti-U1-RNP-containing IgG confirmed that the anti-U1-RNP antibody did up-regulate ICAM-1, ELAM-1 and class II MHC molecule expression. The finding that an IgG F(ab′)2-purified anti-U1-RNP antibody also up-regulated expression of these molecules may indicate that mechanisms other than Fc receptor-mediated stimulation are involved. These in vitro findings suggest that autoantibodies against U1-RNP and dsDNA play important roles in the immunopathological processes leading to the proliferative pulmonary arterial vasculopathy observed in CTD patients with pulmonary hypertension by up-regulating adhesion and class II MHC molecule expression on endothelial cells.
Treatment of idiopathic CD4 T lymphocytopenia with IL-2
Authors: CUNNINGHAM-RUNDLES C , MURRAY H W , SMITH J P
Published: March 2003

Idiopathic CD4 T lymphocytopenia (ICL) is an unusual immune defect in which there is an unexplained deficit of CD4 T cells, leading to fungal, parasitic or other serious opportunistic infections. Current treatment efforts are directed at eliminating infections. Here we describe the use of a novel treatment, subcutaneous polyethylene glycol (PEG)–IL-2 injections, in a woman with this disorder, who had chronic severe mycobacterial disease which led to repeated hospitalizations, and advancing respiratory insufficiency. For this patient, PEG–IL-2, 50 000 U/m2, has been given by weekly subcutaneous injections for 5.5 years. This treatment has resulted in marked (and still continuing) long-term immunological improvement with normalized T cell functions and increased CD4 cell numbers. She has had substantial clinical improvement with clearing of mycobacterial disease, reducing hospitalizations and improved lung functions. The improvement seen in this patient suggests that low-dose IL-2 is a safe and practical therapy, which might be useful in other subjects with this potentially serious immune defect.
Complement activation and expression of membrane regulators in the middle ear mucosa in otitis media with effusion
Authors: NÄRKIÖ-MÄKELÄ M , JERO J , MERI S
Published: March 2003

The aetiopathogenesis of chronic otitis media with effusion (OME) in children is not yet fully understood. OME is characterized by metaplasia of the epithelium and accumulation of sticky, glue-like effusion in the middle ear containing different mediators of inflammation, including activation fragments of the complement system. Here we examined whether the fluid phase complement activation is reflected in the middle ear mucosa and how the mucosa is protected against the cytolytic activity of complement. Mucosal biopsies from 18 middle ears of children with a history of chronic OME were taken. The biopsies were analysed by immunofluorescence microscopy after staining for complement fragments iC3b/C3c, C3d and C9, and regulators membrane cofactor protein (MCP; CD46), decay-accelerating factor (DAF; CD55) and protectin (CD59). There was a strong staining for iC3b/C3c, and a weaker one for C3d and C9 on the surface of the middle ear epithelial cells of OME patients but not in controls without OME. MCP was expressed on the hyperplastic three to four outer cell layers of the epithelium, while CD59 was expressed throughout the middle ear mucosa. The results suggest a strong ongoing complement activation and consequent inflammation in the middle ear cavity. Unrestricted complement damage of the epithelial lining is prevented by the strong expression of MCP and CD59.
HLA class II homozygosity confers susceptibility to common variable immunodeficiency (CVID)
Authors: DE LA CONCHA E G , FERNANDEZ-ARQUERO M , MARTINEZ A , VIDAL F , VIGIL P , CONEJERO L , GARCIA-RODRIGUEZ M C , FONTAN G
Published: March 2003

Most cases of CVID occur sporadically, but familial cases do also occur and 15% of the patients with the disease have first degree relatives with IgA deficiency (IgAD). Our purpose was to study CVID association with HLA class II alleles and to ascertain whether this disease shares a common genetic background with IgAD in our population. Patients with CVID (n = 42), were typed using gene amplification and sequence-specific oligonucleotide probing for HLA-DRB1, DRB3, DQA1 and DQB1 loci and their typing compared with that of 96 IgAD and 334 healthy controls. We observed a positive association between non-Asp residues at position 57 of the HLA-DQβ chain and CVID, although much weaker than in IgAD. Further, we found an association between CVID and homozygosity for genes encoding HLA class II molecules, especially HLA-DQ, not seen in IgAD. The data support the hypothesis that a restricted diversity of HLA class II molecules may contribute to susceptibility to CVID.
Immunological changes in peripheral blood and in lymphoid tissue after treatment of HIV-infected subjects with highly active anti-retroviral therapy (HAART) or HAART + IL-2
Authors: ZANUSSI S , SIMONELLI C , BORTOLIN M T , D'ANDREA M , CREPALDI C , VACCHER E , NASTI G , POLITI D , BARZAN L , TIRELLI U , DE PAOLI P
Published: March 2003

This study presents the immunophenotypic and functional analysis of lymphocyte subsets obtained from peripheral blood and lymphoid tissue from HIV+ individuals treated with highly active anti-retroviral therapy (HAART) alone or in combination with 6 million units international (MUI) s.c. IL-2. Before treatment, the HIV+ patients had reduced CD4 and increased CD8 values in the peripheral blood and lymphoid tissue and impaired cytokine production by peripheral blood mononuclear cells (PBMC). After 24 weeks of treatment, all the HIV+ patients demonstrated increased CD4 values in peripheral blood and lymphoid tissue. The use of IL-2 did not promote an additional CD4 expansion compared with HAART alone; increased ‘naive’ and CD26+ CD4 cells and reduced CD8 cells were found in the peripheral blood and lymphoid tissue of the IL-2-treated, but not of the HAART-treated patients. Both types of treatment induced a significant reduction of the CD8/CD38+ cells. While HAART alone had negligible effects on cytokine production by PBMC, the combined use of HAART + IL-2 was unable to increase the endogenous production of IL-2, but caused an increase of IL-4, IL-13 and interferon-gamma (IFN-γ) and a reduction of monocyte chemoattractant protein-1 (MCP-1) production. These data suggest that, although in this schedule IL-2 has minimal efficacy on CD4 recovery when compared with HAART alone, it produces an increase of ‘naive’ and CD26+ CD4 cells and a partial restoration of cytokine production. These data may be used to better define clinical trials aiming to improve the IL-2-dependent immunological reconstitution of HIV-infected subjects.
Molecular analysis of resolving immune responses in uveitis
Authors: Murray P I , Clay C D , Mappin C , Salmon M
Published: March 2003

To identify the cellular immune processes underlying intra-ocular inflammation, aqueous humour was obtained at cataract surgery from 22 patients with clinically inactive uveitis and 24 patients with age-related cataract. mRNA expression for the cytokines IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, interferon-gamma (IFN-γ), transforming growth factor-beta (TGF-β); T cell subsets CD3, CD4, CD8; monocytes and macrophages (CD14); and B cells (CD19) was measured using reverse transcriptase-polymerase chain reaction (RT-PCR) and radiometric analysis. The majority of uveitis patients demonstrated a T cell-mediated inflammatory response, predominately involving a Th1-like cytokine profile with expression of IL-2 and IFN-γ in 16/22 and 18/22 samples, respectively. These cytokines were present in only a small number of patients with age-related cataract. This Th1-like polarization was supported by an increased expression of CD8 in a number of patients. IL-1β was expressed in only six uveitic eyes. Only four patients expressed either IL-4 or IL-10 and no patient expressed both. TGF-β mRNA could be detected in 18/22 uveitis patients and 15/24 controls. IL-12, the paradigmatic Th1-inducing cytokine, was absent in all samples but CD14 was expressed in the majority of patients and controls. CD19 could not be detected in any sample. The cellular infiltrate in the uveitic eyes showed clear evidence of low IL-1 and absent IL-12 expression despite a Th1-like profile and high expression of macrophages. This strongly suggests that the systemic immunosuppressive therapy used prior to surgery in some patients and/or the chronicity of the uveitis had actively suppressed/switched off macrophage function, leading to resolution of T cell activity.
Limitations of the semisynthetic library approach for obtaining human monoclonal autoantibodies to the thyrotropin receptor of Graves’ disease
Authors: Van Der Heijden J H W , De Bruin T W A , Glaudemans K A F M , De Kruif J , Banga J P , Logtenberg T
Published: March 2003

Graves’ disease (GD) is characterized by the presence of autoantibodies against the TSH-receptor (TSH-R) which are pathogenic and, upon binding to the receptor, trigger intracellular signal transduction. The autoantibodies are oligoclonal and as they are responsible for disease activity, their characterization would lead to a better understanding of the development of GD. Attempts to isolate anti-TSH-R antibodies from patients have proved to be difficult due to the exceedingly low serum levels due to rarity of these B cells, together with difficulties in obtaining purified TSH-R capable of interacting with patients autoantibodies. We employed phage antibody display technology and performed selection with a previously characterized semisynthetic antibody library on the purified extracellular ectodomain of the TSH-R. We report the isolation of six different anti-TSH-R monoclonal phage antibodies (moPhabs) from this library. All the moPhabs recognized TSH-R and its recombinant fragments by Western blotting, but failed to recognize the native TSH-R by flow cytometry. Consequently, the moPhabs did not lead to TSH-R activation. As these were the first moPhabs to TSH-R, they were analysed in terms of nucleotide and amino acid sequence and epitope specificity on the receptor. The moPhabs used immunoglobulin VH1 and VH3 germ line genes, all associated with Vλ3 genes. Interestingly, the CDR3 regions of all moPhabs were remarkably similar, though not identical. In light of the common CDR3 usage, the epitopes recognized on TSH-R appeared to be restricted to amino acids residues 405–411 and 357–364. In summary, our results show that semisynthetic libraries may be limited in isolating human monoclonal antibodies that resemble pathogenic antithyrotropin receptor autoantibodies present in patients with GD. It is likely that until preparations of purified TSH-R that can be recognized by patients autoantibodies become available, similar to the recently described glycosylphosphatidylinositol (GPI) anchored TSH-R ectodomain, monoclonal antibodies from phage antibody display to TSH-R will be limited for isolating the rare, pathogenic antibodies of GD.
Naive human T cells can be a source of IL-4 during primary immune responses
Authors: Bullens D M A , Rafiq K , Kasran A , Van Gool S W , Ceuppens J L
Published: March 2003

IL-4 plays a key role in driving the differentiation of CD4+ Th precursors into Th2 cells, both in mice and in humans. The source of IL-4 during primary immune responses is, however, still debated. When IL-4 consumption in in vitro T cell cultures was blocked with a MoAb to the IL-4 receptor α-chain (IL-4Rα), it became evident that freshly isolated naive (CD45RO−) CD4+ T cells from adults or cord blood produce IL-4 upon activation with anti-CD3 and CD80. IL-4 production by naive T cells is strictly IL-2-dependent. Endogenous IL-4 activity in naive CD4+ T cell cultures modulates the production of interferon-gamma (IFN-γ) on the one hand and IL-5 and IL-13 on the other hand in opposite directions, and it is partly responsible for the low IFN-γ production by cord blood T cells. Comparison of the ratio of IL-4/IFN-γ in supernatants of T cell cultures reveals a skewing towards IL-4 production by cord blood T cells, while naive T cells from (non-atopic) adults predominantly produce IFN-γ. We conclude that CD4+ naive T cells can produce IL-4 without the need for Th2 differentiation, and therefore that they can be the initial source of IL-4 required at the time of priming for T cell differentiation into Th2 cells.
Placenta growth factor (PlGF) induces vascular endothelial growth factor (VEGF) secretion from mononuclear cells and is co-expressed with VEGF in synovial fluid
Authors: Bottomley M J , Webb N J A , Watson C J , Holt L , Bukhari M , Denton J , Freemont A J , Brenchley P E C
Published: March 2003

The aims of this study were (i) to determine whether PlGF, VEGF and PlGF/VEGF heterodimers are detected in synovial fluid (SF) and plasma samples from patients with a range of arthropathies; (ii) to describe whether any correlation exists between SF PlGF, VEGF and PlGF/VEGF heterodimer levels and the total and differential SF leucocyte counts; and (iii) to investigate the regulation of peripheral blood mononuclear cell (PBMC) VEGF secretion by stimuli relevant to inflammatory joints. PlGF, VEGF and PlGF/VEGF heterodimer levels were measured in the SF and plasma of patients with a range of arthropathies and normal controls by ELISA. Western blotting for PlGF was performed on SF from three patients with rheumatoid arthritis (RA) and primary inflammatory arthropathies. VEGF was quantified in cell culture supernatants after stimulation with lipopolysaccharide (LPS), PlGF or cobalt ions of PBMC isolated from RA patients and controls. PlGF and VEGF were detected in all SF samples. PlGF/VEGF heterodimers were detected in 10.2% of SF samples, most frequently in RA samples. Western blotting confirmed the presence of PlGF in RA SF. PlGF was detected in 52% of RA and 31% of control plasma samples, and VEGF was detected in 38% of RA and 38% of control plasma samples. PlGF/VEGF heterodimers were detected in 21% of RA samples and none of the control samples. In primary inflammatory arthropathy patients, SF PlGF and VEGF levels correlated significantly with the SF total leucocyte count and the neutrophil count. PlGF was the most potent inducer of PBMC VEGF production in both RA and control subjects. This is the first report of the detection of PlGF and PlGF/VEGF heterodimers in the SF of patients with inflammatory arthropathies, and we have shown for the first time that PlGF up-regulates PBMC VEGF production. PlGF may therefore play a key role in the production of VEGF in the inflammatory joint.
Tumour necrosis factor (TNF) gene polymorphism in Crohn’s disease (CD): influence on disease behaviour?
Authors: Louis E , Peeters M , Franchimont D , Seidel L , Fontaine F , Demolin G , Croes F , Dupont P , Davin L , Omri S , Rutgeerts P , Belaiche J
Published: March 2003

Crohn’s disease (CD) is a multifactorial disease with genetic heterogeneity. TNF-α plays a key role in the development of the mucosal lesions. The aim of our work was to study a single base pair polymorphism located in the promoter region of TNF gene, in a large population of CD patients with well defined phenotypes. One hundred and ninety-three patients with CD and 98 ethnically matched controls were studied. The −308 single base pair polymorphism of TNF gene was studied using an allele-specific polymerase chain reaction. Genotype and allelic frequencies were compared between patients and controls and between subgroups of patients defined by sex, age at diagnosis, familial history, location of disease, type of disease, extra-intestinal manifestations, and response to steroid treatment. In 29 patients a measure of TNF-α production by colonic biopsies was performed. The frequency of the allele TNF2 as well as the proportion of carriers of the allele TNF2 were slightly but not significantly lower in CD than in controls (11.9% versus 14.8% and 21.5% versus 27.6%, respectively). A more prominent difference in frequencies of allele TNF2 and in proportions of TNF2 carriers was found when comparing subgroups of patients. The frequency of allele TNF2 was significantly higher in steroid-dependent than in non-steroid-dependent disease (28.1% versus 10.3%; Δ = 17.8%, 95% confidence interval (CI) = 6.3–29.5%, P = 0.0027) and tended to be higher in colonic than in small bowel disease and in fistulizing than in stricturing disease. Furthermore, TNF2 carriers tended to be more frequent in patients with steroid-dependent than non-steroid-dependent disease (43.8% versus 19.3%; Δ = 24.5%, 95% CI = 3.6–45.4%, P = 0.022), in patients with fistulizing than stricturing disease (26.5% versus 9.6%; Δ = 16.9%, 95% CI = 1.1–32.6%, P = 0.036), and in patients with colonic than small bowel disease (26.5% versus 11.1%; Δ = 15.4%, 95% CI = −0.8–31.6%, P = 0.063). Finally, patients carrying at least one copy of allele 2 were found to produce slightly more TNF-α at the colonic level. The −308 TNF gene polymorphism may have a slight influence on the behaviour of CD. The carriage of allele 2 may favour steroid-dependent disease and to a lesser extent fistulizing and colonic disease, possibly secondary to a more intense TNF-α-driven inflammatory reaction at the mucosal level.
Proliferative responses of blood mononuclear cells (BMNC) in a cohort of elderly humans: role of lymphocyte phenotype and cytokine production
Authors: Bruunsgaard H , Pedersen A N , Schroll M , Skinhøj P , Pedersen B K
Published: March 2003

Age-related impaired T cell function is associated with increased mortality risk. The purpose of the present study was therefore to identify factors associated with the age-related decreased phytohaemagglutinin (PHA)-induced proliferative response of lymphocytes in a cohort of 174 81-year-old humans and in 91 young controls. Decreased proliferation was associated with a reduced number of true naive CD4+ cells (CD62L+CD45RO−). Furthermore, a low IL-2-stimulated proliferation was correlated with a decreased PHA response in the elderly cohort, whereas reciprocal interactions of IL-10- and IL-2-producing cells were of importance in both elderly and young subjects. Accordingly, a minimum of true naive CD4+ cells was required for a normal proliferative response to PHA, perhaps by providing sufficient IL-2 which is critical for growth of naive as well as memory cells.
Autoantibodies to DEK oncoprotein in systemic lupus erythematosus (SLE)
Authors: Wichmann I , Respaldiza N , Garcia-Lozano J R , Montes M , Sanchez-Roman J , Nuñez-Roldan A
Published: March 2003

Autoantibodies against the transcriptional DEK protein have been considered characteristic of the pauciarticular onset subtype of juvenile rheumatoid arthritis (JRA) associated with iridocyclitis in young girls. In this study we investigated the presence of anti-DEK autoantibodies in the sera of 288 patients with SLE using a recombinant DEK protein as autoantigenic target. Thirty sera (10·4%) were positive against DEK protein by immunoblotting. Patients with anti-DEK autoantibodies show a lower frequency of cutaneous manifestation, exhibit more frequently certain markers of a chronic inflammatory status like anaemia and positivity for C-reactive protein, as well as a higher frequency of anti-double-stranded DNA autoantibodies. In contrast to JRA patients positive for anti-DEK autoantibodies, no association with erosive arthritis nor iridocyclitis were found in SLE. In conclusion, our results show that 10·4% of SLE patients from our area show antibodies against DEK protein, although this feature did not clearly establish a clinical subset of the disease.
Cross-reactive epitopes and HLA-restriction elements in human T cell recognition of theMycobacterium leprae18-kD heat shock protein
Authors: Mustafa A S , Lundin K E A , Meloen R H , Oftung F
Published: March 2003

We have previously demonstrated that the Mycobacterium leprae 18-kD heat shock protein (HSP18) is represented among the antigenic targets of human T cell responses induced by M. leprae immunization and that the peptide 38–50 serves as an immunodominant epitope recognized by CD4+ T cell clones. By using peripheral blood mononuclear cells and T cell lines from the same donor group, we have in this study shown that the M. leprae HSP18 and peptide 38–50 were recognized by memory T cells 8 years after immunization with M. leprae. The finding that M. bovis BCG-induced T cell lines responded to M. leprae HSP18, but not to the peptide 38–50, suggested the existence of additional T cell epitopes of a cross-reactive nature. Consistent with this, testing of the T cell lines for proliferative responses to the complete HSP18 molecule, truncated HSP18 (amino acid (aa) residues 38–148) and overlapping synthetic peptides, made it possible to identify two cross-reactive epitope regions defined by aa residues 1–38 and 41–55. While peptide 38–50-reactive T cell clones showed limited cross-reactivity by responding to M. leprae, M. avium and M. scrofulaceum, the T cell lines specific to the epitopes 1–38 and 41–55 were broadly cross-reactive, as demonstrated by their response to M. leprae, M. tuberculosis complex, M. avium and other mycobacteria. MHC restriction analysis of the HSP18-responding T cell lines showed that the epitopes 1–38 and 38–50 were presented by one of the two HLA-DR molecules expressed from self HLA-DRB1 genes, whereas the epitope 41–55 was recognized in the presence of autologous as well as HLA-DR and HLA-DQ mismatched allogeneic antigen-presenting cells. The results obtained in this study made it possible to identify cross-reactive T cell epitopes of the M. leprae HSP18, and provide an explanation for T cell recognition of this antigen in individuals infected with species of the M. tuberculosis complex or environmental mycobacteria.
Interaction between chronically HIV-infected promonocytic cells and human umbilical vein endothelial cells: role of proinflammatory cytokines and chemokines in viral expression modulation
Authors: Borghi M O , Panzeri P , Shattock R , Sozzani S , Dobrina A , Meroni P L
Published: March 2003

HIV type 1 expression was significantly up-regulated in chronically infected promonocytic cell line (U1) co-cultured with human umbilical vein endothelial cells (HUVEC). Virus replication, evaluated as supernatant p24 release, was higher when U1 were co-cultured with IL-1β-activated HUVEC than with unstimulated HUVEC. When non-adherent U1 were removed from co-cultures, the remaining U1 cells adherent to the endothelial monolayer still showed enhanced HIV replication in comparison with an equal number of U1 cultured alone. While addition of adhesion molecule blocking antibodies (anti-intercellular adhesion molecule-1 (ICAM-1), -vascular cell adhesion molecule-1 (VCAM-1), -CD18 and -very late antigen-4 (VLA-4)) strongly inhibited adherence of U1 cells to endothelial monolayers, such treatment resulted in only a partial reduction in p24 release. Furthermore, HIV replication in U1 cells was enhanced on culture in HUVEC-conditioned media. Such data suggest that soluble mediators secreted by endothelial monolayers may modulate HIV-1 expression. Indeed, addition of cytokine and chemokine antagonists to both U1/HUVEC co-cultures and to U1 cultured in HUVEC-conditioned media clearly down-regulated p24 release. Anti-IL-6, anti-tumour necrosis factor-alpha (TNF-α) and, particularly, anti-MCP-1 MoAbs reduced p24 release, while anti-IL-8 polyclonal antiserum and IL-1 receptor antagonist (IL-1Ra) had no significant effect. Thus, the interaction between HUVEC and infected monocytic cells up-regulates HIV-1 replication predominantly through production of endothelium-derived soluble factors including MCP-1, TNF-α and IL-6. This phenomenon may influence the passage of HIV-1 from latency to productive replication and enhance virus spreading during physiological and/or pathological contact of monocytes with endothelium.
Effects of therapy with highly active anti-retroviral therapy (HAART) and IL-2on CD4+ and CD8+ lymphocyte apoptosis in HIV+ patients
Authors: Caggiari L , Zanussi S , Bortolin M T , D’Andrea M , Nasti G , Simonelli C , Tirelli U , De Paoli P
Published: March 2003

The kinetics and effects of in vivo spontaneous apoptosis and activation-induced cell death (AICD) upon CD4+ and CD8+ lymphocyte subsets and CD4 naive cell numbers were studied in HIV+ subjects with CD4 pretreatment values > 200/mm3, who were subsequently treated for 48 weeks with HAART alone or in combination with six cycles of subcutaneous IL-2. Irrespective of the type of treatment, patients showed a statistically significant increase in CD4 cell counts after 4 weeks, although the CD4 naive subset only increased significantly in the IL-2-treated subjects at the end of treatment. The percentage of CD4 cells undergoing spontaneous apoptosis and AICD was significantly reduced in all patients after 4 weeks and this reduction was maintained until the end of therapy; however, the level always remained significantly higher in comparison with healthy subjects. A statistically significant reduction in CD8 apoptosis levels required at least 24 weeks of therapy. Together these data suggest that a reduction in the level of apoptosis may contribute to the early rise in CD4 numbers measured after HAART, but that later on HAART is unable to improve further this biological parameter. Although the use of IL-2 had no additional effects on spontaneous apoptosis and AICD, it may be beneficial by stimulating a late increase in the numbers of CD4 naive cells in HIV-treated subjects.