Neutrophils discriminate live from dead bacteria by integrating signals initiated by Fprs and TLRs.

ABSTRACT: The mechanisms whereby neutrophils respond differentially to live and dead organisms are unknown. We show here that neutrophils produce 5- to 30-fold higher levels of the Cxcl2 chemokine in response to live bacteria, compared with killed bacteria or isolated bacterial components, despite producing similar levels of Cxcl1 or pro-inflammatory cytokines. Secretion of high levels of Cxcl2, which potently activates neutrophils by an autocrine mechanism, requires three signals. The first two signals are provided by two different sets of signal peptides released by live bacteria, which selectively activate formylated peptide receptor 1 (Fpr1) and Fpr2, respectively. Signal 3 originates from Toll-like receptor activation by microbial components present in both live and killed bacteria. Mechanistic

SUBMITTER: Lentini G 

PROVIDER: S-EPMC8886525 | biostudies-literature | 2022 Mar

REPOSITORIES: biostudies-literature