Establishment and characterization of canine parvovirus-specific murine CD4+ T cell clones and their use for the delineation of T cell epitopes.

Canine parvovirus (CPV)-specific T cell clones were generated by culturing lymph node cells from CPV-immunized BALB/c mice at limiting dilutions in the presence of CPV antigen and interleukin-2 (IL-2). All isolated T cell clones exhibited the cell surface phenotype Thy1+, CD4+, CD8- and proliferated specifically in response to CPV antigen. After stimulation with CPV antigen in culture the T cell clones produced IL-2 and proliferated in the absence of exogenous IL-2. Naive mice to which CPV-specific T cell clones had been adoptively transferred developed a CPV-specific delayed type hypersensitivity reaction upon simultaneous intracutaneous injection of CPV in their ears. The ability of recombinant viral fusion proteins, representing the VP2 capsid protein of the antigenically closely related feline panleukopenia virus and of synthetic peptides derived from the amino acid sequence of the VP2 of CPV, to stimulate these T cell clones enabled the identification of T cell epitopes.