CTL recognition of adenovirus-transformed cells infected with influenza virus: lysis by anti-influenza CTL parallels adenovirus-12-induced suppression of class I MHC molecules.

We examined the ability of influenza-specific cytotoxic T lymphocytes to lyse adenovirus-transformed cells infected with influenza virus. Cytotoxic T lymphocyte lysis of Ad12-transformed cells was greatly reduced relative to that of Ad5-transformed cells. Lysability of adenovirus-12-transformed cells was restored in parallel with interferon-gamma induced increases in major histocompatibility complex class I gene products. These findings establish that recognition of foreign molecules by self-restricted cytotoxic T lymphocytes is reduced in adenovirus-12-transformed cells. This provides further evidence that Ad12 tumorigenicity is related to its ability to suppress class I major histocompatability complex molecule expression thereby avoiding recognition by the host immune system.