# The Host Response Against HIV-1-induced T Cell Syncytia

> **NIH NIH R21** · UNIVERSITY OF VERMONT & ST AGRIC COLLEGE · 2020 · $234,000

## Abstract

HIV-1 dissemination critically depends on migration of infected T cells. Unexpectedly, a minor fraction of
the infected T cells exist as small syncytia, containing up to four nuclei. Importantly, these entities are
not precursors for larger, macrophage- or dendritic cell-based syncytia which can be observed in late
stages of virus dissemination/pathogenesis. Rather, and as shown in three independent intravital
imaging studies, they are present already at the earliest stages of infection. Our analyses in
physiologically relevant in vitro settings further documented that small T cell syncytia can transfer virus
to uninfected cells, suggesting that they directly contribute to virus dissemination.
With this R21 application, we propose to start exploring whether HIV-1-induced small syncytia can also
indirectly contribute to virus spread. We hypothesize that they do that because the surface expression of
immunoregulatory host factors differs from that in infected mononucleated cells. Such an altered surface
profile would trigger different, at least partially stronger innate immune responses and this, in turn, could
support virus spread as, for example, localized inflammation can aid in recruiting potential target cells to
sites of virus replication.
Should the data resulting from this exploratory work support our hypothesis, we will pursue further
funding in order to study the mechanistic basis for the altered host response against syncytia.

## Key facts

- **NIH application ID:** 10082997
- **Project number:** 1R21AI152816-01A1
- **Recipient organization:** UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
- **Principal Investigator:** Markus Thali
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $234,000
- **Award type:** 1
- **Project period:** 2020-06-24 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10082997

## Citation

> US National Institutes of Health, RePORTER application 10082997, The Host Response Against HIV-1-induced T Cell Syncytia (1R21AI152816-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10082997. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*