Regulation of Antibody Response in Vitro

Abstract Effect of anti-γ chain and anti-µ chain on secondary antibody response of rabbit spleen cells was studied in vitro. Spleen cells from rabbits primed with dinitrophenylbovine γ globulin (DNP-BGG) were stimulated in vitro with the antigen either in the presence or absence of anti-heavy chain antibody. After 24 hr of incubation, the cells were washed and cultured in the absence of the antigen. Antibody response was evaluated by enumerating IgG and IgM antibody producing cells and by measuring anti-DNP antibodies in culture media. It was found that anti-γ chain suppressed both IgG and IgM antibody response, while anti-µ chain suppressed only IgM antibody response. When the primed cells were cultured without antigen stimulation, IgM antibody producing cells increased after 3 days' culture. The response was also suppressed by treatment of the cells by either anti-γ or anti-µ chain. The treatment with anti-heavy chains did not inhibit secretion of antibodies from antibody producing cells. It appears that anti-heavy chain suppressed differentiation of precursor cells to antibody-producing cells.