TRACKING ANTIGEN-SPECIFIC HELPER T-CELL RESPONSES

T-cell receptor transgenic animals provide an excellent source of T ce lls for the analysis of antigen-specific helper T-cell development. Al ternatively, studies in normal animals continue to focus on specific i mmune responses dominated by T cells using restricted sets of antigen receptors. These complementary strategies provide direct access to the dynamics of helper T-cell differentiation in vivo.