Phagosomal membranes of Mycobacterium bovis BCG-immune alveolar macrophages are resistant to disruption by Mycobacterium tuberculosis H37Rv.

Data obtained in this study reaffirm that virulent Mycobacterium tuberculosis H37Rv has a potent phagosome-destroying capacity when ingested by normal alveolar macrophages. In contrast, Mycobacterium bovis BCG-immune alveolar macrophages are highly resistant to this virulence mechanism. BCG-immune sera incubated with BCG-immune alveolar macrophages did not increase resistance of BCG-immune alveolar macrophages as compared with the data obtained from experiments with normal sera. BCG-immune sera failed to confer resistance to normal alveolar macrophages against the phagosomal membrane-destroying H37Rv virulence mechanism.