Cytotoxic T cell epitope in cattle from the attachment glycoproteins of rinderpest and peste des petits ruminants viruses.

The surface glycoproteins of rinderpest virus (RPV) confer protective immunity in cattle. We demonstrated that cattle immunized with a recombinant extracellular baculovirus expressing the hemagglutinin (H) protein of RPV (rECV-H) generate virus neutralizing antibody responses, bovine leukocyte antigen (BoLA) class II restricted helper T cell responses and BoLA class I restricted cytotoxic T cell (CTL) responses against RPV-H and hemagglutinin-neuraminidase (HN) glycoprotein of closely related Peste des petits ruminants virus (PPRV). In this study, employing autologous skin fibroblasts transiently expressing truncations of H and HN in a BoLA class I restricted lymphoproliferation assay, we have mapped a highly homologous domain (amino acids 400-423) on these proteins harboring a CTL epitope. Subsequently, based on sequence comparison with available BoLA class I binding motifs, we have identified a BoLA-A11 binding motif (amino acids 408-416) in the stimulatory domain. Autologous cells pulsed with a synthetic peptide corresponding to this sequence stimulated CTLs from rECV-H immunized as well as tissue culture attenuated RPV vaccinated cattle of different breeds and parentage. This is the first epitope identified in cattle on the attachment glycoproteins of RPV and PPRV.