Foamy Macrophages from Tuberculous Patients' Granulomas Constitute a Nutrient-Rich Reservoir for M. tuberculosis Persistence

• DOI: 10.1371/journal.ppat.1000204
• Publication Date: 2008-11-13T22:39:30Z
• Authors: Pascale Peyron; Julien Vaubourgeix; Yannick Poquet; Florence Levillain; Catherine Botanch; Fabienne Bardou; Mamadou Daffé; Jean-François Emile; Bruno Marchou; Pere-Joan Cardona; Chantal de Chaste...; Frédéric Altare
• Keywords: Mycolic acid

Tuberculosis (TB) is characterized by a tight interplay between Mycobacterium tuberculosis and host cells within granulomas. These cellular aggregates restrict bacterial spreading, but do not kill all the bacilli, which can persist for years. In-depth investigation of M. interactions with granuloma-specific cell populations are needed to gain insight into mycobacterial persistence, better understand physiopathology disease. We have analyzed formation foamy macrophages (FMs), population its high lipid content, studied their interaction tubercle bacillus. Within our in vitro human granuloma model, long chain fatty acids, namely oxygenated mycolic acids (MA), triggered differentiation monocyte-derived FMs. In these cells, mycobacteria no longer replicated switched dormant non-replicative state. Electron microscopy observation tuberculosis–infected FMs showed that mycobacteria-containing phagosomes migrate towards bodies (LB), process culminates engulfment bacillus droplets accumulation lipids microbe. Altogether, results suggest from play crucial role might constitute reservoir used long-term persistence host, could provide relevant model screening new antimicrobials against non-replicating persistent mycobacteria.