摘要:

AbstractIn previous studies, it was shown that mice infected withPlasmodium chabaudi adamihave a deficiency in their production of IgG1immunoglobulin, suggesting isotype‐specific immunoregulation. In order to examine this phenomenon in further detail the expression of Fcγreceptors (FcγR) on T cells obtained from mice infected withP. chabaudiwas studied by flow cytometry. There was an increase in the number of splenic T cells which expressed FcγR during infection. At the peak of the acute stage of infection (10–15 days) up to 40% of T cells were positive for FcγR expression. These FcγR were present on about 40% of both Lyt‐2+and L3T4+T cells. The isotype preference of these receptors on control Thy‐l+T cells is IgG1IgG2b>IgG2a as determined by an inhibition assay and fluorescence‐activated cell sorter (FACS) analysis. However, 2 to 3 weeks after infection this pattern was altered such that IgG2band IgG2arepresented the major isotypes binding to the FcγR of the L3T4+T cell. At this stage of infection FcγR on L3T4+cells fail to bind IgG1. In the Lyt‐2+T cells IgG1and IgG2bremained the best inhibitors. These data suggest that there may be changes in FcγR expression on T cells during infection reflected particularly in a decreased ability of IgG1to bind to the

ISSN:0014-2980    

DOI:10.1002/eji.1830180102

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractA monoclonal antibody, 7F7, raised against the Raji B lymphoblastoid cell line reacted with about 35% of peripheral blood B cells, germinal center B cells, follicular dendritic cells and some vascular endothelial cells. Although not found on resting T cells this antigen was strongly expressed on CD4+and CD8+T cells activated with phytohemagglutinin, pokeweed mitogen and anti‐T3, and its expression on B cells was enhanced after stimulation with pokeweed mitogen. It is strongly expressed 24 h after stimulation with phytohemagglutinin and its expression is reduced but not eliminated by cyclosporin A treatment. The molecule defined by antibody 7F7 is found on some, but not all, B cell lines, on an HTLV‐I‐transformed T cell line and on the promyelocytic cell line U937. Immunoprecipitation from externally and metabolically labeled Raji cells revealed a single‐chain molecule of

ISSN:0014-2980    

DOI:10.1002/eji.1830180103

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractWeekly i.p. injections of IgD from birth in (SJL × BALB/c)F1mice were found to accelerate the development of IgG‐ and IgA‐secreting cells and to increase the numbers of Ig‐secreting cells of all isotypes in 17–28‐day‐old mice, but not in 7–10‐day‐old mice. Similarly, repeated weekly injections of IgD in normal adult BALB/c mice increased the numbers of reverse plaque‐forming cells/spleen for all isotypes studied, including IgM, IgG1, IgG2, and IgA, but not for IgD itself. No such effect was observed in IgD‐treated aged (20 months old) BALB/c mice. The absence of an effect of IgD on Ig secretion appeared to correlate with a lack of induction of receptors for IgD on T cells of the host, both in 7–10‐day‐old and in aged mice. In 7–10‐day‐old mice this lack of induction appeared due to their very low numbers of L3T4+T cells. A comparison was made between the effect of a single injection of IgD or lipopolysaccharide (LPS) on numbers of Ig‐secreting cells in the spleen determined 1–7 days after injection. Both agents caused increases, but the increase in IgM‐producing cells was much greater after LPS (day 4), while IgD caused a relatively greater increase in IgG2and IgA (days 4–7). Increases in IgGland IgG3‐producing cells induced by LPS and IgD were of similar magnitude (days 6–7). IgD production, however, was not increased. The number of cells producing antibody of anti‐trinitrophenyl (TNP) specificity was enhanced by LPS (day 4), but not by a single injection of IgD, although more than one injection of IgD caused a significant increase in anti‐TNP‐producing cells above background.LPS, but not IgD, caused B cell proliferationin vitroin the presence or absence of γ ‐irradiated Tδ cells. However,in vivo, IgD injections caused a significant increase in the percentage of lymphoid follicles with germinal centers in lymph nodes from 17–21‐day‐old and normal adult mice, but not in 7–10‐day‐old or aged mice. Such an effect was also absent in 24–28‐day‐old mice

ISSN:0014-2980    

DOI:10.1002/eji.1830180104

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractThis study was done to better define the immunoregulatory mechanisms in the human intestinal lamina propria (LP). Peripheral blood (PB) and LP cells were obtained from patients having intestinal resections. CD4+and CD8+cell subsets were isolated using hybridoma antibodies in a panning technique. Graded numbers of LP and PB CD8+cells were added to cultures of autologous fresh B cells plus CD4+cells plus pokeweed mitogen. After 10 days incubationin vitro, the supernatants were collected, and IgM and IgA synthesis was measured by isotype‐specific sandwich ELSA. Both PB and LP CD8+cells suppressed IgM and IgA synthesis by indicator cultures consisting of 5 × lo4B cells plus 5 × 104CD4+cells to a comparable extent. However, when these same CD8+cells were added to indicator cultures of 5 × 104B cells plus 105CD4+cells, PB CD8+cells still suppressed, but LP CD8+cells enhanced IgM and IgA synthesis. LP but not PB CD8+cells also augmented IgM and IgA synthesis in cultures with suboptimal immunoglobulin synthesis. Despite these results, LP CD8+cells were not able to provide help for B cell immunoglobulin synthesis when these two cell types were cultured together with pokeweed mitogen. The mechanism of immunoglobulin augmentation by LP CD8+cells appeared to involve antagonism of a CD4+rather than CD8+suppressor cells. We conclude that functional heterogeneity is more evident within the LP CD8+subset, with both suppressor and contra‐suppressor activities demonstrable, with the latter representing a major activity in LP but not in PB CD8

ISSN:0014-2980    

DOI:10.1002/eji.1830180105

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractPore‐forming protein (perforin, PFP) was isolated from a mouse large granular lymphocyte (LGL) [natural killer (NK‐like)] cell line. Purified PFP lysed a variety of mouse tumor cell lines and helper T lymphocyte cell lines. However, LGL and cytotoxic T lymphocyte cell lines were resistant to PFP‐mediated cell lysis. The presence of hemolytic activity in the granule was examined in these resistant cell lines. Four out of five of these resistant cell lines had hemolytically active granules. We determined whether NK cells freshly isolated from BALB/c nude mouse spleens were resistant to PFP‐mediated cytolysis. Nylon column‐passed spleen cells with an enriched content of NK cells exhibited more resistance than whole spleen cells. Moreover, when spleen cells were treated with PFP the remaining live cells showed enriched NK activity suggesting that normal peripheral cells with NK activity are resistant to PFP. These results indicate that cytolytic cells containing PFP have developed defense mechanisms to inhibit PEP‐mediated

ISSN:0014-2980    

DOI:10.1002/eji.1830180106

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractMonoclonal antibody RR1/1 directed against the putative LFA‐1 ligand molecule intracellular adhesion molecule‐1 (ICAM‐1) was found to inhibit the T cell prolifera‐tive response to the antigen PPD. Interestingly, the percentage of unstimulated monocytes which expressed ICAM‐1 on their surface appeared to vary greatly from person to person although the majority of monocytes did express high levels of ICAM‐1 within their cytoplasm and surface expression could be rapidly induced on most cells by adherence to fibronectin. Resting T cells showed no evidence of surface or cytoplasmic ICAM‐1 although expression was induced both within the cell and on the membrane as a result of activation with phytohemagglutinin or a combination of OKT3 and phorbol 12, 13‐dibutyrate. The significance of these findings with respect to the function of monocyte and T cell in the generation of an immune respo

ISSN:0014-2980    

DOI:10.1002/eji.1830180107

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe five selections carried out in the mouse for high or low antibody responsiveness to various multideterminant immunogens were successful. In all cases the large interline difference was shown to result from the additive effects of several independently segregating loci (polygenic regulation). However, important peculiarities were demonstrated in these original selections concerning either the cellular mechanisms operating or the effect of the selected genes on antibody responses to antigens unrelated with those used for the selection (multi‐specific effect). In an attempt to improve and generalize the effect of selection, the 5 high and the 5 low lines were inter‐crossed to obtain populations with a balanced proportion of the 5 genomes. These two populations were then submitted to selective breedings in which the phenotypic character was the weighted responses to pluri‐antigen immunization. The data obtained in 16 consecutive generations of two selective breedings (general‐primary, GP and general‐secondary, GS, responses) carried out from these populations are reported. The genetic parameters of the response to GP and GS selections are compared with those obtained in the original selections. The final result of both GP and GS selections demonstrate a marked improvement of the high and low antibody production traits, both quantitatively (interline divergence) and qualitatively (multi‐specific effect). The success of GP and GS selections agrees with the concept that distinct groups of genes are preferentially affected by selection according to the nature of the selection antigen and the immunizatio

ISSN:0014-2980    

DOI:10.1002/eji.1830180108

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractSeveral approaches have been used in our attempts to increase the “natural” ability of normal T splenocytes (Tn) from BALB/c or BC8 mice (both Igha) to induce, in F1hybrids, a suppression of Igh‐lb expression (IgG2aof b haplotype). These heterozygous F1were produced by mating these Ighamice and their Ighb‐congenic partners (CB20 and C57BL/6, respectively). The most powerful approaches were to sensitize the Ighamice by either autologous splenocytes coated with Igh‐lb or B splenocytes from Ighb‐congenic mice. In F1having paternally inherited the b haplotype the sensitized T splenocytes (Tn) prepared from such mice are able to induce, like Tnwhen injected at birth, a chronic suppression of Igh‐lb expression. However, the suppression was established with a much higher efficiency: already at 6 weeks of age in 100% of the F1treated with 1 × 107Tsvs.a final rate of 70% progressively reached only at 42 weeks of age in the F1treated with 4 × 107Ts. In F1having maternally inherited Ighbthe differences were even more pronounced than with 4 × 107Tni.e.the suppression induction was almost totally ineffective, whereas with 2 × 107−4 × 107Tsa rate of 100% treated F1subjected to suppression was reached at 19 weeks of age. As the productions of IgM, IgD and IgA of the b haplotype were not affected by the suppression, the Tsare believed to act on the Igh‐lb′ cells. Attempts were also made to induce allotypic suppression of other b allotypes by the use, as sensitizing cells, of myeloma cells carrying Igh‐6b (IgM of b haplotype). We failed in revealing any sign of a T cell reactivity against Igh‐6b similar to the reactivity against Igh‐lb. The use of Igh‐6b+myeloma cells grown in an Igh′ or in an Ighabackground allowed us to assume that the cells responsible for the sensitization are, in the IghbB lymphocyte population, either the Igh‐lb+lymphocytes or the lymphocytes having passi

ISSN:0014-2980    

DOI:10.1002/eji.1830180109

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractThe biological activities of mycobacteria‐reactive Lyt‐2+T cells were characterizedin vitro.T cells from mice immunized with killedMycobacterium tuberculosisor viableM. boviswere restimulatedin vitroand cloned under limiting dilution conditions. Several L3T4−Lyt‐2+T cell lines, some of them KJ16+, were established. These T cell lines were capable of lysing mycobacteria‐primed macrophages in an antigen‐specific way. The cytolytic activity of some T cell lines was found to be class I restricted, whereas others showed antigen‐specific killing in the absence of apparent H‐2 restriction. Several T cell lines produced interferon‐γ after appropriate stimulation. Furthermore, these T cell lines could induce tuberculostatic macrophage capacities by apparently two different mechanisms, namely by secretion of lymphokines (most probably interferon‐γ) and by direct cell qontact. We conclude that CD8 T cells with antigen‐specific cytolytic potential are generated during tuberculosis and that these T cells are involved in the immune respo

ISSN:0014-2980    

DOI:10.1002/eji.1830180110

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY

摘要:

AbstractA novel anti‐B cell monoclonal antibody UCHB1 is described which detects an antigen present on a selected subpopulation of both normal and leukemic B cells. Approximately 20% of normal tonsil and peripheral blood (PB) B cells are UCHB 1+and the majority of B cells from all cases of prolymphocytic leukemia (PLL) tested, together with a low, variable percentage of PB B cells from non‐Hodgkin's lymphoma patients with centroblastic centrocytic leukemia also express this antigen.Chronic lymphocytic leukemia and hairy cell leukemia B cells, pre‐B acute lymphoblastic leukemia and Epstein‐Barr virus transformed cell lines all lack UCHB1 positivity as do all non‐B lineage leukocytes and cell lines so far tested.In tonsil sections UCHB 1 staining is almost completely confined to surface IgM+mantle zone lymphocytes and follicular dendritic cells, but not B cells, within the germinal centers. UCHB 1 can induce a rise in the level of intracellular free calcium ([Ca2+]i) in PLL B cells and low concentrations of monoclonal antibody can result in the entry of these cells into cell cycle in the absence of additional factors. The proliferative effect of UCHB 1 is greatly enhanced in the presence ofStaphylococcus aureusCowan and, to a lesser extent, phorbol ester. A similar costimulatory effect is exerted on a proportion of normal tonsil B cells although here, despite inducing a rise in [Ca2+]i, UCHB1 alone does not cause cells to proliferate. UCHB 1 may well prove to be a useful antibody both to distinguish between different B cell leukemias and to study the phenotype and function of leukemic and normal B cell subpo

ISSN:0014-2980    

DOI:10.1002/eji.1830180111

出版商:WILEY‐VCH Verlag GmbH    

年代:1988

数据来源: WILEY