摘要:

AbstractNatural resistance to hemopoietic allograft results in functional elimination of the graft from the host within 24 to 48 h. The resistance is specific and is directed to the cell surface target structures of an unidentified nature. These determinants are controlled by the major histocompatibility complex‐linked hemopoietic histocompatibility (Hh) loci and expressed by cells of the hemopoietic system. In this study, the susceptibility of various hemopoietic progenitors, as well as the nature and the kinetics of the early rejection process, were examined by directly following the functional survival of the grafted progenitors by periodic sampling. In both F1hybrid and inbred allogeneic hosts, multipotential progenitors for granulocyte‐erythrocyte‐monocyte‐megakaryocyte lineages, bipotential progenitors for granulocyte‐monocyte lineages and unipotential progenitors of erythrocyte, granulocyte and monocyte were susceptible to elimination. Therefore, within the limited range of comparisons, neither the lineage, nor the degree of commitment or differentiation determines the susceptibility of hemopoietic progenitors to resistance. Functional elimination of the grafted progenitors from the recipient spleen was irreversible upon cultivation in semisolid medium. The frequency of seeding in the spleen at 3 h was comparable in resistant and susceptible hosts elimination commenced shortly afterwards and by 24 h after transplantation<10% of clonogenic progenitors remained functional. Activation of natural killer cells strengthened pre‐existing resistance, but did not convert genetically susceptible mice to resistant. Therefore, the resistance is dependent on an effector mechanism with predetermined

ISSN:0014-2980    

DOI:10.1002/eji.1830190702

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe effects of interferon‐γ (IFN‐γ) on protein synthesis of a pre‐B cell leukemia, L1210, have been studied by two‐dimensional gel electrophoresis. In total cell extracts, at least ten proteins were inducedde novo, or increased in their expression, after an 18‐h IFN‐γ treatment, whereas in the nuclear extracts eight proteins were specifically induced. Of these, increased synthesis of a 40‐kDa/pI 5.9 cytoplasmic protein was the most prominent and reproducible. Most of these proteins appear to be specific for a defined step of differentiation, since they are not found in other B cell leukemias upon IFN‐γ treatment. Others appear to be tissue specific, since they are not induced in fibroblasts nor in T cells. In addition, synthesis of some of the induced proteins appeared to require rapid transcription of new mRNA, because actinomycin D markedly inhibited their formation when added immediately before IFN‐γ. In keeping with this finding,in vitrotranslation of mRNA from IFN‐γ‐treated L1210 cells into a rabbit reticulocyte lysate system, followed by analysis of the labeled proteins by two‐dimensional gel electrophoresis, revealed the appearance of at least seven proteins.Taken as a whole, these results demonstrate that in leukemic pre‐B cells IFN‐γ induces the transcriptional activation of genes coding for cytoplasmic and nuclear proteins, some of which could be employed a

ISSN:0014-2980    

DOI:10.1002/eji.1830190703

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractA fusion between the mouse AKR thymoma BW5147 and a culture of homogeneously OX8+(CD8) rat T lymphoblasts yield interleukin (IL) 2‐dependent T cell hybridomas when selected in HAT medium supplemented with IL 2‐containing supernatants of concanavalin A‐activated cells and dexamethasone. IL 2‐independent variants can be selected from cloned IL 2‐dependent hybrids in the absence of conditioned medium. Karyotype analysis was used to test a previously proposed hypothesis according to which IL 2‐independent variants arise through loss of a specific cytotoxic T lymphocyte (rat) chromosome carrying a gene responsible for IL 2 dependence. Comparison of karyotypes of several independently derived hybrids with those of their IL 2‐independent variants showed that the hybrids contain at least one homologue of all rat chromosomes, and that no pair of rat chromosomes is consistently absent in the IL 2‐indep

ISSN:0014-2980    

DOI:10.1002/eji.1830190704

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe morphologic and functional characteristics of cells freshly isolated from human peripheral blood and bearing a T cell receptor (TcR) γ/δ were analyzed. Cell preparations highly enriched for TcR γ/δ+cells were obtained by treatment of E rosette‐forming lymphocytes with anti‐CD4 and anti‐CD8 monoclonal antibodies (mAb) and complement. These preparations consisted of 64–82% TcR γ/δ+lymphocytes, as indicated by the sum of cells reacting with the BB3 and A13 mAb which define two distinct, nonoverlapping, TcR γ/δ+cell subsets in the peripheral blood. TcR γ/δ cells were able to form conjugates with the natural killer‐sensitive K‐562 and with the natural killer‐resistant HL‐60‐R tumor cell lines. The cytochemical localization of lysosomal acid hydrolases showed that 95%–98% of the cells in the TcR γ/δ+preparations had the morphologic features of granular lymphocytes. Moreover, electron microscopy analyses showed that TcR γ/δ+cells had electron‐dense granules dispersed in the cytoplasm and a variety of smooth vesicles, a morphology identical to that of other CD3‐or CD3+granular lymphocyte subsets. Freshly isolated TcR γ/δ+cells were unable to lyse K‐562 and natural killer‐resistant targets, such as HL‐60‐R and P815. However, low levels of target cell lysis were observed upon triggering of the effectors by anti‐CD3 TcR mAb or by lectin. After short‐term culture with inter‐leukin 2, TcR γ/δ+cells acquired a strong cytolytic activity against K‐562 and HL‐60‐R target cells in the absence of triggering stimuli, and also displayed high levels of cytoly

ISSN:0014-2980    

DOI:10.1002/eji.1830190705

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractSo far, the role of fibroblasts in inflammatory processes has been underestimated. We have previously shown that stimulation of fibroblasts with viruses or bacteria results in a simultaneous production of several cytokines, including interferon‐β, interleukin (IL) 6 and colony‐stimulating factors. We here report that virally infected fibroblasts produce also a chemotactic factor for granulocytes. The activity is inducible not only by measles virus but also by IL 1β and the double‐stranded RNA poly(rI) ˙ poly(rC). This factor, when purified to homogeneity, occurs as a 6–7‐kDa protein doublet upon sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. The pure protein is serologically related to a fully characterized granulocyte chemotactic peptide (GCP) from monocytes, designated IL8. Furthermore, the chemotactic factor from fibroblasts has an NH2‐terminal sequence identical to that of GCP/IL 8, small differences in NH2‐terminal processing being observed. Finally, in addition to diploid fibroblasts, the osteosarcoma MG‐63 cell line is also a producer of GCP/IL 8. It can thus be concluded that GCP/IL8 can be produced by several cell types in response to infection and that fibroblasts can contribute to chemot

ISSN:0014-2980    

DOI:10.1002/eji.1830190706

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractThe ontogenic development of B cell clonal precursors (BCP) reactive to bromelaintreated, syngeneic erythrocytes (BrMRC) and to single‐stranded DNA has been studied by limiting dilution of both spleen and peritoneal cells. It was found that the frequency of anti‐BrMRC BCP in the spleen is very low up to 4 weeks of age and slowly increases thereafter, to reach adult levels by 6–10 weeks. In the peritoneal cavity, no such BCP can be found before 2 weeks, but they occur at a very high frequency already by 3 weeks of age. Injection of adult, normal syngeneic T cells at birth has no apparent effect on the representation of anti‐BrMRC BCP in the peritoneal cavity, but brings these to adult levels or even higher in the spleen already at 3 weeks of age. Accordingly, adult athymic (nude) mice contain normal frequencies of BrMRC‐specific BCP in the peritoneal cavity but are devoid of such clones in the spleen. In contrast, the frequency of anti‐DNA BCP is very high throughout postnatal development in both spleen and peritoneal cavity, of normal and athymic mice, in both resting and naturally activated splenic B cell compartments, and it is independent of T cell transfers into nude animals. These results indicate the role of T cells in the establishment of some clonal specificities in the adult, splenic autoreactive B cell

ISSN:0014-2980    

DOI:10.1002/eji.1830190707

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractSequential appearance of T cell subpopulations occurs in the thymus of irradiated AKR (H‐2k, Thy‐1.1) mice at an early stage after transplantation with bone marrow cells of C3H/HeN (H‐2k, Thy‐1.2) mice. The donor‐derived thymocytes were first detected on day 8 after bone marrow reconstitution. Although most of the thymocytes were CD4‐CD8‐cells, an appreciable level of CD4+CD8+cells was detected in the thymus at this stage. The early appearing CD4+CD8‐cells were a novel subset of thymocytes that were J11d+CD3‐. From day 10 to day 21 the proportion of CD4+CD8‐CD3‐J11d+cells decreased while the proportion of CD4+CD8‐cells and CD4+CD8‐CD3+J11d‐cells increased. The CD4+CD8‐CD3‐cells seem to diversify to form CD4+CD8+thymocytes after short‐term culturein vitro.These results suggested the existence of a differential pathway from CD4‐CD8‐cells to CD4+CD8+

ISSN:0014-2980    

DOI:10.1002/eji.1830190708

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractA minor subset of B cells whichin vivoexpress the surface antigen CD5, has attracted much attention because of its involvement in autoimmune responses. On the basis of observations showing self‐renewal capacity of such cells in mice and also the absence of a substantial change of CD5 phenotype during B cell activationin vitro, the CD5+B cells are now generally considered to represent a separate cell lineage. In the present study, CD5‐B cells were isolated by cell sorter and then stimulatedin vitrowith mutagenized EL4 thymoma cells in the presence of T cell supernatant. About 70% of the B cells were CD5+after 3 days. Thus, the CD5 antigen behaves as a B cell activation marker. In our system we found that the frequency of rheumatoid factor‐producing B cells was on average three times higher in CD5+than in CD5‐B cells isolatedex vivofrom human peripheral blood. Most likely this reflects frequent activation of such autoreactive B cells

ISSN:0014-2980    

DOI:10.1002/eji.1830190709

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractNucleated cells other than sperm (NCOS) were isolated from human semen by centrifugation on a Ficoll density gradient. Using tissue‐specific monoclonal antibodies (mAb)>99% of the NCOS were found to be sperm cell precursors (SpP). These cells were tested for the expression of class I and II (DR, DP and DQ) HLA antigens by using specific mAb. The anti‐HLA class I and II and anti‐β2‐microglobulin mAb reacted with<1% of the NCOS. This was demonstrated by indirect immunofluorescence microscopy and fluorescence‐activated cell sorter analysis. These results were similar to those obtained from testing germ cells in frozen sections of normal adult testis using the same panel of mAb. In mixed lymphocyte‐NCOS cultures, the SpP failed to stimulate allogeneic lymphocytes even when different concentrations of cells were used. These results indicate little or no expression of HLA class I and II including the HLA‐D (T cell‐defined) determinant on the SpP, a phenomenon which could be of biolo

ISSN:0014-2980    

DOI:10.1002/eji.1830190710

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY

摘要:

AbstractWe have investigated several aspects of the inhibitory effects of monoclonal antibodies (mAb) directed against MHC class II antigens in B cell activation/proliferation, using a panel of mAb specifically reactive with antigens encoded by HLA class II loci (DP, DQ, DR). All mAb except the anti‐DP mAb inhibited significantly anti‐μ plus B cell growth factor‐induced DNA synthesis. Only one mAb, however, which was reactive with gene products of all three class II loci (DP, DQ, DR) inhibited anti‐μ‐induced DNA synthesis as well as c‐myc mRNA expression. In addition, the same mAb inhibited the early events induced by anti‐μ stimulation alone, including phosphatidylinositol turnover and elevation of [Ca2+]i. In contrast to previous findings in the murine system, none of the anti‐MHC class II mAb used in this study increas

ISSN:0014-2980    

DOI:10.1002/eji.1830190711

出版商:WILEY‐VCH Verlag GmbH    

年代:1989

数据来源: WILEY