摘要:

AbstractThe integrin αE(HML‐1, αIEL, αM290) is largely expressed on lymphocytes in epithelial sites, especially the gut mucosa. We investigated whether αEhas any role in homing or delineates a phenotype with distinct migratory behavior. Lymph node T cells were stimulated for 5 days with anti‐CD3 in the presence or absence of transforming growth factor (TGF)‐β1to generate αE+or αE−cells, respectively. The two populations were then tested for their homing properties in mice. Both αE+(TGF‐β‐treated) and αE−(control) cells of either CD4+or CD8+subset had a low capacity to enter the gut and showed the same homing behavior with respect to a variety of other organs. The same was true for αE+and αE−cells that had been briefly stimulated with anti‐CD3 (24 h) and then allowed to return to a resting state before injection, though in this case both populations showed a greater capacity to recirculate through lymphoid tissue than was seen with fully activated cells. The results indicate that αEβ7does not act as a homing receptor, and that the expression of the site‐specific marker αEdoes not correla

ISSN:0014-2980    

DOI:10.1002/eji.1830250602

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractA major drawback to the use of OKT3, a mouse anti‐CD3 monoclonal antibody (mAb), as an immunosuppressive agent is the associated cytokine release syndrome. We used a mouse model to elucidate the properties of anti‐CD3 mAb responsible for these cytokine‐related side effects. We have previously demonstrated that the hamster anti‐CD3 mAb 145‐2C11 induced strong cytokine release and morbidityin vivo, whereas two rat anti‐CD3 mAb 17A2 and KT3 did not. In the current study, we show that the mitogenic capacity of soluble anti‐CD3 mAbin vitrocorrelates with their induction of side effectsin vivo. Mitogenesisin vitroand tumor necrosis factor‐α (TNF‐α) releasein vivoinduced by anti‐CD3 mAb could be inhibited by the anti‐FcγR mAb 2.4G2, indicating that FcγR binding of anti‐CD3 mAb is responsible for their mitogenic properties and for their induction of side effects. Importantly, the two non‐mitogenic rat anti‐CD3 mAb were equally capable of suppressing skin allograft rejection as the mitogenic hamster anti‐CD3 mAb, suggesting FcγR binding of anti‐CD3 mAb is not essential for their immunosuppressive properties. This suggestion is reinforced by our demonstration that administration of 2.4G2in vivodid not interfere with immunosuppression of skin allograft rejection by 145‐2C11. These findings suggest that clinical use of non‐mitogenic anti‐CD3 mAb will result in effective immunosuppres

ISSN:0014-2980    

DOI:10.1002/eji.1830250603

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractNephrotic syndrome (NS) is a renal disease characterized by proteinuria and hypoalbuminemia. In NS patients without any allergic disease, serum IgE and IgG4 levels were selectively increased, and peripheral blood mononuclear cells (MNC) spontaneously produced IgE and IgG4. T cells produced interleukin (IL)‐13 spontaneously, and B cells constitutively expressed IL‐13 receptors (IL‐13R). In addition, T cells stimulated surface IgE‐negative (sIgE−) and sIgG4−B cells to produce IgE and IgG4, respectively, and IgE and IgG4 production was specifically blocked by anti‐IL‐13 antibody (Ab). MNC from atopic dermatitis (AD) patients also produced IgE and IgG4 spontaneously. However, in AD patients, T cells spontaneously produced IL‐4, but not IL‐13, and B cells constitutively expressed IL‐4R, but not IL‐13R. T cells stimulated sIgE−and sIgG4−B cells to produce IgE and IgG4, respectively, and the production was specifically blocked by anti‐IL‐4 Ab. On the other hand, sIgE+and sIgG4+B cells from both NS and AD patients spontaneously produced IgE and IgG4, respectively, and this production was not affected by T cells, anti‐IL‐4 Ab, or anti‐IL‐13 Ab. These results indicate that IL‐13 is involved in the enhanced production of IgE and IgG4 in NS, while

ISSN:0014-2980    

DOI:10.1002/eji.1830250604

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe process of mononuclear cell extravasation from the blood into the islets of Langerhans in nonobese diabetic (NOD) mice is dependent on the expression of a set of molecules, most of which remain to be defined. The observation that vascular addressins are expressed in inflamed islets raises the issue of the involvement of one of their ligands, L‐selectin, in the pathogenesis of autoimmune diabetes. Treatment of NOD females with Mel‐14, an antibody specific for L‐selectin, reduced the spontaneous development of both insulitis and diabetes. Pretreatment of diabetic donors with Mel‐14 decreased the capacity of their splenocytes to transfer the disease. However, the treatment of recipients had no effect on the transfer of diabetes by untreated diabetogenic splenocytes. To reconcile these apparently conflicting results, we fractionated spleen T cells from diabetic mice according to L‐selectin expression. Diabetogenic cells were found only in the L‐selectin subpopulation. Thus, diabetogenic cells in adult mice share phenotypic characteristics with activated/memory cells, and enter the pancreas using L‐selectin‐independent mig

ISSN:0014-2980    

DOI:10.1002/eji.1830250605

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe human cell surface molecule CD34 is selectively expressed on uncommitted and committed hematopoietic progenitor cells and on vascular endothelial cells. It has been suggested that CD34 regulates early events in blood cell migration and differentiation, possibly as a cell adhesion molecule. To characterize the patterns of expression of CD34 in the mouse embryo and in the adult, as well as to dissect the function of different portions of the extracellular domain of this molecule, we have generated the first monoclonal antibodies (mAb) specific for mouse CD34. The epitope(s) recognized by these mAb are not carbohydrate moieties, and are comprised either within the immunoglobulin‐like domain or within a portion of the mucin domain, containing approximately half of the predicted O‐ and N‐linked carbohydrate attachment sites. The specificity of the antibodies was established by ELISA and Western blotting. Western analysis revealed that these mAb recognize a protein of approximately 110 kDa in PA6 stromal cell lysates, which can be specifically blocked by the recombinant CD34 protein. To establish the reactivity of these mAb on different cell lineages, a panel of cell lines was stained. This analysis showed strong reactivities with 3T3 fibroblasts, stromal cell lines from fetal liver and with the endothelial cell line D10. Bone marrow hematopoietic progenitors were also stained by these mAb. Immunostaining of frozen sections from embryonic and adult tissues revealed a strong reactivity against vascular endothelial cells at different stages of development, including sinusoidal cells in the fetal liver, yolk sac, and in the fetal bone marrow, endothelial cells from adult lung and kidney, and neural cells, including those of the neural tube of midgestation embryos and neuronal bodies in adult

ISSN:0014-2980    

DOI:10.1002/eji.1830250606

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractTo investigate the role of Fas in the induction of tolerance by viral superantigen (SAG), we infected MRL‐+/+ and MRL‐lpr (Fas mutant) mice with mouse mammary tumor virus (MMTV) (SW), a virus encoding an SAG with the same specificity as endogenous Mtv‐7‐SAG. In normal mice, this infection has two distinct consequences on specific Vβ6+CD4+T cells, consisting of activation followed by clonal deletion. MMTV (SW)‐SAG‐induced activationin vivowas identical in MRL‐+/+ and MRL‐lpr mice. In contrast, clonal deletion showed age‐dependent impairment. Early infection (5 weeks) led to identical clonal deletion of specific T cells in blood lymphocytes from MRL‐+/+ and MRL‐lpr mice, although clonal deletion was slightly impaired in the MRL‐lpr lymph nodes. Late infection (10 weeks) of MRL‐lpr mice led to markedly delayed and reduced clonal deletion. Vβ6+CD4+T cells which escaped clonal deletion in aging MRL‐lpr mice were not anergized by interaction with SAG. These results show that peripheral clonal deletion induced by viral SAG in adult mice is controlled b

ISSN:0014-2980    

DOI:10.1002/eji.1830250607

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractWe have analyzed the expression of VHgene families in IgM, IgD and IgG of peripheral blood B cells from a group of HIV‐infected patients. CD19+CD20+cells were purified and anchored reverse transcriptase‐polymerase chain reaction products were hybridized with VHgene family probes. IgM, IgD and IgG that expressed a VH3 gene family segment, were decreased in patients with low CD4 counts and to a greater extend in patients with AIDS symptoms (up to 85% for IgG) compared to adult healthy donors. This was correlated with elevated levels of IgM and IgG encoded by a VH1 gene family segment (around 60% for IgG). These results confirm and extend previous work that has detected the VH3 gene family under‐representation in HIV infection. Here, we show that,in vivo, this phenomenon actually affects the different B cell populations of the peripheral blood: IgM+or IgG+B cells and also IgM+IgD+naive B cells. In the course of HIV infection, this results in their gradual depletion. Data presented here strengthen the hypothesis that a B cell superantigen exists in HIV infection. These pronounced variations of the normally most‐expressed VHgene family may be related to B cell abnormalities detected in HIV‐infected

ISSN:0014-2980    

DOI:10.1002/eji.1830250608

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe 3′ end of the T cell receptor Vβ7.1 gene contains the five nucleotides CAAGA between the broadly conserved consensus sequence of nucleotides TGC/T GCC AGC AGC (which encode cysteine, alanine, serine and serine at positions 92–95 of the β chain) and the heptamer that signals rearrangement. These nucleotides are frequently preserved during gene rearrangement, resulting in the common presence of glutamine at position 96 and of aspartate or glutamate at position 97 of the Vβ7.1 chain CDR3 loop in peripheral blood lymphocytes. There is selection of Vβ7.1 and of the Vβ7.1 gene‐encoded glutamate at position 97 of the β chain CDR3 loop in the cytotoxic T lymphocyte response to the HLA B2705‐restricted influenza A nucleoprotein epitope SRYWAIRTR. Our results indicate that selection of Vβ7.1 gene‐encoded amino acid residues on CDR3 loops may be one factor driving selection of Vβ7.1

ISSN:0014-2980    

DOI:10.1002/eji.1830250609

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractThe identification of endogenously produced antigenic peptides presented by MHC class I molecules has opened the way to peptide‐based strategies for CTL inductionin vivo. Here we demonstrate that the inductionin vivoof CTL directed against naturally processed antigens can be triggered by injection of syngeneic cells expressing covalent major histocompatibility complex class I‐peptide complexes. In the model system used, the induction of HLA‐Cw3 specific cytotoxic T lymphocytes (CTL) in mice by cell surface‐associated, covalent H‐2Kd(Kd)‐Cw3 peptide complexes was investigated. The Kd‐restricted Cw3 peptide 170–179 (RYLKNGKETL), which mimics the major natural epitope recognized by Cw3‐specific CTL in H‐2dmice, was converted to a photoreactive derivative by replacing Arg‐170 with N‐β‐(4‐azidosalicyloyl)‐L‐2,3‐diaminopropionic acid. This peptide derivative was equivalent to the parental Cw3 peptide in terms of binding to Kdmolecules and recognition by Cw3‐specific CTL clones and could be cross‐linked efficiently and selectively to Kdmolecules on the surface of Con A‐stimulated spleen cells from H‐2dmice. Photocross‐linking prevented the rapid dissociation of Kd‐peptide derivative complexes that takes place under physiological conditions. Cultures of spleen cells or peritoneal exudate cells from mice inoculated i.p. with peptide‐pulsed and photocross‐linked cells developed a strong CTL response following antigenic stimulationin vitro. The cultured cells efficiently lysed not only target cells sensitized with the Cw3 170–179 peptide but also target cells transfected with the Cw3 gene. Moreover, their TCR preferentially expressed Vβ10 and JαpHDS58 segments as well as conserved junctional sequences, as has been observed previously in Cw3‐specific CTL responses. In contrast, no Cw3‐specific CTL response could be obtained in cultures derived from mice injected with Con A‐stimulated spleen cells p

ISSN:0014-2980    

DOI:10.1002/eji.1830250610

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY

摘要:

AbstractT cell receptor (TCR) genes are initially activated in hematopoietic stem cells that have been committed to the T cell lineage during ontogeny. We have established cell lines derived from hematopoietic organs which express truncated TCR δ mRNA (1.3 kbp). In this study, cDNA clones of this mRNA were analyzed to characterize TCR δ gene activation in early T cell development. Transcription started from an intron between Dδ2 and Jδ1, 72 bp upstream from Jδ1, and continued to Jδ1 and Cδ exons, which were directly spliced to Jδ1. Thus, the truncated mRNA expressed by the cell lines was determined to be a germ‐line transcript. The promoter activity of the DNA fragment between Dδ2 and Jδ was assessed by its ability to drive the transcription of a reporter gene linked to it in the cell line expressing the TCR δ germ‐line transcript. TCR δ germ‐line transcription was found not only in these cell lines but also in fetal liver and thymus cells. These findings indicate that the TCR δ germ‐line transcription is a naturally occurring event in developing T cells. The significance of germ‐line transcription of TCR δ genes is unknown, but it may be an event that follows T‐lineage commitment or, at least, may be closely associ

ISSN:0014-2980    

DOI:10.1002/eji.1830250611

出版商:WILEY‐VCH Verlag GmbH    

年代:1995

数据来源: WILEY