Cytotoxic T cell specificity for respiratory syncytial virus proteins: fusion protein is an important target antigen.

We examined the specificity of BALB/c cytotoxic T (Tc) cells for respiratory syncytial virus (RSV) components, using recombinant vaccinia viruses (VV) coding for several individual RSV proteins. We found that immunization with the different VVs yielded the following Tc memory cell populations: high levels of RSV-specific Tc cells were induced with the fusion protein VV, but low levels were induced with VV coding for the RSV nucleoprotein. Tc cell recognition of attachment glycoprotein, part of the matrix molecule or 1A internal protein was poor. While high levels of fusion protein-specific Tc cells were induced by the fusion protein VV, they showed poor cross-reactivity between the A2 and 8/60 RSV strains compared with Tc cells primed by RSV infection.