Human Adenovirus Type 5 Modulates the Biogenesis and Composition of Lung Carcinoma Derived Extracellular Vesicles

Date of Award

Spring 2024

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biological Sciences

First Advisor

Qiana L. Matthews

Second Advisor

Brian Sims

Third Advisor

Vida Dennis

Abstract

Human adenoviruses (HAdVs) affect the respiratory system of both healthy individuals and people with underlying health conditions. These extremely contagious viruses can alter a myriad of cellular and pathophysiological processes. HAdVs can regulate infectivity and pathogenicity by regulating the formation and function of extracellular vesicles’ (EVs). EVs are nanovesicles that facilitate intracellular communication, cell signaling, and immune regulation. We propose that HAdVs can promote infection and transmission between neighboring cells by exploiting EV formation and secretion. In this study, we investigated the effect of HAdV serotype 5 (HAdV-5) on human A549 epithelial cells and A549 cell-derived EVs. Our results illustrated that HAdV-5 reduces the viability of A549 cells and promotes variations in the protein composition of A549 cells. Electron microscopy and/or particle tracking analysis revealed morphological characteristics of exosomes (cup-shaped; size diameter 50 to 150 nm) and apoptotic bodies (round-shaped; size diameter ≤ 1,000 nm). At 24 h or 72 h post-infection, the quantity of EV particles was higher in the vesicles among all experimental groups compared to control vesicles. All EVs possessed a negative surface charge at both time points. The zeta potential in EVs was negative at 24 or 72 h after HAdV-5 infection, indicating the colloidal stability of the particles. HAdV-5 infection increases exosomal RNA levels and total protein in a time-dependent manner. The presence of proteins/markers commonly associated with EVs (Hsp 27, Hsp 70, TLR 6, Rab 35, and IL-12) was detected in the vesicles using Western blot and/or dot blot analysis. Our findings explicitly demonstrated that HAdV-5 significantly altered EV numbers, biogenesis, and composition. These findings imply that HAdV-5 modulates the biological properties and physiological functions of EVs in human lung carcinoma epithelial cells. Taken together, these findings will enhance our knowledge of virus-host interactions and the pathophysiology of human infectious viruses.

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