CROI 2025 Abstract eBook

Abstract eBook

Poster Abstracts

585

HIV Reservoir in Jejunum Exhibits 5 Distinct Phenotypic Features and Evokes 5 Innate Cell Redistribution Marta Calvet-Mirabent 1 , Monet Yuan 1 , Xiaoyu Luo 1 , Julie Frouard 1 , Jason Neidleman 1 , Ashley F. George 1 , Stan Tamaki 2 , Antoine Chaillon 3 , Elizabeth Hastie 3 , Davey Smith 3 , Collin Kieffer 4 , Nadia R. Roan 1 , Sara Gianella Weibel 3 1 Gladstone Institute, San Francisco, CA, USA, 2 University of California San Francisco, San Francisco, CA, USA, 3 University of California San Diego, La Jolla, CA, USA, 4 University of Illinois Urbana-Champaign, Urbana, IL, USA Background: The human gut has a high burden of HIV, but little is known about the phenotypes of HIV reservoir cells at this site or the influence of the local microenvironment. Here, we used standard and 40-parameter multiplexed ion beam imaging by time of flight (MIBI-TOF) microscopy to study the HIV reservoir and their associated environments from 5 different regions of the gut of ART-suppressed PWH (ART-PWH). Methods: Fresh tissue specimens from duodenum (DDM), jejunum (JJM), ileum (ILM), colon (CLR) and rectum (RCT) were obtained through the Last Gift rapid autopsy program from n=6 ART-PWH and n=2 people without HIV (PWOH). Slices from FFPE tissues were prepared for multiplexed RNAscope (to detect HIV RNA) and confocal immunofluorescence imaging (to detect HIV p24). A subset of the samples was used for MIBI-TOF imaging. Results: While on average 85% [range 74-100%] of the HIV RNA+CD4+ T cells in the DDM, CLR, and RCT expressed p24, only 45% [range 25-79%] in the JJM and ILM were p24+. To test the hypothesis that immune-mediated recognition and depletion of p24+CD4+ cells may be occurring in the JJM and ILM, we used MIBI-TOF to assess phenotypic features of the p24+CD4+ cells and their local environment in JJM of an ART-PWH. Relative to uninfected CD4+ T cells, p24+CD4+ T cells expressed higher levels of HIV coreceptor CCR5 (p=0.0056), checkpoint receptors (PDL1 (p<0.0001), TIGIT (p=0.0009)), Tfh marker CXCR5 (p=0.0018), inflammatory/cytolytic markers (Galectin-9 (p<0.0001), Granzyme B (p=0.0006)), proliferation marker Ki67 (p<0.0001), and differentiation marker AIOLOS (p<0.0001). These p24+ cells were in closer proximity to NK cells and dendritic cells (DCs) than to other subsets including B cells, CD8+ T cells, monocytes and macrophages (M0; p<0.0001). The overall numbers of macrophages were significantly decreased (p=0.0072) in the JJM of ART-PWH compared to the JJM of PWOH. Conclusions: Our data suggest that p24+CD4+ T cells are distributed throughout the entire gut of ART-PWH, but that JJM and ILM may possess distinct mechanisms that preferentially eliminate these cells. p24+CD4+ cells in JJM of ART-PWH exhibit distinct phenotypic features including evidence of recent proliferation (Ki67). Their spatial localization suggests they may be recruiting subsets of innate cells (NK cells and DCs), which can help eliminate infected cells, while M0 may be depleted. Overall, our results point to active crosstalk between HIV-infected cells and innate immune effector cells in the gut of ART-PWH. Single Cell Characterization of the Gastrointestinal HIV Reservoir Jackson Peterson, Elizabeth Bennett, Shipra Chandel, Katherine James, Brigitte Allard, Matthew Clohosey, Taylor Whitaker, Caroline Baker, Susan Pedersen, Anne Peery, Cynthia L. Gay, David M. Margolis, Nancie Archin, Edward Browne University of North Carolina at Chapel Hill, Chapel Hill, NC, USA Background: Human gastrointestinal (GI) tissues are a major site of HIV-1 viral replication and persistence, but the nature of the persistent HIV-1 reservoir in the GI remains poorly described. Previous study has identified higher levels of viral DNA but lower levels of transcriptional initiation in the colon as compared to the peripheral blood. Methods: To characterize HIV infected cells in GI tissues from people with HIV (PWH), we developed a protocol to isolate and sequence GI-associated human lymphocytes with 10x Genomics scRNAseq. We analyzed 433,655 high-quality single-cell transcriptomes from GI-associated cells and matched PBMC from eleven PWH on ART. Results: We identified expected patterns of compartment-specific gene expression in GI tissue resident T cells. Non-stimulated GI resident T cells differentially express surface factors including ITGA1/CD103 and CD69 whereas non-stimulated peripheral blood T cells express SELL/CD62L, CCR7, and S1PR1. Non-stimulated GI resident T cells express distinct transcriptional regulators like RUNX3 and STAT4 whereas non-stimulated peripheral blood T cells express KLF2, LEF1, and TCF7/TCF1. We identified 103 HIV RNA positive cells from the GI samples which exclusively clustered with T cells. We observed that the HIV+ cells from PWH were heterogeneous, but nevertheless, we could observe

584

Depletion of CX3CR1+ Effector CD8 TRM Cells Is Associated With HIV-1 Reservoir in the Colon on ART Nived Collercandy 1 , Camille Vellas 1 , Manon Nayrac 2 , Mary Requena 1 , Justine Latour 1 , Karl Barange 1 , Laurent Alric 1 , Guillaume Martin-Blondel 1 , Jacques Izopet 1 , Pierre Delobel 1 1 Toulouse University Hospital, Toulouse, France, 2 Centre de Recherche du CHUM, Montreal, Canada Background: The identification of host immune factors involved in the persistence of tissular HIV-1 reservoirs is crucial for the development of remission strategies. The intact HIV-1 reservoir is higher in the colon compared to other intestinal compartments at the chronic stage on ART, which may be related to the local loss of tissular resident memory CD69 + CD103 + CD8 + T cells (T RM ). Methods: Immunologic and virologic analysis of the intestinal mucosa was performed in 42 virologically suppressed people living with HIV-1 (PWH) on ART and 42 uninfected controls (ANRS EP61 GALT study) using colonic endoscopic biopsies. Characterization of the phenotype and function of T cells within the lamina propria was performed by FACS. Total HIV-1 DNA and residual HIV-1 RNA were quantified in gut samples. Results: Effector CX3CR1 + CD8 + T cells were globally increased in the colonic mucosa of PWH on ART compared to uninfected controls (median 15.1% [13.4 17.7] of CD3 + cells vs. 8.4% [6.2-10.5], respectively; P <0.001), but CD69 + CD103 + T RM among CX3CR1 + CD8 + T cells were decreased (median 32.7% [24.5-42.7] of CX3CR1 + CD8 + vs. 46.3% [36.4-55.3], respectively; P <0.001). The increased proportion of CX3CR1 + non-TRM (CD69 - CD103 - ) correlated with total HIV-1 DNA (ρ=0.42 ; P =0.02) and residual HIV-1 RNA (ρ=0.38 ; P =0.02) in the colon, whereas CX3CR1 + T RM were associated with lower HIV-1 DNA levels (ρ=-0.41 ; P =0.02). CX3CR1 + CD8 + T RM showed a distinct phenotype from non-T RM with higher expression of CD39, CD101, CD127, and lower expression of CD57, KLRG1, PD-1, TIGIT and TIM-3 (Figure). CX3CR1 + CD8 + T RM were predominantly CD27- effector memory cells (median 60%), whereas non-T RM were predominantly CD27 + cells. CD39, CD101, CD127 expression on CX3CR1 + CD8 + T RM all negatively correlated with total HIV-1 DNA in the colon. T reg frequency was also increased in the colon of PWH, and negatively correlated with CD39 expression on CX3CR1 + CD8 + T RM . Conclusions: Effector CX3CR1 + CD69 + CD103 + T RM CD8 + cells are associated with a reduced HIV-1 reservoir in the colon, but appear to be depleted in favor of CX3CR1 + CD69 - CD103 - non-T RM CD8 + T cells with a more exhausted (TIGIT + TIM 3 + LAG-3 + PD-1 hi ) and senescent (CD57 + ) phenotype. Increasing cytotoxic effector CD8 + T RM cells may be an axis to reduce the tissular viral reservoir and achieve HIV-1 remission.

Poster Abstracts

586

CROI 2025 156