Role of the Innate Immune Response in Determining the Tumorigenicity of Neoplastic Cells

Expression of the E1A oncogene of adenovirus serotype 5 (Ad5) sensitizes neoplastic cells from different species, including human, to apoptosis triggered by components of the innate mmune response. This E1A activity causes a marked reduction in the tumorigenicities of sarcoma cells in a manner that is directly linked to the competence of NK cells from the test animals to lyse E1A-expressing tumour cells. The results from this oncogene model indicate that studies of quantitative differences in the tumorigenicities of different neoplastic cells should include considerations of oncogene regulation of susceptibility to immune-mediated injury and the immunocompetence of the animals chosen as tumour challenge recipients.