Recombinant non-human mammalian model for hepatitis infection and immunopathogenesis

Abstract

Provided herein is a recombinant non-human mammal having an immune system including human immune cells and having a liver including human liver cells, and methods for producing the same. Also provided are methods of screening a compound for activity in treating hepatitis, comprising: administering a test compound to a recombinant non-human mammal as described herein; and then detecting the presence or absence of said activity in said mammal (e.g., by biochemical assay), said presence of said activity in said mammal indicating that said compound has activity in treating hepatitis. Methods of making fusion cells useful for the production of human monoclonal antibodies are also provided.

That which is claimed is: 
     
         1 . A recombinant non-human mammal comprising:
 (a) an immune system comprising: human T cells, human B cells, human natural killer cells, human monocytes and macrophages and human dendritic cells, so that said mammal expresses a human immune system phenotype; and   (b) a liver comprising human hepatocytes, so that said mammal expresses a human liver phenotype.   
     
     
         2 . The mammal of  claim 1 , wherein said human liver cells comprise at least 20% by volume of said liver of said mammal. 
     
     
         3 . The mammal of  claim 1 , wherein said mammal is a Rag2-gammaC double knockout mammal. 
     
     
         4 . The mammal of  claim 1 , wherein said mammal comprises non-human cells that contain a liver-specific inducible promoter operatively associated with a nucleic acid encoding a product toxic to said non-human cells. 
     
     
         5 . The mammal of  claim 4 , wherein said liver-specific inducible promoter comprises a FKBP inducible promoter and said nucleic acid encoding a product toxic to said non-human cells comprises a Caspase8 gene. 
     
     
         6 . The mammal of  claim 1 , wherein said mammal is infected with a virus. 
     
     
         7 . The mammal of  claim 1 , wherein said mammal is infected with HIV-1 virus, a hepatitis virus, or both. 
     
     
         8 . The mammal of  claim 7 , wherein said hepatitis virus is Hepatitis B virus (HBV) or Hepatitis C virus (HCV). 
     
     
         9 . The mammal of  claim 1 , wherein said mammal is a mouse. 
     
     
         10 . A method of screening a compound for activity in treating hepatitis, comprising:
 administering a test compound to the recombinant non-human mammal of  claim 1 ; and then   detecting the presence or absence of said activity in said mammal, said presence of said activity in said mammal indicating that said compound has activity in treating hepatitis.   
     
     
         11 . The method of  claim 10 , wherein said detecting step is carried out by a biochemical assay. 
     
     
         12 . A method of making a non-human transgenic mammal comprising an immune system, said immune system comprising: human T cells, human B cells, human natural killer cells, human monocytes and macrophages and human dendritic cells, so that said mammal expresses a human immune system phenotype; and a liver comprising human hepatocytes, so that said mammal expresses a human liver phenotype;
 said method comprising the steps of:   (a) providing a BalbC/Rag2 −/− γ c   −/−  double knockout transgenic mammal;   (b) transplanting human CD34+ hematopoietic stem cells into said double knockout transgenic mammal, wherein said stem cells differentiate into human T cells, human B cells, human natural killer cells, human monocytes and macrophages and human dendritic cells in said transgenic mammal; and   (c) transplanting human liver cells into said double knockout transgenic mammal, wherein said liver cells form human hepatocytes in said liver of said transgenic mammal.   
     
     
         13 . The method of  claim 12 , wherein said human CD34+ hematopoietic stem cells and said human liver cells are autogeneic with respect to each other. 
     
     
         14 . The method of  claim 12 , wherein said human liver cells comprise human parenchyma hepatoblasts. 
     
     
         15 . The method of  claim 12 , wherein said human CD34+ hematopoietic stem cells and said human liver cells are transplanted simultaneously. 
     
     
         16 . The method of  claim 12 , wherein said transplanting steps are carried out when said transgenic mammal is from 0 to 10 days old. 
     
     
         17 . The method of  claim 12 , wherein said transplanting steps are carried out when said transgenic mammal is from 1-3 days old. 
     
     
         18 . The method of  claim 12 , wherein said transgenic mammal further comprises an Alb-FKBP-Casp8 transgene. 
     
     
         19 . The method of  claim 12 , further comprising the step of administering a c-Met agonist selective for human c-Met to said transgenic animal. 
     
     
         20 . The method of  claim 19 , wherein said c-Met agonist is an agonistic antibody against human c-Met. 
     
     
         21 . The method of  claim 19 , wherein said administering step is carried out by injecting an anti-C-met antibody. 
     
     
         22 . A method of making fusion cells useful for the production of human monoclonal antibodies, said method comprising:
 isolating a human antibody-secreting B lymphocyte from a recombinant non-human mammal of  claim 1 ; and then   fusing said antibody-secreting B lymphocyte with immortal cells to form said fusion cells.   
     
     
         23 . The method of  claim 22 , wherein said immortal cell is a human or mouse myeloma cell. 
     
     
         24 . The method of  claim 22 , wherein said antibody-secreting B lymphocyte is isolated from a spleen or lymph node of said recombinant non-human mammal. 
     
     
         25 . The method of  claim 22 , wherein said mammal is infected with a virus. 
     
     
         26 . The method of  claim 22 , wherein said mammal is infected with HIV-1 virus, a hepatitis virus, or both. 
     
     
         27 . The method of  claim 26 , wherein said hepatitis virus is Hepatitis B virus (HBV) or Hepatitis C virus (HCV).