Differences betweenMycobacterium-Host Cell Relationships in Latent Tuberculous Infection of MiceEx Vivoand Mycobacterial Infection of Mouse CellsIn Vitro

Abstract

The search for factors that account for the reproduction and survival of mycobacteria, including vaccine strains, in host cells is the priority for studies on tuberculosis. A comparison of BCG-mycobacterial loads in granuloma cells obtained from bone marrow and spleens of mice with latent tuberculous infection and cells from mouse bone marrow and peritoneal macrophage cultures infected with the BCG vaccinein vitrohas demonstrated that granuloma macrophages each normally contained a single BCG-Mycobacterium, while those acutely infectedin vitrohad increased mycobacterial loads and death rates. Mouse granuloma cells were observed to produce the IFNγ, IL-1α, GM-CSF, CD1d, CD25, CD31, СD35, and S100 proteins. None of these activation markers were found in mouse cell cultures infectedin vitroor in intact macrophages. Lack of colocalization of lipoarabinomannan-labeled BCG-mycobacteria with the lysosomotropic LysoTracker dye in activated granuloma macrophages suggests that these macrophages were unable to destroy BCG-mycobacteria. However, activated mouse granuloma macrophages could control mycobacterial reproduction in cells bothin vivoand inex vivoculture. By contrast, a considerable increase in the number of BCG-mycobacteria was observed in mouse bone marrow and peritoneal macrophages after BCG infectionin vitro, when no expression of the activation-related molecules was detected in these cells.