부산대학교 도서관

Sustainable HIV remission after antiretroviral therapy (ART) withdrawal, or post-treatment control (PTC), remains a top priority for HIV treatment. We observed surprising PTC in an MHC-haplomatched cohort of MHC-M3+ SIVmac239+ Mauritian cynomolgus macaques (MCMs) initiated on ART at two weeks post-infection (wpi). None of the MCMs possessed MHC haplotypes previously associated with SIV control. For six months after ART withdrawal, we observed undetectable or transient viremia in seven of the eight MCMs, despite detecting replication competent SIV using quantitative viral outgrowth assays. In vivo depletion of CD8α+ cells induced rebound in all animals, indicating the observed PTC was mediated, at least in part, by CD8α+ cells. With intact proviral DNA assays, we found that MCMs had significantly smaller viral reservoirs two wpi than a cohort of identically infected rhesus macaques, a population that rarely develops PTC. We found a similarly small viral reservoir among six additional SIV+ MCMs in which ART was initiated at eight wpi, some of whom exhibited viral rebound. These results suggest that an unusually small viral reservoir is a hallmark among SIV+ MCMs. By evaluating immunological differences between MCMs that did and did not rebound, we identified that PTC was associated with a reduced frequency of CD4+ and CD8+ lymphocyte subsets expressing exhaustion markers. Together, these results suggest a combination of small reservoirs and immune-mediated virus suppression contribute to PTC in MCMs. Further, defining the immunologic mechanisms that engender PTC in this model may identify therapeutic targets for inducing durable HIV remission in humans. Author summary: The ultimate goal of human immunodeficiency virus (HIV) therapeutic development is to enable HIV+ individuals to stop taking daily lifelong antiretroviral therapeutics (ART) and remain in virological remission, an outcome called post-treatment control. Post-treatment control is challenging to study because it is very rare in humans. Thus, there are currently no therapeutics that lead to post-treatment control. Simian immunodeficiency virus (SIV) in rhesus macaques is the most widely used preclinical model for HIV. However, post-treatment control is also uncommon in rhesus macaques. The mechanisms that govern post-treatment control remain largely unknown because PTC is so rare. Our lab observed surprising post-treatment control in a cohort of Mauritian cynomolgus macaques that were initiated on ART two weeks post-infection. While Mauritian cynomolgus macaques have been used for SIV research, they are not routinely used to study post-treatment control. We found that small viral reservoirs and immune-mediated virus suppression contribute to post-treatment control in Mauritian cynomolgus macaques. Moving forward, this model can be used to further define the mechanisms that engender post-treatment control as well as identify therapeutic targets in humans for inducing durable HIV remission. [ABSTRACT FROM AUTHOR]