Conditionally immortalized long-term stem cells and methods of making and using such cells

Abstract

Disclosed are methods for conditionally immortalizing stem cells, including adult and embryonic stem cells, the cells produced by such methods, therapeutic and laboratory or research methods of using such cells, and methods to identify compounds related to cell differentiation and development or to treat diseases, using such cells. A mouse model of acute myeloid leukemia (AML) and cells and methods related to such mouse model are also described.

1 .- 55 . (canceled) 
     
     
         56 . A fusion protein, comprising:
 a. a protein transduction domain of a Tat protein; and   b. a MYC protein that is attached to the protein transduction domain of the Tat protein,   wherein the fusion protein has MYC activity.   
     
     
         57 . The fusion protein of  claim 56 , wherein the Tat protein is HIV-1 Tat. 
     
     
         58 . The fusion protein of  claim 56 , wherein the MYC protein is capable of promoting in vitro cell proliferation, cell survival, or both. 
     
     
         59 . The fusion protein of  claim 56 , wherein the MYC protein comprises the amino acid sequence of SEQ ID NO: 2. 
     
     
         60 . A composition comprising:
 a. the fusion protein of  claim 56 ; and   b. a fusion protein comprising a Bcl-2 family member that inhibits apoptosis, and   the protein transduction domain of a Tat protein.   
     
     
         61 . The composition of  claim 59 , wherein the Bcl-2 family member is Bcl-2. 
     
     
         62 . The composition of  claim 61 , wherein Bcl-2 comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO: 8. 
     
     
         63 . A method for promoting one or more of cell proliferation or cell survival of one or more cells cultured in vitro comprising:
 providing to the one or more cells the fusion protein of  claim 56 ; and culturing the one or more cells in a media.   
     
     
         64 . The method of  claim 63 , wherein the culturing promotes in vitro cell proliferation, cell survival, or both; and wherein one or more of the survival or proliferation of the one or more cells is increased as compared with corresponding cells not exposed to the fusion protein or to the composition. 
     
     
         65 . The method of  claim 63 , wherein the one or more cells are immune cells. 
     
     
         66 . The method of  claim 65 , wherein the one or more immune cells are activated immune cells. 
     
     
         67 . The method of  claim 66 , wherein the one or more immune cells are T cells. 
     
     
         68 . The method of  claim 66 , wherein the one or more immune cells are B cells. 
     
     
         69 . The method of  claim 66 , wherein the one or more immune cells are NK cells. 
     
     
         70 . The method of  claim 63 , wherein the one or more cells are stem cells. 
     
     
         71 . The method of  claim 70 , wherein the one or more stem cells are hematopoietic stem cells. 
     
     
         72 . The method of  claim 70 , wherein the one or more stem cells are human stem cells. 
     
     
         73 . The method of  claim 70 , wherein the one or more stem cells are genetically modified. 
     
     
         74 . A method for promoting one or more of cell proliferation or cell survival of one or more cells cultured in vitro comprising: providing to the one or more cells the composition of  claim 60 ; and culturing the one or more cells in a media.