bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tumour cell binding by a human monoclonal IgM antibody from the spleen of a non-tumour-associated patient is due to somatic mutations in the VH gene
Authors: Bohn J , Niemann B , Roggenbuck D , DÖCke W , Jahn S 
Published: July 2010

SUMMARYRecently we described the occurrence of B cells producing polyspecific natural IgM with anti-tumour specificity in the spleen of non-tumour-bearing individuals as well as in fetal organisms. Immunoprecipitation and 2-D electrophoresis showed the binding of such antibodies to a 55-kD (pI 60) membrane surface glycoprotein. In vitro cultivation of human cancer cell lines in the presence of the purified IgM antibodies resulted in growth inhibition and complement-mediated cell lysis. Furthermore, the antibodies were shown to be able to induce MHC class I molecule expression on tumour cells. Because of this, a role for naturally occurring antibodies with anti-tumour specificity in preventing neoplasias had been suggested. We have constructed and expressed in Escherichia coli single-chain fragments (scFv: VH-linker-VL) derived from a polyspecific human monoclonal IgM autoantibody produced by a human × mouse heterohybridoma which was obtained from the spleen of an autoimmune patient. The mutated complementarity determining region (CDR) gene segments were replaced by the equivalent germ-line sequences and the CDR3 region was swapped for that from another polyspecific human natural antibody with no binding to tumours. Using these four scFv constructs for binding analyses and in vitro cultivation experiments we found: (i) scFv containing the mutated VH region of the original antibody were able to bind to tumour cells, to induce MHC class I molecule expression, and to inhibit tumour growth in a way similar to what had been described for the complete antibody; (ii) replacement of the mutated by the germ-line VH gene independently of the CDR3 to which it had been recombined, resulted in failure to bind to tumour cells. Nevertheless, other antigens (ssDNA, tetanus toxin) were still recognized, although with lower affinity. We discuss the significance of the replacement mutations in the VH gene CDRs. selected probably by B cell contact to an (auto)antigen, for generating a tumour binding capacity, not encoded by the germ-line gene.
In vitroproduction of cytokines by peripheral blood mononuclear cells from hydatid patients
Authors: RiganÒ R , Profumo E , Di Felice O , Ortona E , Teggi A , Siracusano A 
Published: July 2010

SUMMARYThe role of cytokines in human hydatidosJs (Echinococcus granulosus infection) was evaluated in immunoassays determining production of IL-4, IL-10 and interferon-gamma (IFN-γ) in peripheral blood mononuclear cell (PBMC) cultures from 30 hydatid patients and 14 uninfected controls. In ceil cultures from hydatid patients parasite and non-parasite antigen stimulation significantly increased IL-4 production (P·0·005). Spontaneous and milogen-driven IL-4 production was similar in patients and controls. IL-10 and IFN-γ production did not differ statistically in the two groups, even though some hydatid patients produced these cytokines in large amounts. Notably, antigen-driven IFN-γ concentrations were invariably higher in patients than in uninfected controls. Data analysis showed a relationship between IgE and IgG4 responses and parasite-driven cytokine production. High IgE and IgG4 responders produced high IL-4 and IL-10 concentrations. High IgE responders showed decreased IFN-γ production, but high IgG4 responders had IFN-γ levels slightly higher than those of low responders. Cytokine response patterns did not relate to the clinical stage of disease. The significantly increased IL-4 and the high IL-10 concentrations found in PBMC from many hydatid patients in this study are consistent with Th2 cell activation in human hydatidosis. The presence of antigen-driven IFN-γ production in patients with E. granulosus infection implies concurrent intervention of the Th1 or Th0 cell subset.
HCV infection in patients with primary defects of immunoglobulin production
Authors: Quinti I , Pandolfi F , Paganelli R , Salman D EL , Giovannetti A , Rosso R , Oliva A , Rainaldi L , Aiuti F 
Published: July 2010

SUMMARY
We tested for infection with hepatitis C virus (HCV) in 58 patients affected by humoral immunodeficiencies: 43 common variable immunodeficiency (CVI), two hyper IgM syndrome (HIM), two IgG subclass deficiency, four ataxia-telangiectasia (AT), and seven X-linked agamma-globulinaemia (XLA). While the assessment of serum specific HCV antibodies in some of these patients was not informative because of the impairment in specific antibody production, the reverse transcriptase polymerase chain reaction (RT-PCR) assay used to detect serum HCV RNA was a useful method for diagnosing infection. We found that 38% of late onset hypogamma-globulinaemic patients (CVI, HIM or IgG subclass deficiency) had evidence of HCV infection. HCV infection was not detectable in patients with XLA or AT. The majority of our pa hems had persistent viraemia. and those who underwent liver biopsy showed histological findings of chronic hepatitis. Moreover, we could demonstrate in vitro that eight of 18 HCV-infected patients were actively producing anti-HCV antibodies, despite their impaired antibody production. The high rate of HCV infection in hypogammaglobulinaemic patients could be related to several nosoeomial routes of transmission, including intravenous immune globulin administration. Despite the persistent viremia only two patients had cirrhosis and none had hepatocarcinoma.
Antifungal mechanisms of activated murine bronchoalveolar or peritoneal macrophages forHistoplasma capsulatum
Authors: Brummer E , Stevens D A 
Published: July 2010

SUMMARYThe first line of defence against natural infection by Histoplasma capsulatum (Hc) consists of bronchoalveolar macrophages (BAM) and an early inflammatory response in the lungs. Little is known about the interaction of BAM and He, consequently we studied murine BAM in vitro to assess their role in the pulmonary defence in histoplasmosis. A short-term 3-h assay was used to measure fungicidal activity of control BAM and interferon-gamma (IFN-γ) plus lipopolysacchar-ide (LPS)-activated BAM. Fungistatic activity of BAM was determined with a 24-h assay. A method devised for measuring colony-forming units (CFU) of non-ingested non-adherent and adherent ingested yeast cells of Hc in BAM cocultures was used. Activated BAM killed He (reduced inoculum CFU by 25 ± 12%; n = 4). The fungicidal activity of BAM was abrogated by 02 MM NG-monomethyl-L-arginine (NMMA) or catalase but not by superoxide dismutase. In fungistatic assays activated BAM inhibited multiplication of He by 61 ± 4% n = 3) compared with cocultures with control BAM. However, He multiplied 100% more in control BAM cocultures than in medium alone. Data indicated that this was due to advantages that He has in the intracellular environment. Only NMMA inhibited fungistatic activity of activated BAM. In experiments with peritoneal macrophages (PM), results similar to those with BAM were obtained. In conclusion, activated BAM and PM kill yeast cells of He by a mechanism dependent on hydrogen peroxide and products of the nitric oxide synthase (NOS) pathway, whereas fungistasis depends only on products of the NOS pathway.
Potentiation ofin vitrosynthesis of human IgE by cyclosporin A (CsA)
Authors: Wheeler D J , Robins A , Pritchard D I , Bundick R V , Shakib F 
Published: July 2010

SUMMARYIn this study, we investigated the modulatory effects of CsA on in vitro synthesis of IgE. IgG1 and lgG4 by human peripheral blood mononuclear cells (PBMC). In contrast to its known immunosuppressive effect, we have demonstrated that a low dose of CsA (10−7 M, 120ng/ml) potentiated IgE production by up to 40-fold (i.e. from 33 ± 4·5 to 1346 ± 290 ng/ml). This potentiation was specific for IgE, since no such effect was demonstrable with IgG1 and IgG4. Potentiation of IgE synthesis by CsA in the PBMC cultures was partly due to CsA acting on T cells, as demonstrated by the addition of CsA-treated T cells to T cell-depleted cultures. However, potentiation was also demonstrable in a T cell-depleted. anti-CD40-stimulated culture (four-fold increase from 400 ± 48 to 1606 ± 127 ng/ml). Our data therefore suggest that there are at least two mechanisms for CsA-induced potentiation of IgE synthesis, one T cell-dependent and the other T cell-independent. The clinical implications of these findings are discussed with regard to the use of CsA in the treatment of Th2-mcdiated diseases.
Autoantibodies against oxidized low density lipoproteins (oxLDL): characterization of antibody isotype, subclass, affinity and effect on the macrophage uptake of oxLDL
Authors: Wu R , Lefvert A K 
Published: July 2010

SUMMARYCirculating antibodies against oxLDL are present in several inflammatory and autoimmune conditions. Such antibodies are also present in patients with atherosclerosis, although the pathogenic significance of the antibodies is still not known. We have characterized the antibodies with regard to isotype, subclass, affinity and effect on macrophage uptake of oxLDL. Antibodies of IgG and IgM isotype were most common and found both in patients with atherosclerosis and in normal individuals. The subclass of IgG antibodies was mainly IgG2 and IgG3. Scatchard analyses of IgG and IgM antibodies showed that IgG antibodies were heterogeneous with regard to affinity, whereas only one population of high-affinity antibodies was found in the IgM antibody population. The high-affinity populations had an average equilibrium constant (KO) of 8.84 × 109 M−1 for IgG antibodies and of 1.65 × 109 M−1 for IgM antibodies. Incubation of 125I-oxLDL with purified IgG and IgM from sera with high amounts of antibodies enhanced the uptake of 125I-oxLDL in the monocyte-like U937 cell line. Antibody preparations from sera containing no anti-oxLDL antibodies and from sera with antibodies against LDL had less effect on this uptake. The increased uptake was competitively decreased by adding unlabelled oxLDL. This study shows that antibodies against oxLDL are mainly IgG2. IgG3 and IgM. Both IgG and IgM antibodies have a high affinity for the antigen and increase the uptake of oxLDL in a monocyte-like ceil line.
Down-regulation of CD55 and CD46 expression by anti-sense phosphorothioate oligonucleotides (S-ODNs) sensitizes tumour cells to complement attack
Authors: Zell S , Geis N , Rutz R , Schultz S , Giese T , Kirschfink M 
Published: July 2010

SummaryOverexpression of one or more membrane-bound complement regulatory proteins (mCRPs) protects tumour cells against complement-mediated clearance by the autologous humoral immune response and is also considered as a barrier for successful immunotherapy with monoclonal anti-tumour antibodies. Neutralization of mCRPs by blocking antibodies, enzymatic removal or cytokine-mediated down-regulation has been shown to sensitize tumour cells to complement attack. In our study we applied, for the first time, anti-sense phosphorothioate oligonucleotides (S-ODNs) to knock down the expression of the mCRPs CD55 and CD46 with the aim of exploiting complement more effectively for tumour cell damage. Potent anti-sense oligonucleotides against CD55 and CD46 were identified by screening various target sequences (n = 10) for each regulator. S-ODN anti-CD55(687) reduced CD55 protein expression up to 84% and CD46 protein expression was inhibited up to 76% by S-ODN anti-CD46(85). Reverse transcription–polymerase chain reaction (RT–PCR) analysis revealed a similar reduction of the CD55 and CD46 mRNA levels, which argues for an RNAse H-dependent anti-sense mechanism. T47D, A549 and PC3 cells, representing breast, lung and prostate carcinoma, were used for functional studies. Dependent on the particular cell line, anti-sense-based inhibition of mCRP expression enhanced complement-dependent cytolysis (CDC) up to 42% for CD55 and up to 40% for CD46, and the combined inhibition of both regulators yielded further additive effects in T47D cells. C3 opsonization of CD55/CD46-deficient tumour cells was also clearly enhanced upon mCRP suppression. Due to the clinical applicability of S-ODNs, the anti-sense approach described in this study may offer an additional alternative to improve the efficacy of antibody- and complement-based cancer immunotherapy.
Altered CD45 isoform expression in C77G carriers influences cytokine responsiveness and adhesion properties of T cells
Authors: Windhagen A , Sönmez D , Hornig-Do H T , Kalinowsky A , Schwinzer R 
Published: July 2010

SummaryThe C77G polymorphism in exon A of the human CD45 gene occurs with low frequency in healthy individuals. An enhanced frequency of C77G individuals has been reported in cohorts of patients suffering from multiple sclerosis, systemic sclerosis, autoimmune hepatitis, hepatitis C and human immunodeficiency virus (HIV)-1. C77G individuals overexpress CD45RA isoforms on activated/memory T cells. We have shown previously that aberrant expression of CD45RA isoforms enhances the intensity of T cell receptor (TCR) signalling. Here we report that the C77G polymorphism also influences the responsiveness of T cells to cytokines and alters their adhesion properties. When stimulated by interleukin (IL)-2, C77G T cells proliferated more strongly than wild-type controls and showed accelerated phosphorylation of Janus kinase (Jak1). Furthermore, C77G T cells exhibited a higher tendency to form homotypic aggregates in culture which could be enhanced significantly by antibody-mediated triggering of the variant CD45RA molecules. These data indicate that the changes in CD45 isoform combination resulting from C77G may not only affect TCR signalling but also cytokine-driven T cell responses and cellular adhesion. Altered immune responsiveness may enhance susceptibility of C77G carriers for certain diseases.
Substance P regulates macrophage inflammatory protein 3α/chemokine C-C ligand 20 (CCL20) with heme oxygenase-1 in human periodontal ligament cells
Authors: Lee S-K , Pi S-H , Kim S-H , Min K-S , Lee H-J , Chang H-S , Kang K-H , Kim H-R , Shin H-I , Lee S-K , Kim E-C 
Published: July 2010

SummaryAlthough substance P (SP), a potent proinflammatory peptide, is involved in inflammation and immune responses, the effect of SP on the expression of macrophage inflammatory protein 3α[MIP-3α, chemokine C-C ligand 20 (CCL20)] in periodontal ligament (PDL) cells is unknown. Equally enigmatic is the link between SP, the stress protein heme oxygenase-1 (HO-1), and CCL20 production. We investigated whether SP induces the release of chemokine CCL20 from immortalized PDL (IPDL) cells, and further clarify SP-mediated pathways. We also examined the relationship between HO-1 and CCL20 by treating PDL cells with SP. Incubating IPDL cells with SP increased expression of CCL20 mRNA and CCL20 protein in a dose–time-dependent manner. Highly selective p38 and extracellular-regulated kinase 1/2 (ERK1/2) inhibitors abrogated SP-induced expression of CCL20 in IPDL cells. SP is also responsible for initiating phosphorylation of IκB, degradation of IκB and activation of nuclear factor (NF)-κB. SP induced expression of HO-1 in both a concentration- and time-dependent manner, and CCL20 reflected similar patterns. The inductive effects of SP on HO-1 and CCL20 were enhanced by HO-1 inducer hemin and the membrane-permeable guanosine 3′,5′-monophosphate (cGMP) analogue 8-bromo-cGMP. Conversely, this pathway was inhibited by the HO-1 inhibitor zinc protoporphyrin IX (ZnPP IX) and the selective inhibitor of guanylate cyclase, 1H-(1,2,4)oxadiazole(4,3-a)quinoxalin-1-one (ODQ). We report herein the pathway that connects SP along with other modulators of neuroimmunoregulation to the induction of HO-1 and the inflammatory mediator macrophage inflammatory protein (MIP)-3α/CCL20 in IPDL cells, which play an important role in the development of periodontitis or inflammation during orthodontic tooth movement.
Differential immunomodulatory properties of Bifidobacterium logum strains: relevance to probiotic selection and clinical applications
Authors: Medina M , Izquierdo E , Ennahar S , Sanz Y 
Published: July 2010

Summary
Modulation of host immunity is one of the proposed benefits of the consumption of probiotics. Nonetheless, comparative studies on the immunological properties that support the selection of strains of the same species for specific health benefits are limited. In this study, the ability of different strains of Bifidobacterium longum to induce cytokine production by peripheral blood mononuclear cells (PBMCs) has been evaluated. Live cells of all B. longum strains greatly stimulated regulatory cytokine interleukin (IL)-10 and proinflammatory cytokine tumour necrosis factor (TNF)-α production. Strains of the same species also induced specific cytokine patterns, suggesting that they could drive immune responses in different directions. The probiotic strain B. longum W11 stimulated strongly the production of T helper 1 (Th1) cytokines while B. longum NCIMB 8809 and BIF53 induced low levels of Th1 cytokines and high levels of IL-10. The effects of cell-surface components obtained by sonication of B. longum strains overall confirm the effects detected by stimulation of PBMCs with live cells, indicating that these components are important determinants of the immunomodulatory activity of B. longum. Genomic DNA of some strains stimulated the production of the Th1 and pro-inflammatory cytokines, interferon (IFN)-γ and TNF-α, but not that of IL-10. None of the cell-free culture supernatants of the studied strains was able to induce TNF-α production, suggesting that the proinflammatory component of these strains is associated mainly with structural cell molecules. The results suggest that despite sharing certain features, some strains can perform a better functional role than others and their careful selection for therapeutic use is desirable.
The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in β cell transplantation
Authors: Wang M , Wang P , Liu Y Q , Peng J L , Zhao X P , Wu S , He F R , Wen X , Li Y , Shen G X 
Published: July 2010

Summary
An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing β cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 β cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from β cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted β cells.
High-fat diet modulates non-CD1d-restricted natural killer T cells and regulatory T cells in mouse colon and exacerbates experimental colitis
Authors: Ma X , Torbenson M , Hamad A R A , Soloski M J , Li Z 
Published: July 2010

SummaryEnvironmental factors such as diet are known to play important roles in inflammatory bowel disease (IBD). Epidemiological studies have indicated that a high-fat diet is a risk factor for IBD. In addition, the balance between effector T cells (Teff) and regulatory T cells (Treg) contributes to the pathogenesis of mucosal inflammation. The aim of this study was to understand the mechanisms by which a high-fat diet can regulate susceptibility to intestinal inflammation. Wild-type C57BL/6 mice were fed either a commercial high-fat diet or a normal diet, then exposed to dextran sulphate sodium (DSS) to induce colonic inflammation. Intraepithelial lymphocytes (IEL) were isolated from the colon, and their phenotype and cytokine profile were analysed by flow cytometry. Mice receiving the high-fat diet were more susceptible to DSS-induced colitis. They had higher numbers of non-CD1d-restricted natural killer (NK) T cells in the colonic IEL, when compared to mice fed a normal diet. These cells expressed tumour necrosis factor (TNF)-α and interferon (IFN)-γ, which are up-regulated by high-fat diets. Mice fed the high-fat diet also had decreased levels of colonic Treg. Depletion of colonic NK T cells or adoptive transfer of Treg reduced the DSS colitis in these mice, and reduced the colonic expression of TNF-α and IFN-γ. We conclude that a high-fat diet can increase non-CD1d-restricted NK T cells and decrease Treg in the colonic IEL population. This altered colonic IEL population leads to increased susceptibility to DSS-induced colitis. This effect may help to explain how environmental factors can increase the susceptibility to IBD.
Natural human antibodies to pneumococcus have distinctive molecular characteristics and protect against pneumococcal disease
Authors: Baxendale H E , Johnson M , Stephens R C M , Yuste J , Klein N , Brown J S , Goldblatt D 
Published: July 2010

SummaryThe molecular and functional characteristics of natural antibody from the preimmune repertoire have not been explored in detail in man. We describe seven human IgM monoclonal antibodies selected on the basis of pneumococcal polysaccharide binding that share both molecular and functional characteristics with natural antibody, suggesting a common B cell lineage origin. Unlike class-switched antibodies, which are serotype-specific, the antibodies were polyreactive and bound all pneumococcal polysaccharide capsular serotypes tested. Some bound endogenous antigens, including blood group antigens and intermediate filament proteins. All the antibodies used unmutated heavy chain V (IGHV) that are expressed at an increased frequency in the elderly and in the preimmune repertoire. The CDR3 was characterized by long length (mean aa 18·4 (±4·2) and selective use of IGHD6 (P &lt; 0·001) and IGHJ6 (P &lt; 0·01) family genes. The clones expressing IGHV1-69 and IGHV 3-21 provided significant passive protection against invasive pneumococcal disease in vivo.
T cell receptor Vβ repertoire of T lymphocytes and T regulatory cells by flow cytometric analysis in healthy children
Authors: McLean-Tooke A , Barge D , Spickett G P , Gennery A R 
Published: July 2010

Summary
Evaluation of the T cell receptor (TCR) Vβ repertoire by flow cytometric analysis has been used for studying the T cell compartments for diseases in which T cells are implicated in the pathogenesis. For the interpretation of these studies information is needed about Vβ usage in healthy individuals and there are few data for normal usage in paediatric populations. We examined the T lymphocyte (sub)populations in 47 healthy controls (age range: 3 months−16 years). We found non-random Vβ usage with skewed reactivity of some families towards CD4+ or CD4– T cells. Importantly, there appeared to be no significant change in Vβ usage according to age group. Some controls showed expansions in some Vβ families, although incidence of such expansions was low. We went on to examine the repertoire of CD4+CD25Bright T regulatory cells in 25 healthy controls. We found overlapping quantitative usage for each of the Vβ families between CD4+CD25– and CD4+CD25Bright T cells. However, there was a significant preferential usage for five Vβ families and decreased usage of two Vβ families in the CD4+CD25Bright T cells, suggesting that although they overlap there may be subtle but important differences in the TCR repertoire of T regulatory cells.