PMID- 11454061
OWN - NLM
STAT- MEDLINE
DCOM- 20010809
LR  - 20190513
IS  - 0019-2805 (Print)
IS  - 1365-2567 (Electronic)
IS  - 0019-2805 (Linking)
VI  - 103
IP  - 3
DP  - 2001 Jul
TI  - Endocytosis and recycling of the complex between CD23 and HLA-DR in human B 
      cells.
PG  - 319-31
AB  - The presentation of extremely low doses of antigen to T cells is enhanced by 
      immunoglobulin E (IgE)-dependent antigen focusing to CD23, the low-affinity 
      receptor for IgE, expressed on activated B cells. CD23 contains a C-type lectin 
      domain in its extracellular sequence and a targeting signal for coated pits, 
      required for endocytosis, in its cytoplasmic sequence. CD23 is non-covalently 
      associated with the major histocompatibility complex class II antigen, human 
      leucocyte antigen HLA-DR, on the surface of human B cells, but the fate of this 
      complex following endocytosis is unknown. To answer this question we have 
      labelled these proteins on the surface of RPMI 8866 B cells and traced their 
      route through the cytoplasm. Endocytosis mediated by anti-CD23 antibodies (BU38 
      and MHM6) led to the loss of CD23 from the cells. Endocytosis mediated by an 
      antibody to HLA-DR (CR3/43) or an antigen-IgE complex (NP-BSA-anti-NP IgE), 
      however, led to recycling of the HLA-DR-CD23 complex to the cell surface on a 
      time scale (3-6 hr) consistent with the recycling of HLA-DR in antigen 
      presentation. Along the latter pathway CD23 label was observed in cytoplasmic 
      organelles that resembled the 'compartments for peptide loading' or 'class II 
      vesicles' described by previous authors. Two features of the recycling process 
      may contribute to the efficiency of antigen presentation. Peptide exchange may be 
      facilitated by the proximity of HLA-DR and antigen in peptide loading 
      compartments of the endosomal network. The return of CD23 with HLA-DR to the cell 
      surface may then help to stabilize specific B-cell-T-cell interactions, 
      contributing to T-cell activation.
FAU - Karagiannis, S N
AU  - Karagiannis SN
AD  - The Randall Centre for Molecular Mechanisms of Cell Function, King's College 
      London, UK. hjg@helios.rai.kcl.ac.uk
FAU - Warrack, J K
AU  - Warrack JK
FAU - Jennings, K H
AU  - Jennings KH
FAU - Murdock, P R
AU  - Murdock PR
FAU - Christie, G
AU  - Christie G
FAU - Moulder, K
AU  - Moulder K
FAU - Sutton, B J
AU  - Sutton BJ
FAU - Gould, H J
AU  - Gould HJ
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Immunology
JT  - Immunology
JID - 0374672
RN  - 0 (Antibodies, Monoclonal)
RN  - 0 (Antigen-Antibody Complex)
RN  - 0 (HLA-DR Antigens)
RN  - 0 (Receptors, IgE)
RN  - 37341-29-0 (Immunoglobulin E)
SB  - IM
MH  - Antibodies, Monoclonal/immunology
MH  - Antigen-Antibody Complex/immunology
MH  - B-Lymphocytes/*immunology/ultrastructure
MH  - Cell Culture Techniques
MH  - Cytoplasmic Vesicles/immunology
MH  - Electrophoresis, Polyacrylamide Gel
MH  - Endocytosis/*immunology
MH  - Endosomes/immunology/ultrastructure
MH  - HLA-DR Antigens/immunology/*metabolism
MH  - Humans
MH  - Immunoglobulin E/immunology
MH  - Microscopy, Confocal
MH  - Microscopy, Electron
MH  - Receptors, IgE/immunology/*metabolism
PMC - PMC1783243
EDAT- 2001/07/17 10:00
MHDA- 2001/08/10 10:01
PMCR- 2002/07/01
CRDT- 2001/07/17 10:00
PHST- 2001/07/17 10:00 [pubmed]
PHST- 2001/08/10 10:01 [medline]
PHST- 2001/07/17 10:00 [entrez]
PHST- 2002/07/01 00:00 [pmc-release]
AID - imm1238 [pii]
AID - 10.1046/j.1365-2567.2001.01238.x [doi]
PST - ppublish
SO  - Immunology. 2001 Jul;103(3):319-31. doi: 10.1046/j.1365-2567.2001.01238.x.