T cell receptor recognizing FP9-PP–derived peptide–MHC complexes (TCR-FP9-PP)

The T cell receptor (TCR) recognizing FP9-PP–derived peptide–MHC complexes refers to the population of T cells induced by the FP9-PP malaria vaccine candidate. FP9-PP is a recombinant fowlpox virus (strain FP9) that expresses a 3240-amino acid polyprotein (L3SEPTL) containing six pre-erythrocytic antigens from Plasmodium falciparum: LSA-1, LSA-3, TRAP, STARP, Exp-1, and CS. These TCRs are the primary effectors intended to recognize and eliminate parasite-infected hepatocytes by binding to specific malaria-derived peptides presented by Major Histocompatibility Complex (MHC) molecules. In clinical trials, the heterologous prime-boost regimen using FP9-PP and MVA-PP was found to be safe and capable of inducing antigen-specific T cell responses. However, the magnitude of these responses was often lower than required for sterile protection, and the vaccine failed to demonstrate significant efficacy in human challenge studies. Research into these TCRs focuses on understanding the structural basis of their interaction with malaria pMHC complexes to improve vaccine design and identify more potent epitopes for future immunotherapies.

Other names

FP9-PP-specific T cell receptorMalaria polyprotein-specific TCRL3SEPTL-specific T cell receptor

The FP9-PP vaccine acts as an immunogen that induces the expansion and activation of T cell receptors (TCRs) specific for Plasmodium falciparum peptides presented on MHC complexes, aiming to provide protective immunity against the liver stage of malaria.