Granzyme B-expressing neutrophils correlate with bacterial load in granulomas from Mycobacterium tuberculosis-infected cynomolgus macaques.

ABSTRACT: The role of neutrophils in tuberculosis (TB), and whether neutrophils express granzyme B (grzB), a pro-apoptotic enzyme associated with cytotoxic T cells, is controversial. We examined neutrophils in peripheral blood (PB) and lung granulomas of Mycobacterium tuberculosis-infected cynomolgus macaques and humans to determine whether mycobacterial products or pro-inflammatory factors induce neutrophil grzB expression. We found large numbers of grzB-expressing neutrophils in macaque and human granulomas and these cells contained more grzB+ granules than T cells. Higher neutrophil, but not T cell, grzB expression correlated with increased bacterial load. Although unstimulated PB neutrophils lacked grzB expression, grzB expression increased upon exposure to M.tuberculosis bacilli, M.tuberculosis

SUBMITTER: Mattila JT 

PROVIDER: S-EPMC4570831 | biostudies-literature | 2015 Aug

REPOSITORIES: biostudies-literature