Regulation of Antibody Response in Vitro
Authors: Kishimoto Tadamitsu , Ishizaka Kimishige 
Published: December 2022

Abstract
Distribution of immunoglobulin heavy chain antigenic determinants on hapten-specific memory cells was investigated by studying the suppressive effect of anti-γ chain and anti-µ chain antibodies on in vitro secondary antibody response and by fractionating primed lymph node cells by cellular immunosorbents. Mesenteric lymph node cells from rabbits primed with DNP-Ascaris (Asc) antigen were stimulated in vitro with homologous antigen in the presence or absence of the anti-heavy chain antibodies and cultured. Antibody response was evaluated by measuring anti-DNP antibodies of IgG, IgM and IgE classes in the culture fluid. The results showed that anti-γ chain antibody suppressed the anamnestic response of both IgG and IgM classes and anti-µ chain antibody suppressed the IgM antibody response. In some rabbits, a partial suppression of IgG antibody formation was obtained by anti-µ chain antibody. Neither anti-γ chain nor anti-µ chain antibody suppressed the IgE antibody response. The suppressive effect of anti-γ chain antibody on IgG and IgM antibody formation, and the effect of anti-µ chain antibody in IgM antibody formation were observed in a system in which a non-adherent cell population of DNP-Asc primed cells was stimulated by DNP-heterologous carrier bovine γ globulin (BGG) conjugate, indicating that the target cells for anti-heavy chain antibody are hapten-specific memory cells.
DNP-Asc-primed lymph node cells were passed through a cellular immunosorbent coated with anti-γ chain, anti-µ chain or anti-Fab antibody and the effluent cells were stimulated in vitro by homologous antigen. The results showed that a) anti-γ chain antibody columns removed the cells essential for IgG and IgM antibody formation, and b) anti-µ chain antibody columns removed most of the cells essential for IgM antibody formation and significantly reduced the ability of the primed cells to form IgG antibody. The ability of the primed cells to form IgE antibody upon stimulation with DNP-Asc was not impaired by passing through either the anti-γ chain column or the anti-µ chain column. It appears that anti-γ chain immunosorbents removed both hapten-specific memory cells for IgG and IgM antibody formation, and that anti-µ chain immunosorbents removed most of the hapten-specific memory cells for IgM antibody formation and a part of the cells for IgG antibody formation. An anti-Fab antibody column, as well as the immunosorbent coated with DNP-HSA, removed the ability of the primed cell suspension to form all of the IgG, IgM and IgE antibodies.
Hapten specific memory cells for IgG and IgM antibody formation were recovered from the anti-γ chain immunosorbent to which DNP-Asc primed cells had been applied. Lymphocytes recovered from the immunosorbent did not form anti-DNP antibody upon stimulation with DNP-Asc but a mixture of the recovered cells with effluent cells from a DNP-HSA column responded to DNP-Asc to form both IgG and IgM but no IgE antibodies. It appears that a significant proportion of hapten-specific memory cells for IgG and IgM antibody formation bear both γ chain and µ chain antigenic determinants on their surface and that the hapten-specific memory cells for IgE antibody lack both antigenic determinants.