GROWTH-FACTORS ENCODED BY VARIOUS HERPESVIRUSES CAN BE RESOLVED IN 2-COMPONENT OR IN 3-COMPONENT

Three human and six animal herpesviruses were shown to produce virus-r elated growth factors. All these factors similary to previously descri bed pseudorabies virus growth factor (PRGF) induced a transformed phen otype in normal MK-2 cells and repressed the transformed phenotype of Hep-2 and T 24 tumor cells. By the use of gel filtration chromatograph y on the FPLC Superose -12 column, seven growth factors could be resol ved into, two and three factors were resolved in three small active co mponents (Mr < 1000). Each of two components of the factors belonging to the first group possessed only transforming activity, the transform ed phenotype repressing activity could be reconstituted by simultaneou s application of both components. The middle component of three-compon ent factors possessed only transformation repressed activity, whereas other two components were transforming only. The middle transformation repressing components, devoid of transforming activity are discussed as possible anticancerogenic substances.