# Determining and Overcoming barriers in translating HIV-1 protease mediated activation of the CARD8 inflammasome to HIV cure research

> **NIH NIH F31** · WASHINGTON UNIVERSITY · 2022 · $32,686

## Abstract

Project Summary/Abstract
Human immunodeficiency virus (HIV) has maintained its status as a global epidemic since the 1980’s and 38
million people are living with HIV globally. While new HIV infections have been decreasing and antiretroviral
therapies (ART) can maintain viral suppression in PLWH, there is no effective cure for elimination of the virus
from the body. HIV is adept in escaping the normal immune response through the seeding of viral latent
reservoirs primarily in quiescent CD4+ T cells. Upon halting ART these latent reservoirs are capable of
spreading infection. In addition to this hurdle, HIV is able to escape the adaptive immune response due to the
reliance upon recognition of the highly mutable HIV envelope. Therefore, it is critical to develop a cure strategy
that can sense a highly immutable aspect of HIV such as those with essential enzymatic activity. Our previous
work has shown that HIV-1 protease is one such protein that can be a target for a cure strategy. The pattern
recognition receptor caspase recruitment domain-contain protein 8 (CARD8) is able to sense HIV-1 protease
and activate pyroptosis, an inflammatory version of programmed cell death. This strategy requires the
premature intracellular activation of the protease which can be achieved through the use of non-nucleoside
reverse transcriptase inhibitors (NNRTIs) Efavirenz or Rilpivirine. Upon addition of NNRTIs to HIV infected
cells, CARD8 activates the inflammasome and induces pyroptosis. Additionally, my previous work showed that
inhibition of the negative regulator of dipeptidyl peptidase 9 (DPP9) is able to enhance NNRTI-mediated
pyroptosis. However, during the discovery of this method for viral reservoir clearance, we found significant
variation in the activation of the CARD8 inflammasome that could be ascribed to both the virus and the host.
In fact, pyroptosis efficiency varied across viral strains, CARD8 isoforms, cell types, CD4+ T cell activation
state, and CD4+ T cell donors. Therefore, the central hypothesis of this study is that there are genetic variants
in both the virus and the host that can confer resistance to NNRTI induced HIV-1 protease activation of the
CARD8 inflammasome and which may be overcome by CARD8 inflammasome sensitization through DPP9
inhibition. I will first test clinical and in vivo applications of CARD8 enhancement through DPP9 inhibition in
Aim 1 by testing clinical isolates and enhancement in a humanized mouse model. Experiments in Aim 2 will
identify the critical viral components needed for CARD8 sensing of HIV-1 protease activity to inform a genome
wide association study of HIV-1 to identify variants responsible for pyroptosis variation. Aim 3 will elucidate
host factors that may cause variation in protease sensing or inflammasome activation. This will be ascertained
through the study of isoform expression in the key cellular targets for HIV-1 infection, through the identification
of donors with varying killing efficiency, and thr...

## Key facts

- **NIH application ID:** 10481087
- **Project number:** 1F31AI165251-01A1
- **Recipient organization:** WASHINGTON UNIVERSITY
- **Principal Investigator:** Kolin Clark
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $32,686
- **Award type:** 1
- **Project period:** 2022-04-01 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10481087

## Citation

> US National Institutes of Health, RePORTER application 10481087, Determining and Overcoming barriers in translating HIV-1 protease mediated activation of the CARD8 inflammasome to HIV cure research (1F31AI165251-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10481087. Licensed CC0.

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