[Immune tolerance inducing effects of soluble human leucocyte antigen G1 on natural killer cells and T cells].
OBJECTIVE
To investigate the immune tolerance inducing effects of soluble human leucocyte antigen G1 (sHLA-G1) on natural killer (NK) cells and T cells.


METHODS
A recombinant plasmid expressing sHLA-G1 was constructed and transfected into human lymphoblastoid cells LCL721.221. sHLA-G1 in the supernatant was purified by immuno-affinity chromatography and then added into the culture of NK cells obtained from the peripheral blood mononuclear cells of 3 unrelated individuals. Target cells, K562 cells, were added too. The killing rate of NK was calculated. Peripheral blood lymphocytes (PBLs) were obtained and stimulated by Ebstein-Barr-virus-transformed B lymphoblastoid cell line (EBV-LCL). The proliferation of the T cells in the mixed lymphocyte culture was examined by enzyme linked immunosorbent assay. The antigen-specific T cells in the peripheral blood was activated. sHLA-G1 was added into the culture. Then the T cells were suspended in the solution of fluorescence isothiocyanate (FITC)-annexin-V. Flow cytometry was used to detect the fluorescent intensity of FITC so as to examine the apoptosis of T cells.


RESULTS
sHLAG-1 inhibited the cytotoxicity of NK cells dose-dependently. sHLAG-1 inhibited the proliferation of activated T cells, and induced the apoptosis of T cells dose-dependently, with a dose-saturation character and without antigen-specificity.


CONCLUSIONS
sHLAG-1 is a kind of immune tolerance inducing molecule.
Fang
Chong-yun
CY
Institute of Immunology, Tongji Medical College, Huanzhong University of Sciences and Technology, Wuhan 430030, China.
Wu
Xiong-wen
XW
Liang
Zhi-hui
ZH
Chen
Hao
H
Han
Jun-yan
JY
Huang
Ya-fei
YF
Gong
Fei-li
FL
D017209:Apoptosis; D003602:Cytotoxicity, Immunologic; D006680:HLA Antigens / Q000502:physiology*; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D006801:Humans; D007108:Immune Tolerance; D007694:Killer Cells, Natural / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D013601:T-Lymphocytes / Q000276:immunology*
D006680:HLA Antigens; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I