Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system...Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system using the poly-γ- glutamate synthetase A （pgsA） protein of Bacillus subtilis as an anchoring matrix to express recombinant fusion proteins of pgsA and nucleocapsid protein of TGEV in Lactobacillus casei. Surface location of fusion protein was verified by ELISA and indirect immunofluorescence test. Oral and intranasal inoculations of pregnant sow and mice with recombinant L. casei resulted in high levels of serum immunoglobulin G （IgG） and secretory immunoglobulin A （slgA） against recombinant N protein as demonstrated by ELISA. More importantly, the level of specific slgA in colostrum significantly increased compared with that of IgG. The serum IgG levels of the piglets increased after suckling colostrum produced by sows was previously inoculated with recombinant L. casei. These results indicate that immunization with recombinant L. casei expressing TGEV N protein on its surface elicited high levels of specific slgA and circulating IgG against TGEV N protein.展开更多
Background Fibroblast growth factor 9 （FGF9）, expressed in brain, kidney and developing skeletal tissues, can physiologically inhibit endochondral ossification; but little is known about how FGF9 affects osteoblasts...Background Fibroblast growth factor 9 （FGF9）, expressed in brain, kidney and developing skeletal tissues, can physiologically inhibit endochondral ossification; but little is known about how FGF9 affects osteoblasts and its detailed regulatory mechanism. Here we examined the effect of FGF9 on the activity of the murine Runt-related transcription factor2 （Runx2） gene promoter in preosteoblast MC3T3-E1 and premyoblast C2C12 cells. Methods Plasmids containing the Runx2 promoter region were transfected into MC3T3-E1 and C2C12 cells and stably transfected cell lines were established. The method of luciferase reporter gene activation was used to examine the effects of FGF9 on the promoter activity. Results FGF9 （10 ng/ml） increased Runx2 promoter activity in MC3T3-E1 cells. When MC3T3-E1 cells were treated with FGF9 plus the various inhibitors or activator of the intracellular signaling transducation pathways, including 10 μmol/L U0126 （the inhibitor of mitogen-activated protein kinase kinase）, 10 pmol/L SB203580 （the inhibitor of p38/mitogen activated protein kinase）, or 1 pmol/L C6 ceramide （an activator of mitogen activated protein kinase）, the luciferase expression did not change significantly compared with that of the cells treated with FGF9 only. However, when C2C12 cells were treated with 10 ng/ml FGF9, Runx2. gene promoter activity first decreased and then increased over a period of 1 to 5 days. Among the above inhibitors, only U0126 （10 μmol/L） completely blocked the effects of FGF9 on Runx2 gene promoter activity. Conclusions Our data showed that FGF9 can affect Runx2 gene promoter activity in MC3T3-E1 and C2C12 cells. The action of FGF9 appears to depend partly on the mitogen-activated protein kinase kinase/mitogen-activated protein kinase pathways in C2C12 cells.展开更多
基金supported by the fund of the Key Science and Technology Research during the 10th Five-Year-Plan period in Heilongjiang Province, China(GB05B501-2).
文摘Mucosal immunity plays an important role in protecting pigs against transmissible gastroenteritis virus （TGEV） infection. To elicit mucosal immune response against TGEV, we developed a surface antigen display system using the poly-γ- glutamate synthetase A （pgsA） protein of Bacillus subtilis as an anchoring matrix to express recombinant fusion proteins of pgsA and nucleocapsid protein of TGEV in Lactobacillus casei. Surface location of fusion protein was verified by ELISA and indirect immunofluorescence test. Oral and intranasal inoculations of pregnant sow and mice with recombinant L. casei resulted in high levels of serum immunoglobulin G （IgG） and secretory immunoglobulin A （slgA） against recombinant N protein as demonstrated by ELISA. More importantly, the level of specific slgA in colostrum significantly increased compared with that of IgG. The serum IgG levels of the piglets increased after suckling colostrum produced by sows was previously inoculated with recombinant L. casei. These results indicate that immunization with recombinant L. casei expressing TGEV N protein on its surface elicited high levels of specific slgA and circulating IgG against TGEV N protein.
文摘Background Fibroblast growth factor 9 （FGF9）, expressed in brain, kidney and developing skeletal tissues, can physiologically inhibit endochondral ossification; but little is known about how FGF9 affects osteoblasts and its detailed regulatory mechanism. Here we examined the effect of FGF9 on the activity of the murine Runt-related transcription factor2 （Runx2） gene promoter in preosteoblast MC3T3-E1 and premyoblast C2C12 cells. Methods Plasmids containing the Runx2 promoter region were transfected into MC3T3-E1 and C2C12 cells and stably transfected cell lines were established. The method of luciferase reporter gene activation was used to examine the effects of FGF9 on the promoter activity. Results FGF9 （10 ng/ml） increased Runx2 promoter activity in MC3T3-E1 cells. When MC3T3-E1 cells were treated with FGF9 plus the various inhibitors or activator of the intracellular signaling transducation pathways, including 10 μmol/L U0126 （the inhibitor of mitogen-activated protein kinase kinase）, 10 pmol/L SB203580 （the inhibitor of p38/mitogen activated protein kinase）, or 1 pmol/L C6 ceramide （an activator of mitogen activated protein kinase）, the luciferase expression did not change significantly compared with that of the cells treated with FGF9 only. However, when C2C12 cells were treated with 10 ng/ml FGF9, Runx2. gene promoter activity first decreased and then increased over a period of 1 to 5 days. Among the above inhibitors, only U0126 （10 μmol/L） completely blocked the effects of FGF9 on Runx2 gene promoter activity. Conclusions Our data showed that FGF9 can affect Runx2 gene promoter activity in MC3T3-E1 and C2C12 cells. The action of FGF9 appears to depend partly on the mitogen-activated protein kinase kinase/mitogen-activated protein kinase pathways in C2C12 cells.
