摘要:

AbstractOptimal conditions have been developed for measuring interactions at the single cell level between effector cells and target cells in the rat NK cell system. Conjugates were formed between splenic leukocytes and target cells to determine the percentage of target binding cells, and after immobilization of the conjugates in agar, single lytic interactions were measured by the uptake of trypan blue by dead target cells. Cytotoxic effector cells were expressed as a percentage of target binding cells. Factors which influenced conjugate formation were the ratio of effector to target cells, temperature, centrifugation and the conditions of culture of the target cells. When comparing a number of rat and mouse strains with various levels of natural killer cell activity, there was found to be a good correlation between the number of target binding cells and cytotoxicity in the standard51Cr‐release assay in rats, but in mice the removal of nylon‐adherent cells was required to achieve a reasonable correlation. However, 60–70% of the cytotoxicity was lost on nylon fractionation, making this approach of doubtful value. The target‐binding cell and cytotoxic effector cell assays were used in conjunction with the51Cr‐release assay to study the specificity, rat strain variation and ontogeny of natural killer cells. During ontogeny target binding cells reached adult levels sooner than did cytotoxic effector cells. The greatest development of natural killer cells occurred during the first 3 weeks of life; the number of cytotoxic cells per spleen increased 138‐fold up to 21 days of age, compared with an 11‐fold increase between 21 days and 9

ISSN:0014-2980    

DOI:10.1002/eji.1830120602

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractThymocytes were separated according to their surface phenotype and tested for cytotoxic T lymphocyte (CTL) precursor function by stimulation with allogeneic or hapten‐coupled cells, with or without addition of T cell growth factor (interleukin 2). The data show that only a minor subpopulation of thymocytes agglutinated by peanut agglutinin, expressing relatively high amounts of H‐2K antigen, contained CTL precursors. The remaining population, approximately 80%, could not be induced to generate CTL, even in the presence of interleuki

ISSN:0014-2980    

DOI:10.1002/eji.1830120603

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractHuman T blasts, obtained by stimulation of peripheral blood mononuclear cells (PBM) with tetanus toxoid, diphtheria toxoid orCandida albicans, were expanded in long‐term culture using alternate periods of antigen restimulation and growth in media containing interleukin 2. The cells gave a proliferative response only to the antigen originally used for stimulation. Such a response was strictly dependent upon the presence of autologous but not of allogeneic mitomycin C‐treated mononuclear cells. When added to autologous PBM depleted of E‐rosetting cells together with the specific antigen, the T blasts induced a polyclonal proliferation and differentiation of B cells. Allogeneic B cells were activated by antigen‐stimulated T blasts only in the presence of irradiated mononuclear cells autologous to the responding T blasts.The above responses seemed not to be regulated solely by the release of soluble factors; apparently cell to cell interactions had to take place to obtain an efficient B cell act

ISSN:0014-2980    

DOI:10.1002/eji.1830120604

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractA dual parameter flow microfluorometric technique for accurately measuring Fcγ receptor (FcR) expression on defined subsets of cells within a heterogeneous cell sample was developed. The FcR distribution of human peripheral blood mononuclear cells consists of three distinct peaks. By analyzing cells fluorescently labeled with the 3A1, an anti‐T cell hybridoma antibody (using a green‐emitting fluorophore) and for FcR (with a red‐emitting fluorophore), and by using cell isolation procedures, it was shown that the cells lying within the peak with intermediate FcR density are mainly monocytes, while cells lying within the peaks with highest and lowest (i.e.negative) FcR densities are predominantly T cells. The FcR+T cells (Tγcells) express higher levels of the 3A1 antigen than other T cells, thus demonstrating the utility of the 3A1 hybridoma antibody as a marker for

ISSN:0014-2980    

DOI:10.1002/eji.1830120605

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractA single injection of the retinal soluble antigen (S‐Ag, 30 pg) to the Lewis or the heterozygous (rnu/+) rats induces a severe bilateral uveitis, characterized initially by infiltration of the retina with inflammatory cells. The athymic nude rat (homozygous rnu/rnu), which lacks the thymus gland and T cell‐mediated functions, does not develop ocular inflammatory disease, clinically or histologically, after repeated challenges with S‐Ag. Circulating anti‐S‐Ag antibodies were found in S‐Ag‐immunized Lewis rats and in the heterozygous, but not the athymic nude rats. Good proliferative responses to concanavalin A, S‐Ag and purified protein derivitive of tuberculin (PPD) were found in lymphocyte cultures prepared from the draining lymph nodes of immunized heterozygous rats, but not when lymphocytes from the athymic nude rats were used. Uveitis could be induced in the athymic nude rat when lymphocytes from S‐Ag‐immunized heterozygous rats were transferred to them. By stimulating the donor lymphocytesin vitrowith S‐Ag before transfer, the number of recipients that developed uveitis was increased. On the other hand, it was impossible to transfer disease with hyperimmune serum alone. The possible role of T lymphocytes in the induction of experimental autoimmune uveitis w

ISSN:0014-2980    

DOI:10.1002/eji.1830120606

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractIn vitrosynthesis studies were performed utilizing poly A(+)‐RNA and lymphocytes from the spleens of rabbits hyperimmunized withMicrococcus luteusorStreptococcus pneumoniae(type III). Poly A(+)‐RNA isolated after 4 M guanidinium thiocyanate extraction and oligo(dT)‐selection appeared to be undegraded on CH3HgOH‐agarose gel electrophoresis and demonstrated biological activity when translated in a rabbit reticulocyte cell‐free system. The electrophoretic patterns of the specifically immunoprecipitated cell‐free products were compared with those of Nonidet‐P40 extracts (lysates) and secretions (supernatants) from rabbit spleen lymphocyte cultures and serum proteins. Kappa light chains with specificballotypes, as well as immunoglobulin heavy chains, were identified. The efficient translation of mRNA of defined allotypes was a necessary prerequisite for production of characterized cDNA clones and identification of genomic sequences for rabbit immunoglobulin heavy and

ISSN:0014-2980    

DOI:10.1002/eji.1830120607

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractIt was found that lectin‐binding proteins (LB) from leguminosae seeds can serve as mitogens for B lymphocytes from athymic nu/nu mice. Most of the experiments were performed using a LB fromVicia fabaas this was the most potent mitogen among all LB tested. When mixed B and T lymphocyte populations were stimulated by LB, a bell‐shaped dose‐response curve resulted which is also characteristic of the corresponding lectins; LB, however, act at much higher concentrations than the lectins. In control experiments, using lymphocytes from C3H/HeJ mice which have a genetic defect with respect to lipopolysaccharide responsiveness, the enhancement of DNA synthesis by LB was comparable to that observed with other strains. This indicates that stimulation by LB does not result from contamination by lipopolysaccharides. B lymphocytes from nu/nu mice were stimulated by LB as efficiently as mixed T and B lymphocyte populations whereas lectinsper sehad no effect on nu/nu lymphocytes.Cyclosporin A, a fungal metabolite, is known to specifically suppress T cell responses. Cyclosporin A did not influence the mitogenic activity of the LB fromVicia fabaon unseparated spleen cells. Cell populations enriched for T cells (lymph node cells: nylon wool‐passed or nylon wool‐passed and anti‐Ia plus complement‐treated) responded poorly to LB, if at all, even in the presence of interleukin 2‐containi

ISSN:0014-2980    

DOI:10.1002/eji.1830120608

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractRabbits were completely suppressed for kappa chain allotype b4.2, and autoantibodies against b4.1 or b4.2 could be raised in 2 out of 3 animals. The animal immunized with b4.1 produced anti‐b4 and anti‐Ms3, two activities which have never as yet been found together in one antiserum.Both autoantisera lacked the capacity to bind b4.2‐IgM, whereas they precipitated b4.2‐IgG very well. In one animal, anti‐b4 IgM activity appeared after the sixth immunization, at the age of 14 months. Allotype suppression was maintained in both rabbits till the end of their lives whereas all control animals recovered within 6 months. The autoantisera which were specific for b4 IgG could not induce suppressionin vivo.However, specific inhibition of b4 IgG secretion was observe

ISSN:0014-2980    

DOI:10.1002/eji.1830120609

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractPolyclonal activation of resting B lymphocytes by either lipopolysaccharide or specific helper cells recognizing antigens on B cell membranes results in selective patterns of IgG subclass expression among plaque‐forming cells. We have studied the IgG subclasses of plaque‐forming cells generated in cultures of purified B cell blasts selected for reactivity to either LPS or helper cells, and restimulated by either lipopolysaccharide, specific helper cells, or as “bystanders”, by nonspecific B cell growth factors. Development of IgG1plaque‐forming cells is observed only when clonal expansion is maintained by specific helper cells, whereas IgG3secretion specifically requires stimulation by lipopolysaccharide and the absence of helper cell activity. Furthermore, exposure of resting B lymphocytes to specific helper cells induces, in 48 h, an irreversible loss of the potential to produce IgG3. Other than showing that helper cell‐dependent B cell growth and maturation is more complex than previously suspected, these results suggest that differentiation signals or factors induce specific DNA recombination and dele

ISSN:0014-2980    

DOI:10.1002/eji.1830120610

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY

摘要:

AbstractHuman peripheral blood mononuclear cells were depleted of surface IgM+or IgD+cells and assayed for mitogen‐induced differentiation to immunoglobulin‐secreting cells (ISC) of IgM, IgG and IgA classes. Stimulatory agents included T cell‐dependent poke weed mitogen, B cell mitogenStaphylococcus aureusbacteria strain Cowan I, and a combination of the two which gives uniform, high levels of ISC from all normal donors. Depletion of either IgM‐ or IgD‐bearing B lymphocytes resulted in loss of cells bearing the other Ig class and blocked most of the mitogenic reactivity to anti‐IgM and anti‐IgD. Proliferative responses to Cowan I in these depleted populations were about 20% that of unfractionated mononuclear cells. Depletion of T cells increased the mitogenic response to Cowan I and to the two antibody preparations, showing that they are T‐independent mitogens. Depletion of IgD+cells caused partial loss of mitogen‐induced IgM ISC (22%‐60% of unseparated controls) but no loss of IgG or IgA ISC. Depletion of IgM‐bearing cells caused complete loss of IgM ISC, but no loss of IgG or IgA ISC. We previously demonstrated that anti‐IgM antibody blocked mitogen induction of Ig secretion of these three classes in spleen cells, but only IgM secretion in blood mononuclear cells. Together, the results suggest that the majority of cells in normal blood responding to mitogens to mature to IgG or IgA production belong to IgM−, IgD−B cell subsets, in contrast to precursors of secreting cells for these isotypes in the spleen. Thus, these blood precursors appear to be more mature than the

ISSN:0014-2980    

DOI:10.1002/eji.1830120611

出版商:WILEY‐VCH Verlag GmbH    

年代:1982

数据来源: WILEY