Lymphokines and monokines as regulators of human lymphoproliferation.

The development of a competent immunoregulatory response in the face of an antigenic challenge is modulated by soluble proteins of relatively low molecular mass. Lymphokines and monokines, secreted by cells of T lineage and cells of the monocyte/microphage series, respectively, function in a bimodal amplification network that results in the proliferation and differentiation of the immunoregulatory cells. Interleukin 1 is typically assayed by its effect on thymocytes or by its ability to promote the T cell-dependent release of interleukin 2. Interleukin 2 is routinely measured by its ability to support the long-term growth of cultured T cells, whereas B cell growth factor is measured by its ability to support the long-term growth of cultured B lymphocytes. The availability of homogeneous purified factors and the subsequent availability of monoclonal antibodies against these reagents should allow for the development of rapid quantitative assays for these analytes in diverse biological fluids. In addition, large quantities of purified reagents will promote studies to determine therapeutic efficacy in several immunodeficiency syndromes.