The Role of Non-classical Regulatory T Cells in HIV-1 Infection

Regulatory T cells represent a specialized subpopulation of T lymphocytes that may modulate spontaneous HIV-1 disease progression by suppressing immune activation or inhibiting antiviral T cell immune responses. While effects of classical CD25hiFoxP3+CD4+ regulatory T cells during HIV-1 infection have been analyzed in a series of recent investigations, very little is known about the role of non-classical regulatory T cells that do not express intracellular FoxP3. Here I evaluated two groups of non-classical Treg cells. One is phenotypically identified by the surface expression of HLA-G, an HLA class Ib molecule. The other Treg cell population is characterized by the surface expression of latency-associated peptide (LAP), a membrane-bound form of TGF-beta. Both HLA-G and LAP-expressing T cells are present in small proportions in peripheral blood of healthy individuals.