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Phagocytosis of myelin by microglia in vitro
Author(s) -
Smith M. E.
Publication year - 1993
Publication title -
journal of neuroscience research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.72
H-Index - 160
eISSN - 1097-4547
pISSN - 0360-4012
DOI - 10.1002/jnr.490350504
Subject(s) - microglia , myelin , phagocytosis , galactocerebroside , opsonin , myelin basic protein , microbiology and biotechnology , immunology , biology , central nervous system , oligodendrocyte , endocrinology , inflammation
Previous experiments from this laboratory have shown that peritoneal macrophages in culture will phagocytize myelin. Myelin preopsonized with myelin antibodies is phagocytized to a much greater extent than untreated myelin, indicating that macrophages ingest myelin by an Fc receptor. The present work was undertaken to determine the characteristics of myelin phagocytosis by microglia, the resident macrophages of the central nervous system. Microglia isolated from 4–5 day primary cultures of newborn rat brains were shown to bind and phagocytize myelin labeled in the lipids by 14 C‐acetate. Both binding and phagocytosis as shown by the appearance of 14 C‐cholesterol ester were greatly increased if labeled myelin was preopsonized with antiserum to myelin basic protein or galactocerebroside. Both preopsonized and untreated myelin were phagocytized more actively by microglia than by peritoneal macrophages under the same culture conditions. Microglia cultured in the presence of GM‐CSF showed slightly increased cholesterol ester production from opsonized myelin, but the effect of GM‐CSF was significantly greater than myelin pretreated with control serum (34% increase) or untreated myelin (154% increase). There was no significant effect of GM‐CSF on myelin phagocytosis by peritoneal macrophages. Cerebrospinal fluid containing immunoglobulin drawn from rabbits with acute EAE also opsonized myelin to increase phago cytosis by microglia, as has been previously shown with peritoneal macrophages. These results indicate that microglia may actively participate in myelin destruction in demyelinating diseases where myelin antibodies or a source of GM‐CSF may be present. © 1993 Wiley‐Liss, Inc. This article is a US Government work and, as such, is in the public domain in the United States of America.