摘要:

SUMMARYSpontaneous E rosette-forming (T) lymphocytes were monitored in the peripheral blood of rhesus monkeys receiving a 5-day course of rabbit anti-human thymocyte globulin (RATG) after skin allotransplantation. Mean graft survival in RATG-treated recipients was 32.3 ± 7.6 (SD) days compared with 8.2 ± 1.7 (SD) days in controls. The percentage and total number of circulating T cells fell precipitously after RATG treatment and recovered slowly. Linear regression analysis showed that the recovery pattern of the total number of circulating T cells, but not the percentage of T cells, was significantly correlated with rejection.Specific antihuman T cell antibody was detected in RATG preparations after extensive absorption with human erythrocytes, platelets, and B lymphoblastoid cells. The cytotoxic titers of B cell-absorbed RATG preparations to human peripheral blood lymphocytes showed a significant correlation with the mean skin allograft survival times obtained in RATG-treated primates. Overall the data suggest that the immuno-suppressive potency of RATG in the primate skin graft assay is related in large part to its anti-T cell activity.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYIn studies analogous to those in which the thymus dependency of immune functions in murine systems was determined, three chimpanzees were thymectomized, splenectomized, exposed to lethal doses of whole body X-irradiation with limited bone marrow shielding, and subsequently evaluated for lymphocyte markers and functions over a period of years. In the oldest animal studied (Irena, 7.2 years at surgery), the percentage of peripheral blood T cells decreased to about 60% of control values and remained at that level for approximately 11/2years before returning to normal. In the two youngest chimpanzees (Adrian and Boris, 1.7 and 2.2 years at surgery), T cell rosette values dropped to 15 to 40% of control values after irradiation. T cell percentages in one of these young chimpanzees (Adrian) returned to about 75% of the controls 11/2years after X-irradiation. Phytohemagglutinin and concanavalin A mitogen responses were less affected in the oldest chimpanzeee. However, even in the oldest animal, the responses to phytohemagglutinin and concanavalin A began to show a gradual and consistent decline 11/2years after irradiation. Mixed leukocyte culture responsiveness was most affected by the experimental procedures, being greatly reduced in all three chimpanzees during varying time intervals. In general, the effects of the experimental procedures used to produce T cell deficiencies varied with the age of the chimpanzee at surgery, the time after irradiation when the animal was tested, and the lymphocyte marker or function studied.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYRat liver cells prepared by collagenase treatment and separated by density gradient centrifugation with Ficoll-Hypaque solution (specific gravity 1.120), containing only hepatocytes (80%) and Kupffer cells (20%), were found to stimulate strongly Ag-B-incompatible lymphocytes without 2-mercapto-ethanol in culture. The same liver cells could also stimulate Ag-B-compatible lymphocytes in the presence of 2-mercapto-ethanol. A positive response was only seen when the liver cell numbers were 1 ∼ 2% of the responding lymphocytes. Viable liver cells inhibited the reaction in a two-way culture.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYIn order to gain insight into the immunosuppressive mechanism of action of corticosteroids, an in vitro model of the cellular immune response was used to study the effect of methylprednisolone on human lymphocyte-mediated cytotoxicity. Concentrations from 0.25 to 10 μg/ml were equally effective in producing 74% suppression of lymphocyte-mediated cytotoxicity when the steroid was present during the entire period of in vitro sensitization. A 12.5-fold increase in effector to target cell ratio was required to achieve 30%51Cr release when cytotoxic lymphocytes were generated in the presence of methylprednisolone. Lymphocyte-mediated cytotoxicity was suppressed 48% when methylprednisolone was present only during the initial 24 hr of the 7-day in vitro sensitization period. Methylprednisolone also effectively inhibited cytotoxicity when it was incubated with sensitized lymphocytes for 3 hr before incubating these cells with target cells. Our observations suggest that two of the major immunosuppressive mechanisms of action of methylprednisolone are suppression of the generation of cytotoxic lymphocytes and suppression of specifically sensitized cytotoxic lymphocytes.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARY(L × BN)F1skin and heart allografts survive about 7 days in unmodified L hosts. Their survival is only prolonged modestly by active immunization with LBN splenocytes or passive immunization with hyperimmune serum, but the combination of active and passive immunization produces dramatic improvement in graft survival. When the components of this synergistic interaction were analyzed, it was found that not only were lymphocyte-borne antigens and antibodies directed against these antigens important, but also that erythrocyte-borne serologically determined antigens and anti-erythrocyte antibodies were required for optimal survival of both skin and heart allografts. Furthermore, thymic or lymph node cells supplemented with erythrocytes were as effective a source of antigen as whole spleen in prolonging graft survival. These data indicate that, in allograft models in rats, antigens and antibodies that may be of minor importance in producing enhancement when administered individually may be more important when administered together. The underlying basis for the increased effectiveness of erythrocyte-borne antigens and anti-erythrocyte antibodies may be related to the observation that the injected erythrocytes remain in the allogeneic host's circulation to interact with the subsequent i.v. injection of antisera to form soluble antigen-antibody complexes.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYIt was demonstrated in this study that bovine odontogenic tissues and the dissociated cell preparations of such tissues, when transplanted to the subcapsular kidney site of hypothymic mice, retained their phenotypic expression and continued function to produce their recognisable products, dentine and enamel matrices. It was also shown that in the grafts of dissociated odontogenic tissues, cell sorting occurred so that histotypical tissues were formed and that their function produced readily recognisable dentine and enamel matrices. Attention has been drawn to the usefulness of this model for studying a variety of events that occur during odontogenesis.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThe structure and chemical nature of the serologically defined (SD) antigens coded by the major histocompatibility complex (RhLA) of rhesus monkeys was studied. The use of specific anti-SD sera allowed the selective isolation of the corresponding antigens from crude antigen preparations. These were obtained by detergent solubilization after incorporation of3H,35S, and14C amino acids in lymphocytes or mitogen-stimulated lymphoblasts.The results indicate that the SD antigens are of proteinaceous nature and are composed of two polypeptide chains with molecular weights of 44,000 and 12,000, the latter being β2-microglobulin. No differences in molecular size and subunit composition were detected between antigens of both segregant series. The results are discussed in relation to similar data available for the analogous human and murine histocompatibility antigens.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYA quantitative model for the assessment of in situ immunity to solid tumor allografts has been developed. Multicellular spheroids of murine EMT6 mammary sarcoma cells were implanted in the peritoneal cavity of normal or specifically alloimmune mice. Damage to spheroids was quantitatively assessed at various times by trypsinizing the recovered spheroids and assaying for surviving EMT6 cells by a cloning technique. In alloimmune mice, significant destruction of spheroids was observed within 24 hr of implantation, and a 99% reduction in the number of clonogenic MT6 cells in spheroids was consistently found after 48 hr. In contrast, little or no cytotoxic effect was observed when spheroids were implanted for 48 hr in nonimmune mice or in mice immunized against unrelated alloantigens. Implantation of spheroids in alloimmune athymic (nu/nu) mice did not result in appreciable spheroid damage as compared with littermate controls. Histological analysis of spheroids taken from alloimmune mice at the time of maximum tumor cell destruction indicated that large numbers of mononuclear cells had infiltrated the spheroid. These results suggests that multicellular spheroids will be a useful model for quantitative studies of the cellular mechanisms responsible for tissue-damaging reactions in vivo.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYAlloimmune lymphoid cells infiltrating multicellular spheroids of EMT6 mammary sarcoma cells (a solid tumor allograft model) have been characterized according to their morphological and functional properties. Both lymphocytes and macrophages were found within spheroids at the time of peak tumor cell damage. Cytotoxic cells specific for allograft antigens were also present. Using a short-term51Cr release assay, the cells responsible for cytotoxicity were characterized as a non-adherent, nonphagocytic T cell population. Velocity sedimentation cell separation further demonstrated that these cytotoxic cells had the physical properties of small lymphocytes. Some evidence for selective spheroid infiltration by specifically alloimmune cells was also obtained. The possible relationship of this cellular infiltrate to graft damage is discussed.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID

摘要:

SUMMARYThe generation of cytotoxic T cells by normal and primed lymphocytes fractionated on spleen cell monolayers was examined by two methods. In the first method, sublethally irradiated recipients were inoculated with the fractionated cells, and 5 to 6 days later the spleens were tested for cytotoxicity against51Cr tumor target cells syngeneic to the host. Significant reduction of cytotoxic activity was observed in one-half of the experiments. In the second method, the fractionated cells were cultured with mitomycin C-treated stimulated cells and tested 6 days later for cytotoxicity. A slight reduction of cytotoxic activity was observed. In both methods, the cytotoxic response generated by the fractionated alloantigen-primed lymphocytes was similar to the response obtained with unprimed cells.

ISSN:0041-1337    

出版商:OVID    

年代:1978

数据来源: OVID