HIV-1 Tat protein, a virally encoded toxin, is secreted by HIV-1 infected cells and acts on uninfected cells, rendering them permissive for HIV-1 replication. HIV-1 Tat enhances chronic viral replication and induces immune suppression. Antibodies to Tat inhibit this Tat-mediated transcellular activation in vitro and minimize chronic plasma viremia. HIV-1 Tat activities can be blocked in vitro and in vivo by anti-Tat antibodies.
The Thymon Universal Tat Immunogen (TUTI-16) is a fully synthetic, self-adjuvanting lipopeptide vaccine that is water soluble and administered by subcutaneous injection. In preclinical studies, a priming dose and a three week boost in rats induced a high titer antibody response to the eight known distinct epitope variants of HIV-1 Tat protein. These antibodies block the function of the HIV-1 Tat protein (toxin), which is essential to the maintenance of chronic HIV-1 viremia. Therefore, TUTI-16 has potential as a therapeutic vaccine for HIV-1 in humans.
