The role of I region gene products in macrophage - T lymphocyte interaction.

The macrophage first gained recognition in the early 192O's and 193O's as the cell responsible for clearing antigen and synthesizing antibody (Sabin 1923). Its importance to the immune response faded with the realization that lymphocytes and not macrophages were the origin of antibody molecules and it was not until the early 196O's that experiments suggested that antigen processing by the macrophage was required for stimulation of immunocompetent lymphocytes (Fishman & Adler 1963). This renewed interest, however, was short lived when it was demonstrated that antigens could be recognized by lymphocytes. Furthermore, although lymphocytes could interact with macrophage bound antigen it did not appear critical that this antigen be processed, or structurally altered, by the macrophage.