Abstract In the era of combination antiretroviral therapy (cART) for HIV infection, a major focus of clinical and scientific investigation lies with the high risk of cardiovascular disease, neurocognitive disorders, nephropathy, and malignancy among persons with HIV (PWH). While strategies are being developed to identify and reverse the latent pool of viral reservoirs, a parallel effort must proceed to enhance immune defenses against viral persistence as well as re-establish immune homeostasis. The focus of this mechanistic proposal is to identify pathways, molecular targets, and small molecule compounds that regulate immune protection in the HIV patient, whose immune function is compromised by chronic opioid use. We hypothesize that defining the unique biochemical signal transduction pathways emanating from all three subtypes of opioid receptors in human T lymphocytes will reveal specific molecular targets that affect the responsiveness of the immune system in HIV+ and HIV- persons with Opioid Use Disorder. This work capitalizes on our recent findings that the G-protein coupled cAMP and the arrestin-associated Mitogen Activated Protein kinase (MAPK) signal transduction pathways triggered by endogenous, semi-synthetic, and synthetic opioids are distinctly and uniquely regulated in human T lymphocytes. This summer intern’s project will focus on the following Specific Aim: Aim 1 for the NIDA Summer Undergraduate Research Intern: Identify molecular signal transduction pathways in CD8+ and CD4+ T cells that are differentially triggered by opioid agonists, selective for each of the three opioid receptors. Our overall goal is to generate a refined list of therapeutic targets for pharmacologic restoration of immune function in persons with HIV that require opioid therapy for analgesia.