US EPA

1103794 

Journal Article 

Review 

HLA-DM, HLA-DO and tapasin: functional similarities and differences 

Brocke, P; Garbi, N; Momburg, F; Hämmerling, GJ 

2002 

Yes 

Current Opinion in Immunology
ISSN: 0952-7915 

14 

1 

22-29 

English 

11790529 

WOS:000173193900003 

In both the MHC class II and class I pathways of antigen presentation, accessory molecules influence formation of MHC-peptide complexes. In the MHC class II pathway, DM functions in the loading and editing of peptides; recent work demonstrated that it is acting not only in late endosomal compartments but also in recycling compartments and on the surface of B cells and immature dendritic cells. DM activity is modulated by another accessory molecule, DO, but this modulation is mainly operative in B cells, where it may lead to preferential activation of B cells producing high-affinity antibodies. In the MHC class I pathway of antigen presentation, recent in vivo experiments with knockout mice confirmed the role of tapasin in antigen presentation and indicate that it acts as a peptide editor and as a chaperone for TAP and the MHC class I heavy chain. In the class I loading complex, calreticulin and the thiol-dependent oxidoreductase ER60/ERp57 appear to support the function of tapasin in an as-yet-unknown fashion. The picture emerges that DM and tapasin have analogous functions in shaping the peptide repertoire presented by the respective MHC class II and class I molecules.