Regulatory Mechanism of Anti-Idiotypic Antibody on Anti-DNA Ab Production of Hybridoma Cells

Abstract

The regulatory mechanism of anti-idiotypic antibody(anti-id Ab) in the immune response is not fully understood. It has been reported that anti-id Ab suppresses Ab production of lymphocytes or hybridoma cells in vitro, but it does not affect the proliferation of cells or Ab secretion. We investigated whether or not polyclonal anti-id Ab regulates the production of anti-DNA Ab(lgG2a) in hybridoma cells. In addition, the effects of anti-id Ab on the proliferation of cells and on the transcription levels of lg genes were studied to elucidate the cellular and molecular mechanisms for regulation of anti-DNA Ab production in hybridoma cells. The treatment of hybridoma cells with anti-id Ab resulted in an increase in the number of cells producing anti-DNA Ab. However, there was no significant difference in the proliferation rate and mRNA levels of Ig genes between hybridoma cells treated with anti-id Ab, and those treated with normal rabbit serum. These results and our previous data suggest that the number of hybridoma cells producing anti-DNA Ab by anti-id Ab is not directly related with the rate of proliferation of the cells. Furthermore, it appears that the number of hybridoma cells producing IgG class anti-DNA Ab is increased by anti-id Ab, whereas the number of hybridoma cells producing IgM class anti-DNA Ab is down-regulated by anti-id Ab.