Antigen-primed helper T cell function in CBA/N mice is radiosensitive

CBA/N mice have an X-linked immunodeficiency that includes a deficient humoral response to sheep red blood cells (SRBC). In order to study the cellular mechanisms of this deficiency we have examined helper T cell function to SRBC in an adoptive transfer system by using 2 different sources of helper T cells. When thymocytes were used as the source of helper T cell precursors in an adoptive transfer system, CBA/N thymocytes were as effective as CBA/Ca thymocytes in inducing CBA/Ca bone marrow cells to develop into both direct and indirect anti-SRBC plaque-forming cells (PFC). However, when SRBC-primed, irradiated recipient mice were used as the source of helper T cells, primed and irradiated CBA/N recipiets developed significantly fewer direct and indirect anti-SRBC PFC than similarly treated CBA/CA recipients when reconstituted with CBA/Ca bone marrow cells and challenged with SRBC. We conclude that antigen-primed helper T cell function in CBA/N mice is radiosensitive. Possible reasons for this are evaluated and discussed