Identification of T-cell epitopes in nonstructural proteins of foot-and-mouth disease virus

Porcine T-cell recognition of foot-and-mouth disease virus (FMDV) nonstruct ural proteins (NSP) was tested using in vitro lymphoproliferative responses , Lymphocytes were obtained from outbred pigs experimentally infected with FMDV, Of the different NSP, polypeptides 3A, 3B, and 3C gave the highest st imulations in the in vitro assays. The use of overlapping synthetic peptide s allowed the identification of amino acid regions within these proteins th at were efficiently recognized by the lymphocytes. The sequences of some of these antigenic peptides were highly conserved among different FMDV seroty pes, They elicited major histocompatibility complex-restricted responses wi th lymphocytes from pigs infected with either a type C virus or reinfected with a heterologous FMDV, A tandem peptide containing the T-cell peptide 3A [21-35] and the B-cell antigenic site VP1 [137-156] also efficiently stimul ated lymphocytes from infected animals in vitro. Furthermore, this tandem p eptide elicited significant levels of serotype-specific antiviral activity, a result consistent with the induction of anti-FMDV antibodies. Thus, incl usion in the peptide formulation of a T-cell epitope derived from the NSP 3 A possessing the capacity to induce T helper activity can allow cooperative induction of anti-FMDV antibodies by B cells.