摘要:

AbstractIt has been shown previously that lymphoid cells from mice which have rejected a tumor induced by the Moloney sarcoma virus‐leukemia virus (MSV‐MLV) complex develop high levels of specific H‐2‐restricted cytolytic T lymphocyte (CTL) activity afterin vitrostimulation with syngeneic, irradiated MLV‐induced lymphoma cells in mixed leukocyte‐tumor cell cultures (MLTC). Attempts to further increase lytic activity by restimulating long‐term MLTC cells with syngeneic, irradiated lymphoma cells have met but with limited success. This report shows that, in contrast to the lack of increased activity observed after specific stimulation with lymphoma cells, nonspecific stimulation of long‐term MLTC cells either with supernatants from secondary mixed leukocyte cultures (2º MLC SN) or with supernatants from concanavalin A‐stimulated spleen cells leads, on a per cell basis, to a further 5 to 10‐fold increase in CTL activity. The stimulatory activity of 2º MLC SN is due to a factor(s) of apparent mol. wt. of 25 000 to 40 000. The activity of the CTL populations formed under these conditions is at least 100‐fold higher against syngeneic as compared to allogeneic MLV‐induced

ISSN:0014-2980    

DOI:10.1002/eji.1830090302

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractA mitogen prepared fromMycoplasma neurolyticumhas been demonstrated to induce extensive transformation ofin vitrocultured rat B lymphocytes. The data summarized in this report show that rat thymus cells as well as hydrocortisone‐resistant thymocytes were not activated by this mitogenic agent. On the other hand, spleen cells obtained from thymectomized, lethally irradiated and bone marrow‐reconstituted rats were extensively activated byM. neurolyticum.Furthermore,M. neurolyticumwas shown to induce the development of antibody‐producing cells, as attested by the appearance of direct plaque‐forming cells against sheep red blood cells and trinitrophenylated sheep red blood cells in spleen cell cultures exposed to this mitogen. It was also demonstrated that stimulation of rat lymphocytes by this mitogen was inhibited by anti‐rat immunoglobulin antibodies.In view of these data, it was suggested thatM. neurolyticum, which activates mouse B lymphocytes, is a potent mitogen for rat B lymphocytes as well. This mitogen is a significantly more powerful mitogen for rat B lymphocytes than any other known mitogens. The availability of such mitogenic material in the rat system will enable studies on control mechanisms of action and differentiation of rat B ly

ISSN:0014-2980    

DOI:10.1002/eji.1830090303

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractMilk fat globules (MFG), which are formed by exocytosis of lipid from epithelial cells of the mammary gland, are enveloped by plasma membrane from the epithelial cells. Highly purified, detergent‐solubilized MFG membranes have been shown to contain molecules reactive with a rabbit antiserum against HLA‐DR antigens. Indirect immunoprecipitation combined with polyacrylamide gel electrophoresis in sodium dodecyl sulfate demonstrated that the MFG membrane material reactive with the antiserum comprised molecules which under denaturing conditions displayed molecular weights of 28 000 and 35 000. The two types of polypeptide chains, which were both glycosylated, were held together by noncovalent forces under nondenaturing conditions. Various types of chemical and physicochemical analyses failed to reveal any significant differences between the HLA‐DR‐like antigens from MFG and from spleen cells. Since the HLA‐DR‐like antigens bound detergent in micellar form and were expressed on the outside of intact MFG, as revealed by indirect immunofluorescence, it is concluded that these antigens are embedded in the hydrocarbon matrix of the MFG and not merely passively adsorbed o

ISSN:0014-2980    

DOI:10.1002/eji.1830090304

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractSpleen cells fromTrypanosoma congolense‐infected mice showed a drastic depression in their capacity to respond to B and T lymphocyte mitogens and to allogeneic spleen cells in mixed lymphocyte cultures. Spleen cells from infected mice were also poor stimulators in mixed lymphocyte cultures. The poor responsiveness or stimulation capacity was not due simply to dilution of relevant B or T lymphocytes by the large number of null cells found in the spleens of infected animals. These null cells expressed approximately eight times more H‐2 antigen than spleen cells from normal (uninfected) mice and were devoid of Ia antig

ISSN:0014-2980    

DOI:10.1002/eji.1830090305

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractSpleen cells from trypanosome‐infected mice strongly suppressed lymphocyte stimulation induced in normal spleen cell populations by lipopolysaccharide, concanavalin A or allogeneic (H‐2‐different) stimulator cells. This suppression was not H‐2‐restricted, as responses of spleen lymphocytes both allogeneic and syngeneic to the suppressors were inhibited. Irradiation or mitomycin C treatment of suppressor populations markedly reduced but did not eliminate suppressor activity. Suppressor populations were effective when present in very low numbers. Addition of suppressor cells to mixed lymphocyte cultures at various intervals after initiation of the cultures showed that the suppressors require 48 h to manifest their activity. Cell depletion or enrichment experiments indicate that the mechanism of suppression is complex and involves more than one

ISSN:0014-2980    

DOI:10.1002/eji.1830090306

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractSpleen cells from a BALB/c mouse that had been immunized with human thymocytes were fused with the myeloma line P3‐NS1/1Ag 4.1. One of the resulting hybrid clones (NA1/34) secreted an antibody that was highly specific for human thymocytes. Eighty‐five % of thymocytes expressed the antigen designated HTA1. There were an estimated 15 × 104molecules of HTA1 per cell, and it is therefore a major surface molecule. The expression of this antigen on thymocytes appears to be reciprocal to HLA, as recognized by another monoclonal antibody W6/32. Immunoprecipitated material from [125I]‐labeled thymocyte membranes was analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate which disclosed a single component of 45 000 molecular

ISSN:0014-2980    

DOI:10.1002/eji.1830090307

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractCytotoxic T lymphocytes (CTL) were generated to syngeneic cells derivatized with serologically cross‐reactive compounds (4‐hydroxy‐3‐nitro‐phenyl)acetyl (NP) and (4‐hydroxy‐5‐iodo‐3‐nitro‐phenyl)acetyl (NIP) in order to investigate the possible role of a heteroclytic T and B cell receptor marker (U. Krawinkel et al.,Eur. J. Immunol.1977.7: 566) in CTL‐target cell interaction. The cytotoxic cells of both BALB/c and C57BL/10 (B 10) origin react specifically with target cells of the inducer type; no heteroclicity of the overall cytotoxic response can be observed by CTL of B 10 origin. The results suggest that in this system, the specificity of CTL is determined by a receptor with a variable region different from that of the isolated NP‐specific antigen‐ bindi

ISSN:0014-2980    

DOI:10.1002/eji.1830090308

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractTolerance to the hapten 2,4‐dinitrophenyl (DNP) induced by the injection of DNP coupled to isologous IgG (carrier‐determined tolerance) is associated with a receptor blockade of antigen‐binding lymphocytes. In the present study, hapten‐specific suppressor cells were detected in the spleens of mice made tolerant by intravenous injection of 200 μg DNP‐IgG. When spleen cells from mice rendered tolerant to DNP were co‐cultured with normal spleen cells in Marbrook cultures, the response to DNP‐Ficoll was suppressed, while the response to sheep red blood cells was not altered. Depletion of T cells from these spleens restored the normal anti‐DNP response. The suppressor cells were not detectable in the spleen lymphocyte population of mice in the early stages of tolerance but were present on day 7 after injection of tolerogen, and disappeared by day 14. Mice injected with larger doses of 1 mg or four weekly doses of 200 μg DNP‐IgG did not have detectable suppressor cells. Thus, it appears that a short‐lived suppressor T cell is generated in carrier‐determined tolerance. This cell most likely plays a minor role in the mechanism of carrier‐determined tolerance and may be associated with the receptor blockade which i

ISSN:0014-2980    

DOI:10.1002/eji.1830090309

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractRat alloantibodies recognizing classical transplantation antigens (CTA) or non‐H‐1 determinants were able to compete effectively with monomeric IgE or IgG‐coated sheep erythrocytes for receptor sites on the rat mast cell surface. Inhibitory capacity, however, was entirely confined to anti‐CTA antibodies of the IgG2asubclass, whereas IgG1antibodies lacked this ability.Analogously, F(ab')2fragments of anti‐CTA antibody consistently failed to affect IgE binding, but exposure of cell‐bound F(ab′)2to anti‐rat IgG restored its inhibitory capacity. From these results it was concluded that receptor sites recognizing the Fc portion of the anti‐CTA molecule are involved in the inhibition process.Based on a cytotoxicity assay and on comparative absorption studies on alloantisera, the existence and relative amount of CTA and I region‐associated antigens on purified rat mast cells and lymph node cells were analyzed. Whereas the CTA concentration per unit surface area on both cell types was very similar, rat mast cells consistently

ISSN:0014-2980    

DOI:10.1002/eji.1830090310

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY

摘要:

AbstractThe surface IgM of Daudi Burkitt lymphoma cells has been shown to consist of μ chains and x chains covalently linked, by disulfide bonding, to a novel polypeptide chain of approximate molecular weight 33 000. This novel polypeptide chain (P33) is similar in several properties to the heavy chain of the Ia antigen: glycoprotein nature; apparent molecular weight; isoelectric behavior and cysteine content. The linkage of P33 to surface immunoglobulin has not been observed with any other human lymphoma or lymphoblastoid cell lines

ISSN:0014-2980    

DOI:10.1002/eji.1830090311

出版商:WILEY‐VCH Verlag GmbH    

年代:1979

数据来源: WILEY