Blimp-1 overexpression is associated with low HIV-1 reservoir and transcription levels in central memory CD4+ T cells from elite controllers.

Objectives: The aim of the study was to determine the molecular mechanisms underlying the quasi-equilibrium between HIV and its host in the model of functional cure represented by elite controllers who spontaneously maintain exceptionally low levels of HIV reservoirs. Design: Whole-genome transcriptional study and quantification of the cell-associated HIV DNA and HIV RNA levels of the four major resting CD4(+) T-cell subsets in HIV-1-infected elite controllers, viremic long-term nonprogressors (vir-LTNPs), and uninfected individuals. Methods: We compared the whole-genome transcriptional profiles (ArrayExpress accession number E-MTAB-1480) of the four major resting CD4(+) T-cell subsets [naive (T-N), central-memory (T-CM), transitional-memory (T-TM), and effector-memory (T-EM)] from 14 HIV-1-infected individuals including seven elite controllers (E-LTNPs) and seven vir-LTNPs, and from seven uninfected individuals. The HIV-1 cellular DNA and mRNA levels were quantified in parallel in each sorted subset. Results: Host gene transcriptomes followed subset differentiation and viremia except in E-LTNPs wherein T-CM, the main CD4(+) cell compartment, showed the highest activity with three specific signatures involving overexpression of T-cell receptor and costimulation signaling pathways, overexpression of the PRDM-1/Blimp-1 transcriptional repressor, and downmodulation of type-I IFN-related genes. Among subsets, the PRDM1/Blimp-1 upregulation was associated with lower levels of both cellular HIV-DNA and HIV mRNA levels. Conclusion: This unique Blimp-1 transcriptional repressor signature and the contrast between host and virus transcriptional activities in T-CM from elite controllers suggest Blimp-1 might be involved in controlling the HIV reservoirs in the key TCM subset. (C) 2014 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins