# Cell-to-cell communication within gestational membranes in response to bacterial infection

> **NIH NIH F32** · VANDERBILT UNIVERSITY MEDICAL CENTER · 2020 · $67,446

## Abstract

The response of tissues to infection can significantly differ from that of individual cell types, challenging the
utility of existing, reductionist in vitro model systems to solve complex in vivo problems. During pregnancy,
decidual stromal cells (DSC) and cytotrophoblasts (CTB) form the choriodecidua, the outer layer of the
gestational (fetal) membrane, and immune cells within the choriodecidua are skewed towards a tolerogenic
phenotype. However, bacterial infection provokes inflammation (chorioamnionitis), which can result in
preterm birth (PTB) and other adverse outcomes. New evidence suggests that DSCs and CTBs actively
participate in immune surveillance and shape innate immune responses to infection. We have evidence that
DSCs and CTBs can each regulate the response of macrophages (Mφ) to bacterial infection in different ways
and when all three cells are cocultured responses are also distinct, underscoring the need for new model
systems of heterocellular tissue immunobiology. In this proposal we use innovative organ-on-chip
heterocellular tissue models to test a central hypothesis that microRNA (miRNA)-containing extracellular
vesicles (EVs) mediate the paracrine regulation of NFκB-dependent Mφ immune responses to bacterial
infection by DSCs and CTBs within fetal membranes. Aim 1 will define the extent to which CTBs and/or DSCs
modulate Mφ responses to infection, testing the specific hypothesis that CTB and DSC tri-culture with Mφ
promote a unique and specific set of Mφ inflammatory responses to bacterial infection. We will culture CTB,
DSC, and Mφ and assess cytokine production, major immune pathway activation, and reporter assays for the
proinflammatory transcription factor NFκB and compare this to immune profiles of monoculture and 2-way
co-culture. Aim 2 will determine the impact of choriodecidually-derived EV cargo on Mφ activation during
bacterial infection, testing the specific hypothesis that EV miRNAs inhibit Mφ cytokine production. Subaim 2a
will determine involvement of EVs in Mφ immune modulation. We will purify EVs from untreated or infected
CTB and/or DSC culture to stimulate Mφ, selectively block CTB or DSC EV release and assess Mφ activation
by cytokine release and activation of NFκB. Subaim 2b will compare the transcriptome of EVs with the cells
that produce them. We will perform miRNA profiling of 1) CTB, 2) CTB-derived EVs, 3) DSC, and 4) DSC-
derived EVs and determine whether specific miRNA sequences are selectively packaged within EVs. We will
use gene silencing approaches to determine which miRNAs found in EVs might be inhibiting Mφ NFκB
activation (e.g., miR146a, miR155) and cytokine activation. This project will define the precise immune
regulation taking place within human gestational membranes at the tissue level using a novel, microfluidic
organotypic system. Findings from our research could identify actionable targets for the prevention or
treatment of intrauterine bacterial infection during pregnancy, a significa...

## Key facts

- **NIH application ID:** 9991208
- **Project number:** 1F32HD100087-01A1
- **Recipient organization:** VANDERBILT UNIVERSITY MEDICAL CENTER
- **Principal Investigator:** Alison Joan Eastman
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $67,446
- **Award type:** 1
- **Project period:** 2020-05-18 → 2021-10-17

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9991208

## Citation

> US National Institutes of Health, RePORTER application 9991208, Cell-to-cell communication within gestational membranes in response to bacterial infection (1F32HD100087-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/9991208. Licensed CC0.

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