Adjuvant activity of mycobacterial fractions. I. Purification and in vivo adjuvant activity of cell wall skeletons of Mycobacterium bovis BCG, Nocardia asteroides 131 and Corynebacterium diphtheriae PW8.

The adjuvant activity of cell wall skeletons (mycolic acid-arabino-galactan-mucopeptide, CWS) prepared from the cells of mycobacteria, nocardia and corynebacteria was examined in vivo in mice and guinea pigs. The cell wall skeletons of Mycobacterium bovis BCG (BCG-CWS), Nocardia asteroides 131 and Corynebacterium diphtheriae PWC suspended in Freund's incomplete adjuvant (FIA) as water-in-oil emulsions showed potent adjuvant activity on the formation of circulating antibody and cell-mediated immunity to bovine serum albumin (BSA), sheep erythrocytes (SRBC) and sulfanylazo-bovine serum albumin (SA-BSA) in mice and guinea pigs. After acetylation or acid treatment, BCG-CWS retained its adjuvant activity, but the activity of BCG-CWS was destroyed completely by alkaline treatment. The cell wall constituents, arabinose-mycolate and arabino-galactan, prepared from BCG-CWS showed no adjuvant activity. It was also shown that BCG-CWS suspended in phosphate buffered saline or associated with oil droplets augmented cell-mediated cytotoxicity in which thymus-derived lymphocytes (T-cells) are effector cells.