An immunologic test-system for an oncornavirus of Type B isolated from an HEp2 cell line was obtained. The virus-specific serum detects both extracellular and intracellular antigens of the virus as well as antigens of oncornaviruses of Type B revealed in HeLa, DAPT, RH, Detroit 6, and A1 cell lines. This group specific antigen cross-reacts with the antigen of the rhesus monkey oncornavirus Type B and does not cross-react with the antigen of the mouse mammary tumor virus. No cross-reaction was revealed between the virus studied and oncornavirus of Type C isolated from an H-22 cell line.
Cancer 34:532-538, 1974.
NCORNAVIRUSES OF TYPE B ARE KNOWN AS 0 agents of mouse4,20.?5 and rhesus mon-keylv6J3~9J6-1"23 mammary tumors. Morphologically similar viruses were revealed in human breast cancer cells.7~21 It has been shown previously that a clone of HEp2 cells produces a virus that possesses the main properties of oncornaviruses of Type B,'2 being immunologically distinct from the mouse mammary tumor virus.l"l4 Several continuous human cell lines were studied thereafter, and similar viruses have been revealed in some of them.2s This paper decribes the results of comparative immunologic study of the virus isolated from HEp2 cells with other viruses of Type B isolated from human, monkey, and mouse tissues.
MATERIALS AND METHODS
Cell Lines
The following cell lines producing oncornaviruses of Type B were used: H E P ~, ~~ HeLa,l0 DAPT,2 RH,5 Detroit 6,3 and Al.'O An H22 cell line producing oncornavirus of Type C was also used.* The cells were grown in medium 199 with 10% calf serum.
From the N. F.