Pilot Award Recipient: Michael Anthony Thomas, PhD

Novel Strategy to Develop Ad-based HIV-1 vaccine
June 1, 2023

Despite significant advancements made in treatment, in 2021 about 650 thousand people died from HIV related causes. Thus, reducing the incidence of HIV/AIDS remains a global priority. This can be accomplished by an effective preventative HIV vaccine. Of the potential vaccine delivery vectors Adenovirus (Ad) is recognized for its priming ability. However, trials to date have not been successful. One potential problem is our incomplete understanding of the interplay between adenoviral and cellular factors. Since these interactions determine the outcome of an Ad infection, this knowledge gap prevents meaningful improvements in clinical applications where Ads are used. Our goal is to develop an improved understanding of Ad early gene products and to use this knowledge to design and develop an effective Ad-based HIV-1 vaccine. Common to all Ads, including those used in vaccine delivery, is the early region 4 (E4) open reading frame 3 (E4orf3). We recently reported that levels of phosphorylated and otherwise activated ATM are elevated in cells infected with E4orf3 containing Ads where MRN complex formation is disrupted when compared to cells infected with E4orf3 deleted Ads where the MRN complex is functional (1). In the field of cancer biology, several reports have gone to show that inhibiting the kinase activity of ATM or ATR improves specific immune responses. Thus, to better describe the role of E4orf3 in vaccine induced immune responses we test the hypothesis that during Ad infections inhibiting the activity of ATM and or ATR will improve innate and HIV specific immune responses. In Aim 1 we will use IP/western to identity ATM and ATR interacting partners, qPCR ro identify the expressed innate immune system genes and multiplex ELISA to identify the secreted cytokines in cells infected with E4orf3 containing Ads that are treated with or without ATM and or ATR inhibitors. This we expect will help in identifying the mechanism by which E4orf3 limits innate immune responses. In Aim 2 we will use flow cytometry to characterize the immune cells, and ELISA to identify the secreted cytokines, and systemic antibodies over time in randomly allocated male and female groups of mice inoculated with HIV-1 gp120-expressing E4orf3 containing or E4orf3 deleted Ads treated with or without ATM and or ATR inhibitors. This DCCFAR pilot award will allow us to obtain preliminary data for our Aims 1 and 2. With these anticipated outcomes, we are confident that this pilot funding will improve and facilitate our chances of obtaining a larger NIH R grant to test our finding in nonhuman primates.