Preparation , expansion, and uses of adult pluripotent stem cells

Abstract

Certain relatively small cells present in the periphery blood of mammals can be activated to form pluripotent stem cell populations. These small cells are generally less than five micrometers in diameter and are CD45-positive, and are referred to herein as CD45+ cells or dormant tiny cells. Accordingly, provided are cell populations and compositions with enriched dormant tiny cells from blood samples and methods and compositions for activating these dormant tiny cells. Upon differentiation, the activated stem cells can be used for various therapeutic purposes.

1 . A composition comprising at least 1000 cells, wherein
 at least 50% of the cells are CD45 +  cells that express CD45 and have a diameter of less than 5 μm.   
     
     
         2 . The composition of  claim 1 , wherein the CD45 +  cells are further characterized as positive in CD34 and negative in ABCG2. 
     
     
         3 . The composition of  claim 1 , wherein at least 75% of the cells are CD45 +  cells. 
     
     
         4 . (canceled) 
     
     
         5 . The composition of  claim 1 , comprising at least 10,000 cells. 
     
     
         6 . The composition of  claim 1 , wherein less than 20% of the cells are red blood cells. 
     
     
         7 . (canceled) 
     
     
         8 . The composition of  claim 1 , wherein the diameter of the CD45+ cells is about 2 μm to about 3 μm. 
     
     
         9 . The composition of  claim 1 , wherein the CD45 +  cells are further characterized as negative in Lin. 
     
     
         10 . The composition of  claim 1 , wherein the CD45 +  cells comprise small RNA and ribosomal RNA at a ratio of at least about 20:1. 
     
     
         11 . The composition of  claim 1 , wherein the CD45 +  cells have a nucleus to cytoplasm ratio (v/v) that is at least about 9:1. 
     
     
         12 . The composition of  claim 1 , wherein the CD45 +  cells further express one or more markers selected from the group consisting of CD44, CD150, Sca1, c-kit, Thy1.1(CD90.1), Oct 4, SSEA1, Nanog, Vasa, CD133, and CD105. 
     
     
         13 . The composition of  claim 1 , wherein the CD45 +  cells do not express one or more markers selected from the group consisting of CD41, Lin, E-cadherin, and CD184. 
     
     
         14 . The composition of  claim 1 , wherein the CD45 +  cells can be activated to express ABCG2. 
     
     
         15 . A method of culturing cells, comprising
 culturing a plurality of mammalian cells in a medium that is in contact with or has been conditioned with at least one selected from the group consisting of primary hepatocytes, human hepatoblastoma (HepG2) cells, a hepatocyte cell line, and a mouse embryo fibroblast (MEF) cell line.   
     
     
         16 - 37 . (canceled) 
     
     
         38 . An isolated mammalian cell that expresses CD34 and ABCG2, and does not express CD45. 
     
     
         39 . The isolated mammalian cell of  claim 38 , further characterized as positive in Oct4, Nanog, and/or keratin epithelium, and negative in Lin. 
     
     
         40 . The isolated mammalian cell of  claim 38 , which further expresses one or more markers selected from the group consisting of CD117, CD29, CD44, CD73, CD90, CD105, Sca1, CD31, CD184, Nestin, and Osteocalcin. 
     
     
         41 - 43 . (canceled) 
     
     
         44 . The isolated mammalian cell of  claim 38 , wherein the cell does not express one or more markers selected from the group consisting of CD3, CD4, CD8a, CD11b, CD13, CD140a, E-cadherin, and Lin. 
     
     
         45 . The isolated mammalian cell of  claim 38 , wherein the cell is Lin − . 
     
     
         46 - 48 . (canceled) 
     
     
         49 . A stem cell derived from a cell that (a) has a diameter of less than 5 μm, (b) expresses CD45, and (c) does not express ABCG2, wherein the stem cell expresses ABCG2, and is further characterized as (a) CD34 + /CD45 + ; (b) CD34 + /CD45 − ; (c) CD34 − /CD45 + ; or (d) CD34 − /CD45 − . 
     
     
         50 - 52 . (canceled) 
     
     
         53 . A method of treating a disease or condition in a subject in need thereof, comprising administering an effective amount of the stem cell of  claim 49  to the subject. 
     
     
         54 . (canceled)