bluuebunny/crossref_metadata_2025_split huggingface dataset:
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

SUMMARYWe 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

SUMMARYHIV 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

SUMMARYThe 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 &gt; 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.
Neutrophils play a critical role in the pathogenesis of experimental cerebral malaria
Authors: Chen L , Zhang Z-H , Sendo F 
Published: March 2003

SUMMARYThe role of neutrophils in experimental cerebral malaria (ECM) is not well understood. In this study we used a MoAb, RB6-8C5, to deplete the peripheral neutrophils of ECM-susceptible CBA/NSlc mice 24 h before Plasmodium berghei ANKA (PbA) infection. We found that early neutrophil depletion prevented the development of ECM and dramatically decreased the sequestration of monocytes and microhaemorrhage in the brain. The depletion of neutrophils also down-regulated tumour necrosis factor-alpha, interferon-gamma and IL-2 mRNAs and abrogated IL-12p40 mRNA expression in the brain as examined by competitive reverse transcriptase-polymerase chain reaction. Although depletion of neutrophils decreased the expression of Th1 cytokines in both spleen and brain, our results did not show the shift of a Th1 to a Th2 immune response since there was no obvious augmentation of expression of Th2 cytokine mRNAs (IL-4 and IL-10). We conclude that neutrophils play a role in the pathogenesis of ECM via enhancement of the expression of Th1 cytokines in the brain.
Diesel exhaust particles up-regulate expression of intercellular adhesion molecule-1 (ICAM-1) in human bronchial epithelial cells
Authors: Takizawa H , Abe S , Ohtoshi T , Kawasaki S , Takami K , Desaki M , Sugawara I , Hashimoto S , Azuma A , Nakahara K , Kudoh S 
Published: March 2003

SUMMARYEpidemiological and experimental studies suggest that diesel exhaust particles (DEP) may play an active role in the increased respiratory mortality and morbidity. We have shown that DEP augmented the production of inflammatory cytokines by human airway epithelial cells in vitro. ICAM-1 has been shown to play an important role in the local accumulation of inflammatory cells. We studied the effect of DEP on ICAM-1 gene expression and surface expression in human bronchial epithelial cell line BEAS-2B. DEP (5–50 μg/ml) showed a stimulatory effect on ICAM-1 mRNA levels as evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Flow cytometric analysis demonstrated an increased ICAM-1 expression on the epithelial cell surfaces. The soluble form of ICAM-1 molecules was also increased by the stimulation of DEP. In vitro neutrophil attachment onto DEP-stimulated epithelial cells was augmented, which was partially blocked by anti-ICAM-1 neutralizing antibody. Finally, these events were significantly inhibited by pretreatment with anti-oxidants pyrrolidine dithiocarbamate and N-acetyl cysteine, and p38 mitogen activated protein kinase (MAPK) inhibitor SB203580. These findings suggested that DEP induced up-regulation of ICAM-1 gene, and this process might be largely dependent on oxidant-mediated NF-κB activation and p38-MAPK pathways.
Detection of Bruton's tyrosine kinase mutations in hypogammaglobulinaemic males registered as common variable immunodeficiency (CVID) in the Japanese Immunodeficiency Registry
Authors: Kanegane H , Tsukada S , Iwata T , Futatani T , Nomura K , Yamamoto J , Yoshida T , Agematsu K , Komiyama A , Miyawaki T 
Published: March 2003

SUMMARY
CVID is frequently diagnosed in male and female individuals with hypogammaglobulinaemia of unknown aetiology. To examine the possibility that sporadic male cases with X-linked agammaglobulinaemia (XLA), which is caused by mutations in the Bruton's tyrosine kinase (Btk) gene, might be misregistered as having CVID, we employed a flow cytometric test to identify XLA in hypogammaglobulinaemic males registered as CVID in the Japanese Immunodeficiency Registry. From 30 male cases registered as having CVID between 1992 and 1998, we selected 21 males with low or unreported peripheral B cell counts. Blood samples could be obtained from 11 patients and their mothers. Using flow cytometric analysis, the Btk-deficient status in monocytes was demonstrated in seven out of nine cases with decreased numbers of peripheral B cells. The diagnosis of XLA was confirmed in each of the seven patients by demonstration of Btk gene mutations in the patients or cellular mosaicism in the mother. This study demonstrates misregistration of XLA as CVID.
T cell receptor repertoire and function in patients with DiGeorge syndrome and velocardiofacial syndrome
Authors: Pierdominici M , Marziali M , Giovannetti A , Oliva A , Rosso R , Marino B , Digilio M C , Giannotti A , Novelli G , Dallapiccola B , Aiuti F , Pandolfi F 
Published: March 2003

SUMMARYDiGeorge syndrome (DGS) and velocardiofacial syndrome (VCFS) are associated with chromosome 22q11.2 deletion. Limited information is available on the T cell receptor (TCR) Vβ repertoire. We therefore investigated TCR Vβ families in lymphocytes isolated from blood and thymic samples of seven patients with DGS and seven patients with VCFS, all with 22q11.2 deletion. We also studied activities related to TCR signalling including in vitro proliferation, anti-CD3-induced protein tyrosine phosphorylation, and susceptibility to apoptosis. Reduced CD3+ T cells were observed in most patients. Spontaneous improvement of T cell numbers was detected in patients, 3 years after the first study. Analysis of CD4+ and CD8+ TCR Vβ repertoire in peripheral and thymic cells showed a normal distribution of populations even if occasional deletions were observed. Lymphoproliferative responses to mitogens were comparable to controls as well as anti-CD3-induced protein tyrosine phosphorylation. Increased anti-CD3-mediated apoptosis was observed in thymic cells. Our data support the idea that in patients surviving the correction of cardiac anomalies, the immune defect appears milder than originally thought, suggesting development of a normal repertoire of mature T cells.
Neutrophil lactoferrin release induced by IgA immune complexes differed from that induced by cross-linking of Fcαreceptors (FcαR) with a monoclonal antibody, MIP8a
Authors: Zhang W , Bi B , Oldroyd R G , Lachmann P J 
Published: March 2003

SUMMARYThe human IgA Fc receptor (FcαR, CD89) plays an important role in host defence against invading pathogens. To study the properties of the receptor, 12 MoAbs, namely, MIP7c, MIP8a, MIP9a, MIP10c, MIP11c, MIP14b, MIP15b, MIP38c, MIP59c, MIP65c, MIP68b and MIP71a, were generated. The inhibitory effects of the antibodies on FcαR functions were tested. Three of the antibodies, MIP7c, MIP8a and MIP59c, were able to block up to 90% of soluble FcαR binding to IgA-coated beads and 70–80% of neutrophil phagocytosis of IgA immune complexes (IC). MIP8a could also inhibit IgA IC-induced neutrophil lactoferrin release, while cross-linking of FcαR with MIP8a and anti-mouse IgG could elicit neutrophil lactoferrin release. However, IgA IC-induced lactoferrin release required both extracellular calcium and magnesium, whereas MIP8a-induced release did not require extracellular magnesium and only partially required extracellular calcium. In addition, the time course of IgA IC-induced lactoferrin release was slow. Lactoferrin was not detectable if the incubation time was less than 0·5 h. In contrast, MIP8a-induced lactoferrin release was fast. Lactoferrin could be detected within 5 min of incubation. Therefore, neutrophil lactoferrin release induced by IgA IC differed from that induced by cross-linking of FcαR with MIP8a.
Exogenous type-1 cytokines modulate mercury-induced hyper-IgE in the rat
Authors: Gorrie M J , Qasim F J , Whittle C J , Gillespie K M , Szeto C-C , Nicoletti F , Bolton E M , Bradley J A , Mathieson P W 
Published: March 2003

SUMMARYSuppression of IgE responses is a major goal for immunotherapy, especially in the field of allergy. The Th2 subset of helper T cells plays a vital role in class switching of B cells to IgE production by releasing IL-4. In susceptible rat strains, mercuric chloride (HgCl2) induces activation of Th2 cells, with enhanced expression of IL-4, polyclonal B cell activation and very high levels of circulating IgE. We have previously shown that spontaneous regulation of this response coincides with enhanced expression of Th1/type-1 cytokines, including interferon-gamma (IFN-γ) and IL-12. We now report the effects of administration of exogenous type-1 cytokines on HgCl2-induced Th2 responses. At high doses, recombinant rat IFN-γ markedly reduced serum IgE levels. Recombinant mouse IL-12 was less effective at suppressing the IgE response following HgCl2, although it caused marked up-regulation of IFN-γ gene expression in the spleen. In Lewis rats, which are resistant to HgCl2-induced autoimmunity, a rise in serum IFN-γ was observed after HgCl2, but administration of polyclonal anti-IFN-γ antibodies did not render them susceptible to induction of a Th2 response by HgCl2. Our data show that individual type-1 cytokines are capable of suppressing the dramatic Th2 response induced by HgCl2 in the rat, even when they are not given until after starting HgCl2 administration. IFN-γ is a pivotal cytokine in ameliorating the Th2 response and measures aimed at selective up-regulation of this cytokine may be of therapeutic value in suppression of unwanted IgE responses.
Up-regulation of the tumour-associated marker CD44V6 in experimental kidney disease
Authors: Takazoe K , Foti R , Tesch G H , Hurst L A , Lan H Y , Atkins R C , Nikolic-Paterson D J 
Published: March 2003

SUMMARYCD44 is an adhesion molecule involved in a wide range of cell–cell and cell–matrix interactions. The standard form of CD44 (CD44S) is a 85–90-kD glycoprotein, but alternative splicing of RNA encoding 10 variable exons (V1-V10) can give rise to many different CD44 variant protein isoforms of higher molecular weight. CD44 isoforms containing the V6 exon play a crucial role in tumour metastasis and lymphocyte activation. However, the role of CD44V6 in the kidney is unknown. The aim of this study was to examined renal CD44V6 expression in health, disease and in vitro. Immunohistochemistry staining with the V6-specific 1.1ASML antibody identified constitutive CD44V6 expression by occasional cortical tubular epithelial cells and medullary tubules in normal rat kidney. In immune-induced kidney disease (rat anti-glomerular basement membrane glomerulonephritis), there was a marked increase in CD44V6 expression by cortical tubules, particularly in areas of tubulointerstitial damage, which was associated with focal macrophage infiltration. There was also a marked increase in CD44V6 expression by damaged tubules in a model of non-immune kidney disease (unilateral ureteric obstruction). Reverse transcription-polymerase chain reaction revealed a complex pattern of CD44V6-containing mRNA isoforms in normal rat kidney. This pattern of CD44V6 splicing was essentially unaltered in disease. The NRK52E normal rat kidney tubular epithelial cell line expresses both CD44S and CD44V6. Stimulation of NRK52E cells with IL-1 or transforming growth factor-beta 1 induced a two-to-five-fold increase in the expression of both CD44S and CD44V6. Furthermore, triggering of NRK52E cells by antibodies to CD44S or CD44V6, but not isotype control antibodies, induced secretion of monocyte chemoattractant protein-1. In conclusion, this study has identified expression of the tumour-associated marker CD44V6 in tubular epithelial cells in normal and diseased rat kidney, and suggests that signalling through the CD44V6 molecule may participate in the pathogenesis of experimental kidney disease.
Glucocorticoids hamper theex vivomaturation of lung dendritic cells from their low autofluorescent precursors in the human bronchoalveolar lavage: decreases in allostimulatory capacity and expression of CD80 and CD86
Authors: Verhoeven G T , Van Haarst J M W , De Wit H J , Simons P J , Hoogsteden H C , Drexhage H A 
Published: March 2003

SUMMARYDendritic cells (DCs) were prepared from human bronchoalveolar lavage (BAL) cells. We previously reported that, in particular, the CD1a fraction of the low autofluorescent (LAF) cells contains the precursors for DCs: after overnight culture, 40% of the LAF cells change into functionally and phenotypically prototypic dendritic/veiled cells. There are, as yet, no data on the modulatory effects of glucocorticoids (GC) on the maturation and function of such DCs isolated from the human lung. Functional tests (allogeneic mixed lymphocyte reaction: allo-MLR) were therefore performed with CD1a+ LAF cells at different stimulator-to-T-cell ratios and after preincubation with different dexamethasone (DEX) concentrations. DEX caused suppression of the T-cell stimulatory capacity of CD1a+ LAF cells, which was dose-dependent, and more evident at the higher stimulator-to-T-cell ratios. Here, we also show that CD80 and CD86 are normally expressed at low levels on CD1a+ LAF cell-derived DCs compared to other DC populations. This low-level expression of costimulatory molecules is discussed here in relation to the previously reported low-level expression of CD80 (and CD86) on lung DCs in experimental animals. This appears to play a role in a predominant Th2 cell stimulating potential of DC from the lung environment. DEX exposure of CD1a+ LAF cells prevented the upregulation of even this low-level expression of CD80 and CD86. The veiled/dendritic morphology and the expression of other relevant cell surface markers and adhesion molecules was not affected by DEX exposure. It is concluded that DEX hampers the maturation of CD1a+ LAF cells into active lung DCs.
Treatment with a monoclonal antibody to IL-8 attenuates the pleocytosis in experimental pneumococcal meningitis in rabbits when given intravenously, but not intracisternally
Authors: Østergaard C , Yieng-Kow R V , Larsen C G , Mukaida N , Matsushima K , Benfield T , Frimodt-Møller N , Espersen F , Kharazmi A , Lundgren J D 
Published: March 2003

SUMMARYThe role of interleukin (IL)-8 as mediator in the recruitment of leucocytes into the CSF was investigated during experimental pneumococcal meningitis. Rabbits were inoculated intracisternally with approximately 106 CFU Streptococcus pneumoniae, and treated (i) intravenously with 5 mg of a monoclonal antibody to IL-8 (n = 7) or 5 mg of an isotype control antibody (n = 6); (ii) intracisternally with anti-IL-8, 100 µg (n = 5), 10 µg (n = 4), 1 µg (n = 4), 0·1 µg (n = 2). Ten rabbits served as untreated control group. Intravenous treatment with anti-IL-8 attenuated the pleocytosis significantly compared to untreated rabbits (P &lt; 0·04) or rabbits treated with an isotype control antibody (P &lt; 0·02). In contrast, intracisternal treatment with anti-IL-8 failed to attenuate the pleocytosis (P &gt; 0·05). These results show, that IL-8 plays an important role in the recruitment of leucocytes during experimental pneumococcal meningitis, and that the functional activity of IL-8 in this process appears to be on the bloodstream side of the microvascular endothelium of the brain.
Secretory autoantibodies in primary biliary cirrhosis (PBC)
Authors: Palmer J M , Doshi M , Kirby J A , Yeaman S J , Bassendine M F , Jones D E J 
Published: March 2003

SUMMARYIt is unclear how breakdown in immune tolerance to the ubiquitous self-antigen pyruvate dehydrogenase complex (PDC), seen in the autoimmune liver disease PBC, gives rise to tissue damage with such a limited distribution (restricted to the liver and salivary and lachrymal glands). One property shared by these tissues is the ability to export secretory IgA by the process of transcytosis. The aim of this study was to address whether active transcytosis of anti-PDC IgA occurs across epithelial surfaces in PBC, a finding that might implicate mucosal specific immune mechanisms in the pathogenesis of this disease. Parotid saliva was collected from PBC patients (n = 44), normal controls (n = 28) and PBC patients post-liver transplantation (n = 11). IgA and secretory component-positive antibodies specific for human PDC were quantified by ELISA and immunoblotting. PBC patients (but not control subjects) had anti-PDC IgA in their saliva. The strong correlation seen between titres detected using anti-IgA and anti-secretory component antibodies suggests that this is predominantly secretory IgA reaching the saliva by the active process of epithelial transcytosis. Titres of anti-PDC IgA remain high in PBC patients saliva post-liver transplant. Findings from studies of IgA in viral infection models raise the possibility that anti-PDC IgA could, whilst undergoing transcytosis, bind to newly translated PDC components in the cytoplasm of the epithelial cells transporting them out of the cell and inducing metabolic damage. This model would, if correct, help to explain the mechanism and tropism of tissue damage in PBC and the aberrant pattern of expression of PDC on the apical surface of biliary and salivary epithelial cells reported in this disease.
Patients with systemic vasculitis have increased levels of autoantibodies against oxidized LDL
Authors: Swets B P , Brouwer D A J , Tervaert J W Cohen 
Published: March 2003

SUMMARY
Oxidation of low density lipoprotein (LDL) is considered to play an important role in the development of atherosclerosis and increased levels of autoantibodies against oxidized LDL have been found in patients with various manifestations of atherosclerosis. Patients with vasculitis are prone to the development of atherosclerosis. Since production of radical oxygen species in these patients may result in increased production of oxidized LDL (Ox-LDL), we hypothesized that antibodies against Ox-LDL are elevated during lesion development in vasculitis. Therefore we measured anti Ox-LDL antibodies in 25 patients with ANCA-associated vasculitis and in 42 healthy controls using an ezyme-linked immunosorbent assay (ELISA) in which malondialdehyde modified LDL (MDA-LDL) was coated on microtitre plates. Anti Ox-LDL antibodies were significantly higher in patients as compared to controls (P = 0·0001). Anti Ox-LDL levels were also measured in 11 patients during active disease and in these same patients during complete remission. Anti Ox-LDL levels were significantly higher in patients during active disease than during full remission (P = 0·001). Our results suggest that patients with ANCA-associated vasculitis are more susceptible to oxidation of LDL, which may contribute to accelerated atherosclerosis development.