Expression and Function of Class II I-Ak Antigens on an Antigen-Specific T-Suppressor Cell Clone

The question of whether similar or different modes of Ia-antigen expression exist in different cell classes and mediate different cell type functions is of primary interest to current class II antigen research. Among cells of the lymphoid system in the mouse, class II antigens are primarily expressed on B lymphocytes (Sachs and Cone 1973) and cells of the macrophage lineage (Cowing et al. 1978), whereas the majority of T lymphocytes do not seem to express endogenously synthesized class II antigens.