The carrier effect in the secondary response to hapten-protein conjugates. IV. Uptake of antigen in vitro and failure to obtain cooperative induction in vitro.

Abstract

AbstractUptake of antigen in the cooperative adoptive secondary response of mice to hapten‐protein conjugates was examined. Spleen cells from donors primed with bovine serum albumin (BSA) took up 4‐Hydroxy‐5‐iodo‐3‐nitro‐phenacetyl(NIP)‐BSA in vitro, as judged by their subsequent ability to induce a response to NIP in cooperation with NIP‐ovalbumin‐primed spleen cells. Competitive inhibition by BSA could be demonstrated, indicating that uptake occured onto specific receptors. The antibody‐forming‐cell‐precursor population also could take up conjugates in vitro.Allogeneic helper and antibody‐forming‐cell‐precursors were incubated together under conditions likely to support cooperative induction of the secondary response and then transferred into hosts alloimmune to the helper cells. Under these conditions the response did not proceed after the transfer. It is likely therefore that continuous cooperation is required in order to support a full response.