Brain is a potential sanctuary for subtype C HIV-1 irrespective of ART treatment outcome

Authors

For Yue Tso, University of Nebraska-LincolnFollow
Guobin Kang, University of Nebraska-LincolnFollow
Eun Hee Kwon, University of Nebraska-Lincoln
Peter Julius, University Teaching Hospital
Qingsheng Li, University of Nebraska-LincolnFollow
John T. West, University of Nebraska-LincolnFollow
Charles Wood, University of Nebraska-LincolnFollow

Date of this Version

2018

Citation

PLoS ONE 13(7): e0201325

Comments

© 2018 Tso et al.

Open access

https://doi.org/10.1371/journal.pone.0201325

Abstract

Subtype C HIV-1 is responsible for the largest proportion of people living with HIV-1 infection. However, there is limited information about the roles of the brain and its cell types as a potential sanctuary for this subtype and how the sanctuary may be affected by the administration of anti-retroviral therapy (ART). To address this issue, we collected postmortem brain tissues from ART treated HIV-1 infected Zambian individuals who experienced complete viral suppression and those who did not. Tissues from various brain compartments were collected from each individual as frozen and formalin-fixed paraffin embedded brain specimens, for detection and quantification of HIV-1 genomes and identification of the infected cell type. Genomic DNA and RNA were extracted from frozen brain tissues. The extracted DNA and RNA were then subjected to droplet digital PCR for HIV-1 quantification. RNA/DNAscope in situ hybridization (ISH) for HIV-1 was performed on formalin-fixed paraffin embedded brain tissues in conjugation with immunohistochemistry to identify the infected cell types. Droplet digital PCR revealed that HIV-1 gag DNA and RNA were detectable in half of the cases studied regardless of ART success or failure. The presence of HIV-1 lacked specific tissue compartmentalization since detection was random among various brain tissues. When combined with immunohistochemistry, RNA/DNAscope ISH demonstrated colocalization of HIV-1 DNA with CD68 expressing cells indicative of microglia or peripheral macrophage. Our study showed that brain is a potential sanctuary for subtype C HIV-1, as HIV-1 can be detected in the brain of infected individuals irrespective of ART treatment outcome and no compartmentalization of HIV-1 to specific brain compartments was evident.