Abstract
We have used gene targeting in embryonic stem cells to generate mice with mutations in T-cell receptor (TCR) gene-α, TCR-β, TCR-δ or the Recombination Activating Gene-1 (RAG-1). TCR-α or TCR-β mutant mice are deficient in αβ T cells, but still contain γδ T cells and B cells. TCR-δ mutant mice are deficient in γδ T cells, but still contain αβ T cells and B cells. Mice doubly mutant for TCR-β and TCR-δ do not have any mature T cells, but still have B cells. RAG-1 mutant mice are totally deficient in both mature T cells and B cells. Here, I describe recent studies of thymocyte development in the mutant mice, and I review experiments addressing the function of the immune system of the mutant mice.