Table 1 Summary of the features of FIV and HIV-1 latency discussed in this review
Feature | FIV | HIV-1 |
|---|---|---|
Latently infected peripheral CD4+ T cells per million, approximate | 10 | 1-10 |
Primary T cell reservoir | CD4+ T cells | Central memory CD4 + T cells |
Viremia in chronic infection (untreated) | Undetectable to low | Low to moderate |
Accessory genes | rev, vif, orf-A | rev, vif, tat, vpr, vpu, nef |
Tat-like function | NO | YES |
Paused RNA Polymerase II detected on LTR in vivo | YES | YES |
Detection of short, promoter-proximal transcripts in vivo | YES | YES |
Detection of multiply-spliced viral mRNA in vivo | NO | NO |
Promoter associated histone modifications involved in chromatin control of latency | Acetylation and methylation (others unknown) | Acetylation, methylation, phosphorylation and ubiquitination |
CpG methylation of latent proviral promoter in vivo | NO | NO |
Transcriptional reactivation by HDAC inhibitors | YES | YES |
Transcriptional reactivation by HMT inhibitors | YES | YES |
Transcriptional reactivation by DNMT inhibitors | Unknown | NO |
Transcriptional reactivation by PKC activators | YES | YES |