Degree Name

PhD (Doctor of Philosophy)


Biomedical Sciences

Date of Award


Committee Chair or Co-Chairs

Zhi Qiang Yao

Committee Members

Zhi Q. Yao, Jonathan P. Moorman, Alok Agrawal, Krishna Singh, Chuanfu Li


CD4 T cell homeostasis and competency are critical for the effectiveness of antiviral immunity. However, CD4 T cells derived from people living with HIV (PLWH) and individuals with chronic HCV infection often exhibit an inflammaging phenotype, evidenced by persistent inflammation, immune activation, exhaustion, senescence, and cellular apoptosis. Despite intensive investigations, the molecular mechanisms underlying CD4 T cell dysfunction in antiretroviral therapy (ART)-controlled PLWH and HCV-infected patients remain poorly understood. By investigating the roles of non-coding (nc)RNA transcripts in regulating the functions of CD4 T cells derived from PLWH and HCV-infected patients, we demonstrated that long non-coding (lnc)RNA - growth arrest-specific transcript 5 (GAS5) - is downregulated and plays a crucial role in regulating CD4 T cell functions through and beyond the microRNA (miR)-21-mediated signaling network. Our data suggest that disrupting the GAS5-miR21 axis may restore CD4 T cell homeostasis and competency during latent HIV infection and prevent premature CD4 T cell aging or immune senescence. Moreover, our results also showed that TRF2, a component of the shelterin complex maintaining the integrity of telomeres, is post-transcriptionally inhibited, which is one of the major forces driving cellular dysregulation in CD4 T cells from PLWH and HCV patients. Importantly, our study identified miR-23a as the key regulator of TRF2 translational expression by targeting its 3’UTR in CD4 T cells and that targeting miR-23a may restore the TRF2 protein level, and thereby reconstitute CD4 T cell homeostasis and competency to rescue CD4 T cells from premature aging and immunosenescence during latent HIV infection. The findings from these studies improved our understanding and knowledge of how ncRNA-mediated networks regulate the functions of CD4 T cells during chronic viral (HIV and HCV) infections. Understanding such mechanisms is important for developing therapeutic approaches to reverse the inflammaging phenotype observed in CD4 T cells from ART-controlled PLWH and chronically HCV-infected patients to improve their immunological functions and quality of life.

Document Type

Dissertation - embargo


Copyright by the authors.

Available for download on Monday, June 15, 2026