Antigenic competition between two sequentially acting antigens. Immunosuppressive effect of T cells in spleen and lymph nodes of mouse.

This study concerns the antigenic competition among heterologous red cells, a T suppressor-dependent phenomenon, in three cases, when the two antigens are administered by various routes, in (a) splenectomized mice or in Nude mice reconstituted with (b) lymph node cells, or spleen cells. Competition occurs whatever the routes of antigenic introduction, except when the two antigens are injected subcutaneously in the same leg and the anti-SRC plaque-forming cells are counted in the draining lymph nodes. In that case, the first antigen plays the role of adjuvant to the second. An adjuvant effect is also observed in splenectomized mice when the antigens are introduced intraperitoneally. However, competition does not occur in Nude mice but is present when those animals have been reconstituted either with lymphnode cells or with spleen cells. Those results play in favor of the presence of T suppressors, both in lymph nodes and in spleen; however, in lymph nodes, the immunosuppressive action induced by the first antigen is exceeded by an concomitant adjuvant effect.