Cell-mediated immune reaction against BK virus-transformed cells.

Syngeneic or allogeneic cells transformed by BK virus (BKV) were used to immunize C57BL/6J mice. After in vitro stimulation, lymphocytes prepared from the spleens of immunized mice were used in in vitro cytotoxicity tests. The results of these tests revealed the presence of a cell surface antigen, presumably corresponding to the viral transplantation antigen, common to all tested BKV- and SV40-transformed cell lines of C57BL/6J origin. An allogeneic cell line transformed by BKV also contained the same antigen. Immunization, i.e., in vivo priming, did not require syngeneic transformed cells, whereas cytolysis was only observed when the virus-specific antigen on target cells was associated with the same H2 haplotype as was expressed by effector cells. An additional unidentified antigen was shared by some of the BKV-transformed cell lines and cell lines transformed by simian adenovirus SA7.