Altered antigen presentation in mice lacking H2-O.
HLA-DM catalyzes the release of MHC class II-associated invariant chain-derived peptides (CLIP) from class II molecules. Recent evidence has suggested that HLA-DO is a negative regulator of HLA-DM in B cells, but the physiological function of HLA-DO remains unclear. Analysis of antigen presentation by B cells from mice lacking H2-O (the mouse equivalent of HLA-DO), together with biochemical analysis using purified HLA-DO and HLA-DM molecules, suggests that HLA-DO/H2-O influences the peptide loading of class II molecules by limiting the pH range in which HLA-DM is active. This effect may serve to decrease the presentation of antigens internalized by fluid-phase endocytosis, thus concentrating the B cell-mediated antigen presentation to antigens internalized by membrane immunoglobulin.
Liljedahl
M
M
The R.W. Johnson Pharmaceutical Research Institute, San Diego, California 92121, USA.
Winqvist
O
O
Surh
C D
CD
Wong
P
P
Ngo
K
K
Teyton
L
L
Peterson
P A
PA
Brunmark
A
A
Rudensky
A Y
AY
Fung-Leung
W P
WP
Karlsson
L
L
D000818:Animals; D017951:Antigen Presentation; D000938:Antigen-Presenting Cells / Q000276:immunology*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000032:analysis; D001402:B-Lymphocytes / Q000276:immunology*; D005455:Fluorescent Antibody Technique; D018390:Gene Targeting; D006681:HLA-D Antigens / Q000235:genetics / Q000276:immunology*; D000949:Histocompatibility Antigens Class II / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007074:Immunoglobulin G / Q000097:blood; D008198:Lymph Nodes / Q000166:cytology / Q000276:immunology; D051379:Mice; D008817:Mice, Mutant Strains; D010455:Peptides / Q000276:immunology; D011233:Precipitin Tests; D013154:Spleen / Q000166:cytology / Q000276:immunology
D000944:Antigens, Differentiation, B-Lymphocyte; C416186:H-2O antigen; C416189:H2-M antigens; D006681:HLA-D Antigens; C084245:HLA-DM antigens; C046148:HLA-DO antigens; D000949:Histocompatibility Antigens Class II; D007074:Immunoglobulin G; D010455:Peptides; C045084:invariant chain