Endogenous retroviruses and schizophrenia

Retroviruses are biologically complex infectious agents which are capable o f cellular infection and subsequent integration into the host genome. Retro viruses can exist in an endogenous form in which viral sequences are integr ated into the human germline and are vertically transmitted in a Mendelian fashion. The transcriptional activation of these viral sequences in cells w ithin the central nervous system can affect the transcriptional regulation of adjacent genes and result in alterations of neural functioning. This rep ort discusses evidence for a possible role of endogenous retroviruses in th e etiopathogenesis of schizophrenia and other human brain diseases. Evidenc e of endogenous retrovirus activity is manifested by the identification of viral sequences in the brains and cerebrospinal fluids of affected individu als. In addition, affected individuals display evidence of increased activi ty of virally-encoded reverse transcriptase. The identification of a retrov iral component of schizophrenia would be consistent with genetic, environme ntal, and neurodevelopmental aspects of the disease process. The delineatio n of a role for retroviruses in disease pathogenesis might lead to new meth ods for the diagnosis and treatment of schizophrenia. (C) 2000 Elsevier Sci ence B.V. All rights reserved.