Factors Affecting Primary and Secondary Antibody Production by Splenic Tissues

The capacity of isolated rabbit splenic tissues to form antibody was investigated by using tissue culture and cell transfer procedures. Hemagglutinating antibodies to bovine γ-globulin (BGG) were regularly demonstrated when splenic tissues were cultured in vitro three or more days following a single injection of antigen. After a second injection of BGG, splenic tissues produced antibodies in vitro when removed two or three days after antigen administration. Bacterial endotoxin given simultaneously with antigen did not increase the primary or secondary antibody levels of splenic tissues cultured in vitro. The addition of BGG in vitro to splenic explants from normal or previously immunized rabbits failed to initiate a primary or a secondary antibody response. The capacity of splenic tissues to form antibody after a single injection of BGG into rabbits was transferrable to x-irradiated recipients on days 1, 2, and 3 after antigenic stimulation. The enhancing effect of endotoxin, given either to the donor simultaneously with BGG or to the recipient immediately following cell transfer, was equivocal. Fluorinated pyrimidines, 5-fluorouracil and 5-fluoro-2′-deoxyuridine, inhibited secondary antibody formation when added to splenic tissues obtained 2 days after a second injection of BGG. Preliminary experiments indicated that thymidine partially reversed the inhibitory effect of 5-fluoro-2′-deoxyuridine.