CROI 2024 Abstract eBook

Abstract eBook

Poster Abstracts

Conclusion: The long survival of infected BrMCs leads to ineffectiveness of ART, which can be controlled by the addition of HIV transcription inhibitors into the current ART regimen.

Methods: Admitted adult PWH who died at Klerksdorp Tshepong Hospital, North West Province, South Africa were included in this study. Relatives of eligible deceased PWH provided informed consent. Causes of death were documented. Ultrasound-guided core needle biopsies were used to sample a broad range of body fluids and organs ≤16hrs after death. Trocars were used for minimal contamination. Organs were verified by histopathological analyses. HIV reservoir analysis from stored fluid and organ samples was conducted by digital droplet PCR, as HIV copies per million cells (cpm). Results: Sixty recently deceased PWH (38 virally suppressed; 22 unsuppressed of whom 13 were cART-naive) were enrolled with a median time to autopsy of 10.4hrs (IQR 6.9). FIND046 was COVID-19 positive and excluded. Most patients were of Black African descent (94.9%), male (57.6%) 50 y/o (IQR 18), with a median VL<24 RNA copies/ml (IQR 2,401). Virally suppressed PWH were on cART for a median of 66.6 months (IQR 80.3). A total of 489 unique specimens from 11 anatomically distinct compartments were analyzed for HIV proviral DNA, including bone marrow aspirate and trephine, brain, bronchioalveolar lavage, cervicovaginal lavage, kidney, lymph nodes, liver, lung, spleen and whole blood. Overall, all anatomical compartments of suppressed and unsuppressed PWH were positive for HIV proviral DNA. Highest copy numbers were detected in lymph nodes (7,384±28,669cpm) and lowest copies in brain (513.7±866cpm) and bone marrow trephine (416±814cpm). No statistically significant differences in HIV proviral DNA concentrations between compartments, irrespective of viremic status were noted. However there was an overall trend of higher proviral DNA in all compartments of viremic patients. Sequence analysis showed viral compartmentalization. Conclusion: Findings provide new insights on anatomical location of HIV infected cells that persist despite prolonged cART that should be targeted for effective cure interventions. The Extended Survival of Infected Brain Myeloid Cells Contributes to HIV Persistence During ART Yuyang Tang 1 , Antoine Chaillon 2 , Sara Gianella Weibel 3 , Gabriela D. Prates 1 , Xiaoyi Li 1 , Brendon L. Brown 1 , Eduardo de la Parra Polina 1 , Magali Porrachia 2 , Caroline Ignacio 2 , Brendon Woodworth 2 , Davey M. Smith 3 , David M. Margolis 1 , Guochun Jiang 1 1 University of North Carolina at Chapel Hill, Chapel Hill, NC, USA, 2 University of California San Diego, La Jolla, CA, USA, 3 University of California San Diego, San Diego, CA, USA Background: HIV spreads in the Central Nervous System (CNS) and establishes a persistent viral infection. Recently, we demonstrated that the replication competent HIV persists in long-lived brain myeloid cells (BrMCs) as a definitive proof of HIV persistence in the CNS (PMID: 37317962). We found that HIV lies dormant within BrMCs (mainly microglia), rather than CNS T cells. In BrMCs during suppressive antiretroviral therapy (ART), HIV mainly persists as a latent infection but residual HIV transcription exists. Here, we investigate BrMC cell type-specific mechanisms of persistent HIV expression in the brains of Last Gift participants. Methods: Brain tissues were obtained through a rapid autopsy from 4 people with HIV (PWH) on suppressive ART and one PWH after ART interruption (plasma viral load 68,007 copies/ml). HIV RNA expression and spatial distribution in brain tissue were examined by RNAscope. Isolated BrMCs were studied ex vivo to characterize their responses to ART and inhibitors of HIV transcription machinery to define the cell type-specific mechanisms that modulate persistent HIV expression during ART. Results: We consistently detected low levels of HIV RNA in the brains by quantitative RNAscope. The levels ranged from 0.67 to 16.67 RNA dots per 1000 nuclei in the brains of four ART-suppressed donors while it was 117.3 HIV RNA dots per 1000 nuclei in the brain of viremic PWH . Co-staining with the myeloid cell marker CD68, HIV RNA expression was colocalized with BrMCs. When examining BrMCs isolated from the viremic PWH, it became evident that ART alone lacked efficacy in inhibiting HIV expression. However, when combined with an HIV Tat inhibitor (Triptolide), ART demonstrated a remarkable capacity to significantly reduce HIV transcription (Figure A). In vitro, although ART was effective in inhibiting new infection by HIV recovered from BrMCs of PWH, it failed to suppress the established HIV infection in BrMCs. In contrast, in PHA stimulated PBMC blasts, ART blocked both new and established infections of the same viral strain. Further studies showed that BrMCs were resistant to the cytopathic effects after viral infection, and cell viability remained comparable between infected cells and mock-infected wells (Figure B). This was in contrast with observations of virus-induced cytopathic effects in PBMCs.

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HIV Infection and Reactivation Heterogeneity in Tonsillar and Intestinal Models of HIV Persistence Ana Gallego Cortes 1 , Nerea Sanchez Gaona 1 , Cristina Mancebo Perez 1 , Joan Rey Cano 1 , Oriol Ruiz i Isant 1 , Stefania Landolfi 2 , Felix Pumarola 2 , Nuria Ortiz 2 , Ines Llano 2 , Julia G. Prado 3 , Enrique Martín Gayo 4 , Vicenç Falcó 2 , Meritxell Genescà 1 , María Buzón 1 1 Vall d'Hebron Research Institute, Barcelona, Spain, 2 Hospital Universitario de la Vall d’Hebron, Barcelona, Spain, 3 IrsiCaixa Institute for AIDS Research, Badalona, Spain, 4 Universidad Autónoma de Madrid, Madrid, Spain Background: Tissue reservoirs constitute a significant source of latent and persistent HIV infection in people living with HIV (PLWH) on antiretroviral treatment (ART). While extensive research has focused on understanding HIV reservoirs in the blood, the intrinsic characteristics of viral reservoirs within tissue compartments remain largely unknown. In this study, using tonsillar and intestinal explant models of HIV persistence, we characterized the cellular composition of these anatomical reservoirs and evaluated the effectiveness of latency reversal agents (LRAs) in inducing viral reactivation after ART. Methods: Human tonsillar (n=5) and intestinal (n=7) tissue resections from uninfected donors were ex vivo infected with HIVBAL for 5-6 days, followed by ART treatment for 2 days to establish persistent viral infection. CD4+ T cells were then isolated and cultured for 22 hours in the presence of various LRAs. Using unsupervised clustering analysis (FlowSOM) we identified distinct CD4+ T subsets. We confirmed the presence of viral reservoirs and assessed the effectiveness of LRAs by quantifying intracellular p24 levels after viral reactivation. Results: We identified fifteen CD4+ T cell clusters exhibiting significant inter-tissue variations in the proportions of the majority of these subsets (p<0.05). In both tonsillar and intestinal tissues, viral infection predominantly occurred in various populations of effector memory (TEM: C06, C09, C11 and C14), central memory (TCM: C03 and C07) and T follicular helper (TFH: C10 and C12) cells. However, we found differential enrichment of infected CD4+ T subpopulations between tissues (Fig. 1A). Intestinal latently infected CD4+ T cells exhibited greater reactivation with IL15 and AZD5582; whereas the tonsillar reservoirs responded better to ingenol (ING) and the combination of ingenol and romidepsin (ING+RMD). Notably, IL-15 induced potent reactivation in intestinal C06 and C10 (Fig. 1B) while ING and ING+RMD in tonsillar C09. Notably, we observed no significant differences in the proportion of these clusters before and after LRA treatment. Furthermore, no significant changes were observed for the LRAs RMD and panobinostat. Conclusion: In our tonsillar and intestinal tissue models of HIV persistence, CD4+ T cell populations exhibited varying susceptibility to viral infection and reactivation, showing significant differences between tissues. Further research is required to identify LRAs effective against distinct HIV cellular reservoirs within these tissues.

Poster Abstracts

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CROI 2024 129