Dominance of an immune response by secondary cells: quantitation by allotype analysis.

Dominance of an immune response by secondary cells was demonstrated in a cell transfer system utilizing allotype-congenic mice. Spleen cells from BALB/c mice immunized with TNP-KLH were adoptively transferred into sublethally irradiation (200 R) congenic partners of a different allotype (C.B.-17 mice). Subsequent to the cell transfer, the recipients were challenged with TNP-KLH and bled periodically. Anti-TNP antibodies were isolated and analyzed for their content of donor and host IgG allotypes. Through day 58 after the adoptive transfer, 80% or more of the IgG antibody measured was of donor allotype. By day 110, most but not all recipients made IgG antibody principally of host allotype. In contrast, control C.B-17 recipients, which received nonimmune BALB/c spleen cells but otherwise treated as above, produced IgG antibodies almost entirely of host allotype. Total anti-TNP synthesis was reduced markedly in recipients of immune BALB/c cells so that there was a decrease of about 95% in the production of anti-TNP antibodies of host allotype, as compared with controls that received nonimmune cells. The results are discussed in terms of dominance of an immune response by secondary B cells.