Abstract
Spleen cells from immunized young mice unresponsive to Shigella paradysenteriae antigens, induced by a neonatal injection of a relatively large dose of soluble Shigella extract, were not capable of transferring an agglutinin forming capacity to nonimmune recipient mice. Such spleen cells could not confer an adoptive immunity against Shigella infection following transfer to nonimmune recipients. However, spleen cells from similar mice obtained following reversal from the observed immunologic unresponsive state were capable of transferring agglutinin formation and adoptive immunity to recipient animals.