Patent ID: 8883507

Claim:
A method of producing at least one permanently conditionally immortalized hematopoietic stem cell in vitro, comprising: a) transducing at least one hematopoietic stem cell with: a first vector comprising a nucleic acid sequence encoding a MYC-ER molecule, and a second vector comprising a nucleic acid sequence encoding a Bcl-2 b) inducing one or more of the expression, or the activity of the MYC-ER molecule in the at least one hematopoietic stem cell; and c) culturing the at least one hematopoietic stem cell in media comprising at least one of: stem cell factor (SCF), thrombopoietin (TPO), insulin-like growth factor 2 (IGF-2), fibroblast growth factor 1 (FGF-1), or a combination thereof; d) wherein following b), the at least one hematopoietic stem cell retains multi-potent differentiation potential in the absence of one or more of the induced expression, or activity of the MYC-ER molecule, while maintaining an amount of a Bcl-2 protein in the at least one hematopoietic stem cell, and wherein inducing the expression or activity of the MYC-ER molecule comprises contacting the hematopoietic stem cell with: 4-hydroxytamoxifen (4-OHT) or an agonist thereof.