Abstract Body


Persistence HIV reservoirs in lymphoid tissues is one of the main barriers to cure. We and others have shown that follicles within secondary lymphoid tissues are a major site of HIV persistence during antiretroviral therapy (ART).


We used spatial transcriptomics and several imaging approaches to spatially define cellular subsets and molecular pathways associated with HIV persistence in LNs. Study participants included 10 young women (16 to 24 years old) who initiated therapy in Fiebig stages I-V, and 10 age matched women who started therapy after Fiebig V. Excisional LN were obtained after a year or more on uninterrupted ART.


Using multicolor immunofluorescence staining and in situ hybridization we were able to detect HIV Gagp24 protein and Gag-pol RNA in GC T follicular helper cells (GCTFH) and macrophages in 18 of 20 individuals studied. GCs had greater amounts of HIV Gag p24 protein and Gag-pol RNA compared to extrafollicular areas (p=0.0001). Very early ART was associated with more functional (proliferative) HIV-specific CD8+ T cells compared to late treated donors (p=0.002). However, most of the CD8+ T cells were spatially segregated fromHIV harbouring GCTFH and macrophages. The few CD8+ T cells within GCs lacked expression of cytolytic molecules granzyme B and perforin. Spatial transcriptomic analysis revealed lower expression of adaptive immune response genes in GCs harbouring HIV antigens relative to adjacent GCs without HIV antigens. Inversely, immunoregulatory genes namely, Foxp3 and Tbet (tbx21) were upregulated in HIV positive GCs relative to HIV negative GCs.


We show that persistent HIV transcription in GCs generates spatially defined immunosuppressive microenvironment. These data suggest that reversing immunosuppressive environment within HIV infected GCs is critical to the development of CD8+ T cell-mediated strategies aimed at eliminating HIV infection in lymphoid tissue during ART.