HUMAN OLIGODENDROCYTES ARE NOT SENSITIVE TO COMPLEMENT - A STUDY OF CD59 EXPRESSION IN THE HUMAN CENTRAL-NERVOUS-SYSTEM

BACKGROUND: One or more components of the oligodendrocyte-myelin unit are the target of immune attack in multiple sclerosis. The role of com plement in this process has been suggested by the demonstration in vit ro that rat oligodendrocytes are sensitive to lysis by Ab-independent complement attack, partly because of a lack of the complement regulato ry protein molecule, CD59. EXPERIMENTAL DESIGN: This study assessed th e sensitivity in vitro of human oligodendrocytes derived from neurosur gical specimens to complement attack and analyzed CD59 expression on t heir surface. The presence of CD59 was also examined in the human cent ral nervous system during myelination and in both the normal and disea sed adult brain. RESULTS: Human oligodendrocytes are insensitive in vi tro to complement attack in the absence of Ab and using the Ab YTH 53. 1 and were shown to possess CD59 on their surface. CD59 is absent from the human central nervous system before myelination, at which stage s trong expression occurs in areas of myelin production. CD59 expression is then normally downregulated but is particularly strong in reactive astrocytes in diseases such as multiple sclerosis. CONCLUSIONS: The f indings suggest that the previous demonstration of rat oligodendrocyte complement sensitivity and lack of CD59 expression do not extend to t he human central nervous system. There may be a role for CD59 in norma l human myelination.