The production of IgE and IgG1 antibodies in guinea-pigs immunized with antigen and bacterial lipopolysaccharides

Abstract

The adjuvant action of lipopolysaccharide (LPS) on the IgE and IgG1 antibody production by guinea-pigs was studied. It was observed that LPS induces an early preferential production of IgE antibody. The optimal dose of LPS to cause this effect was of the order of 20 μg/kg. Low amounts of LPS as well as low amounts of antigen favoured the production of IgE antibody whereas high amounts of LPS or antigen favoured the production of IgG1. Later, in the course of immunization, the IgE antibody content decreased and the IgG1 antibody content increased. Booster injection of antigen resulted in a considerable and simultaneous increase in both IgE and IgG1. The preferential production of IgE was consistently obtained when LPS and antigen were injected simultaneously. Injection of LPS 24 hours after antigen resulted in a higher production of IgE and IgG1 but in the loss of the preferential production of IgE. Guinea-pig IgE antibody was able to persist in homologous skin for at least 46 days.