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Toll-like receptor 3 (TLR3) promotes the resolution of Chlamydia muridarum genital tract infection in congenic C57BL/6N mice.

Authors :
Carrasco SE
Hu S
Imai DM
Kumar R
Sandusky GE
Yang XF
Derbigny WA
Source :
PloS one [PLoS One] 2018 Apr 06; Vol. 13 (4), pp. e0195165. Date of Electronic Publication: 2018 Apr 06 (Print Publication: 2018).
Publication Year :
2018

Abstract

Chlamydia trachomatis urogenital serovars primarily replicate in epithelial cells lining the reproductive tract. Epithelial cells recognize Chlamydia through cell surface and cytosolic receptors, and/or endosomal innate receptors such as Toll-like receptors (TLRs). Activation of these receptors triggers both innate and adaptive immune mechanisms that are required for chlamydial clearance, but are also responsible for the immunopathology in the reproductive tract. We previously demonstrated that Chlamydia muridarum (Cm) induces IFN-β in oviduct epithelial cells (OE) in a TLR3-dependent manner, and that the synthesis of several cytokines and chemokines are diminished in Cm-challenged OE derived from TLR3-/- 129S1 mice. Furthermore, our in vitro studies showed that Cm replication in TLR3-/- OE is more efficient than in wild-type OE. Because TLR3 modulates the release inflammatory mediators involved in host defense during Cm infection, we hypothesized that TLR3 plays a protective role against Cm-induced genital tract pathology in congenic C57BL/6N mice. Using the Cm mouse model for human Chlamydia genital tract infections, we demonstrated that TLR3-/- mice had increased Cm shedding during early and mid-stage genital infection. In early stage infection, TLR3-/- mice showed a diminished synthesis of IFN-β, IL-1β, and IL-6, but enhanced production of IL-10, TNF-α, and IFN-γ. In mid-stage infection, TLR3-/- mice exhibited significantly enhanced lymphocytic endometritis and salpingitis than wild-type mice. These lymphocytes were predominantly scattered along the endometrial stroma and the associated smooth muscle, and the lamina propria supporting the oviducts. Surprisingly, our data show that CD4+ T-cells are significantly enhanced in the genital tract TLR3-/- mice during mid-stage Chlamydial infection. In late-stage infections, both mouse strains developed hydrosalpinx; however, the extent of hydrosalpinx was more severe in TLR3-/- mice. Together, these data suggest that TLR3 promotes the clearance of Cm during early and mid-stages of genital tract infection, and that loss of TLR3 is detrimental in the development hydrosalpinx.

Details

Language :
English
ISSN :
1932-6203
Volume :
13
Issue :
4
Database :
MEDLINE
Journal :
PloS one
Publication Type :
Academic Journal
Accession number :
29624589
Full Text :
https://doi.org/10.1371/journal.pone.0195165