PMID- 8662817
OWN - NLM
STAT- MEDLINE
DCOM- 19960820
LR  - 20210210
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 271
IP  - 24
DP  - 1996 Jun 14
TI  - Conformation of human leukocyte antigen class II molecules. Evidence for 
      superdimers and empty molecules on human antigen presenting cells.
PG  - 13993-4000
AB  - Subpopulations of human leukocyte antigen (HLA) class II molecules were studied 
      in antigen presenting cells. We present evidence for double dimers or 
      "superdimers" of HLA class II molecules that were stable in an SDS solution at 
      room temperature but dissociated when heated to 50 degrees C into 60-kDa 
      alphabeta heterodimers. Development of an immunofluorescence assay allowed us to 
      quantify the expression of HLA antigens as reflected by the number of bound 
      isotype-specific monoclonal antibodies per cell. The total expression of class II 
      (DR, DQ, and DP) augmented 6-fold after a 36-h interferon-gamma (IFNgamma) 
      treatment of freshly isolated monocytes. Next, we used a recombinant and 
      fluorescein-conjugated form of the class II-associated invariant chain as a 
      quantitative probe for empty peptide-binding sites. The fraction of empty class 
      II molecules was 0.73-2.9% in resting monocytes but was reduced to 0. 12-0.5% of 
      the total after IFNgamma treatment. The fraction of empty sites in B lymphocytes 
      was 0.09-0.36%. The mean number of empty sites per cell were: 6.3 x 10(3) 
      (monocytes), 7.2 x 10(3) (IFNgamma-activated monocytes), 5.2 x 10(2) (B 
      lymphocytes), and 3.6 x 10(3) (Raji B cells). A minor population (4.3-7.4% of 
      total cells), which expressed a much higher number of empty sites, was 
      consistently present in all cell types studied.
FAU - Roucard, C
AU  - Roucard C
AD  - Laboratoire d'Immunogenetique Humaine, INSERM U396, Institut Biomedical des 
      Cordeliers, 15 rue de l'Ecole de Medecine, 75006 Paris, France.
FAU - Garban, F
AU  - Garban F
FAU - Mooney, N A
AU  - Mooney NA
FAU - Charron, D J
AU  - Charron DJ
FAU - Ericson, M L
AU  - Ericson ML
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (Antibodies, Monoclonal)
RN  - 0 (HLA-D Antigens)
RN  - 0 (HLA-DP Antigens)
RN  - 0 (HLA-DQ Antigens)
RN  - 0 (HLA-DR Antigens)
RN  - 0 (Macromolecular Substances)
SB  - IM
MH  - Antibodies, Monoclonal
MH  - Antigen-Presenting Cells/*immunology
MH  - B-Lymphocytes/*immunology
MH  - Cell Line
MH  - Cell Membrane/immunology
MH  - Cells, Cultured
MH  - HLA-D Antigens/biosynthesis/*chemistry
MH  - HLA-DP Antigens/biosynthesis/chemistry
MH  - HLA-DQ Antigens/biosynthesis/chemistry
MH  - HLA-DR Antigens/biosynthesis/chemistry
MH  - Humans
MH  - Macromolecular Substances
MH  - Monocytes/immunology
MH  - *Protein Conformation
MH  - T-Lymphocytes/*immunology
MH  - Transfection
MH  - Tumor Cells, Cultured
EDAT- 1996/06/14 00:00
MHDA- 1996/06/14 00:01
CRDT- 1996/06/14 00:00
PHST- 1996/06/14 00:00 [pubmed]
PHST- 1996/06/14 00:01 [medline]
PHST- 1996/06/14 00:00 [entrez]
AID - S0021-9258(18)46757-9 [pii]
AID - 10.1074/jbc.271.24.13993 [doi]
PST - ppublish
SO  - J Biol Chem. 1996 Jun 14;271(24):13993-4000. doi: 10.1074/jbc.271.24.13993.