Early regions of JC virus and BK virus induce distinct and tissue-specific tumors in transgenic mice.

JC virus and BK virus are ubiquitous human viruses that share sequence and structural homology with simian virus 40. To characterize tissue-specific expression of these viruses and to establish model systems for the study of human viral-induced disease, transgenic mice containing early regions of each of the viruses were produced. The viral sequences induced tumors in a distinct and tissue-specific manner that was similar to their tissue tropism in humans. Ten JC virus-containing founder mice were produced, of which 5 survived to maturity. Four of them developed adrenal neuroblastomas, which metastasized to several other tissues. JC virus tumor-antigen RNA was detected at high levels in the tumor tissues and at low levels in the normal tissues of these mice. One of the three BK virus-containing mice was abnormally shaped and died at 2 weeks of age. The other two BK virus-containing mice developed primary hepatocellular carcinomas and renal tumors and died at 8-10 months of age. BK virus tumor-antigen RNA was expressed in tumor tissues of both mice. Since each of the viruses retained the general tissue tropism that it exhibits in humans, these data suggest that transgenic mice harboring human viruses will be useful as animal models for viral-induced diseases.