MEASLES-VIRUS IN THE BRAIN

Measles Virus can give three different forms of infections in the cent ral nervous system. These are acute postinfectious encephalitis, acute progressive infectious encephalitis, and subacute sclerosing panencep halitis (SSPE). The postinfectious acute disease is interpreted to ref lect an autoimmune reaction. The acute progressive form of brain disea se, also referred to as inclusion body encephalitis, reflects a direct attack by the virus under conditions of yielding cell-mediated immuni ty. The late progressive form of encephalitis (SSPE) has been extensiv ely analyzed. Recent molecular genetic studies have unravelled a range of mechanisms by which a defective expression of either the matrix, t he fusion, or the hemagglutinin proteins may lead to viral persistence in brain cells under conditions not allowing identification by immune surveillance mechanisms. Many aspects of virus-cell interactions have been examined by use of explant cultures of neuronal cells of human a nd animal origin. Some of the findings are reviewed. Experimental anim als, in particular rodents, have been used to establish systems in whi ch phenomena, pivotal to the evolution of acute as well as persistent measles virus infections in the brain, can be studied. A wide range of potentially important mechanisms has been highlighted and is discusse d. More recently, mice with genetic defects in immune functions were u sed to evaluate consequences as to initiation and dissemination of vir us infection in the brain. (C) 1997 Elsevier Science Inc.