[Expression of NKG2D ligands on dendritic cells at different development stages and its effect on cytotoxicity of NK cells].
OBJECTIVE
To investigate the expression of NKG2D ligands on dendritic cells(DC) at different development stages and its effect on cytotoxicity of natural killer(NK) cells.


METHODS
The monocytes were cultured into immature dendritic cells(iDC) and mature dendritic cells(mDC) with cytokines. NK cells were obtained from normal peripheral blood by CD56 antibody magnetic isolation.The expression of NKG2D ligands (MICA/B, ULBP1-3) was detected by flow cytometry. Cytotoxicity of NK cells and the NK cells blocked with anti-NKG2D mAbs against iDC and mDC was tested using LDH-releasing method.


RESULTS
IDC and mDC were of typical morphology and phenotypes. MICA, MICB, ULBP1, and ULBP3 were expressed on iDC and their expression rate was (32.39+/-8.30)%, (17.75+/-3.40)%, (26.71+/-6.48)%, (38.37+/-6.89)%, respectively. MICA and ULBP3 were expressed on mDC and their expression rate was (7.81+/-3.33)% and (8.36+/-2.42)%, respectively, which was lower than that on mDC (P<0.01). At the each E:T ratio cytotoxicity of NK cells against iDC was stronger than that against mDC (P<0.01). cytotoxicity of NK cells blocked with anti-NKG2D mAb against iDC was decreased compared with that of NK cells unblocked (P<0.05) while cytotoxicity of NK cells blocked with anti-NKG2D mAb against mDC showed no decrease compared with that of NK cells unblocked (P>0.05).


CONCLUSIONS
The expression of NKG2D ligands on iDC is higher than that on mDC, which plays an important role in the cytotoxic effect of NK cells against iDC, but has no effect on that against mDC. NKG2D-NKG2D ligands shows one of the molecular mechanisms that NK cells kill iDC selectively.
Tu
San-fang
SF
Department of Hematology, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. tusanfanghappy@21cn.com
Guo
Kun-yuan
KY
Hu
Liang-shan
LS
Mei
Jia-zhuan
JZ
Zhou
Jian
J
Sun
Ming
M
D000906:Antibodies / Q000276:immunology / Q000494:pharmacology; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic / Q000187:drug effects; D003713:Dendritic Cells / Q000378:metabolism* / Q000648:ultrastructure; D005434:Flow Cytometry; D058851:GPI-Linked Proteins; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D015395:Histocompatibility Antigens Class I / Q000378:metabolism; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D007694:Killer Cells, Natural / Q000276:immunology* / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D046529:Microscopy, Electron, Transmission; D055655:NK Cell Lectin-Like Receptor Subfamily K / Q000276:immunology
D000906:Antibodies; D058851:GPI-Linked Proteins; D015395:Histocompatibility Antigens Class I; D036341:Intercellular Signaling Peptides and Proteins; D047908:Intracellular Signaling Peptides and Proteins; C099187:MHC class I-related chain A; C098080:MICB antigen; D008565:Membrane Proteins; D055655:NK Cell Lectin-Like Receptor Subfamily K; C423231:ULBP1 protein, human; C423230:ULBP2 protein, human; C423229:ULBP3 protein, human