Kaposi's sarcoma-associated herpesvirus: epidemiology, virology, and molecular biology.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the eighth human herpesvirus (HHVS) and is the subject of considerable interest because of its association with several major acquired immunodeficiency syndromes (AIDS)-related malignancies. Epidemiologic studies now largely agree that this virus is the required infectious cofactor responsible for Kaposi's sarcoma (KS) and related neoplastic disorders. Although the virus is important from a clinical and a public health standpoint, it also promises to provide a surprisingly rich source of basic information on how viruses induce cellular proliferation. As with other tumor viruses, there are also a number of important obstacles to the study of KSHV. Although KSHV can be cultured to high titer in naturally infected lymphoma cell lines, the virus cannot be sustainably cultivated from KS lesions analogous to Epstein-Barr virus (EBV or human herpesvirus 4/HHV4) in nasopharyngeal carcinoma.