Immunological variation in the 'common region' of the T antigens of polyoma virus.

Characterization of a series of mouse monoclonal antibodies (designated alpha Py C21 to 26) against the region common to the large, middle and small T antigens of polyoma virus has revealed immunological diversities among the N termini of these antigens. Four of the antibodies (alpha Py C21 to 24) appeared to recognize all the T antigens present in lytically infected cells, but two of them (alpha Py C25, 26) failed to immunoprecipitate small T antigen either from 35S- or 32P-labelled cells and recognized only a subset of middle and large T antigens. None of the antibodies recognized the protein kinase activity normally associated with middle T antigen or the 60K mol. wt. antigen-related protein observed in polyoma virus lytically infected or transformed cells. The possible immunodominance of the N termini of the early gene products (as well as VP1) in the natural host of polyoma virus and the observed antigenic heterogeneity are considered.