The affinity of bacterial polysaccharide-containing fractions for mammalian cell membranes and its relationship to immunopotentiating activity.

The natural affinity of various bacterial glycopeptides and lipopolysaccharides for mammalian cell membranes was estimated quantitatively by comparison with the adsorption of lipopolysaccharide from Escherichia coli NCTC 8623 to erythrocytes, thymocytes, bone marrow cells, spleen cells, peritoneal lymphocytes and macrophages. Immunopotentiating activity was estimated by measuring the ability of the bacterial fractions to stimulate a humoral response to ovalbumin in HAM/1CR mice. When the affinity for mammalian cell membranes was compared with the stimulation of the antibody response, it was found that a negative correlation for peritoneal macrophages (rs = -0.94, P less than 0.0005) and a positive correlation for peritoneal lymphocytes (rs = +0.97, P less than 0.0005) and spleen cells (rs = +0.76, P less than 0.005) existed.