Characterization of the mouse monoclonal antibody TJ4C4 directed at human p68 kinase

This report describes the production and characterization of a mouse monoclonal antibody (mAb) TJ4C4, which is directed against the interferon-induced double-stranded RNA-activated protein kinase p68 (PKR). The mAb TJ4C4 was produced against p68 which was isolated using a partially purified p68 preparation from human cells. The specificity of this mAb is demonstrated in competitive inhibition assays using recom-binantly produced p68 protein and by immunoprecipitation. This mAb is of particular value in that it detects an epitope on p68 which is not destroyed in routinely prepared, formalin- fixed paraffin-embedded tissues, or in a variety of other commonly used clinical fixatives. The inhibition of mAb TJ4C4 by recombinantly produced p68, on human tissues sections, validates the specificity of this mAb in histological studies. Therefore, mAb TJ4C4 serves as a specific probe to study p68 expression in clinically derived tissue specimens.