bluuebunny/crossref_metadata_2025_split huggingface dataset:
Regulation of C3 deposition on gp120 coated CD4 positive cells by decay accelerating factor and factor H
Authors: SADLON T. A. , PARKER S. J. , GORDON D. L. 
Published: July 2007

SummaryWe investigated complement activation by recombinant gp120 (rgp120) treated CD4 cells and the role host complement regulatory proteins play in controlling C3 deposition. Complement activation was determined by detection of C3 on rgp 120 coated cells in the presence and absence of HIV seropositive sera using flow cytometry. Treatment of rgp 120 coated cells with complement resulted in C3 deposition only if HIV positive sera was included. Examination of C3 fragments on these cells demonstrated rapid cleavage of C3b to iC3b. The role of the regulatory proteins was examined by pretreating cells with mAb to block decay accelerating factor (DAF) or membrane cofactor protein (MCP) or by using factor H depleted sera as a complement source. Inhibition of DAF or use of factor H depleted sera significantly increased C3 deposition on rgp120 coated cells. In contrast, C3 deposition on rgp120 coated cells was not increased after blocking MCP. The sensitivity of rgp120 coated cells to complement lysis was unchanged after inhibition of the regulatory proteins, despite the increase in C3 deposited. These results indicate that in a model of virus infected cells, C3 deposition is regulated by DAF and factor H but MCP appears to have no role.
Differential expression of CD45R0 on natural killer (NK) cells in patients with an NK lymphocytosis
Authors: WARREN HILARY S. , KINNEAR BEVERLEY F. , SKIPSEY LOUISE J. , PEMBREY RICHARD G. 
Published: July 2007

SummaryNK cells from three donors with a NK (CD3− CD56+ CD 16+) lymphocytosis of unknown aetiology showed differential expression of CD45R0, an isoform of CD45 not expressed by NK cells from normal donors unless stimulated to proliferate in vitro. For donor FC, 60% of NK cells expressed CD45R0 over a 16 month period during which there was a partial resolution of the NK lymphocytosis. For donor SW, 37% of NK cells expressed CD45R0, increasing to 87% over a 14 month period during which the NK lymphocytosis increased. For donor RN few if any NK cells expressed CD45R0. After in vitro proliferation, 100% of NK cells generated from all donors expressed CD45R0. For donors FC and SW, CD45R0 remained expressed on more than 90% of cells at 3–4 weeks following cessation of proliferation. By contrast CD45R0 expression was gradually lost during long‐term culture of NK cells from donor RN, with 58% of NK cells regaining the pre‐culture CD45R0‐phenotype. NK cells from normal donors also varied in the extent to which activation acquired CD45R0 was lost during long‐term culture. The results obtained are consistent with the notion that NK cells from the NK lymphocytosis donors studied have previously undergone proliferation in vivo.
Politics, personalities and the development of science
Authors: LAFFERTY KEVIN J. 
Published: July 2007

SummaryThis lecture recounts a story that attempts to trace the history of ideas relating to tissue transplantation from the earliest times through to the present. This story was shaped by the strong Darwinian approach to biology championed by Burnet and Medawar. It also describes the political influence developed from the strong Lamarckian leanings of the communist supporters in the USSR, and the fact that the biological argument between those supporting Lamarck and those supporting Darwin was seen by the Praesidium of the USSR Academy of Sciences to be equated with the ideological class struggle between socialism and capitalism. This story points out that while science is valued for its objectivity, its dependence on personalities adds a subjective element. This subjective element is always present and it colours our science by reflecting both the political and cultural movements of the time.
Why do class I MHC molecules bind smaller peptides than class II MHC molecules?
Authors: BLANDEN R. V. 
Published: July 2007

SummaryThis article attempts to assemble theoretical‐teleological argument to explore possible answers to the question of why class I MHC molecules bind smaller peptides than class II MHC molecules and the associated question of why the size of peptides binding to class I molecules is approaching the limit of the self‐non‐self discrimination. I propose that the small size of most class I‐binding peptides precludes the production of ‘MHC‐restricted’ antibodies. Such a strategy avoids the possibility of antibodies binding to the epitopes recognized by CD8+ T cells, thus blocking effector function required for clearance of potentially lethal infections.
Do autoantibodies to IgE play a role in IgE‐mediated events?
Authors: SHAKIB FAROUK , SMITH SUSAN J. , PRITCHARD DAVID I. 
Published: July 2007

SummaryElevated blood levels of IgG anti‐IgE are detectable in individuals exhibiting enhanced IgE production, namely those with allergic conditions and helminthic parasite infections. The fact that there are epitope‐specific subpopulations of autoanti‐IgE suggests that this autoantibody could potentially have multiple effects in immunological events involving IgE.
Hypothesis: A memory lymphocyte‐specific soma‐to‐germline genetic feedback loop
Authors: ROTHENFLUH HARALD S. 
Published: July 2007

SummaryAnalysis of recently published DNA sequence data obtained for related germline Ig variable (IgV) genetic elements of several vertebrate species revealed the presence of a number of extremely non‐random patterns of sequence variability among these genes. Strikingly, the patterns were also observed in two sets of chicken IgV pseudogenes. Since the observed patterns are clearly incompatible with existing theories of multigene family evolution, a new model that can account for all of the data is presented in this paper. The model is a modification and extension of an earlier proposed mechanism whereby somatically expressed genes can be returned to the germline by endogenous retroviruses that may act as soma‐to‐germline genetic vectors. The mechanism described proposes that the interactions that may result in the soma‐to‐germline transfer of somatically selected IgV genes occur in the epididymis of the male reproductive tract and are restricted to memory lymphocytes. This mechanism makes a number of predictions that are amenable to experimental testing. From the data presently available in the literature it is not possible to extend the mechanism to the female reproductive tract.
Recombinant expression of vaccinia virus‐encoded TAP1 and TAP2 promotes MHC class I‐restricted antigen presentation in a Syrian hamster cell line
Authors: LOBIGS MARIO , MULLBACHER ARNO 
Published: July 2007

SummaryTransporter associated with antigen presentation (TAP) molecules supply small peptides to the lumen of the endoplasmic reticulum for assembly with MHC class I glycoproteins. Here we report that a Syrian hamster cell line, BHK, which is commonly used in cell biological and virological investigations, is deficient in antigen presentation in a xenogeneic model. Thus when the mouse MHC class I restriction element, Kd, is expressed in BHK cells via a vaccinia virus (VV) recombinant, no significant recognition by VV‐immune and Kd‐restricted cytotoxic T cells is induced. This defect is apparently a consequence of a deficiency in TAP‐dependent peptide transport and can be repaired when rat TAP1 and TAP2 are provided by recombinant VV expression.
Effect of visible light on some cellular and immune parameters
Authors: KUBASOVA TAMARA , HORVÁTH MAGDOLNA , KOCSIS KATALIN , FENYÖ MÁRTA 
Published: July 2007

SummaryThe biological effect of visible light of low energy density was investigated in this study. The effects of diffuse (DL) and linearly polarized (LPL) light were compared on models in vitro and in vivo.Experiments in vitro were performed on human lymphocytes to study their blast‐transformation and rosette‐formation abilities. Both DL and LPL increased the number of blast‐transformed cells even in a lymphocyte culture without PHA, and reduced rosette‐formation of T lymphocytes. LPL had a more pronounced effect. In vivo exposure to DL and LPL of the spleens of tumour‐bearing mice caused the appearance of factor(s) in their serum, inhibiting the incorporation in vitro of [3H]‐thymidine into the tumour cells obtained from non‐exposed animals. In the other series of experiments serum samples were taken from tumorous animals after the exposure of their spleens to LPL. Following the daily administration of these sera to another group of non‐exposed tumorous mice a decreasing tendency of the mitotic kinetics of ascites tumour was observed.The application of visible (preferably linearly polarized) light for the stimulation of human immune competent cells, and clinical trials with extracorporeal irradiation of blood for the promotion of natural defences of an immune‐repressed organism are suggested.
Effect of TGF‐β on differentiated organoids of the colon carcinoma cell line LIM 1863
Authors: HAYWARD IP , WHITEHEAD RH , WARD L , GIANELLO R , DEMPSEY P , BATES R , BURNS GF 
Published: July 2007

SummaryThe LIM 1863 colon carcinoma cell line grows in suspension as morphologically and functionally organized organoids in serum‐containing medium. Addition of TGF‐p caused the organoids to adhere and inhibited DNA synthesis. A 20 min incubation with TGF‐β was sufficient to induce adherence and this could be inhibited by cycloheximide. The adhesion and DNA synthesis inhibition were demonstrated to be separate events. We were not able to detect any changes in matrix or cell membrane antigens. Similarly there were no changes in synthesized proteins (by two‐dimensional gel electrophoresis), and no upregulation of proteoglycan. When adhered organoids were lysed from the tissue culture plastic surface, untreated organoids adhered to this surface. This ‘conditioned’ surface was destroyed by trypsin but not collagenase or medium from normal LIM 1863 cultures. However, the adherent phenotype was prevented when organoids were treated with transforming growth factor‐β (TGF‐β) in the presence of medium conditioned by normal LIM 1863 cultures rather than in fresh medium. The adhesion process was inhibited by an antibody (QE2E5) against β1 integrin although no quantitative changes in integrins were observed (by immunoprecipitation or RNA analysis). A second anti‐β1 integrin antibody (61.2C4) inhibited LIM 1863 adhesion to collagen but not TGF‐β induced adhesion, implying that TGF‐β induced a specific conformational change or interaction of a β1 integrin. In this morphologically structured system TGF‐β induced a number of subtle effects including formation of new extracellular matrix and conformational change of a β1 integrin, rather than the major quantitative changes in cell/matrix molecules reported previously.
Protection against non‐typable Haemophilus influenzae following sensitization of gut associated lymphoid tissue: Role of specific antibody and phagocytes
Authors: WALLACE FIONA J , WITT CAMPBELL S , CLANCY ROBERT L , CRIPPS ALLAN W 
Published: July 2007

SummaryRats intestinally immunized with whole killed non‐typable Haemophilus influenzae clear this organism from the lungs faster than non‐immunized rats. This study investigated the role of antibody and phagocytes in the clearance mechanism. First, dose‐response experiments demonstrated that while lowering the dose of non‐typable H. influenzae reduced the level of detectable specific antibody in bronchial washings, the ability to accelerate bacterial clearance persisted to much lower doses. Second, specificity experiments showed that intestinal immunization with non‐typable H. influenzae cross‐protected against Pseudomonas aeruginosa. even though antibodies were not absorbed out of serum by incubation with P. aeruginosa. Third, serum antibody was shown to be bactericidal for non‐typable H. irtfltienzae in the presence of complement (P < 0.05), while bronchial washings antibody was not. The bactericidal effect of the serum was abrogated by the addition of bronchial washings. Fourth, an ELISA quenching assay demonstrated that neutrophils from intestinally immunized rats were able to phagocytose more bacteria in a given time period (P < 0.05) than unimmunized rats and rats immunized by other routes. In the fifth experiment, the chemotactic response of neutrophils to casein was shown to be significantly depressed by the addition of bronchial washings obtained from immunized rats (P < 0.01). It is proposed that specific antibody in bronchial washings does not have a direct role in opsonizing bacteria for killing or phagocytosis, but instead has an anti‐inflammatory effect. Non‐specific effectors such as neutrophils driven by specific immune cells are a likely means of clearance of bacteria following intestinal immunization and acute challenge.
MHC proteins and heparan sulphate proteoglycans regulate murine cytomegalovirus infection
Authors: PRICE PATRICIA , ALLCOCK RICHARD JN , COOMBE DEIRDRE R , SHELLAM GEOEFREY R , McCLUSKEY JAMES 
Published: July 2007

SummaryFactors influencing MCMV infection mediated by MHC class I molecules were analysed further as previous studies showed that the effects of the MHC genotype on sensitivity to this virus are important in vivo. Here we show that H‐2d, H‐2b, H‐2r and H‐2v macrophages are highly sensitive to MCMV.Moreover, transfection of H‐2k L‐cells with Kb or Dd conferred sensitivity to MCMV. This was not affected by amino acid substitutions in Kbα1 or α2, although previous studies demonstrated that exchange of the αl domain of Dd with Ldα1 compromised sensitivity. Here replacement of Kbα3 with Ldα3 reduced susceptibility to low doses of MCMV. In addition, extracellular β2‐microglobulin (β2m) promoted infection of β2m‐negative R1E/TL8X.1 cells transfected with Db with or without a β2m gene. Hence MCMV infection can involve p2m and the al and β3 domains of MHC heavy chains.MCMV infection of L‐cells expressing Dd or Kb was also inhibited by heparin, but infection of the parental L‐cell line was not reproducibly affected. A role for heparan sulphate proteoglycan in MHC‐mediated MCMV infection was confirmed using cells pre‐treated with heparinase I or III, or propagated in chlorate to inhibit the sulphation of the glycosaminoglycan chains.
Establishment of a natural suppressor cell line producing soluble suppressor factor other than transforming growth factor‐β
Authors: YANAGIE HIRONOBU , SUGIYAMA HIROTAKA , SEKIGUCHI MORIMASA 
Published: July 2007

SummaryNatural suppressor (NS) cell line (Clone 59) was established from the bone marrow of adult C3H/Hej mice in the presence of WEHI‐3 conditioned media. Clone 59 cells suppressed the generation of cytotoxic T lymphocytes from normal mouse spleen. This suppression was seen at a responder‐to‐suppressor cell ratio of 1000:1 and lacked antigen specificity or MHC restriction. Clone 59 cells expressed the ‘null’ surface phenotype (Thyl.2−, CD3−, Lyt‐2−, L3T4 −, surface Ig−, MAC–l−) by immunofluorescent staining. Clone 59 cells exhibited no cytolytic activity against NK cell‐sensitive YAC‐1 and natural cytotoxic L929 target cell lines. Non‐specific suppression, with a cell‐free supernatant from the Clone 59‐NS cells, also was observed. The supernatant did not inhibit [3H]‐thymidine uptake by CTLL‐2 cells which were proliferating in response to IL‐2. Anti‐transforming growth factor‐β (TGF‐β) monoclonal antibody had no effect on suppression, suggesting that the non‐specific suppression is mediated by some soluble factors other than TGF‐β. Clone 59 cells may be useful in identifying non‐specific suppressor cells in adult bone marrow and studying their functional role in the regulation of tolerance and self‐reactivity.
Co‐operative effect between insulin‐like growth factor‐1 and interleukin‐2 on DNA synthesis and interleukin‐2 receptor‐α chain expression in human lymphocytes
Authors: SCHILLACI ROXANA , BROCARDO MARIANA G , ROLDAN ALICIA 
Published: July 2007

SummaryRecently we demonstrated that IGF‐1 has the same effect on DNA synthesis and G1‐phase length during human lymphocyte proliferation as IL‐2. In order to determine the link between IGF‐1 and IL‐2 on lymphocyte proliferation, we tested the ability of these cytokines, alone or in combination, to induce DNA synthesis and increase the number of cells expressing IL‐2‐α chain receptors. Our results showed that the increase in DNA synthesis produced by the addition of IGF‐1 to cells cultured with saturable concentrations of IL‐2, correlated well with an increase in the number of cells expressing IL‐2‐α chain receptor. The effect on both DNA synthesis and IL‐2‐α chain receptor expression was greater at lower concentrations of PHA. This study suggests that the proliferative effect of IGF‐1 might be due to separate stimulation of different cell populations and/or by activation of a tyrosine‐kinase signal transduction pathway complementary to the IL‐2 activation signal.
Modifiers of the human mucosal immune system
Authors: GLEESON MAREE , CRIPPS ALLAN W , CLANCY ROBERT L 
Published: July 2007

SummaryThis review focuses on saliva as a measure of mucosal immunity in man. The review will cover studies of parameters that modify the early ontogeny patterns of mucosal immunity and the impact of infections and physiological variables on the human mucosal immune response. The most significant modifiers of human mucosal immunity are events that occur in the neonatal maturation period and, later in life, the interplay between the immune system and the neuroendocrine systems. IgA antibodies are the predominant isotype involved in the human mucosal immune response and are important for protection at mucosal surfaces. The level of IgA in mucosal secretions is modified by antigenic stimulation as well as by many physiological variables. Studies have also revealed that IgM plays a significant immunoregulatory role at mucosal surfaces, particularly during episodes of infection or stress. The detection patterns of IgD in saliva of neonates suggests a role for IgD in the initial maturation process of mucosal immunity. The role of IgG at mucosal surfaces is unclear and although IgG may play a compensatory role in IgA deficiency, the detection of high levels of IgG in saliva appears to be associated with periods of increased membrane permeability.
Prolactin and insulin regulate the release of IL‐1‐α and IFN‐γ from murine splenocytes activated with porins or LPS of Salmonella typhimurium
Authors: VITIELLO MARIATERESA , SCARFOGLIERO PASQUALE , GALDIERO MARILENA , GORGA FERNANDA , SOMMESE LINDA 
Published: July 2007

SummaryMurine splenocytes treated with prolactin (PRL) or insulin were stimulated in vitro with porins or lipopolysaccharide (LPS) of Salmonella typhimurium. It was seen that PRL inhibits the release of IFN‐γ from splenocytes treated with porins by about 20% while having no effect on the release of IL‐1‐α. Splenocytes stimulated with LPS, in the presence of PRL, had a reduced release of IFN‐γ (35%) and IL‐1‐α (70%). The porin‐stimulated splenocytes exhibited a remarkable increase in IL‐1‐α release (100%) and a diminished release of IFN‐γ (about 50%) in the presence of insulin. The splenocytes stimulated with LPS had a reduced release of IL‐1‐α (75%) and IFN‐γ (about 50%) when insulin was added.The data suggest that the classical endocrine system participates in a bioregulatory feedback loop that may prevent unwanted toxicity from cytokine excess. However, some bacterial products sometimes enormously unbalance this regulatory network.
Cycloheximide‐induced apoptosis in Burkitt lymphoma (BJA‐B) cells with and without Epstein‐Barr virus infection
Authors: ISHII HIDEAKI H , ETHERIDGE MARIA R , GOBÉ GLENDA C 
Published: July 2007

SummaryEpstein‐Barr virus (EBV) has been shown, in many instances, to protect B cells from apoptosis via expression of select EBV proteins and up‐regulation of bcl‐2 or its homologues. However, at present little is known about the influence of EBV infection against cancer therapy‐induced apoptosis in EBV‐associated cancers. Many anti‐cancer treatments act via inhibition of protein synthesis and so could influence the reported protein‐dependent mechanisms involved in EBV inhibition of apoptosis. In the present study. Burkitt lymphoma (BJA‐B) cells were treated with a potent protein synthesis inhibitor, cycloheximide (CHX). Two variants of BJA‐B cells were used, one with EBV infection (EBV(+)), and one free of infection (EBV(‐)). Cells were collected 0, 3, 6, 12, 24 and 48 h after addition of either 1 or 50 μg/mL of CHX. Control cultures were untreated. Apoptosis was quantified using established morphological and biochemical characteristics, and protein concentrations assessed. CHX treatment of EBV(‐) BJA‐B cells induced massive levels of apoptosis. Apoptosis was inhibited, but remained significantly higher than that found in control cultures, in similarly treated EBV(+) cells. The study demonstrates that induction of apoptosis in EBV(‐) and EBV(+) cells is not dependent on new protein synthesis, and may be caused by removal of a ‘cell survival’ protein. In addition, the reduction in CHX‐induced apoptosis in the EBV(+) cells, when compared with similarly treated EBV(‐) cells, is not dependent on new protein synthesis and so may be indicative of a bcl‐2 independent mechanism in this instance. The results have important implications for devising and assessing treatment of EBV‐associated malignancies.
Extrathymic and thymic origin of murine IEL: Are most IEL in euthymic mice derived from the thymus?
Authors: LIN TESU , MATSUZAKI GORO , KENAI HIROYUKI , NOMOTO KIKUO 
Published: July 2007

SummaryAlthough an abundance of literature supports the hypothesis that murine intestinal intraepithelial lymphocytes (IEL) can develop extrathymically, whether most IEL in euthymic mice are extrathymically derived is unknown. Recent evidence, however, suggests that the development of most IEL in euthymic mice is influenced either directly or indirectly by the thymus. While some evidence suggests that the thymus can influence the extrathymic development of IEL through thymus‐derived factors, clearly a substantial portion (if not most) of the IEL in euthymic mice are derived directly from the thymus. The ability of the thymus to generate IEL depends on the age of the thymus, as fetal/neonatal thymus up to approximately 2 weeks of age generates a totally different subset of IEL than the adult thymus. These results suggest that the IEL generated from the fetal early neonatal thymus recognize a different antigen than the IEL generated from the adult thymus. The former probably recognizes self‐antigen and the later recognizes bacterial antigen.
The T cell antigen receptor beta chain interacts with the extracellular domain of CD3‐γ
Authors: MANOLIOS NICHOLAS , LI ZHAN GUO 
Published: July 2007

SummarySelective pairwise interactions between a number of CD3 chains and the clonotypic T cell antigen receptor (TCR‐α, ‐β) chains have recently been reported.1 What still remains unanswered is the site of interaction between TCR‐β and CD3‐γ chains. To examine the region of interaction between TCR‐β and CD3‐γ chains, a variety of genetically altered TGR‐β and CD3‐γ chains were constructed using recombinant cDNA techniques. Non‐T cells (COS‐7) were transfected with cDNA constructs, metabolically labelled, and immunoprecipitates were analysed for assembly using non‐equilibrium pH gel electrophoresis (NEPHGE)/ SDS‐PAGE. The results demonstrated that assembly between TCR‐β and CD3‐γ chains was localized to their extracellular domain. These findings, when coupled with the information on pairwise interactions and formation of higher order subcomplexes, extend our model of the structure of the TCR complex.