The role of cell number and source in adoptive immunity.

The use of bacteriophage and bovine serum albumin as antigens for adoptive immunization has been investigated. Cells were transplanted from normal or previously immunized (`primed cells') donor mice into isologous hosts, and then stimulated with antigen. The reactions to phage of normal and primed cells could be distinguished and measured; for BSA, only primed cells could be used without the help of adjuvant. Irradiation of the prospective host enhanced the activity of the transplanted cells. Saturation was easily reached by increasing the number of phage-primed cells in the transplant. BSA-primed cells saturated less easily, probably because BSA is a relatively poor immunogen. Primed cells were localized, to a limited extent, in the lymph nodes draining the sites of injection of antigen, but could usually also be found in the blood.