Immunological adjuvants promote activated T cell survival via induction ofBcl-3

Injection of soluble protein antigen into animals causes abortive prolifera tion of the responding T cells. Immunological adjuvants boost T cell respon ses at least in part by increasing the survival of activated T cells during and after the initial proliferative phase of their clonal expansion,To und erstand how adjuvants promote T cell survival, we used gene microarrays to analyze gene expression in T cells activated either with antigen alone or i n the presence of two different adjuvants. Among the genes whose expression was increased by both adjuvants was the I kappaB family member Bcl-3. Retr oviral infection experiments showed that expression of Bcl-3 increased surv ival of activated T cells in vitro and in vivo. Adjuvants may therefore imp rove survival of activated T cells via induction of Bcl-3.