CELL COOPERATION IN THE IMMUNE RESPONSE.

The article analyses the cooperation between different cells in the immune response. It has long been recognized that the immune response to foreign substances is of two basic kinds, immediate hypersensitivity, associated with and transferable by serum antibody, and delayed hypersensitivity, only transferable by, and therefore presumably mediated by, living cells from the lymphoid organs, notably spleen and lymph nodes. The study of skin graft rejection in mice added a third kind of reaction, but since this type of immunity, too, could be easily transferred from immune to normal animals by lymphoid cells, it was eventually put in the same category as the delayed response, under the general title of cell mediated immunity.