Thiol-specific antioxidant protein (TSA) (TSA)

Leishmania antigen TSA (Thiol-Specific Antioxidant) is a 22.1 kDa protein belonging to the peroxiredoxin family, highly conserved across various Leishmania species including L. major, L. infantum, and L. braziliensis (UniProt: P16156). Its primary biological function is to protect the parasite from oxidative damage by scavenging reactive oxygen species (ROS) such as hydrogen peroxide, which are generated by host macrophages during infection (PubMed: 10417340). Because of its critical role in parasite survival and its high immunogenicity, TSA is a prominent target for vaccine development against both cutaneous and visceral leishmaniasis (PubMed: 22435874). It has been incorporated into several multi-antigen fusion vaccines, most notably LEISH-F1 (formerly Leish-111f), LEISH-F2, and LEISH-F3, which are typically administered with adjuvants like MPL-SE or GLA-SE to elicit a protective Th1-type immune response (PubMed: 19123965). These vaccines aim to induce the production of pro-inflammatory cytokines, particularly interferon-gamma (IFN-gamma) and TNF, which activate macrophages to eliminate the intracellular amastigotes (PubMed: 25517990). While primarily pursued as an immunotherapeutic or prophylactic target, the enzymatic site of TSA also represents a potential site for small-molecule inhibition to compromise the parasite's redox homeostasis.

Other names

PeroxiredoxinLeishmania TSATSA antigenThiol-specific antioxidant

Induction of Th1-type cellular immune response and interferon-gamma production