The dissociation of adjuvant properties of mycobacterial components from mitogenicity, and from the ability to induce the release of mediators from macrophages.

Twelve preparations from mycobacterial cell walls and culture supernatant fluids were tested for their ability to activate lymphocytes from Balb/c or Nu/Nu mice, and to increase the release of mediators from macrophages in vitro. The peptidoglycolipids (wax D) were B-cell mitogens and induced plaque-forming cells. These properties were lost if the glycopeptide component was removed, leaving the pure lipid, mycolic acid. Neither the glycopeptide fractions, with well-documented adjuvant properties, nor mycobacterial polysacchardie II-activated B cells. Only intact peptidoglycolipid showed synergy with the mitogenic effect of phytohaemagglutinin (PHA) on thymocytes from Balb/c mice. The effect was much smaller than with E. coli lipopolysacharide (LPS) or dextran sulphate. The peptidoglycolipid also enhanced the release of factors from macrophages able to modify the response of Balb/c thymus cells to PHA. In this respect it resembled E. coli LPS. Adjuvant active glycopeptides did not share this property.