PSEUDORABIES VIRUS GROWTH-FACTOR CAN BE RESOLVED INTO 2 ACTIVE COMPONENTS

Pseudorabies virus (PRV) growth factor (PRGF) which induces a transfor med phenotype in normal MK-2 cells and represses the transformed pheno type of Hela cells was partially purified and resolved into two compon ents (M(r)<300 and <180). Each of the PRGF components retained the tra nsforming activity of the original factor in MK-2 cells but lost its t ransformation-repressing activity in Hela cells. The latter activity o f PRGF could be reconstituted by simultaneous application of its two c omponents. Two monoclonal antibodies against gII glycoprotein of PRV w ere able to neutralize both PRGF activities, thus supporting the previ ously suggested hypothesis that the PRV gene for glycoprotein gII migh t be involved in PRGF synthesis.