Date of Graduation

Summer 2025

Degree

Master of Science in Cell and Molecular Biology

Department

Biomedical Sciences

Committee Chair

Amy Hulme

Abstract

HIV-1 is the virus that causes acquired immunodeficiency syndrome (AIDS), and currently, there is no cure once an individual is infected. The development of new drugs targeting HIV-1 replication steps is essential for keeping viral loads low or undetectable to prevent further transmission. An attractive replication step for new drug targets is viral capsid uncoating, where the virus loses the protein structure encapsulating the genome. The exact mechanism of capsid uncoating is unknown; however, several host-factors may be involved including protein SPTBN1. Recent studies have shown a significant decrease in viral infectivity when SPTBN1 is knocked down, yet its role in replication has not been characterized. Preliminary data in the Hulme Lab revealed a delay in early time points of uncoating in vivo when SPTBN1 was knocked down. The goal of this thesis was to determine the role of SPTBN1 in HIV-1 capsid uncoating. The plus/minus cyclosporine A assay demonstrated that interactions of SPTBN1 with the capsid are independent of the host factor cyclophilin A. Furthermore, using the cyclosporine washout assay, we did not observe a delay in capsid uncoating when SPTBN1 was depleted. However, the data indicates a knockdown threshold greater than 84% is required to decrease HIV-1 infectivity as observed in previous literature. Our uncoating assays did not achieve the SPTBN1 knockdown threshold, which may explain why uncoating was unaffected. SPTBN1 may still play a role in capsid stability through binding or indirectly impact uncoating through interactions with molecular motor proteins kinesin and dynein. Understanding the role of host cell factors in uncoating will open a door for the development of new capsid inhibitors.

Keywords

human immunodeficiency virus, HIV-1, replication, capsid uncoating, host factor, SPTBN1

Subject Categories

Biology | Cell Biology | Immunology of Infectious Disease | Other Immunology and Infectious Disease | Virus Diseases

Copyright

© Callie Marie Fry

Download

Open Access

Share

COinS