Functional heterongeneity among the T-derived lymphocytes of the mouse. VI. Memory T cells stored in the T2 subpopulation.

Memory T cells were demonstrated in mice which were the precursors for cells causing sheep red blood cell-(SRBC) specific helper activity in the in vitro response of spleen cells to trinitrophenyl (TNP)-SRBC. These memory cells were distinguished from the effectors of helper activity generated during the primary response and were shown to belong to the T2 subpopulation of peripheral T cells on the basis of 1) their rapid response to a challenge with SRBC, 2) their long lifetime, and 3) their sensitivity to small in vivo doses of anti-thymocyte serum.