Poly (I:C) and LPS induce distinct immune responses by ovarian stromal fibroblasts

Abstract

Despite its anatomical location, the ovary is a site of pathogen exposure in the human female reproductive tract (FRT). However, the role of ovarian stromal fibroblasts in immune protection is unclear. We generated a population of ovarian stromal fibroblasts derived from normal human ovaries that expressed the pattern recognition receptors TLR3, TLR4, RIG-I, & MDA5. Poly (I:C) and LPS, respective mimics of viral and bacterial infections, selectively upregulated antiviral gene expression and secretion of chemokines and antimicrobials. Poly (I:C) exclusively stimulated the expression of interferon (IFN) β, IFNλ1, and the IFN-stimulated gene OAS2. Poly (I:C) also significantly increased secretion of elafin, CCL20, and RANTES, but had no effect on SDF-1α. In contrast, LPS had no effect on IFN or ISG expression but significantly increased secretion of RANTES and SDF-1α. Secretions from poly (I:C)-treated fibroblasts had both greater anti-HIV activity and induced higher levels of CD4 + T cell chemotaxis than those from LPS-treated cells. Our studies demonstrate a potential key role for ovarian fibroblasts in innate immune protection against incoming pathogens in the normal ovary.

Estradiol‐regulated innate antiviral responses of human endometrial stromal fibroblasts

“…Ovarian, skin, lung, intestinal and foreskin fibroblasts respond to poly (I:C) by upregulating the expression of interferon (IFN) β, cytokines and interferon-stimulated genes (ISG). 34,[40][41][42] Our findings indicate that following exposure to poly (I:C), a dsRNA analogue that is a common intermediate in viral replication, FRT fibroblasts upregulate the expression and secretion of ISGs, cytokines and chemokines. Together these create a hostile intracellular and extracellular environment to pathogen survival, that is likely essential in preventing successful infection.…”

“…We demonstrate for the first time that following PRR stimulation, stromal fibroblast secretions from the EM, similar to those from ovarian stromal fibroblasts 34 , are capable of reducing HIV infection of CD4+ T cells. This is probably due to the increased secretion of antiviral cytokines such as RANTES and CCL20 in response to PRR treatment.…”

“…Responsiveness to PRR ligands is a characteristic feature of fibroblasts throughout the body. Ovarian, skin, lung, intestinal and foreskin fibroblasts respond to poly (I:C) by upregulating the expression of interferon (IFN) β, cytokines and interferon-stimulated genes (ISG) 34,40–42 . Our findings indicate that following exposure to poly (I:C), a dsRNA analogue that is a common intermediate in viral replication, FRT fibroblasts upregulate the expression and secretion of ISGs, cytokines and chemokines.…”

“…PCR was conducted using the following cycle parameters: 95°C, 12 minutes for 1 cycle (95°C, 20 seconds; 60°C, 1 minutes), for 40 cycles. Gene expression was normalized to β-actin which we have used in previous studies of stromal fibroblasts 13,14,24,34 and whose expression was unaffected by any of the treatments performed in this study. Analysis was conducted using the sequence detection software supplied with the ABI 7300.…”

“…Previously we found that both EM epithelial cell and ovarian fibroblast conditioned media (CM) contain anti-HIV activity. 34,37 To determine if stromal fibroblast secretions protect CD4+ T cells against viral infection, we investigated the effect of EM fibroblast CM on HIV infection of CD4+ T cells using two strains of HIV: BaL (CCR5-tropic) and IIIB (CXCR4-tropic). We incu- fibroblasts, in addition to their role as structural cells, are essential in regulating inflammation and immune responses to pathogens and commensal organisms.…”