158results about How to "High infection efficiency" patented technology

The invention provides improved compositions and methods for achieving gene therapy in hematopoietic cells and hematopoietic precursor cells, including erythrocytes, erythroid progenitors, and embryonic stem cells. The invention further provides improved gene therapy methods for treating hematopoietic-related disorders. Retroviral gene therapy vectors that are optimized for erythroid specific expression and treatment of hemoglobinopathic conditions are disclosed.

Adenovirus serotypes differ in their natural tropism. The adenovirus serotypes 2, 4, 5 and 7 all have a natural affiliation towards lung epithelia and other respiratory tissues. In contrast, serotypes 40 and 41 have a natural affiliation towards the gastrointestinal tract. The serotypes described differ in at least capsid proteins (penton-base, hexon), proteins responsible for cell binding (fiber protein), and proteins involved in adenovirus replication. This difference in tropism and capsid protein among serotypes has led to the many research efforts aimed at redirecting the adenovirus tropism by modification of the capsid proteins.

The invention discloses a method for producing animal rabies viruses and animal rabies vaccines on a large scale. By using a bioreactor, the animal rabies viruses and the animal rabies vaccines are produced by a cell micro-carrier suspension culturing system on a large scale by the following steps of: inoculating cells for preparing the vaccine into a carrier tank containing culture solution and micro-carriers to attach the cells to the micro-carriers; growing the cells on the micro-carriers until the concentration of culture solution is 5 to 20 times the inoculation concentration under a proper culturing environment; preparing virus suspension from the rabies virus to adsorb the virus suspension to the cells; replacing cell maintenance culture solution to culture the virus under the proper culturing environment; continuously culturing for 3 to 5 days and harvesting the virus solution for the first time, wherein the solution replacement ratio is 50 percent by using a semi-continuous process; continuously culturing for 9 to 11 days and harvesting and replacing the solution once every 24 hours; and mixing the harvested virus solution and the virus solution of the bioreactor, repeatedly performing freeze-thawing twice at the constant temperature of -20 DEG C, inactivating, purifying and adding adjuvants to prepare the rabies vaccine. The method has the advantages of large production scale, high single-batch yield and relatively low production cost.

The invention discloses a method for preparing a classical swine fever (CSF) vaccine by using a cell microcarrier suspension culture system, which comprises the following steps of: (1) inoculating cells for preparing the vaccine to a carrier tank containing culture solution and a microcarrier, and uniformly mixing the cells and the microcarrier to make the cells attached to the microcarrier; (2) when the concentration after cell proliferation is 5 to 40 times of the initial inoculation concentration, inoculating CSF virus (lapinized virus) to the cells according to multiplicity of infection (M.O.I.) of the virus of 0.01-1 and reproducing the virus; and (3) mixing prepared virus liquid, adding an appropriate freeze-drying protective agent, fully and uniformly mixing, quantitatively packaging, and freeze-drying to obtain the CSF vaccine. The CSF vaccine produced by the method has the advantages of high density of cultured cells, continuous culture, high yield of the virus, high immune effect, high safety, complete immune protection on attack of violent CSF, and the like.

The invention discloses a method for preparing virus of porcine reproductive and respiratory syndrome on a large scale. In the method, the virus of the porcine reproductive and respiratory syndrome is prepared in a cell microcarrier suspension culture system by a bioreactor. The method comprises the following steps of: inoculating host cells for preparing the virus to a carrier tank containing culture solution and a microcarrier, and mixing the cells and the microcarrier uniformly to ensure that the cells are attached to the microcarrier; providing sufficient nutrients and appropriate gas environment for the cells under the appropriate culture environment to ensure that the cells are grown until the cells are in an amount which are 10 to 20 times of the inoculation concentration on the microcarrier; preparing virus suspension from the virus of the porcine reproductive and respiratory syndrome by using cell maintenance culture solution to ensure that the suspension is adsorbed to the cells; culturing the virus under the appropriate culture environment; culturing continuously for 2 to 3 days to obtain virus solution; and after the virus solution passes inspection, performing freeze thawing on the virus solution twice at the temperature of -20 DEG C, and inactivating and purifying to prepare an inactivated vaccine of the porcine reproductive and respiratory syndrome or adding a freeze-drying protective agent for freeze drying to prepare a live vaccine of the porcine reproductive and respiratory syndrome. The method has large production scale, high yield of single batch and low production cost.