부산대학교 도서관

Lipids are important antigens that induce T cell-mediated specific immune responses. They are presented to T lymphocytes by a specific class ofMHC-Ilike proteins, termed CD1. The majority of the described CD1-presented mycobacterial antigens are presented by the CD1b isoform.Wepreviously demonstrated that the stimulation of CD1b-restricted T cells by the hexamannosylated phosphatidyl-myo-inositol (PIM6), a family of mycobacterial antigens, requires a prior partial digestion of the antigen oligomannoside moiety by α-mannosidase and that CD1e is an accessory protein absolutely required for the generation of the lipid immunogenic form. Here, we show that CD1e behaves as a lipid transfer protein influencing lipid immunoediting and membrane transfer of PIM lipids. CD1e selectively assists the α-mannosidase-dependent digestion of PIM6 species according to their degree of acylation. Moreover, CD1e transfers only diacylated PIM from donor to acceptor liposomes and also from membranes to CD1b. This study provides new insight into the molecular mechanisms by whichCD1econtributes to lipid immunoediting and CD1-restricted presentation toTcells. [ABSTRACT FROM AUTHOR]