Permissive cells and uses thereof

Abstract

Described are methods for determining the permissiveness of a cell for a virus that is a member of the family Arteriviridae or Coronaviridae or Asfarviridae, in particular, for Porcine Reproductive and Respiratory Syndrome Virus (PRRSV). Further described are methods and compositions related to the generation of host cells permissive for a virus that is a member of the family Arteriviridae or Coronaviridae or Asfarviridae, in particular, for PRRSV. Methods of utilzing the cells thus identified or thus generated, in preparing a culture of a virus that is a member of the family Arteriviridae or Coronaviridae or Asfarviridae, as well as the use of the virus for the purpose of vaccine production or diagnosis, are also described.

1 .- 30 . (canceled) 
     
     
         31 . A method for generating a cell that is permissive for Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the method comprising:
 treating a cell to express CD 163 and sialoadhesin proteins, thereby generating the cell that is permissive for PRRSV.   
     
     
         32 . The method according to  claim 31 , wherein treating the cell comprises introducing into the cell an exogenous nucleic acid encoding CD 163 protein. 
     
     
         33 . The method according to  claim 32 , wherein the CD163 protein encoded by the exogenous nucleic acid is at least 70% identical to porcine CD163 encoded by SEQ ID NO:1. 
     
     
         34 . The method according to  claim 32 , wherein the CD163 protein encoded by the exogenous nucleic acid includes at least one Scavenger Receptor Cysteine Rich (SRCR) domain. 
     
     
         35 . The method according to  claim 31 , wherein treating the cell comprises introducing into the cell an exogenous nucleic acid encoding sialoadhesin protein. 
     
     
         36 . The method according to  claim 35 , wherein the sialoadhesin protein encoded by the exogenous nucleic acid is at least 70% identical to porcine sialoadhesin encoded by SEQ ID NO:9. 
     
     
         37 . The method according to  claim 36 , wherein the sialoadhesin protein encoded by the exogenous nucleic acid includes at least the N-terminal domain of porcine sialoadhesin. 
     
     
         38 . The method according to  claim 31 , wherein treating the cell comprises introducing into the cell exogenous nucleic acid(s) encoding CD163 and sialoadhesin proteins. 
     
     
         39 . The method according to  claim 31 , wherein treating the cell to express CD163 and sialoadhesin proteins comprises chemical treatment. 
     
     
         40 . The method according to  claim 39 , wherein the chemical treatment results in the expression of sialoadhesin protein in the cell. 
     
     
         41 . The method according to  claim 31 , wherein the cell is selected from the group consisting of an insect cell, a yeast cell, a porcine kidney (PK) cell, a feline kidney (FK) cell, a swine testicular (ST) cell, an African green monkey kidney cell, a MA-104 cell, a MARC-145 cell, a VERO cell, a COS cell, a Chinese hamster ovary (CHO) cell, a baby hamster kidney cell, a human 293 cell, a murine 3T3 fibroblast, and a plant-cell based production platform. 
     
     
         42 . The method according to  claim 31 , wherein the cell is not an alveolar macrophage. 
     
     
         43 . A cell that is permissive for Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), generated by the method according to  claim 31 . 
     
     
         44 . The cell of  claim 33 , wherein the cell is selected from the group consisting of an insect cell, a yeast cell, a porcine kidney (PK) cell, a feline kidney (FK) cell, a swine testicular (ST) cell, an African green monkey kidney cell, a MA-104 cell, a MARC-145 cell, a VERO cell, a COS cell, a Chinese hamster ovary (CHO) cell, a baby hamster kidney cell, a human 293 cell, a murine 3T3 fibroblast, and a plant-cell based production platform. 
     
     
         45 . The cell of  claim 44 , wherein the cell is a PK-15 cell, a CHO cell, a BHK-21 cell, a MARC-145 cell, or a Hek293t cell. 
     
     
         46 . A method for producing Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the method comprising:
 infecting the cell of  claim 43  with PRRSV.   
     
     
         47 . The method according to  claim 46 , wherein the method further comprises harvesting PRRSV from the cell. 
     
     
         48 . The method according to  claim 47 , wherein the method further comprises inactivating the harvested PRRSV. 
     
     
         49 . A method to determine infection of a subject with Porcine Reproductive and Respiratory Syndrome Virus (PRRSV), the method comprising:
 contacting the cell of  claim 43  with a sample taken from the subject;   culturing the cell under conditions suitable for replication of PRRSV in the cell; and   determining the presence in the cell culture of PRRSV, wherein the presence of PRRSV indicates that the subject is infected with PRRSV.   
     
     
         50 . The method according to  claim 49 , wherein the method further comprises treating the subject for PRRSV infection.