Follicular Immune Landscaping Reveals a Distinct Profile of FOXP3hiCD4hi T Cells in Treated Compared to Untreated HIV.

Follicular helper CD4hi T cells (TFH) are a major cellular pool for the maintenance of the HIV reservoir. Therefore, the delineation of the follicular (F)/germinal center (GC) immune landscape will significantly advance our understanding of HIV pathogenesis. We have applied multiplex confocal imaging, in combination with the relevant computational tools, to investigate F/GC in situ immune dynamics in viremic (vir-HIV), antiretroviral-treated (cART HIV) People Living With HIV (PLWH) and compare them to reactive, non-infected controls. Lymph nodes (LNs) from viremic and cART PLWH could be further grouped based on their TFH cell densities in high-TFH and low-TFH subgroups. These subgroups were also characterized by different in situ distributions of PD1hi TFH cells. Furthermore, a significant accumulation of follicular FOXP3hiCD4hi T cells, which were characterized by a low scattering in situ distribution profile and strongly correlated with the cell density of CD8hi T cells, was found in the cART-HIV low-TFH group. An inverse correlation between plasma viral load and LN GrzBhiCD8hi T and CD16hiCD15lo cells was found. Our data reveal the complex GC immune landscaping in HIV infection and suggest that follicular FOXP3hiCD4hi T cells could be negative regulators of TFH cell prevalence in cART-HIV.

HIV infection is associated with compromised tumor microenvironment adaptive immune reactivity in Hodgkin Lymphoma.

The impact of Human Immunodeficiency Virus (HIV) infection on the tumor microenvironment (TME) of classic Hodgkin lymphoma (cHL), one of the most common co-morbidities following HIV infection, is not well understood. Here, we have employed multiplexed immunofluorescence (mIF) and spatial transcriptomic analysis to dissect the impact of viral infections (EBV, HIV/EBV) on cHL TME. Compared to HIV-EBV-, HIV-EBV+ cHL TME was characterized by higher cell densities of CD8high T cells co-expressing inhibitory receptors (PD-1, TIGIT), macrophage subsets and an in situ inflammatory molecular profile associated with increased expression of TCR and BCR cell signaling pathways. Compared to HIV-EBV+, HIV+EBV+ cHL TME was characterized by significantly less CD8high T cells co-expressing PD-1 and TIGIT, a profile concomitant with significantly increased cell densities of CD155high neoplastic cells. Significant downregulation of in situ TCR-signaling and upregulation of extracellular matrix reorganization pathways were found in HIV+EBV+ cHL TME, in line with an altered topological organization of CXCL13 and heparan sulfate, an extracellular matrix glycosaminoglycan. Our data reveal the complexity of the cellular and molecular composition of cHL TME in the presence of viral infections, with possible implications for combinatorial immunotherapies. Furthermore, the data suggest specific molecular targets and pathways for further investigation that could improve our understanding of possible mechanistic links between HIV and lymphomagenesis.