Effect of the Number of Antigens on the Quantity of Cells producing Several Kinds of Antibody

Abstract

DATA concerning the quantity of cells which synthetize two kinds of antibody simultaneously are contradictory^1–3. The kinetics of such cells has not been extensively investigated. Accordingly, we have attempted to investigate the effect of the number of antigens used for immunization on the quantity of cells synthetizing more than one kind of antibody. For this purpose, several groups of Wistar rats were given single subcutaneous injections, in both hind foot pads, of endotoxins from Salmonella cerro, S. aberdeen and Shigella flexneri in different combinations. The dose of each of the antigens was 5 µg/injection. The animals were killed 5 days after the injection of antigen and cell suspensions prepared from the tissues of their popliteal lymph nodes⁴ were assayed for antibody producing cells. The assays were carried out by techniques of motile bacteria adherence⁵ and indirect haemadsorption⁶. Test antigens utilized for the first procedure were live cultures of active motile S. cerro or S. aberdeen bacteria and those used for the second procedure were small round sheep erythrocytes or large dog erythrocytes sensitized by specific antigens. In control experiments, designed to verify the specificity of the chosen tests, the cells of the animals immunized with only one antigen were checked by all three test antigens. To rule out the possibility of passive “induction” of adherence reactions, cells of intact animals treated with serum or saline extracts of lymph nodes of immunized rats have also been tested. The results of the control experiments have shown that the techniques used are of adequate specificity.