Cellular Events Involved in the True Primary Immune Response of Splenocytes in Vitro

Abstract

The immunization of lymphoid cells can be readily achieved in vitro with common antigens such as syngeneic erythrocytes, serum proteins or chemical haptens. More antibody forming cells (AFCs) usually are induced when lymphoid cells are derived from antigen primed donor animals. A “true” primary immune response by splenocytes from unprimed animals is difficult to induce. In general, pre-existing immunocytes to most antigens are present even before specific immunization. Furthermore, even in the absence of specific antigen, AFC usually appear in vitro to most antigens, including erythrocytes and bacterial antigens, suggesting that there is a cross-reacting antigen in the culture medium or environment (1–5).