Human Herpesvirus Type 8 and Kaposi's Sarcoma

Kaposi's sarcoma-associated herpesvirus or human herpesvirustype8 (HHV-8) is present in all forms of Kaposi's sarcoma(KS) aswell as in primary effusion lymphomas and some cases ofCastleman'sdisease. In KS tissues, HHV-8 is present inendothelial andspindle cells. Current serologic tests suggestthat HHV-8 ispredominantly found in those at risk of KS and isnot as widespreadas most other human herpesviruses. HHV-8encodes various proteinsthat may play a role in promotion ofcellular growth, includingcyclin- and G-coupled protein receptorhomologues, and anti-apoptoticproteins, including Bcl-2, IL-6(i.e., interleukin 6), and FLIP(i.e., FLICE inhibitory protein)homologues. In addition, HHV-8encodes two macrophageinflammatory-like proteins with anti-humanimmunodeficiency virusand angiogenic potential.