IMMUNOLOGICAL RESPONSES OF MAMMALIAN HOST AGAINST TAPEWORM INFECTIONS .8. SOME EVIDENCE AGAINST CELLULAR IMMUNITY INDUCED IN SHEEP BY ACTIVATED EMBRYOS OF TAENIA HYDATIGENA AND T OVIS

Resistance to Taenia hydatigena can be artificially induced by an injection of the homologous activated embryos, and also, but to a lesser degree, by those of T. ovis. Two experiments were undertaken to determine whether the immunity so induced to the establishment of T. hydatigena could be due to a passively transferable cellular immunity. Cells from immunized donors were transferred to nonimmune recipients. These animals were subsequently challenged with the eggs of T. hydatigena. The results showed that no immunity associated with the transfer of cells could be demonstrated; and that, therefore, within the limits of the experimental technique, no evidence could be found supporting the involvement of cellular immunity in the development of resistance to T. hydatigena by sheep following active immunization with the embryos of either T. hydatigena or T. ovis. © 1969.