Manipulations of the phagosome-lysosome fusion response in cultured macrophages. Enhancement of fusion by chloroquine and other amines

The fusion of secondary lysosomes of cultured normal mouse peritoneal macrophages with phagosomes containing ingested Saccharomyces cerevisiae is inhibited by polyanions previously incorporated in the medium. In contrast, this fusion process can be accelerated by chloroquine and some other secondary and tertiary amines; and these compounds can reverse the inhibition induced by a polyanion. The non-fusion pattern usually associated with intracellular Mycobacterium tuberculosis can also be reversed by chloroquine. Our observations offer a possible new approach to the study of subcellular membrane fusion, and of factors influencing the course of experimental intracellular infections.