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Updated: Aug 11, 2026

Peptide-based Identification of Functional Motifs and their Binding Partners
Published on: July 1, 2013
Endogenously expressed HIV-1 nef down-regulates antigen-presenting molecules, not only class I MHC but also CD1a, in
Eiji Shinya1, Atsuko Owaki, Masumi Shimizu
1Department of Microbiology and Immunology, Nippon Medical School, Bunkyo, Tokyo 113-8602, Japan.
Abstract:
The effects of Nef molecules on immature dendritic cells (iDCs) were analyzed using recombinant human immunodeficiency virus type 1 (HIV-1) with intact nef gene, pseudotyped with vesicular stomatitis virus glycoprotein, HIV/VSV-G/+Nef. When iDCs were infected with HIV/VSV-G/+Nef, the surface expression of CD1a, a molecule for presenting glycolipid/lipid antigens, was selectively down-regulated among CD1 molecules (CD1a, -b, -c, and -d) as well as class I MHC. Moreover, the CD1a molecules were also down-modulated and co-localized with DsRed2-tagged-Nef in CD1a-transfected cells. Their co-localization was dependent upon CD1a cytoplasmic tail and the CD1a was redistributed from cell surface to LAMP-1+ late endosomal/lysosomal compartment. These findings reveal that the HIV-1-Nef interferes with the intracellular trafficking of CD1a, and suggest the involvement of CD1a-restricted immune effectors in the protective immunity against HIV-1 infection, which implicates the feasibility of virus-derived glycolipid/lipid antigens together with epitope peptides for the vaccine development.
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