摘要
B7-H3 is a recently identified member of the B7 gene family. Its ubiquitous expression in both lymphoid and nonlymphoid tissues suggests that it could play an important role in the maintenance of self-tolerance. However, the exact function of B7-H3 is still elusive. The purpose of current study is to demonstrate the possible function of soluble mouse B7-H3 for prevention of DC-mediated T cell activation. For this purpose, we established a soluble mouse B7-H3 fusion protein （mB7h3-hIg） eukaryotic expression vector （pmB7h3-hIg） with a C-terminal human IgG1 Fc. A C57BL/6 （B6）-derived dendritic cell line （DC2.4 cells） was used for the establishment of stable transfectants for generation of soluble mB7h3-hIg. Ectopic mB7h3-hIg expression was confirmed by RT-PCR, Western blot and ELISA analyses. A 49.7 kD protein was detected by Western blot from DC2.4 cells transfected with pmB7h3-hlg. It was found that soluble mB7h3-hIg expression has no effect on cell cycling and apoptosis and the expression of CD80 and CD86 of the DC2.4 cells. However, ectopic soluble mB7h3-hIg expression was found to significantly affect the allo-stimulatory capability for DC2.4 cells. DC2.4 cells expressing soluble mB7h3-hIg showed a significant reduced allo-stimulatory capability as compared with the controls determined by MLC. Further studies revealed that soluble mB7h3-hIg could also inhibit IL-2 and IFN-γ, production of allogenic T cells. These results suggested a great potential of soluble B7-H3 for treatment of graft rejection and autoimmume disease. Cellular ＆ Molecular Immunology. 2006;3（3）：235-240.
B7-H3 is a recently identified member of the B7 gene family. Its ubiquitous expression in both lymphoid and nonlymphoid tissues suggests that it could play an important role in the maintenance of self-tolerance. However, the exact function of B7-H3 is still elusive. The purpose of current study is to demonstrate the possible function of soluble mouse B7-H3 for prevention of DC-mediated T cell activation. For this purpose, we established a soluble mouse B7-H3 fusion protein （mB7h3-hIg） eukaryotic expression vector （pmB7h3-hIg） with a C-terminal human IgG1 Fc. A C57BL/6 （B6）-derived dendritic cell line （DC2.4 cells） was used for the establishment of stable transfectants for generation of soluble mB7h3-hIg. Ectopic mB7h3-hIg expression was confirmed by RT-PCR, Western blot and ELISA analyses. A 49.7 kD protein was detected by Western blot from DC2.4 cells transfected with pmB7h3-hlg. It was found that soluble mB7h3-hIg expression has no effect on cell cycling and apoptosis and the expression of CD80 and CD86 of the DC2.4 cells. However, ectopic soluble mB7h3-hIg expression was found to significantly affect the allo-stimulatory capability for DC2.4 cells. DC2.4 cells expressing soluble mB7h3-hIg showed a significant reduced allo-stimulatory capability as compared with the controls determined by MLC. Further studies revealed that soluble mB7h3-hIg could also inhibit IL-2 and IFN-γ, production of allogenic T cells. These results suggested a great potential of soluble B7-H3 for treatment of graft rejection and autoimmume disease. Cellular ＆ Molecular Immunology. 2006;3（3）：235-240.
基金
We thank Dr.Cong-Yi Wang from Georgia's Health Sciences University for his kind present of DC2.4 and for his revision to this paper.We thank Dr.Guan-Xin Shen,Xiong-Wen Wu and Zhuo-Ya Li from Tongji Medical College for their thoughtful scientific discussions.This work was supported by the National Key Basic Research Program of China from the Ministry of Science and Technology of the People's Republic of China(No.2001CB510008)
Science Foundation from the Ministry of Education of China(No.20040487056).
