A significant productive in vivo infection of resting cells with simian immunodeficiency virus in a macaque with AIDS

Abstract

Identifying the cells that can be infected with HIV in vivo, and thus potentially persist as latent reservoirs is of high priority. Here, we report the major infected cells in a chronically-SIV infected macaque that developed AIDS and encephalitis. Majority of the infected cells were detected as non-proliferating resting cells. SIV infected non-proliferating resting cells were found to be playing an important role in viral pathogenesis, persistence or reservoir formation.

Quantification of Viral RNA and DNA Positive Cells in Tissues From Simian Immunodeficiency Virus/Simian Human Immunodeficiency Virus Infected Controller and Progressor Rhesus Macaques

“…SIV infected T-cells, HAM56+ macrophages, and DC-SIGN (a marker of dendritic cells) were detected in several tissues, demonstrating that all of these cells contribute to viral persistence and even viral replication which is also in agreement with other reports (Wang et al, 2010;Ribeiro Dos Santos et al, 2011;Soulas et al, 2011;Nowlin et al, 2015;Pahar et al, 2017). Although SIV-infected proliferating cells were frequently detected, the majority of infected cells were Ki67 negative , indicating both proliferating and non-proliferating cells serve as source for harboring infection.…”

“…SIV RNA ISH was performed on tissue sections as described previously (Borda et al, 2004;Wang et al, 2007;Ahsan et al, 2013;Pahar et al, 2017). Formalin-fixed, paraffin-embedded tissue sections were de-paraffinized overnight at 60 • C, then dehydrated by xylene washes followed by re-hydration with alcohol and DEPC water.…”

“…Formalin fixed, paraffin embedded, tissue sections were processed for immunofluorescent staining with one or a combination of primary antibodies as previously described (Wang et al, 2007;Pan et al, 2014;Pahar et al, 2015Pahar et al, , 2017 Negative control slides were incorporated in each experiment either by omitting the primary antibody or using isotype IgG1 and IgG (H + L) controls (Pan et al, 2012(Pan et al, , 2013(Pan et al, , 2014Pahar et al, 2015Pahar et al, , 2017. For phenotyping SIV-infected cells, tissues were first processed for SIV RNA ISH and immunohistochemistry for Ham56 (clone Ham56, IgM Kappa; Dako), CD3 (Rabbit anti-human polyclonal; Dako), dendritic cell-specific ICAM-3 grabbing non-integrin (DC-SIGN, clone DCN46, IgG2b kappa; BD Biosciences, San Jose, CA, United States), and Ki67 (clone MIB-1, IgG1 kappa; Dako) by multilabel confocal microscopy as previously described (Pahar et al, 2017).…”

Potent Inhibition of HIV-1 Replication in Resting CD4 T Cells by Resveratrol and Pterostilbene

“…Vaginal, ectocervical, and endocervical tissue explant studies observed resting CD4 T cell infection to be confined to the mucosal stroma (31)(32)(33)(34)(35). In addition, infection of resting CD4 T cells contributes substantially to viral replication and immune depletion (27,29,(36)(37)(38)(39) and to formation of the latent reservoir (40,41). Some studies of SIV infection in rhesus macaques have observed infection of non-CD3 cells as a minority population (30) or in substantial proportions, including Langerhans cells (42,43) and dendritic cells (44).…”

“…Resting T cells are less permissive to productive HIV-1 infection, owing to several blocks, including the lack of transcription factors and the presence of restriction factors, such as SAMHD1 (45,46); nevertheless, both in vivo and in vitro abundant productive infection in resting CD4 T cells is observed (29,39,(47)(48)(49). Importantly, resting T cells contain dNTPs at levels 2 orders of magnitude lower than those in activated T cells (50), which slows the kinetics of reverse transcription (51) but does not prevent its eventual completion, resulting in productive infection and virus spread (49,52).…”