DO TYPE-D RETRO VIRUSES PLAY A ROLE IN THE AETIOLOGY OF KAPOSI'S SARCOMA?

Abstract

Acquired and epidemic Kaposi's Sarcoma (KS) is prevalent among human immunodeficiency virus (HIV) positive homosexual males and other immunosuppressed patients as a far more aggressive tumor than classic KS, suggesting that an infectious agent may play a role in its aetiology. That only a subset of HIV infected individuals and some HIV negative individuals acquire KS implies that the HIV virus is not directly responsible for KS. A similar neoplasm, retroperitoneal fibromatosis (RF), is associated with simian acquired immunodeficiency syndrome (SAIDS) in primates, and is considered a model for acquired immunodeficiency syndrome (AIDS) associated KS. The causative agent of SAIDS associated RF is a type-D retrovirus, simian retrovirus type 2 (SRV2). The similarities between the two diseases has invited speculation that KS may also be caused by a type-D retrovirus. Electron microscope images of a budding retroviral particle in association with tissue from KS lesions from HIV-1, HIV-2 and human T-cell leukemia virus type 1 (HTLV-1) seronegative individuals have lent credence to this theory. The study presented here was undertaken in order to determine if a link between exogenous type-D retrovirus infection and Kaposi's Sarcoma exists. A highly sensitive and specific approach utilizing nested polymerase chain reaction (PCR) amplification and subsequent Southern blot analysis was developed and optimized in order to examine the question.