The diversity of the CD4+ T cell response in influenza.

We have analyzed the specificity and structural basis of the CD4+ helper T cell (Th) response of BALB/c mice to influenza virus. We find that many of the viral proteins are recognized by Th, and for one of these proteins we have defined eight distinct Th determinants. Moreover, Th that recognize a single determinant use structurally diverse T cell receptors, and display many unique specificities for the same determinant. These findings demonstrated extensive diversity at several levels of the Th response to influenza virus.