in the secondary in vitro stimulation system , l cell component ( s ) that were introduced into hybrid cells by cell fusion play a role in the induction of ctl , as shown by the fact that stimulation with a mixture of l and fm3a/r cells could induce mm antigen-specific ctl , and that the killer helper effect of l cells could be replaced by cell free culture supernatants obtained from co-cultures of unprimed c3h spleen and l cells .
C0243092
cell component
C0007634
cells