摘要:

AbstractThe topographical distribution of HLA class I antigens has been investigated by the immunoperoxidase technique on normal frozen thymic tissue sections with a panel of mono‐ and polymorphic monoclonal anti‐HLA antibodies. HLA class I framework determinants detected by the monoclonal antibody W6/32. HL were present on 80–90% of cortical thymocytes, as well as on all cortical epithelial and medullary cells. However the staining intensity of cortical thymocytes with this reagent was about threefold weaker than that of the medullary thymocytes. Labeling patterns of selected monoclonal antibodies against matching HLA‐A/B allospecificities revealed striking variations in the quantitative expression of certain HLA‐Avs.HLA‐B locus alloantigenic determinants on cortical thymocytes compared to a consistent staining on almost all medu

ISSN:0014-2980    

DOI:10.1002/eji.1830130512

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractWe studied lines of rat T cells, specifically reactive against myelin basic protein (BP), that were functional in mediating autoimmune encephalomyelitis or in vaccinating rats against induction of active EAE. Herein we report that these functions depended on activation of the cells by incubation with BP or with a T cell mitogen prior to inoculation into recipient rats. Activation was accompanied by the exposure of membrane‐binding sites specific for the lectin peanut agglutinin. Accumulation of activated line cells in the central nervous system and thymus gland was observe

ISSN:0014-2980    

DOI:10.1002/eji.1830130513

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractAllosensitized lymphoid cell populations contain T lymphocytes that can bind to target cells and lyse them. We asked whether there was a relationship between lymphocyte target cell‐binding strength and occurrence of cytolysis. Using graded shear forces to dissociate effector‐target cell conjugates, we found that (a) within an allosensitized lymphoid cell population derived from an heterogeneous mixed leukocyte culture, there were lymphocyte‐target cell conjugates with binding strengths differing by a factor of at least 102, (b) even the minimal force required to release a significant amount of bound target cells could disrupt the plasma membranes of some tumor cells and (c) these tumor cells disrupted by shear forces were probably part of cytolysis‐conducive rather than of non‐cytolysis‐conducive conjugates.We combined this approach with the use of cytolysis‐inhibiting monoclonal antibodies (mAb), and found that antibody‐induced decrease of cytolysis was correlated with a decrease in the percentage of strong or total conjugates, depending on the mAb used. When lectins were added to overcome the inhibitory effect of the mAb, reappearance of cytolytic activity correlated with reappearance of conjugates. This was especially striking using wheat germ agglutinin (WGA): the addition of WGA to irrelevant effector‐target cell combinations did not lead to cytolysis; however, the addition of WGA to relevant effector‐target cell combinations inhibited by mAb led to reappearance of cytolysis and of strong conjugates. Taken together, these and other results suggested that under our experimental conditions a threshold level of binding strength between effector and target cells might be important, although not sufficient, for T cell‐mediated cytotoxicity. These results were not inconsistent with the involvement of mechanical factors in this process. Also, they were in line with the concept of nonantigen‐specific lymphoid cell surface interacting molecules, detected by the mAb used and important for the establishment of strong, functional lymphocyte target cell interactions. Finally, they underlined the necessity of a quantitative estimate of cell‐cell binding strength when investigating the effect of a given agent (e.g. a mAb) on lymphocyt

ISSN:0014-2980    

DOI:10.1002/eji.1830130514

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractDNA synthesis and release was studied in unstimulated splenocytes of strains of mice known to develop spontaneous systemic lupus erythematosus (SLE)‐like disease and in non‐SLE age‐ and sex‐matched strains as well. Newly synthesized DNA was measured as total acid‐insoluble radioactive material present in cell pellet plus supernatant of unstimulated 0–72 h cell cultures [3H]thymidine‐pulsed, whereas DNA release was measured as amount of acid‐precipitable radioactivity found in supernatant of those cultures. In all strains known to develop spontaneous murine SLE the amount of newly synthesized DNA was 1.3–2.1‐fold increased when compared to normal strains studied concomitantly. Furthermore, a significant increase in DNA release into medium, unrelated to cell viability, was observed in those strains as well. These observations clearly demonstrate different metabolic rates of synthesis and release of DNA in murine SLE. This difference suggests the existance of an underlying mechanism responsible for extracellular DNA abundancy, which may be important for the formation of circulating DNA‐anti

ISSN:0014-2980    

DOI:10.1002/eji.1830130515

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThere is evidence that natural cytotoxic (NC) cells are in the T cell lineage. To lyse targets, cytotoxic T cells (TK) must recognize any of the myriad antigens plus syngeneic major histocompatibility complex (MHC) determinants. In spite of the evidence which indicates TKand NC are in the same lineage, NC cells can recognize few determinants (perhaps only one) and do not require recognition of MHC determinants.In addition to differences in the requirement for target recognition, in this report we show that TKcells and NC cells also use different lytic mechanisms to lyse the same targets. NC effectors initiate a lytic mechanism in NC‐sensitive and NC‐resistant targets. This lytic mechanism requires approximately 4 h before target lysis is apparent in NC‐sensitive targets; it is inactivated by a protein synthesis‐dependent counterlytic mechanism in NC‐resistant targets. In contrast the TKlytic mechanism causes a rapid release of51Cr from both NC‐sensitive and NC‐resistant targets and is not inhibited by the NC counterlytic mechanism present in NC‐resistant cells. These findings lead to the conclusion that the mechanism used by NC cells to lyse targets is fundamentally different from that

ISSN:0014-2980    

DOI:10.1002/eji.1830130516

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

ISSN:0014-2980    

DOI:10.1002/eji.1830130517

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

ISSN:0014-2980    

DOI:10.1002/eji.1830130501

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY