Thymosin α 1 potentiates the release by CD8+cells of soluble factors able to inhibit HIV-1 and human T lymphotropic virus 1 infectionin vitro

Thymosin α-1 (Tα1) exploits a specific action on lymphoid cells and is able to induce in peripheral blood mononuclear cells (PBMCs) a strong transcriptional response. CD8 antiviral factor activity plays a role in the control or prevention of HIV-1 infection by a non-cytolytic mechanism. The ability of Tα1 to modulate the release of antiretroviral soluble factors by CD8(+) cells was investigated.Supernatants from lipopolysaccharide (LPS) stimulated CD8(+)-isolated cells treated with Tα1 were screened on in vitro infection of human monocyte-derived macrophages (MDMs) and PBMCs with HIV-1, and of PBMCs with human T lymphotropic virus 1 (HTLV-1). In CD8(+) cells, as well as in PBMCs of healthy donors as from HIV(+) individuals, a microarray analysis to assess the transcriptional response after treatment was performed.Tα1 potentiates the release, in LPS-stimulated CD8(+) cells, of soluble factors able to inhibit both in vitro HIV-1 infection of MDMs and PBMCs and in vitro HTLV-1 infection of PBMCs. A distinctive transcriptional profile was induced by Tα1 in PBMCs from HIV(+) donors.These findings suggest that Tα1 would represent a re-evaluated approach to antiretroviral therapy in combination with innovative treatments and with vaccine administration.