THE MAJOR MYELIN PROTEIN GENES ARE EXPRESSED IN THE HUMAN THYMUS

Demyelinating diseases, such as multiple sclerosis (MS) in man or expe rimental allergic encephalomyelitis (EAE) in rodents, may include an a ssociated immune response directed against myelin protein antigens suc h as the proteolipid protein (PLP) and the myelin basic protein (MBP), Development of an immune response has been attributed, in part, to th e sequestration of central nervous system antigens behind the blood-br ain barrier. Recently, we identified a novel gene, the golli gene, whi ch overlaps the mbp gene, The Golli transcription unit produces a fami ly of mRNAs, and their corresponding proteins possess MBP epitopes kno wn to be encephalitogenic in EAE, Transcription of the golli gene was detected in immune system tissue. Therefore, we wished to determine wh ether genes that encode the two major myelin protein components, PLP a nd MBP, were expressed in the human thymus, Our data demonstrate that both the pip and golli genes are transcribed in thefetal human thymus, Moreover, both the PLP and DM-20 transcripts are produced from the pl p gene, and the HOG 7 and HOG 5 transcripts are produced from the goll i gene. Confocal fluorescent immunohistochemistry using antibodies for the PLP/DM-20 and Golli proteins, co-localized expression of these an tigens to thymic macrophages, Thus, the pip and golli genes are expres sed, and their corresponding protein produced, in an antigen presentin g cell in the human immune system. (C) 1996 Wiley-Liss, Inc.