Macrophage uptake and retention of radiolabeled glycopeptidolipid antigens associated with the superficial L sub(1) layer of Mycobacterium intracellulare) serovar 20

Glycopeptidolipid (GPL) antigens which are associated with the superficial L sub(1) layer of Mycobacterium intracellulare) serovar 20 were labeled with radioisotopes by means of internal labeling techniques and used in macrophage uptake and retention studies. The use of tritiated alanine and phenylalanine allowed the incorporation of label into the GPL invariant fatty acyl peptide core, which is common to all members of the Mycobacterium avium-M. intracellular complex. Radiolabeled GPL antigens were then purified by a one-step column chromatographic procedure and subsequently used to determine the maximum uptake and retention in peritoneal macrophages isolated from C57BL/6 and CBA/J mice. The ability of the GPL antigens to become associated with macrophages is demonstrated by these results, which strongly suggest that these potentially important mycobacterial antigens are inert to degradation by those cells.