02310nas a2200277   4500000000100000008004100001260001300042653001200055653001100067653003700078653001200115653001600127653000900143653002500152653002500177653002500202653001700227653001300244653001500257100001000272245012600282300001100408490000700419520159200426022001402018       1983                            d  c1983 Nov10aAnimals10aFemale10aImmunologic Deficiency Syndromes10aleprosy10aMacrophages10aMice10aMice, Inbred Strains10aMicroscopy, Electron10aMycobacterium leprae10aPhagocytosis10aRifampin10aThymectomy1 aMor N00aIntracellular location of Mycobacterium leprae in macrophages of normal and immune-deficient mice and effect of rifampin.  a802-110 v423 a<p>Soon after more than 10(6) Mycobacterium leprae, freshly harvested from armadillo liver or harvested and 60CO irradiated, were inoculated into the hind footpads of either normal or thymectomized and irradiated (T900R) mice, the organisms were found to reside within phagosomes of polymorphonuclear and mononuclear cells. On the other hand, 7 and 8 months after 10(4) freshly harvested M. leprae were inoculated into the footpads of normal or T900R mice and the organisms had multiplied to their maximum in the normal mice, many organisms, largely intact by electron-microscopic criteria, were found to reside free in the cytoplasm of the footpad macrophages, whereas damaged organisms were contained within phagosomes. After 11 months, many intact organisms were found to lie free in the cytoplasm of the macrophages of T900R mice, whereas only damaged intraphagosomal M. leprae cells were observed in the macrophages of normal mice. Finally, a remarkably large proportion of damaged extraphagosomal M. leprae was found in T900R mice administered rifampin for 2 days in a bactericidal dosage. It appears that M. leprae multiplies free in the cytoplasm of the footpad macrophages of infected mice, whereas the M. leprae cells resident within the phagosomes of the macrophages are dead. As the result of treatment with rifampin, the organisms appeared to have been killed in their extraphagosomal location, only afterwards being incorporated into phagosomes. However, the intracellular site in which M. leprae is killed in the course of an effective immune response remains unclear.</p>  a0019-9567