Epstein-barr virus induction by a serum factor: IV. Ubiquitous occurrence of the factor within vertebrates and its...

We have recently reported the existence of a serum factor that induces Epstein-Barr virus antigens in Raji cells (Bauer et al., 1982b, c). Here we demonstrate the ubiquitous presence of this factor in sera of vertebrates of all five classes. Furthermore, we tested 48 EBV-genome-positive lymphoid cell lines of different origins for responsiveness to the serum factor. Only cells from lines of two groups, i.e. Burkitt's lymphoma and EBV-transformed marmoset lines, responded to the factor, whereas human lymphoblastoid cell lines were not induced by the serum factor.