Leishmania disease development depends on the presence of apoptotic promastigotes in the virulent inoculum.

ABSTRACT: The obligate intracellular pathogen Leishmania major survives and multiplies in professional phagocytes. The evasion strategy to circumvent killing by host phagocytes and establish a productive infection is poorly understood. Here we report that the virulent inoculum of Leishmania promastigotes contains a high ratio of annexin A5-binding apoptotic parasites. This subpopulation of parasites is characterized by a round body shape, a swollen kinetoplast, nuclear condensation, and a lack of multiplication and represents dying or already dead parasites. After depleting the apoptotic parasites from a virulent population, Leishmania do not survive in phagocytes in vitro and lose their disease-inducing ability in vivo. TGF-beta induced by apoptotic parasites is likely to mediate the silencing of p

SUBMITTER: van Zandbergen G 

PROVIDER: S-EPMC1564231 | biostudies-literature | 2006 Sep

REPOSITORIES: biostudies-literature