Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface ant...Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.展开更多
Background The regulation of t-PA gene is the essence and core of thrombosis. Therefore, the present study aimed to prepare nano t-PA gene coated stent and to observe its effect on coronary stent thrombosis in dogs.Me...Background The regulation of t-PA gene is the essence and core of thrombosis. Therefore, the present study aimed to prepare nano t-PA gene coated stent and to observe its effect on coronary stent thrombosis in dogs.Methods Highly expressed t-PA gene plasmid was constructed and albumin nano t-PA gene coating stent was prepared. The major branch vessels of dog coronary artery were pre-expanded with a 3.0 mm×20 balloon with 8-10 atmospheric pressure. 10 dogs of the control group were implanted with bare metal stent; while 12 dogs of the experimental group were implanted with nano t-PA gene coating stent. Both groups were not given anti-coagulation treatments. Blood samples were taken for t-PA and D-dimer before the operation, at 1,2,4 and 8 weeks after operation. Pathological analysis found thrombosis in the cavity and the hyperplasia of the intima. t-PA expression was detected by immunohistochemical indirectly, and the thickness of the intima of the section cross was directly measured by morphometry. Liver, heart, kidneys and lung were taken for pathological observation. Results All experimental animals survived at postoperative 8 weeks. Vascular stent thrombosis was seen in 10 cases of the control group with the thrombosis rate of 100%; while was seen in 2 cases among 12 cases of the experimental group with the thrombosis rate was 16.67%（P=0.00087）. Immunohistochemical staining showed that the positive t-PA gene transfection of the experimental group was mainly distributed on the surface of hyperplasia intima, and vascular wall t-PA expression of the control group was negative. Positive t-PA signal was not found in the liver,heart, kidneys and lung. Conclusion Nano t-PA gene vector coating stent can effectively express t-PA in vascular wall and effectively prevents stent thrombosis.展开更多
文摘Hepatitis B virus (HBV) is one of the major causes of chronic hepatitis, cirrhosis and liver cancer. In combating HBV infections, HBV diagnosis and vaccination are therefore critical. The hepatitis B virus surface antigen (HBsAg) is a key target molecule in developing vaccines and diagnostic systems. To date, although HBsAg has been expressed in bacteria, yeasts and mammalian cells, there are still limitations in the existing ones, which leave the necessity for searching new HBsAg production methods. In this study, a simple phage display-based method was developed to produce the purified full-length HBsAg molecules for further immunization studies. For this purpose, the HBsAg coding gene was cloned into a pCANTAB5E phagemid vector and expressed on the surface of M13 filamentous phages. The HBsAg-expressing phage nanosystem was then used as immunization agent in BALB/cJ mice. The ELISA results for sera obtained from mice immunized with HBsAg-displaying phage particles revealed an immune response against HBsAg. These results demonstrate the potential use of a full-length antigen to be displayed on phages as cost effective adjuvant-free immunization agents as an alternative to the highly purified and more expensive antigens conjugated with carrier molecules.
基金supported by Basic research project of knowledge innovation program From Shenzhen Science and Technology Innovation Committee(No.JCYJ2015040209 4341903)
文摘Background The regulation of t-PA gene is the essence and core of thrombosis. Therefore, the present study aimed to prepare nano t-PA gene coated stent and to observe its effect on coronary stent thrombosis in dogs.Methods Highly expressed t-PA gene plasmid was constructed and albumin nano t-PA gene coating stent was prepared. The major branch vessels of dog coronary artery were pre-expanded with a 3.0 mm×20 balloon with 8-10 atmospheric pressure. 10 dogs of the control group were implanted with bare metal stent; while 12 dogs of the experimental group were implanted with nano t-PA gene coating stent. Both groups were not given anti-coagulation treatments. Blood samples were taken for t-PA and D-dimer before the operation, at 1,2,4 and 8 weeks after operation. Pathological analysis found thrombosis in the cavity and the hyperplasia of the intima. t-PA expression was detected by immunohistochemical indirectly, and the thickness of the intima of the section cross was directly measured by morphometry. Liver, heart, kidneys and lung were taken for pathological observation. Results All experimental animals survived at postoperative 8 weeks. Vascular stent thrombosis was seen in 10 cases of the control group with the thrombosis rate of 100%; while was seen in 2 cases among 12 cases of the experimental group with the thrombosis rate was 16.67%（P=0.00087）. Immunohistochemical staining showed that the positive t-PA gene transfection of the experimental group was mainly distributed on the surface of hyperplasia intima, and vascular wall t-PA expression of the control group was negative. Positive t-PA signal was not found in the liver,heart, kidneys and lung. Conclusion Nano t-PA gene vector coating stent can effectively express t-PA in vascular wall and effectively prevents stent thrombosis.
