All ETDs from UAB

Advisory Committee Chair

Kevin Harrod

Document Type


Date of Award


Degree Name by School

Doctor of Philosophy (PhD) Heersink School of Medicine


Around 39 million people globally are currently infected with Human immunodeficiency virus 1 (HIV-1), more than half of whom are women. HIV-1 is a retrovirus that infects and depletes an individual’s immune cells, culminating in the development of acquired immunodeficiency syndrome (AIDS) if not managed with anti-retroviral therapies (ART). Most women acquire HIV-1 through heterosexual intercourse. However, the early mechanisms and virologic determinants of HIV-1 transmission to women remain unclear. Herein, we demonstrate transmitted/founder (TF) HIV-1 representing two genetically and pathogenically distinct subtypes (A and D) in vivo have distinct replication phenotypes in an ex vivo cervical explant tissue (CET) model of mucosal HIV-1 transmission. We identified significant differences in the replication of biologically relevant infectious molecular clones (IMCs) representing subtype A and D TF HIV-1 in the CET model. This finding was enabled by our development and application of innovative HIV-1 reporter virus approaches, which underpin exceptional sensitivity and reproducibility in the quantification of HIV-1 replication ex vivo and in cellulo. We conceptualized a novel reporter IMC in which a luminescent peptide, HiBiT, was appended to C-terminally truncated HIV-1 Vif. Previous research suggested that the19 C-terminal residues of Vif were dispensable for Vif function. The Vif C-terminus was hypothesized to be interchangeable with HiBiT. The resulting Vif-HiBiT IMC was sensitively detected and replication-competent in HIV-1 target cells and retained the ability of Vif to mediate APOBEC3G degradation. Our ex vivo studies of HIV-1 transmission were based on the hypothesis that properties mapping to Env affect the efficiency of mucosal HIV-1 transmission. Human cervical explant tissues were inoculated with IMCs engineered with an isogenic proviral backbone, a reporter gene, and encoded the Env ectodomains of pathogenically distinct HIV-1 subtypes. We determined that Env-based properties, CD4 binding and subtype of Env, affected viral transmission and replication ex vivo. Our application of reporter virus technologies for studies of HIV-1 biology provides a powerful approach for the elucidation of HIV-1 mucosal transmission mechanisms, which is urgently needed for guiding the development of targeted HIV prevention strategies to improve the health outcomes of women at high risk of HIV infection worldwide.



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