[Study of paired immunoglobin-like receptor B expression on dendritic cells and its relationship with immune tolerance in mouse].
OBJECTIVE
To investigate the expression of paired immunoglobin-like receptor B (PIR-B) on dendritic cells (DCs) and its relationship with tolerogenic DCs (T-DCs) in mouse.


METHODS
DC2.4 cells, an immature dendritic cell line derived from C57BL/6 mouse, were stimulated by lipopolysaccharide (LPS) for 48 h to induce the mature dendritic cells (mDC) and cultured respectively with the recombined mouse interleukin-10 (rmIL-10) or recombined human transforming growth factor beta1 (rhTGF-beta1) to develop the tolerogenic dendritic cells (T-DC). Special small interference RNA (siRNA) molecular of PIR-B was chemically synthesized and transfected into DC2.4 cells (si-DC) by lip2000. The expression of PIR-B on DC2.4 cells was measured by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blot. The allogeneic lymphocyte proliferative capacity of DCs was measured by mixed lymphocyte reaction (MLR) using 3H-thymidine incorporation test. The concentration of IFN-gamma in supernatants of MLR was analyzed by ELISA.


RESULTS
Semi-quantitative RT-PCR and Western blot showed that PIR-B mRNA and protein were expressed on DC2.4 cells. RmIL-10 and rhTGF-beta1 induced the higher PIR-B mRNA and protein level on T-DCs (Relative values were 0.51 +/- 0.08 and 0.58 +/- 0.23; 0.85 +/- 0.07 and 0.87 +/- 0.14; 0.79 +/- 0.10 and 0.85 +/- 0.34, respectively) (P < 0.05). LPS down-regulated the PIR-B expression on mDC (0.35 +/- 0.10 and 0.32 +/- 0.04) (P < 0.05). The PIR-B mRNA and protein expression were inhibited by siRNA transfection (decreased by 78.9% and 74.2% respectively after 48 h interference) (P < 0.05). DC2.4 cells stimulated the proliferation of BALB/c mouse allo-genetic spleen cell. The mDC enhanced alloreactivity in MLR and the IFN-gamma secretion in supernatants. The T-DCs alleviated the allo-genetic spleen cell proliferation (P < 0.05) and IFN-gamma secretion in MLR (P < 0.05). Silence of the PIR-B expression (si-DC) also promoted of alloreactivity and enhanced the IFN-gamma secretion in MLR (P < 0.05).


CONCLUSIONS
High expression of immune inhibition receptor PIR-B is one of the general features and molecular mechanism of dendritic cells to acquire immune tolerance in mouse.
Liu
Zheng-Rong
ZR
Institute of Hematology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China.
Zhang
Min
M
Li
Wei-Ming
WM
Zhou
Hao
H
Zou
Ping
P
D000818:Animals; D002460:Cell Line; D003713:Dendritic Cells / Q000276:immunology / Q000378:metabolism*; D007108:Immune Tolerance; D016753:Interleukin-10 / Q000494:pharmacology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D034741:RNA, Small Interfering / Q000235:genetics; D011971:Receptors, Immunologic / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D014162:Transfection; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
D008562:Membrane Glycoproteins; C105949:Pirb protein, mouse; D034741:RNA, Small Interfering; D011971:Receptors, Immunologic; D053773:Transforming Growth Factor beta1; D016753:Interleukin-10