摘要:

AbstractHybrid myeloma cell lines secreting monoclonal antibodies to mouse cell surface antigens have been prepared. Spleen cells from a DA rat immunized with B10 mouse spleen cells that had been enriched for T cells were fused to cells from a nonsecreting mouse myeloma line (NSI). The presence in the culture supernatants of antibodies binding to mouse spleen cells was tested by a binding assay with125I‐labeled anti‐rat IgG. From a large number of positive cultures, ten independent hybrid clones were purified, each secreting a different antibody. Each antigenic target was analyzed by (a) gel electrophoresis of immunoprecipitated125I‐labeled cell surface molecules, (b) heat stability, (c) strain and species distribution and (d) cross‐inhibition of binding of different monoclonal antibodies.It was concluded that the ten monoclonal antibodies regognized four types of antigen. One was the heterophile, heat‐stable, Forssman antigen. The second (mol.wt. 210 000) appears to be a major125I‐labeled lymphoid cell surface protein. The third, a minor component of spleen cells, was precipitated as two polypeptides of mol.wt. 190 000 and 105000. Five IgG‐secreting clones identify the fourth antigen, a heat‐stable, possibly glycolipid component expressed on mouse red blood cells and also on thymocytes. Cross‐inhibition studies suggest that these last monoclonal antibodies bind to overlapping, but not identical, determinants. The class and chain composition of the monoclonal antibodies were studied by gel electrophoresis, isoelectric focusing and ability to lyse red blood cel

ISSN:0014-2980    

DOI:10.1002/eji.1830080802

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThe decline in antibody‐forming potential with age was studied in mice by analyzing the relative contributions of T and B cells in collaborative PFC responses to the T cell‐dependent antigens, dinitrophenylated (DNP) keyhole limpet hemocyanin, DNP‐human IgG, fowl IgG and sheep red blood cells. The experimental system involved the adoptive transfer of purified lymphocyte populations derived from the spleens of old and young mice into young irradiated recipients. An unequivocal reduction in B cell function was demonstrated in both primary and secondary antibody responses. In the former, young T cells failed to restore responsiveness to old B cells, while in the latter, similar results were obtained, even if old B cells were primed in the presence of young T cells. Despite the lower level of antibody production in old mice compared with young, no decrease in the number of antigen‐binding cells (detected by resetting and autoradiography) was observed. Taken together, these results suggest that a defect exists in B cells which is independent of T cell help, and that it is not due to cell depletion but rather to a qualitative abnormality in the cells themselves.Old T cells did not collaborate with young B cells as well as young T cells did, indicating a loss of helper T cell activity. Spleen cells from old mice, when mixed with young spleen cells at a 1:1 ratio, caused a reduction in their antibody‐forming potential which was consistent with the presence of cells with suppressive activity. The suppressor cells were shown to be T cells since their effect was abrogated by treatment with anti‐Thy‐1.2 serum plus complement and enriched by passage through nylon wool columns.These findings emphasize the need to use purified cell populations in analysis of responsiveness in old animals and highlight the multifactorial nature of the mechanisms involved in the a

ISSN:0014-2980    

DOI:10.1002/eji.1830080803

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThe mechanism of adjuvant activity of the synthetic glycopeptide N‐acetylmuramyl‐L‐alanyl‐D‐isoglutamine or muramyl dipeptide (MDP) was studied usingin vitroplaque‐forming cell (PFC) response to sheep erythrocytes (SRBC). Addition of MDP to DBA/2 mouse spleen cell cultures resulted regularly in a 2 to 3‐fold increase of PFC numbers/106recovered cells (p<0.01). Supernates (SPN) from MDP‐stimulated cultures added to standard spleen cell + SRBC cultures brought about even more important increases of PFC numbers (p<0.01 to p<0.001). SPN from cultures supplemented with MDP alone (without SRBC) were more active than those of cell + MDP + SRBC cultures, and SPN removed on day 3 of culture were more active than those of day 5. This activity of SPN was maintained accross an H‐2 histocompatibility barrier. Although pretreatment of spleen cells with anti‐θ antigen serum entirely suppressed the anti‐SRBC PFC response in spite of the presence of MDP, SPN from these cultures were as active as SPN from normal spleen cell MDP‐stimulated cultures. In contrast, pretreatment of spleen cells with specific rabbit anti‐mouse macrophage serum entirely suppressed both anti‐SRBC response and SPN activity. It was concluded that the target cell for MDP is the macrophage which releases factors ultimately acting on B ce

ISSN:0014-2980    

DOI:10.1002/eji.1830080804

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractAdoptive lymphocyte transfers between Iga, Igband Igdallotype‐congenic mouse strains revealed host barriers against the production of certain donor allotypes. First, as recipients of Igbcells, Igaand Igdmice permitted the production of donor Ig‐4b but not that of Ig‐lb. The apparent mediators of this Ig‐lb barrier were T cells specific for Ig‐lb determinants on B cells. Additional cell transfers showed Igamice to have a second barrier against allotype production by Igddonor cells. Reciprocal cell transfers showed Igband Igdmice to have comparatively weak barriers against Iga‐producing cells.As host barriers were absent in mice deficient for T cells (athymic nude mice), it appears that they are T cell‐mediated. Further, the allotype‐dependence of such barriers means that the antigens responsible must be under the control of allotype‐linked genes. The regulatory implications of this for the immune sys

ISSN:0014-2980    

DOI:10.1002/eji.1830080805

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThe anti‐hapten response of spleen cells from mice primed with hapten‐carrier (dinitrophenylated keyhole limpet hemocyanin) was decreased by depletion of T cells during the first four days after secondary antigenic stimulation, but was unaffected when the T cells were depleted on day 5. The response of cultures that were depleted of T cells prior to secondary antigenic stimulation was restored by addition of carrier‐primed cells during the first two days of culture, partially restored on day 3, but not at later times. Thus, T cells were required only at about day 4 of a secondary response to a T‐dependent antigen that peaked on day 8. Autoradiography experiments showed that the frequency of antigen‐binding cells increased with time regardless of the presence of T cells in the cultures. We conclude that helper T cells are not required for B cell proliferation, but are required for the differentiation of B cells to antibody‐secr

ISSN:0014-2980    

DOI:10.1002/eji.1830080806

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractUnprimed spleen cells from A and C57BL/6 mice could not produce cytotoxic responses to their syngeneic tumors: a Moloney virus‐inducedin vitrosubline YAC‐1 and a Rauscher virus‐inducedin vitrosubline RBL5, respectively. Spleen cells from A and C57BL/6 mice immunized with YAC‐1 or RBL5 (which cross‐react serologically) generated significant syngeneic cytotoxicities after cultivationin vitro.Thein vivocarried tumor of A mice, unlike thein vitrosublines, could not stimulate a priming effect. In contrast, YAC stimulated the formation of suppressor cells in both A and C57BL/6 mice. The suppressor cells abrogated the priming effect of the syngeneic tumors, but not the priming effect of the allogeneic tumors. Furthermore, YAC did not suppress normal allogeneic anti‐tumor responses. The theoretical and the practical implications of these studies ar

ISSN:0014-2980    

DOI:10.1002/eji.1830080807

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractDifferentiation of myogenic stem cells from undifferentiated thymic stem cells is thought to play a critical role in the pathogenesis of myasthenia gravis. The expression of membrane acetylcholine receptor (AChR) on the membranes of developing muscle clones in cultures of murine thymus reticulum was followed and found to be transient. AChR are first expressed shortly after fusion of myotubes. In subsequent stages of myogenic development, the density of homogenously distributed AChR is strongly increased, and, in addition, concentrated “hot spot” AChR areas appear. During further maturation, membrane AChR are lost. Highly mature myotubes (3 months in culture) lack substantial amounts of homogenous AChR, as well as hot sp

ISSN:0014-2980    

DOI:10.1002/eji.1830080808

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractThe production of macrophage migration inhibitory factor (MIF) and immune interferon (IF) by concanavalin A (Con A)‐stimulated cultures of thymus, lymph node and spleen cells was investigated. It was found that all cultures produced MIF activity, whereas only spleen cells produced marked IF activity. The capacity to produce IF was found to be correlated with the macrophage content of a cell preparation as evidenced by staining for esterase‐positive cells. Furthermore, column‐purified spleen T cells produced MIF but no IF. Migration inhibition caused by residual mitogen could be ruled out. On the other hand, when macrophages grown from bone marrow cells were pre‐exposed to supernatants of mitogen‐stimulated lymphocytes, IF activity was released into freshly added medium while no significant MIF activity was found. IF was also found in supernatants of macrophage cultures after exposure to conventional inducersin vitro(polyinosinic‐polycytidylic acid,Corynebacterium parvum) orin vivo(C. parvum), whereas no MIF was detected. An anti‐Type I IF serum neutralized IF in supernatants from Con A‐stimulated spleen cells but did not affect MIF in the same supernatants. This indicates that IF and MIF activity are associated with different molecules. It is, therefore, concluded that under the described conditions, IF and MIF are produced by different cells. T cells are the prime producers of MIF while IF is released by macrophages following induction

ISSN:0014-2980    

DOI:10.1002/eji.1830080809

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractAlthough resting, rat thymus‐derived spleen lymphocytes do not bear insulin receptors, these receptors emerge upon the membrane of alloimmune rat T cells subsequent to skin grafting. These studies examine conditions that permit the emergence of lymphocyte insulin receptors upon T or B‐enriched rat lymphocyte populations. Allogeneic stimulation was accomplishedin vivoby skin grafting from (Lewis × Brown Norway)F1(LBN) to Lewis male rats or by Graft‐vs.‐host (GVH) reaction established by intraperitoneal injections of 2 × 108Lewis leukocytes each week for a total of four injections into LBN animals.In vitroallogeneic stimulation was provided by one‐way mixed lymphocyte cultures between the same strains. Lastly, both T and B‐enriched populations were interacted with mitogens concanavalin A (Con A), phytohemagglutinin (PHA‐P), and lipopolysaccharide (LPS). The T‐enriched populations were highly enriched for T lymphocytes (90%) and macrophage‐depleted while B‐enriched populations contained nearly 85% B cells. Insulin receptors emerged upon T‐enriched cell populations consequent to allogeneic skin grafting with saturability, specificity and high affinity (kd= 1.1 nM) as well as after GVH. Responder strain lymphocytes developed an insulin receptor during allogeneic mixed lymphocyte cultures within 72 h of initiation. Specific insulin‐binding sites also appeared upon T‐enriched populations after culture with PHA‐P and Con A but not LPS. Conversely, B cells developed an insulin receptor after interactions with LPS but not PHA‐P or Con A. Anti‐Ig and complement but not rat anti‐T cell antibody abrogated the ability of LPS to induce an insulin receptor on B‐enriched cells. Binding specificity was demonstrated by the inhibition of [125I]‐labeled insulin in the order porcine insulin ≊ desalanine insulin>proinsulin ≫ desoctapeptide insulin with growth hormone exhibiting no such inhibition. These data demonstrate that a true insulin receptor appears upon both T and B cells consequent to activation. The lymphocyte insulin receptor is a universal marker of cellular activation as it is not restricted to clone or species and may be applied t

ISSN:0014-2980    

DOI:10.1002/eji.1830080810

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY

摘要:

AbstractAddition of supernatant from concanavalin A‐stimulated spleen cells toin vitroprimed cytolytic T lymphocytes in semisolid medium stimulated the growth of colonies of cytolytic lymphocytes. Optimal results were obtained using a peritoneal adherent cell underlayer where a 10% plating efficiency (⩾ 4 cells per colony) was achieved when between 5000 and 100000 cells were plated per dish.Individual colonies were harvested and tested in a short‐term (5 h)51Cr release microassay, employing 200 target cells. The frequency of lytic colonies varied from 46–67%. The observed lytic activities were specific for the relevant allogeneic targe

ISSN:0014-2980    

DOI:10.1002/eji.1830080811

出版商:WILEY‐VCH Verlag GmbH    

年代:1978

数据来源: WILEY