Tumor Necrosis Factor Alpha-Induced Interleukin-1 Alpha Synthesis and Cell Death Is Increased in Mouse Epithelial Cells Infected With Chlamydia muridarum

Abstract

Chlamydia trachomatis-genital infection in women can be modeled in mice using Chlamydia muridarum. Using this model, it has been shown that the cytokines tumor necrosis factor (TNF)α and interleukin (IL)-1α lead to irreversible tissue damage in the oviducts. In this study, we investigated the contribution of TNFα on IL-1α synthesis in infected epithelial cells. We show that C muridarum infection enhanced TNFα-induced IL-1α expression and release in a mouse epithelial cell line. In addition to IL-1α, several TNFα-induced inflammatory genes were also highly induced, and infection enhanced TNF-induced cell death. In the mouse model of genital infection, oviducts from mice lacking the TNFα receptor displayed minimal staining for IL-1α compared with wild-type oviducts. Our results suggest TNFα and IL-1α enhance each other's downstream effects resulting in a hyperinflammatory response to chlamydial infection. We propose that biologics targeting TNF-induced IL-1α synthesis could be used to mitigate tissue damage during chlamydial infection.

Keywords: Chlamydia muridarum; IL-1α; TNFα; model; mouse; mouse epithelial cells.