Neisseria gonorrhoeae Elicits Extracellular Traps in Primary Neutrophil Culture While Suppressing the Oxidative Burst

Carl W. Gunderson, H. Steven Seifert

10 February 2015, mBio 6(1):e02452-14.

Speaker: Yi-Ching, Chiu (邱意晴)                      Time: 14:00~ 15:00, Jun, 10, 2015

Commentator: Dr. Lien-I Hor (何漣漪 教授)     Place: Room 601

Abstract:

        Infection with the obligate human pathogen Neisseria gonorrhoeae triggers a potent, local inflammatory response driven by polymorphonuclear leukocytes (PMNs). Interactions between gonococci and PMNs are influenced by the expression of opacity-associated proteins (Opa) and pili, and these proteins are stochastically expressed in wild-type gonococci as to evade destruction by the host’s immune defenses [1]. Gonococci have been described to both induce and suppress the PMN oxidative burst [2, 3], but the authors determined that gonococci differentially affect induction of the PMN oxidative burst depending on the multiplicity of infection (MOI). Infecting PMN at low MOIs gonococci elicits an oxidative burst, while high MOIs suppresses the burst.Neutrophil extracellular traps (NETs) were observed in gonococcus-infected PMNs, a process which requires an oxidative burst, yet in this study, authors found that NET formation did not correlate with oxidative burst. Furthermore, the NETs were unable to kill gonococci but killed Lactobacillus crispatus and other genital commensal bacteria, potentially opening the niche to further colonization by gonococci due to reduced competition. Thus, gonococci can influence PMNs antimicrobial activities to promote infection, creating a better environment for gonococcal replication, with reduced ROS and less competition from the normal flora.

Reference:

1.    Criss AK, Seifert HS. 2012. A bacterial siren song: intimate interactions between Neisseria and neutrophils. Nat Rev Microbiol 10:178–190.

2.    Chen A, Seifert HS. 2011. Neisseria gonorrhoeae-mediated inhibition of apoptotic signaling in polymorphonuclear leukocytes. Infect Immun 79: 4447–4458.

3.    Criss AK, Seifert HS. 2008. Neisseria gonorrhoeae suppresses the oxidative burst of human polymorphonuclear leukocytes. Cell Microbiol 10: 2257–2270.