scholarly journals Concanavalin A potentiates syngeneic response in murine lymphocytes.

1976 ◽  
Vol 143 (1) ◽  
pp. 1-14 ◽  
Author(s):  
K Ozato ◽  
J D Ebert

In an attempt to modulate the recognition processes that occur on lymphocyte membranes in mixed lymphocyte culture, responding cortisone resistant thymocytes or stimulating spleen cells (treated with mitomycin C) were pretreated with native concanavalin A (N-Con A) or succinyl-Con A (S-Con A). Highly significant cell proliferation was observed in syngeneic combinations when either the responding cells or the stimulating cells were so treated with Con A, although Con A pretreatment alone was never mitogenic. In allogeneic combinations the proliferative response with Con A pretreatment of either partner on day 3 was five to seven times higher than in the normal mixed lymphocyte reactions. The triggering of proliferation was dependent on two factors: (a) The presence of spleen cells as the stimulating cells (thymocytes were much less effective). (b) The binding of Con A molecules to either one of the partners, the effect being abrogated by the specific inhibitor of Con A, alpha-mannopyranoside. The optimal concentration of S-Con A was about twice that of N-Con A. Even more striking was the observation that cultures in which either one of the partners was pretreated with Con A in allogeneic combinations showed a strong suppression (60-80% inhibition) in the subsequent generation of the cytotoxic lymphocytes (CL). The Con A concentration required to trigger a proliferative response corresponded to that for suppressing the generation of CL. Con A pretreatment did not result in a cytotoxic activity toward syngeneic tumor cells.

1974 ◽  
Vol 140 (5) ◽  
pp. 1410-1415 ◽  
Author(s):  
Barbara J. Alter ◽  
Fritz H. Bach

The cell-mediated lympholytic capability of mouse spleen cells stimulated in mixed lymphocyte culture is determined by lymphocyte-defined (LD) and serologically-defined (SD) antigenic differences present during sensitization. Cells which are activated by LD differences alone are markedly less effective in causing lysis of target cells. This lack of cytotoxicity is shown to be, at least in part, due to the inability of LD differences to allow the efficient generation of cytotoxic lymphocytes. SD antigens not only serve as good targets for CML but are also shown to be important for the generation of cytotoxic lymphocytes during the mixed lymphocyte culture.


1977 ◽  
Vol 145 (2) ◽  
pp. 293-301 ◽  
Author(s):  
B Bonavida

A secondary specific cytotoxic response is obtained when lymphocytes primed in vivo to a tumor allograft are exposed to Con A in culture. The secondary cytotoxic cells generated are specific to target cells bearing antigens of the primary sensitizing cells and are qualitatively indistinguishable from the response obtained upon secondary antigenic stimulation. The cell-mediated cytotoxicity is independent of concanavalin A (Con A) and is not affected by the Con A-specific inhibitor, alpha-methyl-D-mannose pyranoside. Furthermore, cultures containing a mixture of submitogenic concentrations of Con A and stimulating antigens showed synergy and augmentation of cytotoxic activity. It is suggested that activation of prekiller cells by Con A into CTL may be mediated via the same or similar receptors normally triggered by the stimulating antigens. Functional similarities between ConA and the lymphocyte-defined antigens of the major histocompatibility complex region are discussed.


1983 ◽  
Vol 157 (1) ◽  
pp. 141-154 ◽  
Author(s):  
P J Fink ◽  
I L Weissman ◽  
M J Bevan

To detect a strong cytotoxic T lymphocyte (CTL) response to minor histocompatibility (H) antigens in a 5-d mixed lymphocyte culture, it is necessary to use a responder that has been primed in vivo with antigen-bearing cells. It has previously been shown that minor-H-specific CTL can be primed in vivo both directly by foreign spleen cells and by presentation of foreign minor H antigens on host antigen-presenting cells. This latter route is evident in the phenomenon of cross-priming, in which H-2 heterozygous (A x B)F1 mice injected 2 wk previously with minor H-different H-2A (A') spleen cells generate both H-2A- and H-2B-restricted minor-H-specific CTL. In a study of the kinetics of direct- vs. cross-priming to minors in F1 mice, we have found that minor H-different T cells actually suppress the induction of virgin CTL capable of recognizing them. CTL activity measured from F1 mice 3-6 d after injection with viable A' spleen cells is largely H-2B restricted. The H-2A-restricted response recovers such that roughly equal A- and B-restricted activity is detected in mice as early as 8-10 d postinjection. This temporary hyporeactivity does not result from generalized immunosuppression--it is specific for those CTL that recognize the foreign minor H antigen in the context of the H-2 antigens on the injected spleen cells. The injected spleen cells that mediate this suppression are radiosensitive T cells; Lyt-2+ T cells are highly efficient at suppressing the induction of CTL in vivo. No graft vs. host reaction by the injected T cells appears to be required, as suppression of direct primed CTL can be mediated by spleen cells that are wholly tolerant of both host H-2 and minor H antigens. Suppression cannot be demonstrated by in vitro mixing experiments. Several possible mechanisms for haplotype-specific suppression are discussed, including inactivation of responding CTL by veto cells and in vivo sequestration of responding CTL by the injected spleen cells.


1975 ◽  
Vol 141 (4) ◽  
pp. 775-787 ◽  
Author(s):  
P F Piguet ◽  
H K Dewey ◽  
P Vassalli

Caryotypic analysis of the cells dividing in mouse parent-hybrid MLC showed an F1 hybrid cell proliferation, which varied depending upon the source of lymphoid cells used: strong in spleen MLC (sometimes equal to that of the parental cells), less marked in lymph node cell MLC, and most often absent in MLC between cortisone-resistant (CR) thymocytes. MLC between parental spleen cells and F1 CR thymocytes showed, however, that in certain conditions of culture F thymocytes can also proliferate. Using parental or F1 spleen cells lacking T lymphocytes, it was found that F1 cell proliferation is entirely dependent upon the presence of parental T cells, but does not require the presence of T lymphocytes among the F1 cells. Immunofluorescence analysis of the blasts observed in one-way MLC showed that about 70% of the parental blasts were T blasts, and 25%B blasts (containing a high proportion of plasmablasts); among the F1 blasts, there was also the same percentage of B blasts and plasmablasts, but many of the T blasts bore only small amounts of T-cell antigen (MTLA), and there was also about 20%of unstained blasts, possibly T blasts bearing MTLA in amounts undetectable by immunofluorescence. The possibility is discussed that the F1 responding T cells belong to a subpopulation performing a suppressive function; MLC lacking F1 T cells showed increased [3H] thymidine incorporation. The proliferation and differentiation of parental and F1 B cells may result mainly from an unspecific, "polyclonal" triggering.


1974 ◽  
Vol 140 (6) ◽  
pp. 1646-1659 ◽  
Author(s):  
Richard J. Hodes ◽  
Barry S. Handwerger ◽  
William D. Terry

Two subpopulations separated from normal spleen have been shown to synergize as responding cells in the in vitro induction of specific cell-mediated cytotoxicity during the mixed lymphocyte culture (MLC). The synergizing populations are a nylon wool column-adherent and a nylon wool column-nonadherent fraction, enriched for B lymphocytes and T lymphocytes, respectively. When a mixture of these fractions is used as the responding cell population in MLC, greater cytotoxicity is generated than would be expected from the sum of activities generated in the two subpopulations sensitized separately. The synergy appears to occur at the sensitization rather than the effector phase. The synergizing cell which is contained in the nylon-adherent subpopulation is distinct from the cytotoxic effector T lymphocyte, is resistant to lysis by rabbit antimouse brain serum, and is unresponsive to phytohemagglutinin; its synergizing function could not be replaced by either plastic-adherent spleen cells or peritoneal exudate cells. These results suggest a role of a non-T-cell nonmacrophage population in the generation of cytotoxic activity.


1974 ◽  
Vol 140 (2) ◽  
pp. 356-369 ◽  
Author(s):  
Duane L. Peavy ◽  
Carl W. Pierce

The effects of soluble concanavalin A (Con A) or Con A-activated spleen cells on the generation of cytotoxic lymphocytes (CL) in mixed leukocyte cultures (MLC) were examined. Mitogenic concentrations of soluble Con A or small numbers of Con A-activated spleen cells substantially inhibited CL responses. The suppression was partial rather than absolute and was critically dependent upon the concentration and time of addition of soluble Con A or Con A-activated spleen cells to the MLC. Suppressive effects of Con-A activated spleen cells were mediated by T cells since suppressor cell activity was abrogated by treatment of spleen cells with anti-θ serum and complement before or after Con A activation. X irradiation of spleen cells before Con A treatment also abrogated generation of suppressor cell activity. After activation by Con A, however, the function of suppressor cells was radioresistant. Although the precise mechanism(s) of suppression is, as yet, unknown, the precursors of CL must be exposed to Con A-activated cells during the early phases of the immune response for suppression to occur. Kinetic studies revealed that suppression of CL responses was not due to a failure to initiate an immune response, but represented a response which developed initially, but subsequently aborted. The relevance of these observations to the concepts of T-cell-T-cell interaction and regulatory control of immune responses by T cells is discussed.


1977 ◽  
Vol 146 (2) ◽  
pp. 468-482 ◽  
Author(s):  
S Gillis ◽  
KA Smith

In vivo or in vitro immunity to murine leukemia virus (MuLV)-induced leukemia cells which do not effectively produce virus, has been difficult to demonstrate. Because immunizations with allogeneic murine leukemia cells have been used to confer syngeneic tumor immunity to virus- producing cells, we attempted to generate lymphocytes, cytotoxic to syngeneic nonproducer leukemia cells, by stimulating normal murine spleen cells with allogeneic nonproducer leukemia cells in mixed tumor lymphocyte culture (MTLC) reactions in vitro. Secondary allogeneic MTLC of normal C57BL/6 or DBA/2 spleen cells effectively produced syngeneic tumor-specific cytotoxic lymphocytes. Target cells lysed in lymphocyte- mediated cytolysis (LMC) assays, included both Friend and Rauscher virus- induced syngeneic murine leukemia cells and chemically-induced hematopoietic tumor cells. Syngeneic tumor cells were lysed regardless of whether they produced infectious MuLV or expressed viral antigens gp-71, p-30, or p-12 at the cell surface. Syngeneic normal cells (thymus, lymph node, or Concanavalin A-stimulated spleen cells) used as targets in LMC assays were uneffected by lymphocytes harvested from secondary allogeneic MTLC. Several other in vitro culture treatments including secondary syngeneic MTLC and repetitive mixed lymphocyte culture stimulations were incapable of generating tumor-specific cytotoxic lymphocytes. Based upon these results, we propose that secondary MTLC stimulation of normal spleen cells with allogeneic nonproducer leukemia cells selects for the proliferation of two subpopulations of antigen-specific cytotoxic lymphocytes. The population capable of effecting syngeneic tumor cell lysis is directed against tumor-associated cell surface antigens which may be distinct from viral structural proteins or glycoproteins. The growth of these tumor-specific cytotoxic lymphocytes may be enhanced by a soluble allogeneic effect factor produced by the proliferation of the second subpopulation of lymphocytes generated in repetitive allogeneic MTLC, namely those lymphocytes with specificities directed against differing histocompatibility antigens.


1973 ◽  
Vol 137 (5) ◽  
pp. 1303-1309 ◽  
Author(s):  
Barbara J. Alter ◽  
Dolores J. Schendel ◽  
Marilyn L. Bach ◽  
Fritz H. Bach ◽  
Jan Klein ◽  
...  

The cell-mediated lympholytic capability of mouse spleen cells stimulated in mixed lymphocyte culture is related to the major histocompatibility complex genotype on target lymphocytes. The strain combinations AQR-B10. T(6R) and B10.A(4R)-B10.A(2R) that result in significant mixed lymphocyte culture activation do not mediate cell-mediated lympholysis on sensitizing target lymphocytes; serologically defined regions (H-2K and H-2D) are identical within each combination. H-2K or H-2D region disparity alone does not cause cell-mediated lympholysis. However after mixed lymphocyte culture activation as seen with B10.A-B10.T(6R), a target cell bearing only an H-2K region difference from the effector cell is sensitive to cell-mediated lympholysis. Likewise an H-2D region difference is an adequate target after mixed lymphocyte culture activation of the effector cell in the combination B10.A(2R)-B10.D2.


1982 ◽  
Vol 156 (3) ◽  
pp. 918-923 ◽  
Author(s):  
M S Sy ◽  
S H Lee ◽  
M Tsurufuji ◽  
K L Rock ◽  
B Benacerraf ◽  
...  

Treatment of responder cells with monoclonal anti-Ly-1,2 antibodies plus complement in vitro completely eliminated their ability to generate azobenzenearsonate (ABA)-specific cytolytic T lymphocytes (CTL). However, addition of the concanavalin A-stimulated supernatants of rat spleen cells (Con A-Sup) can fully reconstitute the response. Therefore, Lyt-1,2-bearing T cells are required for the generation of ABA-specific CTL, and such requirement can be replaced by factors present in the Con A- sup. Suppressor T cells (Ts), when adoptively transferred into naive recipients, will inhibit the in vivo priming of CTL. This inhibition can also be reversed by in vitro addition of Con A-Sup. furthermore, mice serving as donors of Ts also show profound unresponsiveness when primed and restimulated in vitro. In contrast to the Ts-mediated inhibition, in vitro addition of Con A-Sup was unable to abolish the unresponsiveness observed in these cultures. Thus, we identified two unresponsive states in a hapten-specific killing system that differ in their ability to be reconstituted by Con A-Sup.


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