Immunoglobulin isotype regulation by antigen‐presenting cellsin vivo

摘要

AbstractThe isotype and magnitude of the B cell response clearly depends on thein vivoactivation of T helper (Th) cells which secrete different lymphokines. Since Th are activated by the presentation of the antigen on specialized cells, we wished to test whether the nature of the antigen‐presenting cells (APC) influences the isotypic profile of the humoral response. Data are presented showing that antigen‐pulsed dendritic cells (DC) and peritoneal macrophages induce the synthesis of specific antibodies when injected in syngeneic animals. By contrast, a single injection of antigen‐pulsed resting B cells does not prime the micein vivo.Moreover, the injection of antigen‐pulsed DC induces the synthesis of specific IgG2a and IgG1 antibodies, whereas peritoneal macrophages favor the production of IgG1 and IgE antibodies specific for the antigen. These data show that the isotype and the amplitude of the B cell response can be regulated by the nature of the APC, and indirectly suggest that Th cell differentiation is controlled at the level of antigen prese