CD4 T-cell regeneration in HIV-1 elite controllers.

Background: Elite controllers spontaneously control HIV-1 replication, which in many cases is associated with preservation of normal CD4 T-cell counts. However, a subset of elite controllers has progressive CD4 T-cell losses despite undetectable viral loads, for reasons that remain undefined. Here, we assessed mechanisms of CD4 T-cell homeostasis in elite controllers with progressive vs.

Dendritic cell dysfunction during primary HIV-1 infection.

Dendritic cells have critical roles for generating and fine-tuning adaptive immune responses and for regulating immune activity through cytokine secretion. In this study, we analyzed functional properties of dendritic cells in primary human immunodeficiency virus type 1 (HIV-1) infection. We found substantial disarray of the functional properties of myeloid and plasmacytoid dendritic cells in acute HIV-1 infection, which included defective antigen-presenting and cytokine secretion properties and was associated with a distinct surface expression profile of immunomodulatory dendritic cell receptors from the leukocyte immunoglobulin-like receptor family.

CD4+ T cells from elite controllers resist HIV-1 infection by selective upregulation of p21.

Elite controllers represent a unique group of HIV-1-infected persons with undetectable HIV-1 replication in the absence of antiretroviral therapy. However, the mechanisms contributing to effective viral immune defense in these patients remain unclear. Here, we show that compared with HIV-1 progressors and HIV-1-negative persons, CD4+ T cells from elite controllers are less susceptible to HIV-1 infection.

Soluble HLA-G inhibits myeloid dendritic cell function in HIV-1 infection by interacting with leukocyte immunoglobulin-like receptor B2.

Dendritic cells represent a specialized class of professional antigen-presenting cells that are responsible for priming and maintaining antigen-specific effector cell responses and regulating immune activation by cytokine secretion. In HIV-1 infection, myeloid dendritic cells are highly dysfunctional, but mechanisms contributing to their functional alterations are not well defined. Here, we show that soluble molecules of the nonclassical major histocompatibility complex class Ib (MHC-Ib) antigen HLA-G are highly upregulated in the plasma during progressive HIV-1 infection, while levels of membrane-bound HLA-G surface expression on dendritic cells, monocytes, and T cells only slightly differ among HIV-1 progressors, HIV-1 elite controllers, and HIV-1-negative persons.

Epigenetic regulation of telomerase expression in HIV-1-specific CD8+ T cells.

Telomerase activity in HIV-1-specific CD8(+) T cells from controllers contributes to the maintenance of highly functional cytotoxic T cell responses against HIV-1. Here, we show that high expression of telomerase in controllers is associated with hypermethylation at the distal and hypomethylation at the proximal human telomerase catalytic subunit promoter, whereas HIV-1-specific CD8(+) T cells from progressors showed an inverse pattern with distal promoter hypomethylation and proximal promoter hypermethylation. These data suggest distinct epigenetic signatures in HIV-1-specific T cells in progressors and controllers.