Isolation and partial characterization of glycolipid fractions from Mycobacterium avium serovar 2 (Mycobacterium paratuberculosis 18) that inhibit activated macrophages.

Glycolipid fractions from Mycobacterium avium serovar 2 (Mycobacterium paratuberculosis 18) inhibited the killing of Candida albicans by activated bovine peripheral-blood-derived macrophages. Fractions were derived by using the matrix solid-phase dispersion technique, which is a new method of simultaneous lysis and partial fractionation of components of bacterial cells. Further purification of active fractions was performed by concanavalin A affinity chromatography, centrifugal filtration, and differing solvent solubility. Three different fractions were isolated and partially characterized. Two of these fractions have characteristics typical of glycolipids, and the third fraction has characteristics compatible with a peptidoglycolipid. This peptidoglycolipid fraction has been purified and named MIF-A3.