The Biochemistry of Antigen-Specific T-Cell Factors

Soluble factors produced by immunocompetent cells in response to antigenic stimulation present one communications link by which the immune system regulated its activities. These factors may be specific for the inducing antigen or may be non-antigen-specific. This communication focuses on the biochemical and serological nature of antigen-specific regulatory molecules. These molecules are exclusively the products of T-cells. They may be divided into two categories: helper factors, which help T effector cells or B cells to respond; and suppressor factors, which suppress T and/or B cell responses.