Activation and regulation of human immune responses: implications in normal and disease states.

A model of activation, proliferation, and differentiation of human lymphocyte responses is described, and the complex immunoregulatory modulation of this system discussed with regard to normal immune function and the aberrancies expressed in diseases characterized by abnormalities of immune function. Recent advances in technology of cloning and hybridizing human T cells as well as hybridizing human B cells have had a critical impact on the field of human immunobiology and have made available potentially unlimited amounts of purified antibodies and immunoregulatory factors. Of particular note has been the optimization of conditions for the production of B-cell hybridomas from human peripheral blood B cells secreting monoclonal antibody directed against predetermined antigenic specificities to which a subject has been immunized. Furthermore, the development of antigen-specific human T-cell clones has allowed a precise delineation of the genetic restriction in monocyte-T-cell interactions as well as the functional capability of T-cell subsets. Precise definition of these systems has allowed a greater understanding of the mechanisms of diseases characterized by aberrancies of immune function.