We study the human system to address fundamental questions in the context of the immune response to different classes of antigens,including microbial pathogens and self-antigens,to gain insights into mechanisms that mediate host protection or immune-mediated pathology.Our efforts towards human immunology have resulted in the development of high-throughput cell-based screening methods to analyze the human immune response and,in particular,the functional diversity and repertoire of human effector and memory T cells.