# Design of Protease Inhibitors to Target HTLV-1

> **NIH NIH R21** · UNIV OF MASSACHUSETTS MED SCH WORCESTER · 2020 · $209,375

## Abstract

Design of Protease Inhibitors to Target HTLV-1
Human T cell leukemia virus type 1 (HTLV-1) is the first identified human retrovirus that infects
millions of people worldwide. HTLV-1 is highly carcinogenic, and infection can lead to life-
threatening cancers and disabling inflammatory conditions. A recent major outbreak in Australia,
persistent infected populations over the globe, and spread to non-endemic regions with
immigration urges immediate action to address this largely neglected disease. Recently, the
Global Virus Network Task Force leadership has strongly recommended expanding research on
HTLV-1. In stark contrast to the highly related HIV-1, no direct-acting antiviral (DAA) agents
have been developed to target HTLV-1 since its discovery almost 40 years ago.
Although enzymatically similar, the HTLV-1 protease substrate specificity is quite distinct from
HIV-1 protease. This prevents the current HIV-1 protease inhibitors from being effective against
HTLV-1, although some have very weak binding. Designing inhibitors to target the substrate
envelope of HTLV-1 protease represents the best opportunity for developing a highly potent and
robust HTLV-1 inhibitor. Characterization of the substrate envelope will also reveal the
molecular basis of substrate specificity for the highly neglected HTLV-1 protease. Translation of
our strategies coupled with our extensive experience with HIV-1 will immensely benefit the
discovery of small molecule inhibitors against HTLV-1.

## Key facts

- **NIH application ID:** 10057413
- **Project number:** 1R21AI149716-01A1
- **Recipient organization:** UNIV OF MASSACHUSETTS MED SCH WORCESTER
- **Principal Investigator:** Celia A. Schiffer
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $209,375
- **Award type:** 1
- **Project period:** 2020-06-24 → 2022-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10057413

## Citation

> US National Institutes of Health, RePORTER application 10057413, Design of Protease Inhibitors to Target HTLV-1 (1R21AI149716-01A1). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10057413. Licensed CC0.

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