title: Metabolism of Mycobacterium leprae in macrophages.
abstract: The incorporation of 14C-labeled palmitic acid ( [U-14C]PA) into the phenolic glycolipid-I (PGL-I) fraction of Mycobacterium leprae was studied in a murine macrophage system in vitro. Peritoneal macrophages from Swiss Webster mice were infected with fresh viable or Formalin-killed M. leprae harvested from infected footpads of nu/nu mice, and [U-14C]PA was added to the culture medium. Labeled glycolipid synthesized by live M. leprae was fractionated on a Florisil-silicic acid column and identified as PGL-I by using thin-layer chromatography and localization on a polysulfone membrane with an anti-PGL-I monoclonal antibody. Increased incorporation of [U-14C]PA into the PGL-I fraction was observed in macrophages infected with only live M. leprae. Treatment of the infected macrophages with rifampin caused a significant reduction in the incorporation of palmitic acid into PGL-I. These preliminary studies suggest that PGL-I synthesis can be used to quantitate the metabolism of M. leprae in macrophages in vitro.
mesh_terms: D000818:Animals; D006017:Glycolipids / Q000096:biosynthesis; D066298:In Vitro Techniques; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000382:microbiology*; D051379:Mice; D009166:Mycobacterium leprae / Q000187:drug effects / Q000378:metabolism*; D019308:Palmitic Acid; D010169:Palmitic Acids / Q000378:metabolism; D012293:Rifampin / Q000494:pharmacology
chemical_list: D006017:Glycolipids; D010169:Palmitic Acids; D019308:Palmitic Acid; D012293:Rifampin