Approaches to the study of human immunoregulation

The specificity of the immune response appears to have originated at the cellular and clonal level through the evolution and development of separate T- and B-cell function. With the introduction of molecular techniques, it has become possible to examine the basis of these differences at the level of gene expression. Since less than 2 % of mRNA is different in T and B cells and there appear to be about 200 cell-specific genes, it has seemed increasingly likely that regulation of gene expression and signal transmission effectively forms a third component of the immune system. This was the theme of a recent meeting. Studies on the normal development of the immune system, focusing on key points of transition, and studies on primary and acquired immunodeficiency, focusing on molecularly defined alterations, suggest new approaches to human immunoregulation.