摘要:

AbstractThe phenotypic properties of lymphoid cells in the developing embryonic thymus were characterized using monoclonal antibodies and flow microfluorometry. CBA/J‐T6/T6 thymocytes stained with antibodies directed against Thy‐1.2, Lyt‐1, Lyt‐2 or H‐2Kkwere simultaneously analyzed for fluorescence intensity and forward light scatter (FLS), a cell size‐related parameter. Whereas Thy‐1 and Lyt‐1 antigens were already present on 15‐day fetal thymocytes, Lyt‐2 expression was first detectable on day 16 and increased rapidly thereafter to reach adult levels by day 19. Concomitant with these phenotypic changes, rapid changes in FLS occurred during this time period. The FLS distribution of Lyt‐2+cells was initially homogeneously high (day 16) but became biphasic at days 17–18. Thereafter, the lower FLS subpopulation predominated. FLS changes in Lyt‐2−cells could be dissociated kinetically from changes in the Lyt‐2+subpopulation. Thus high FLS Lyt‐2−cells were the predominant subpopulation throughout the entire fetal period and could still be detected after birth, when a population with lower FLS first appeared. The embryonic thymus developingin vivowas then compared with the 13‐day embryonic thymus maintained for 14 days in anin vitroorgan culture system. Based on a combination of fluorescence and FLS analysis, the organ‐cultured thymus appeared to share certain phenotypic properties with

ISSN:0014-2980    

DOI:10.1002/eji.1830130302

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractCultures of T cell‐depleted mouse spleen cells (B cells) were reconstituted with either allogeneic or syngeneic untreated T cells. The primary (day 4) antibody‐forming cell responses to sheep red blood cells were then compared. In almost all combinations and regardless the nature of the H‐2 incompatibility between the T and B cells tested, small numbers of untreated allogeneic T cells provided better help [positive allogeneic effect (AE)] than the same numbers of syngeneic T cells; only in the combination in which B10.A(2R) T cells were added to B10.A(4R) B cells (differing at I‐B, I‐J, and S), no AE at all appeared. A strong positive AE was induced when the incompatibility included or consisted of I‐A. A strong positive AE was also induced across an I‐E difference, provided the B cells expressed the Eαmolecule on the cell surface and did not differ at K/D. A negative AE only occurred when the H‐2 incompatibility on the B cells included or consisted of a difference at the K and/or D locus.In contrast to untreated T cells, anti‐Lyt‐1 plus complement‐treated T cells induced neither a positive nor a negative AE. T cells treated with anti‐Lyt‐2 plus complement, too, were incapable of inducing a negative AE; instead, addition of anti‐Lyt‐2‐treated T cells to B cells that differed either at all of H‐2, at K plus I‐A, or at I‐a alone consistently led to the induction of a strong positive AE. Only a syngeneic‐like response was induced, however, when anti‐Lyt‐2 and complement‐treated T cells were ad

ISSN:0014-2980    

DOI:10.1002/eji.1830130303

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractDifferent human IgM rheumatoid factor (IgM RF) idiotypes have been described defined by polyclonal rabbit anti‐idiotypic antibodies. These antisera do not allow clear genetic analysis of the idiotypic determinants, be they cross‐reactive or private. Therefore, we tried to obtain a set of monoclonal anti‐idiotypic antibodies directed against RF idiotypes. Purified IgM RF serum from a patient with classical rheumatoid arthritis was used to immunize BALB/c mice. The spleen cells were fused with Sp 2/0 Ag 14, a nonsecreting mouse myeloma cell line, and a hybrid producing monoclonal anti‐idiotypic antibody was selected. The mouse antibody, an IgG1x, reacts with an identical or similar determinant located on (or close to) the binding site of all tested monoclonal or polyclonal IgM RF from totally unrelated patients with Waldenströms's macroglobulinemias or rheumatoid arthritis. The monoclonal antibody also reacts with 2 rheumatoid arthritis patients' IgG RF and with a low proportion of normal polyclonal IgM without detectable RF activity. An hypothesis is proposed to explain the existence of a such highly conserved determinant on RF i

ISSN:0014-2980    

DOI:10.1002/eji.1830130304

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractHuman lymphocyte function antigen (HLFA) is a cell surface protein defined by two monoclonal antibodies MHM23 and MHM24. It is present on both B and T lymphocytes but in greater amounts on the latter. Both antibodies precipitated antigen, from radiolabeled HSB‐2 cells, which ran as two chains on sodium dodecyl sulfate polyacrylamide gel electrophoresis at 180 and 94 kDa. Neither antibody inhibited binding of the other, indicating that distinct epitopes were recognized. Both antibodies were shown to inhibit HLA‐restricted lysis of influenza virus‐infected and Epstein‐Barr virus‐transformed target cells by cytotoxic T lymphocytes. Blocking occurred at the level of the effector cells and in the presence of subsaturating concentrations of antibody. Both reagents also inhibited lysis of K562 cells, mediated by natural killer cells. These blocking effects differ from the inhibitory effects of monoclonal anti‐HLA ABC and anti‐suppressor cytotoxic T cell antibodies which inhibit only HLA‐restricted lysis when present in saturating amounts. It is concluded therefore that HLFA is likely to be involved in the nonspecific adherence or lytic functions of killer cells rather than specific anti

ISSN:0014-2980    

DOI:10.1002/eji.1830130305

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractTo gain insight into the function of cell surface IgM (sIgM) and IgD (sIgD), the expression of these markers on B lymphocytes was quantitated during activation and progression through the cell cycle. Specifically, analysis and correlation of changes in cell cycle state, sIgM and sIgD expression and cell size following exposure of murine B cells to mitogenic levels of lipopolysaccharide and dextran sulfate is reported. As assessed by flow cytometric acridine orange analysis, a large proportion of normal splenic B cells respond within 48 h of exposure to these mitogens by entry into the cell cycle. This response is accompanied by an increase in cell size as determined by flow cytometric “time of flight” measurement. Flow cytometric immunofluorescence analysis reveals a simultaneous alteration in sIg expression. Specifically, cells leaving G0and transiting G1increase in diameter from 5 μm to 6 μm and lose>80% of sIgD while sIgM remains constant. Progression through the remainder of the cell cycle is accompanied by a further increase in mean cell diameter to approximately 12 μm while sIgM and sIgD levels remain at G1levels. The abrupt loss of sIgD as cells transit G1suggests that an active process mediates this de

ISSN:0014-2980    

DOI:10.1002/eji.1830130306

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractMice were injected with fluoresceinated human gamma globulin (FLU‐HGG) either at 2–3 days of age or as pregnant females. At 2 weeks of age, the spleen cells of the injected suckling mice or offspring were fractionated on FLU‐gelatin dishes to yield FLU‐binding B cells. These B cells were then cloned in microcultures using one of two recently described systems in which single B cells grow in the absence of feeder or filler cells, namely following stimulation with FLU‐polymerized flagellin (FLU‐POL) and conditioned media containing B cell growth and differentiation factor(s); or mitogenic activation by a mixture ofE. colilipopolysaccharide (LPS) and dextran sulfate (DxS). As such cultures permit visualization of clonal proliferation as well as ultimate harvesting of cultures for assay of hemolytic plaque‐forming cells, it was possible to ask whether the lesion in the tolerant state affected the B cell's capacity to divide, to differentiate to antibody secretion, or both.The results indicated that, when stimulated with antigen, the anergic cells could neither divide nor differentiate. However, when the strong mitogen mixture was used, clonal anergy was partially broken. The cells proliferated, and a small proportion of them differentiated into anti‐FLU antibody‐forming cells. A marked variation in antigen‐binding avidity of the FLU‐binding cells made it difficult to quantitate the degree of uncoupling of proliferation and differentiation among tolerant, LPS plus DxS‐stimulated cells. Nevertheless, a partial reversibility of clonal anergy must affect views on mecha

ISSN:0014-2980    

DOI:10.1002/eji.1830130307

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractA reverse hemolytic plaque assay has been developed which specifically detects secretion of human immune interferon (Hu IFN‐γ) at the single cell level. Unstimulated peripheral blood lymphocytes from healthy adult volunteeers spontaneously secreted IFN‐γ. Stimulation of these cells with concanavalin A, phytohemagglutinin, or the UCHT1 monoclonal anti‐human T cell antibody significantly increased the number of IFN‐γ‐secreting cells. The cell producing IFN‐γ, both spontaneously and after UCHT1 antibody stimulation, is an OKT3+, 4+,8−,HLA‐DR−T lymphocyte as determined at the single cell level. Finally, cyclosporin A, a potent and selective immunosuppressive drug for T cells, strongly inhibited the secretion of IFN‐γ as assayed at the cell level. This IFN‐γ reverse hemolytic plaque assay has great potential for the further study of IFN‐γ both in physiologic

ISSN:0014-2980    

DOI:10.1002/eji.1830130308

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractXanthan gum (XG), a microbial polysaccharide produced extracellularly by fermentation ofXanthomonas campestris, has unique physical properties. We studied the effects of XG on murine lymphocytesin vitroand found that XG induced both a significant increase of DNA synthesis in mouse splenic B cells and thymocytes as well as polyclonal IgM and IgG antibody responses in B cells. XG‐activated thymocytes, however, did not display helper or suppressor functions. XG was almost as effective in inducing polyclonal antibody responses as lipopolysaccharide (LPS) in murine systems. Hamster spleen cells, however, were weakly triggered to nonspecific antibody production by XG but they were not triggered at all by LPS. Spleen cells from normal neonatal mice and from adult CBA/N mice, a strain which possesses an X‐linked defect affecting B cell differentiation, responded relatively well to XG and LPS, suggesting that XG can stimulate immature B cells as well as LPS does. It was found that XG activated B cells in the relative absence of T cells and macrophages. Spleen cells from LPS‐nonresponder C3H/HeJ mice and seven other mouse strains were stimulated to polyclonal antibody production by XG. In contrast, spleen cells from C57BL/10 mice were unresponsive or only slightly responsive to XG, but fully responsive t

ISSN:0014-2980    

DOI:10.1002/eji.1830130309

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractA common idiotype was defined by a rabbit anti‐idiotypic antiserum generated against human antibodies to hepatitis B surface antigen (anti‐HBs). This idiotype was detected in anti‐HBs from eight different individuals who had been previously infected with hepatitis B virus and is referred to as the CHBs idiotype. The CHBs idiotype was also identified in sera from rabbits, mice, guinea pigs, swine, goats and chimpanzees that had been immunized with hepatitis B surface antigen (HBsAg). Expression of the CHBs idiotype in sera from other species was associated with anti‐HBs molecules. These results suggested that variable‐region genes responsible for the CHBs idiotype have been conserved through long periods of evolution. It was noteworthy that the CHBs idiotype was not detected in the sera of a nonmammalian species, chickens, that had been successfully immunized w

ISSN:0014-2980    

DOI:10.1002/eji.1830130310

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY

摘要:

AbstractThe role of spleen and thymus in maturation processes of B cell subpopulations was examined using mice which underwent fractionated total lymphoid irradiation (TLI). (BALB/BL)F1mice received 200 rds lymphoid irradiation daily for 8 days. Mice were spleen‐shielded or ‐unshielded, or thymus‐shielded or ‐unshielded during the irradiation. One day after termination of the irradiation, TLI‐treated unshielded mice were reconstituted with 10 × 106spleen, thymus or bone marrow cells of normal untreated syngeneic mice. Two and a half months after termination of the treatment, the ability of the treated mice to producein vivoanti‐trinitrophenyl (TNP)‐Ficoll antibodies, and the capability of spleen cells of those mice to respondin vitroto dextran sulfate and lipopolysaccharide was checked. In parallel, stained spleen cells were analyzed on the fluorescence‐activated cell sorter. The results indicate that B cell maturation occurs only in mice where the spleens were shielded during TLI‐treatment or in TLI‐treated mice reconstituted with spleen cells of normal untreated mice. In these mice, the light scatter and the fluorescence distribution profiles were the same as those obtained from spleen cells of control mice: the treated mice gave a high anti‐TNP‐Ficoll antibody response and the proliferative response of the cells was low to dextran sulfate and high to lipopolysaccharide.Thymus shielding during TLI treatment or reconstitution of TLI‐treated mice with thymus or bone marrow cells could not abolish the blockage of B cell maturation processes. These findings indicate that the spleen plays an obligatory role in B cell subset maturation pathways, whereas the thymus appears to play no essenti

ISSN:0014-2980    

DOI:10.1002/eji.1830130311

出版商:WILEY‐VCH Verlag GmbH    

年代:1983

数据来源: WILEY