The effect of Freund's complete adjuvant on the cellular immune response in mice to a porcine strain of Escherichia coli lipopolysaccharide.

The effect of Freund's complete adjuvant (FCA), known to enhance and prolong both cellular and humoral responses to thymus dependent (TD) antigens, was studied with regard to the cellular response in BALB/c mice to the thymus independent lipopoly-saccharide antigen of Escherichia coli O138, a porcine pathogen. Techniques based on immunocytoadherence (ICA), inhibition of ICA with an antiserum to the brain-associated theta alloantigen, immune adherence and macrophage migration inhibition, were used in this study. Apart from enhancing the rosette forming cell response, it is suggested that FCA appears to promote the action of the lipopolysaccharide on assembled macrophages with subsequent release of humoral factors which, in turn, activate T cells with consequent cell-mediated response.