Flavivirus-specific murine L3T4+ T cell clones: induction, characterization and cross-reactivity.

Murine T cell clones specific for the Kunjin (KUN), West Nile (WN) and Murray Valley encephalitis (MVE) flaviviruses were generated in vitro following priming in vivo. Clones were isolated by limiting dilution and maintained in culture with antigen stimulation and interleukin-2(IL-2). The cells were characterized as having the Thy 1+, L3T4+ and Lyt 2- phenotype by immunofluorescence. All clones proliferated strongly and secreted high levels of IL-2 and IL-3 in response to homologous antigen. Both KUN- and WN-specific clones showed extensive cross-reactivity to KUN and WN antigen, but recognized MVE to a lesser extent. In contrast, MVE-specific clones cross-reacted strongly with both KUN and WN. These data show that antigen-specific, major histocompatibility complex-restricted L3T4+ T cells are generated during flavivirus infection and are cross-reactive for viruses of the same subgroup.