01826nas a2200325   4500000000100000008004100001260001300042653001200055653002000067653001400087653001100101653001900112653001600131653000900147653001500156653002400171653002500195653001600220653001700236653003600253100001500289700001200304700001500316700001300331245008000344300000900424490000700433520104600440022001401486       2009                            d  c2009 Feb10aAnimals10aCells, Cultured10aCytokines10aHumans10aInterleukin-1010aMacrophages10aMice10aMice, Nude10aMicrobial Viability10aMycobacterium leprae10aTemperature10aTime Factors10aTransforming Growth Factor beta1 aFukutomi Y1 aMaeda Y1 aMatsuoka M1 aMakino M00aTemperature dependency for survival of Mycobacterium leprae in macrophages.  a7-160 v783 a<p>Hansen's disease is caused by an infection with an intracellular pathogen, Mycobacterium leprae, which mainly inhabits macrophages and Schwann cells. However, little is known about the survival or growth mechanisms of the bacilli in mouse and human macrophages. In the present study, by using radiorespirometry analysis for the evaluation of the viability of M. leprae, we observed that in vitro incubation of M. leprae-infected macrophages at 35 degrees C was more growth permissive than at 37 degrees C, and supplementation with the immunosuppressive cytokine IL-10 supported the survival of the bacilli in the macrophages for 3 weeks, whereas viability of the bacilli was gradually lost if cultured without IL-10. In human macrophages, M. leprae retained its viability when cultured at 35 degrees C for at least 4 weeks without IL-10. However, the viability of M. leprae was almost lost within 2 weeks if cultured at 37 degrees C. These data suggest that temperature is a crucial factor for the survival of M. leprae in host cells.</p>  a1342-3681