PAb 2000 specifically recognizes the large T and small t proteins of JC virus.

A monoclonal antibody, PAb 2000, has been derived which recognizes the large T protein of JC virus (JCV), but not the corresponding proteins of the related polyomaviruses BK virus (BKV) and SV40. The epitope bound by PAb 2000 was localized to the amino-terminal 81 amino acids of this multifunctional protein. As observed previously with several monoclonal antibodies that bind a similar region of SV40 large T antigen, PAb 2000 was found to interact with the small t antigen and the denatured form of large T antigen. This monoclonal antibody recognized a subpopulation of T protein, the abundance of which varied in different species of cells transformed by JCV. The availability of PAb 2000, the first JCV T antigen-specific monoclonal antibody, will facilitate the purification and biochemical characterization of the JCV oncoproteins.