[The effects of B7H4 on human bone marrow mesenchymal stem cell inhibiting proliferation of PHA activated T cells].
OBJECTIVE
To investigate the effects of B7H4 on human bone marrow mesenchymal stem cells (HBMSC) mediating immune suppression.


METHODS
The expression of the negative immunoregulatory factor B7H4 on HBMSC were analyzed by RT-PCR and flow cytometry (FCM), respectively. The blocking experiment was used to detect the effects of B7H4 on HBMSC mediating suppression on PHA induced T cell activation, proliferation and cell cycle. HBMSC inhibiting T cell proliferation was examined by transwell cell culture system.


RESULTS
B7H4 was highly expressed on HBMSC. Blocking the B7H4 expression by B7H4mAb significantly attenuated the inhibitory effects of HBMSC on T cell proliferation. Compared with that of the unblocking group, T cell stimulator index (SI) of the B7H4 blocked group was significantly increased (53 +/- 5 vs 15 +/- 8, P < 0.01) and the inhibitory effects of HBMSC on T cell cycle were weakened significantly through down-regulating the cell number in G(0)/G(1) phase \[(85.6 +/- 9.9)% vs (95.8 +/- 9.9)%\] and up-regulating those in S phase\[(5.8 +/- 3.2)% vs (2.3 +/- 2.2)%, P < 0.05\]. The suppressive effects of HBMSC on T cell proliferation were significantly weakened after separating HBMSC from T cells by transwell cell culture system. Compared with the cell to cell contact group, T cell SI was significantly increased (27 +/- 17 vs 15 +/- 3, P < 0.01).


CONCLUSIONS
HBMSC highly express B7H4, which plays an important role in the suppressive effects of HBMSC on T cell proliferation.
Luan
Xi-Ying
XY
Department of Immunology, Binzhou Medical College, Yantai 264003, China.
Yu
Wen-Zheng
WZ
Cao
Qi-Zhi
QZ
Fu
Qiang
Q
Zhang
Hai-Xia
HX
D018122:B7-1 Antigen / Q000378:metabolism / Q000502:physiology*; D001854:Bone Marrow Cells / Q000276:immunology* / Q000378:metabolism; D002453:Cell Cycle / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D006801:Humans; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D059630:Mesenchymal Stem Cells / Q000276:immunology* / Q000378:metabolism; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1
D018122:B7-1 Antigen; D010835:Phytohemagglutinins; D060907:V-Set Domain-Containing T-Cell Activation Inhibitor 1; C475826:VTCN1 protein, human