摘要:

Primary and secondary cell-mediated immune responses are inhibited in vitro and in vivo by polyunsaturated fatty acids, which may have an immune regulatory function in the organism.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Previous reports have shown that one cytolytic T lymphocyte (CTL) can kill more than one allogeneic target cell, but have not established whether after its action on one or more target cells, each CTL can attack a second set of target cells at a later time. The experiments described here show that one CTL can kill more than six target cells, and they suggest that CTL can do this sequentially in time. Hence, the small number of specifically sensitized lymphocytes found in rejecting grafts could play an important role. Moreover, sequential killing would imply that CTL are not harmed during their interaction with specific target cells. If killing were effected by secretion of a nonspecific toxin, the killer cell would then have evolved some device for resisting its own toxin in order to survive. Whether or not this is the case has not yet been fully resolved.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

“Hodgkin's-like” reticulum cell sarcoma develops spontaneously in most SJL mice. Germ-free and conventional SJL mice bearing advanced reticulum cell sarcoma were treated with X-irradiation and transplantation of bone marrow from SJL or C3H/He donors. The 120-day survival rate of germ-free mice receiving allogeneic bone marrow (70%) exceeded that of all control groups; more importantly, germ-free mice that survived more than 4 months after treatment with allogeneic cells had no evidence of neoplastic lesions when killed. The germ-free environment effectively prevented graft-versus-host disease that was lethal to conventional mice. The results of these experiments offer additional evidence that bone marrow transplantation can be used as a therapeutic tool for spontaneous murine neoplasms.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Eggs of varying degrees of genetic foreigness were implanted into the hemocoel of an insect larvae (Pimpla instigator, Hymenoptera). For xenogenic implants, eggs of Drosophila melanogaster (Diptera) and eggs of Apechthis compuctor (Hymenoptera) were employed. Pimpla eggs of stock culture and Pimpla eggs of genetically defined pure strains were used for allogenic implants and isogenic implants, respectively. The host response that has been studied is that of encapsulation; it was possible to examine quantitatively the effect of genetic relationship on the degree of cellular reaction, i.e., thickness of capsule. Encapsulation occurred with increasing intensity as the degree of genetic difference increased, indicating that Pimpla larvae were able to discriminate not only between self and not-self, but also between different degrees of not-self.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Adult thymectomized mice were sublethally irradiated and reconstituted with various doses of syngeneic bone marrow. Immunological reactivity was assessed by allogeneic skin grafting at various intervals after reconstitution. It was found that reconstitution with high doses (1 × 107, 2 × 107) of bone marrow was associated with an ability to reject allogeneic skin grafts and that this reactivity increased with time. Following rejection of a first skin graft, second grafts were rejected in an accelerated manner. These mice had measurable levels of Thy 1.2 positive cells in the spleen. In contrast, low-dose bone marrow reconstitution (1 × 106, 2 × 106) produced mice which did not reject either first or second allogeneic skin grafts, and such mice had at most only very low levels of Thy 1.2 positive cells in their spleens.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effect of azathioprine on in vitro baboon lymphocyte function tests was evaluated using the mitogen stimulation test, the mixed lymphocyte culture test, the migration inhibition factor test, the cell-mediated lymphocytotoxicity test and the antibody dependent cell-mediated cytotoxicity test. It was found that azathioprine inhibited phytohemagglutinin and Concanavalin A stimulation at lower concentrations than those required to inhibit pokeweed mitogen stimulation. It inhibited the MLC reaction with as little as 0.2 μg/culture in the microculture system. Azathioprine had no effect on (a) the release of migration inhibition factor, (b) the cell-mediated lymphocytotoxicity assay if presensitized cells were used, and (c) the antibody-dependent cell-mediated cytotoxicity assay. However, azathioprine inhibited CML if it was added during in vitro sensitization and induction of killer cells. These in vitro results suggest that azathioprine inhibits those reactions which require cellular division.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The mammalian equivalent of the Bursa of Fabricius, the organ responsible for B cell maturation in avian species, has not been identified despite anatomic and ablative studies which suggest that the gut-associated lymphoid tissues (GALT) subserve this function. By analogy to the Bursa, the mammalian organ directing B cell ontogeny should be the site where IgM-bearing cells (B cells) are first identifiable. In this study, fluorescein-tagged heavy chain specific antirabbit IgM is used to localize initial sites of B cell appearance in rabbit fetal and neonatal lymphoid tissues. IgM-bearing cells are found 2 days before birth in the thymus and 1 day before birth in GALT. Immunoglobulin-bearing cells in spleen, lymph node, and bone marrow are undetectable until after birth. B cells bearing the IgM marker precede the appearance of IgG-bearing cells by 1 to 4 days in all instances. Intraperitoneal implantation of Millipore chambers containing immature fetal thymic tissue into neonatal hosts reveals that in situ development of IgM cells takes place independent of host cell traffic. The results suggest that B cell ontogeny in mammals is more complex than in avian species and demonstrates probable involvement of the thymus in the maturational process.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

H-2dmice treated before skin grafting with either soluble alloantigen prepared from H-2bcells or with serum obtained from similarly sensitized mice showed a significantly prolonged survival of H-2bskin allografts. This in vivo enhancement was paralleled by a depression of cell-mediated cytotoxicity to [51Cr]H-2btarget cells in vitro. Such in vitro and in vivo effects were abrogated when mice were repeatedly injected with soluble alloantigen before and after skin grafting, demonstrating that enhancing antibody present could be neutralized by this mode of antigen administration. The data suggest that serum factors present in mice pretreated with soluble alloantigen lead to specific blocking at the induction phase of the cell-mediated immune response and result in skin graft enhancement.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Monocytes from human peripheral blood, when incubated in vitro, spread onto the surface of the glass. Horse antihuman lymphocyte globulin (ALG) added to the incubation chamber inhibits the spreading, while normal horse globulin (NHG) does not. The inhibition depends on the concentration of ALG admixed to the mononuclear blood cells. Eleven coded samples of antihuman ALG were assayed for the ability to inhibit monocyte spreading. This potential was then compared to the in vivo immunosuppressive effect of the same samples determined by the prolongation of skin allograft survival in subhuman primates. It was found that the in vitro inhibitory activity correlated rather well with the in vivo immunosuppression. Therefore, the inhibition of monocyte spreading is proposed as an additional test system for the in vitro evaluation of the immunosuppressive potential of antihuman ALG.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Six individuals were immunized once, intradermally, with buffy coat cells from 100 ml of whole blood. The donor differed from the recipient for four HL-A antigens, two from the first and two from the second series. Two of the six recipients developed complement dependent cytotoxic antibodies, one of them against the immunizing donor only. Four of the six developed antibodies which were able to induce cell-mediated cytotoxicity, and which also inhibited the mixed lymphocyte culture interaction. Mainly the responding cell in mixed lymphocyte culture was found to be inhibited. Antibodies with HL-A specificity seemed, at least partly, to be responsible for the observed effects.

ISSN:0041-1337    

出版商:OVID    

年代:1976

数据来源: OVID