T-helper heterogeneity and immune response patterns.

We have long known that helper T cells regulate antibody-dependent humoral responses; we are now beginning to understand how they do so. In murine systems, there are two TH subsets: One secretes IL-2 and gamma-interferon, the other IL-4 and IL-5. The helper-subset-specific cytokines affect B cells, and therefore the regulation of antibody secretion, in profoundly different ways.