Mathematical modeling in immunology.

The first step in the sequence of events leading to antibody synthesis and secretion is antigen encounter by B cell receptors. The reaction leads to major membrane perturbations, including the capping and endocytosis of receptors. These events might play an important role in various aspects of the B cell response, but they are not well understood, and in any event it seems unlikely that a satisfactory explanation of response regulation to most antigens can be advanced in terms of these phenomena alone, without explicit consideration of other cell populations. Suppressor and helper T cell populations qualitatively and quantitatively regulate the response to almost all antigens. Knowledge of the antigen dose dependence of the response of these populations will undoubtedly be important for a complete understanding of major immune response phenomenology such as suppression and affinity regulation. T cell dose response patterns are currently unavailable, nor is much known of the molecular mechanisms mediating interactions among antigen responsive T cells. In order to explain why this information is important, and to connect disparate data on immunoregulation in a simple way, I introduced dose response patterns based on analogy with basophils, assumed cell interactions mediated by autoantiidiotypic antibodies, and briefly pursued the consequences. In the final section, the genetic experiments that are providing information on the molecular constraints on cell interactions were mentioned, and some of the outstanding theoretical questions were briefly discussed.