MINOR MYELIN PROTEINS CAN BE MAJOR TARGETS FOR PERIPHERAL-BLOOD T-CELLS FROM BOTH MULTIPLE-SCLEROSIS PATIENTS AND HEALTHY-SUBJECTS

T cell recognition of myelin is likely to play a role in the pathogene sis of multiple sclerosis. Predominant protein components of myelin, m yelin basic protein (MBP) and proteolipid protein (PLP), have been con sidered as possibly relevant autoantigens, especially since both prote ins are encephalitogenic in various laboratory animals. It has remaine d unclear, however, to what extent the numerous minor proteins contain ed in myelin may serve as targets for human T cell responses to myelin . In this study, the abilities of several minor myelin proteins to tri gger proliferative responses of human peripheral blood T cells were co mpared to that of MBP. By using a water soluble collection of myelin p roteins as an antigen, including MBP as the major component, short-ter m T cell lines were generated. Proliferative responses were determined against the various proteins after their fractionation by HPLC. Short -term T cell lines from both multiple sclerosis patients and healthy c ontrol subjects displayed significant responses to several minor myeli n proteins but failed to respond to MBP. Only the use of purified MBP as trigger antigen allowed the selective expansion of MBP-specific T c ell lines. These findings indicate that minor myelin proteins may act as relevant targets for autoreactive human T cells.