Early antiretroviral therapy (ART) limits viral reservoir establishment in infants but also constrains viral-specific immunity required to clear reactivated cells. In the early ART context, we evaluated whether combining adeno-associated virus serotype 9 (AAV9)–vectored eCD4-IgG1 with pharmacologic latency reversal using the second mitochondria-derived activator of caspases (SMAC) mimetic AZD5582 could promote reservoir reduction and control in simian immunodeficiency virus (SIV)–infected infant macaques. AAV9 delivery achieved sustained eCD4-IgG1 expression and AZD5582 induced on-ART viremia, but the combination did not reduce intact SIV proviral DNA relative to controls. Partial post-intervention control of viremia during Analytical Treatment Interruption (ATI) occurred in 2/6 infants receiving AAV9-eCD4-IgG1 + AZD5582 with restricted reservoir expansion during recrudescence at week 13. Intact reservoir size during ATI correlated inversely with on-ART viremia during AZD5582 treatment. Controllers did not show increased eCD4-IgG1 expression nor increased on-ART viremia during AZD5582 treatment, but harbored less pre-ART intact SIV DNA in PBMCs than non-controllers. Controllers also exhibited higher frequencies and greater polyfunctionality of virus-specific CD8+ T-cells prior to ATI. These findings implicate immune control of reservoir size and post-ART viral dynamics in early-treated infants and suggest that AAV9-eCD4-IgG1 + AZD5582 increases the likelihood of post-ART viral control.
Jairo A. Fonseca, Alexis C. King, Kaleaha S. Davis, Daniel O'Hagan, Adrian Khoei, Lucas Alves Britto Da Costa, Camryn Cockerham, Mackenzie Cottrell, Stephanie Ehnert, Jennifer S. Wood, Michael D. Alpert, Matthew R. Gardner, Jeffrey D. Lifson, Maud Mavigner, Mauricio A. Martins, Ann Chahroudi