Homozygous mice are viable and fertile with normal immune system development and function. They exhibit no spontaneous autoimmune disorders. No gene product (mRNA or protein) from the targeted gene is detected in the epididymis. At embryonic day 10.5, endogenous protein is absent from all cells at the maternal-fetal interface when both parents are homozygous for the targeted gene. Allogeneic and syngeneic pregnancy outcomes are unaffected by this mutation. In contrast to wild-type, anti-proliferative treatments (CTLA4-Ig, IFNalpha, or CpG-ODN) do not suppress T cell expansion both in vivo and in vitro. In addition, homozygous dendritic cells isolated from lymph nodes draining (induced) tumor sites have no suppressor activity. These mice may be useful in studies of pregnancy and reproductive immunology (tryptophan degradation, T cell activation, clonal expansion) as well as autoimmune disease, tissue transplantation, fostering, acquired tolerance/T cell anergy, and immunosuppressive pathways.
