Internal Medicine Commons^™

Topological Dna Damage, Telomere Attrition And T Cell Senescence During Chronic Viral Infections, Yingjie Ji, Xindi Dang, Lam Ngoc Thao Nguyen, Lam Nhat Nguyen, Jaun Zhao, Dechao Cao, Sushant Khanal, Madison Schank, Xiao Y. Wu, Zheng D. Morrison, Yue Zou, Mohamed El Gazzar, Shunbin Ning, Ling Wang, Jonathan P. Moorman, Zhi Q. Yao

ETSU Faculty Works

Background: T cells play a key role in controlling viral infections; however, the underlying mechanisms regulating their functions during human viral infections remain incompletely understood. Here, we used CD4 T cells derived from individuals with chronic viral infections or healthy T cells treated with camptothecin (CPT) - a topoisomerase I (Top 1) inhibitor - as a model to investigate the role of DNA topology in reprogramming telomeric DNA damage responses (DDR) and remodeling T cell functions.

Results: We demonstrated that Top 1 protein expression and enzyme activity were significantly inhibited, while the Top 1 cleavage complex (TOP1cc) was …

Disruption Of Telomere Integrity And Dna Repair Machineries By Kml001 Induces T Cell Senescence, Apoptosis, And Cellular Dysfunctions, Dechao Cao, Juan Zhao, Lan N. Nguyen, Lam N. T. Nguyen, Sushant Khanal, Xindi Dang, Madison Schank, Bal K. Chand Thakuri, Xiao Y. Wu, Zheng D. Morrison, Mohamed El Gazzar, Yue Zou, Shunbin Ning, Ling Wang, Jonathan P. Moorman, Zhi Q. Yao

ETSU Faculty Works

T cells in chronic viral infections are featured by premature aging with accelerated telomere erosion, but the mechanisms underlying telomere attrition remain unclear. Here, we employed human CD4 T cells treated with KML001 (a telomere-targeting drug) as a model to investigate the role of telomere integrity in remodeling T cell senescence. We demonstrated that KML001 could inhibit cell proliferation, cytokine production, and promote apoptosis via disrupting telomere integrity and DNA repair machineries. Specifically, KML001-treated T cells increased dysfunctional telomere-induced foci (TIF), DNA damage marker γH2AX, and topoisomerase cleavage complex (TOPcc) accumulation, leading to telomere attrition. Mechanistically, KML001 compromised telomere integrity …

P62-Mediated Selective Autophagy Endows Virus-Transformed Cells With Insusceptibility To Dna Damage Under Oxidative Stress, Ling Wang, Mary E. A. Howell, Aryianna Sparks Wallace, Caroline Hawkins, Camri A. Nicksic, Carissa Kohne, Kenton H. Hall, Jonathan P. Moorman, Zhi Q. Yao, Shunbin Ning

ETSU Faculty Works

DNA damage response (DDR) and selective autophagy both can be activated by reactive oxygen/nitrogen species (ROS/RNS), and both are of paramount importance in cancer development. The selective autophagy receptor and ubiquitin (Ub) sensor p62 plays a key role in their crosstalk. ROS production has been well documented in latent infection of oncogenic viruses including Epstein-Barr Virus (EBV). However, p62-mediated selective autophagy and its interplay with DDR have not been investigated in these settings. In this study, we provide evidence that considerable levels of p62-mediated selective autophagy are spontaneously induced, and correlate with ROS-Keap1-NRF2 pathway activity, in virus-transformed cells. Inhibition of …