Chlamydia-secreted protease CPAF degrades host antimicrobial peptides

Lingli Tang, Jianlin Chen, Zhiguang Zhou, Ping Yu, Zhangsheng Yang, Guangming Zhong

Research output: Contribution to journalArticlepeer-review

30 Scopus citations


Chlamydia trachomatis infection in the lower genital tract, if untreated, can ascend to the upper genital tract, potentially leading to complications such as tubal factor infertility. The ascension involves cell-to-cell spreading, which may require C. trachomatis organisms to overcome mucosal extracellular effectors such as antimicrobial peptides. We found that among the 8 antimicrobial peptides tested, the cathelicidin LL-37 that is produced by both urogenital epithelial cells and the recruited neutrophils possessed a most potent antichlamydial activity. Interestingly, this antichlamydial activity was completely inhibited by CPAF, a C. trachomatis-secreted serine protease. The inhibition was dependent on CPAF's proteolytic activity. CPAF selectively degraded LL-37 and other antimicrobial peptides with an antichlamydial activity. CPAF is known to secrete into and accumulate in the infected host cell cytoplasm at the late stage of chlamydial intracellular growth and may be released to confront the extracellular antimicrobial peptides before the intra-inclusion organisms are exposed to extracellular environments during host cell lysis and chlamydial spreading. Thus, the finding that CPAF selectively targets host antimicrobial peptides that possess antichlamydial activities for proteolysis suggests that CPAF may contribute to C. trachomatis pathogenicity by aiding in ascending infection.

Original languageEnglish (US)
Pages (from-to)402-408
Number of pages7
JournalMicrobes and Infection
Issue number6
StatePublished - 2015


  • CPAF
  • Chlamydia trachomatis
  • Proteolysis of antimicrobial peptides

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Infectious Diseases


Dive into the research topics of 'Chlamydia-secreted protease CPAF degrades host antimicrobial peptides'. Together they form a unique fingerprint.

Cite this