ABSTRACT
The entire S1 protein gene of five infectious bronchitis (IB) vaccine strains (JAAS, IBN, Jilin, J9, H120) used in China were compared with that of the IB field isolate CK/CH/LDL/97 I present in China. The nucleotide and deduced amino acid similarities between the five IB vaccine strains and the field strain, CK/CH/LDL/97 I, were not more than 76.4% and 78.7%, respectively. Phylogenetic analysis based on the S1 gene showed that the vaccine strains and the field strain belonged to different clusters and had larger evolutionary distances, indicating that they were of different genotypes. The five vaccine strains were used for protection test against challenge of the field isolate CK/CH/LDL/97 I. The chickens inoculated with five vaccine strains showed morbidity as high as 30%-100% after challenged with the CK/CH/ LDL/97 I strain. The organ samples at 5 days post challenge showed that the viral detection rates were 50%-90% and 10%-30% for trachea and kidney, respectively. The live attenuated vaccines only provided partial protection to the vaccinated chickens against heterologous IBV infection, CK/CH/LDL/97 I.
Subject(s)
Animals , Antibodies, Viral , Blood , Chickens , Virology , Coronavirus Infections , Infectious bronchitis virus , Classification , Genetics , Allergy and Immunology , Membrane Glycoproteins , Genetics , Phylogeny , Poultry Diseases , Spike Glycoprotein, Coronavirus , Vaccines, Attenuated , Allergy and Immunology , Viral Envelope Proteins , Genetics , Viral Vaccines , Allergy and ImmunologyABSTRACT
Objective To explore repair of spinal cord injury by neural stem cells (NSCs) modified with brain derived neurotrophic factor (BDNF) gene (BDNF-NSCs) in rats. Methods Neural stem cells modified with BDNF gene were transplanted into the complete transection site of spinal cord at the lumbar 4 (L4) level in rats. Motor function of rats' hind limbs was observed and HE and X-gal immunocytochemical staining, in situ hybridization, and retrograde HRP tracing were also performed. Results BDNF-NSCs survived and integrated well with host spinal cord. In the transplant group, some X-gal positive, NF-200 positive, GFAP positive, BDNF positive, and BDNF mRNA positive cells, and many NF-200 positive nerve fibers were observed in the injury site. Retrograde HRP tracing through sciatic nerve showed some HRP positive cells and nerve fibers near the rostral side of the injury one month after transplant and with time, they increased in number. Examinations on rats' motor function and behavior demonstrated that motor function of rats' hind limbs improved better in the transplant group than the injury group. Conclusion BDNF-NSCs can survive, differentiate, and partially integrate with host spinal cord, and they significantly ameliorate rats ' motor function of hind limbs, indicating their promising role in repairing spinal cord injury.