Restimulated memory Tc cells have a higher apparent avidity of interaction with targets than primary virusimmune Tc cells as indicated by anti‐CD 8 blocking

Previous experiments have shown that whereas a secondary in vitro Kunjin‐immune cytotoxic T (Tc) cell population lysed equally well targets infected with either native flavivirus or a recombinant vaccinia virus expressing the immunodominant determinant, primary in vivo Kunjinimmune Tc cells were able to lyse only the recombinant vaccinia virus‐infected targets. Using CD8 blockade to assess the avidity of T cell‐target interaction, recombinant‐infected targets express antigen more efficiently than native flavivirus infected targets and secondary in vitro Kunjin‐immune Tc cells have a higher avidity for targets than do primary in vivo Kunjin‐immune Tc cells. Secondary in vivo influenza‐immune Tc cells are also of higher avidity than primary in vivo influenza‐immune Tc cells. Thus, a restimulated memory Tc cell population interacts with targets with greater avidity than does a recently activated naive population.