POSTER

Lazarini F¹, Ruprecht K², Péchoux

C², Seilhean D³, Sazdovitch V³, A. Créange⁴,

Battail-Poirot N⁵, Sibaï

G⁵, Marcel F⁵, Souillet Y⁵, Santoro L⁵

Jolivet M⁵, Lassmann H.³, Hauw JJ³, and Perron

A retroviral element (MSRV)

defining a family of genetically-inherited endogenous retroviruses (HERV-W) has

been characterized in cell cultures from patients with multiple sclerosis.  The

present immunohistological study was performed by three independent groups using

the same panel of antibodies raised against recombinant MSRV antigens but also

detecting highly conserved HERV-W family proteins.  A physiological expression

of HERV-W Env and Gag proteins in normal brain was observed in neuronal cells,

whereas upregulation of HERV-W Gag alone was detected in axonal structures of

demyelinated white matter from patients with Progressive Multifocal

Leukoencephalopathy (PML) and with Multiple Sclerosis (MS).  In MS plaque,

HERV-W upregulation was also detected in endothelial cells and in few

microgliocyte-like cells.  In parallel, antibodies against another endogenous

retrovirus family (HERV-K) gave constantly negative results in all brain

samples.  This multicenter study provides novel physiopathological insights in

diseases such as MS and PML, but also raises questions about a possible

physiological function in normal neurons by analogy with previous reports

KEY-WORDS:  Retrovirus,

HERV-W, Antigen, Brain, Neuron, Axon, Endothelial Cell; microgliocyte, Multiple