Co-culture of placental cells and stem cells from a second source

Abstract

The present invention relates to a combination of placental stem cells and stem or progenitor cells derived from a second source, wherein the combination shows improved engraftment as compared to placental stem cells or stem cells from a second source, alone. The combination is referred to as a combined stem cell population. The invention also provides in vitro and in vivo methods for identifying and producing combined stem cell populations, and models of engraftment. In accordance with the present invention, the placental stem cells may be combined with, e.g., umbilical cord blood-derived stem or progenitor cells, fetal or neonatal stem cells or progenitor cells, adult stem cells or progenitor cells, hematopoietic stem cells or progenitor cells, stem or progenitor cells derived from bone marrow, etc.

1 . A combined cell population comprising a number of cells in vitro, said number of cells comprising placental perfusate cells that comprise placental stem cells, and stem cells from a second source, wherein said combined cell population, when cultured for a time and under conditions that allow the formation of colony-forming units, produces more colony-forming units than a number of placental perfusate cells equivalent to the number of cells in the combined cell population or a number of the stem cells from a second source equivalent to the number of cells in the combined cell population, alone. 
     
     
         2 . The combined cell population of  claim 1 , wherein said placental perfusate cells and stem cells from a second source show improved engraftment when introduced into a recipient compared to a number of placental perfusate cells equivalent to the number of cells in the combined cell population, or a number of stem cells from a second source equivalent to the number of cells in the combined cell population, alone. 
     
     
         3 . The combined cell population of  claim 1  comprising said placental perfusate cells and said stem cells from a second source in a ratio, out a plurality of ratios, that, when cultured under conditions allowing the formation of colony forming units, produces the most colony forming units. 
     
     
         4 . The combined cell population of  claim 1 , wherein said stem cells from a second source are cord blood stem cells, bone marrow stem cells, hematopoietic stem cells, or mesenchymal stem cells. 
     
     
         5 . The combined cell population of  claim 4 , wherein said hematopoietic stem cells are cord blood hematopoietic stem cells. 
     
     
         6 . The combined cell population of  claim 4 , wherein said hematopoietic stem cells are CD34 +  cells. 
     
     
         7 . The combined cell population of  claim 1 , wherein said placental perfusate cells comprise CD34 +  cells. 
     
     
         8 . The combined cell population of  claim 1 , wherein said placental perfusate cells comprise CD34 −  cells. 
     
     
         9 . The combined cell population of  claim 1 , wherein said placental perfusate cells comprise cells that are OCT4 +  or ABC-p + . 
     
     
         10 . The combined cell population of  claim 1 , wherein said placental perfusate cells comprise cells that are CD34 +  and cells that are OCT4 +  or ABC-p + . 
     
     
         11 . The combined cell population of  claim 1 , wherein said placental stem cells are contained within placental perfusate substantially lacking red blood cells and cellular debris. 
     
     
         12 . The combined cell population of  claim 1 , wherein said combined cell population comprises placental stem cells isolated from placental perfusate. 
     
     
         13 . The combined cell population of  claim 1 , wherein said combined cell population comprises placental stem cells isolated from enzyme-digested placental tissue. 
     
     
         14 . The combined cell population of  claim 1 , wherein said placental perfusate cells and said stem cells from a second source are obtained from the same individual. 
     
     
         15 . The combined cell population of  claim 1 , wherein said placental stem cells and said stem cells from a second source are obtained from different individuals. 
     
     
         16 . The combined cell population of  claim 1 , wherein said placental stem cells are derived from a plurality of placentas. 
     
     
         17 . The combined cell population of  claim 1 , wherein said stem cells from a second source are obtained from a plurality of individuals. 
     
     
         18 . A combined cell population comprising in vitro a number of placental perfusate cells that comprise placental stem cells, and stem cells from a second source, in a ratio, wherein the ratio of said placental perfusate cells to said stem cells from a second source is such that, when the composition is introduced into a recipient, the composition exhibits enhanced stem cell engraftment in said recipient compared to a number of placental perfusate cells equivalent to the number of cells in the combined cell population, or a number of stem cells from a second source equivalent to the number of cells in the combined cell population, alone. 
     
     
         19 . A method of transplantation, comprising transplanting to a recipient a combined cell population comprising isolated placental perfusate cells comprising a number of placental stem cells and stem cells from a second source, wherein said combined stem cell population, when transplanted, results in enhanced engraftment compared to transplantation of a number of placental stem cells equivalent to the number of cells in the combined stem cell population, or stem cells from a second source equivalent to the number of cells in the combined stem cell population, alone. 
     
     
         20 . The method of  claim 19 , wherein the combined cell population comprises placental perfusate cells and stem cells from a second source in a ratio that, when said combined cell population is cultured for a time and under conditions sufficient to allow formation of colony-forming units, produces a greater number of colony-forming units than a number of placental perfusate cells equivalent to the number of cells in the combined cell population, or a number of said stem cells from a second source equivalent to the number of cells in the combined cell population, alone. 
     
     
         21 . The method of  claim 20 , wherein said ratio is selected by selecting, within a plurality of ratios of placental perfusate cells and stem cells from a second source cultured for a time and under conditions sufficient to allow the formation of colony-forming units, a ratio that produces the greatest number of colony-forming units. 
     
     
         22 . The method of  claim 19 , wherein said stem cells from a second source are cord blood stem cells, bone marrow stem cells, hematopoietic stem cells, or mesenchymal stem cells. 
     
     
         23 . The method of  claim 19 , wherein said stem cells from a second source are hematopoietic stem cells. 
     
     
         24 . The method of  claim 23 , wherein said hematopoietic stem cells are cord blood hematopoietic stem cells. 
     
     
         25 . The method of  claim 23 , wherein said hematopoietic stem cells are CD34 +  cells. 
     
     
         26 . The method of  claim 19 , wherein said placental perfusate cells comprise CD34 +  cells. 
     
     
         27 . The method of  claim 26 , wherein said placental perfusate cells comprise cells that are CD34 +  and cells that are OCT4 +  or ABC-p + . 
     
     
         28 . The method of  claim 19  wherein said placental perfusate cells are contained within placental perfusate substantially lacking red blood cells and cellular debris. 
     
     
         29 . The method of  claim 19 , wherein said combined cell population comprises placental stem cells isolated from placental perfusate. 
     
     
         30 . The method of  claim 19 , wherein said combined cell population comprises placental stem cells isolated from enzyme-digested placental tissue. 
     
     
         31 . The method of  claim 19 , wherein said transplantation results in a statistically significantly enhanced engraftment of CD34 +  or CD45 +  cells in said recipient as compared to transplantation of a number of stem cells from a second source equivalent to the number of cells in the combined cell population alone. 
     
     
         32 . The method of  claim 19 , wherein said transplantation results in a statistically significantly higher engraftment of CD34 +  or CD45 +  cells in said recipient as compared to transplantation of a number of cord blood stem cells equivalent to the number of cells in the combined cell population alone. 
     
     
         33 . The method of  claim 22 , wherein the ratio of said placental perfusate cells and said hematopoietic stem cells is from about 1:100 to about 100:1 at the time of transplantation, as determined by total numbers of nucleated cells. 
     
     
         34 . The method of  claim 33 , wherein the ratio of said placental perfusate cells and said hematopoietic stem cells is from about 1:10 to about 10:1 at the time of transplantation, as determined by the total numbers of nucleated cells. 
     
     
         35 . A composition comprising a combined cell population in a container, wherein said combined cell population comprises a number of placental perfusate cells comprising placental stem cells, and stem cells from a second source, wherein said composition produces detectably higher engraftment in an individual receiving the composition, compared to an individual who receives said number of placental perfusate cells or said number of stem cells from a second source, alone. 
     
     
         36 . The composition of  claim 35 , wherein the container is a bag, flask, or jar. 
     
     
         37 . The composition of  claim 35 , wherein said placental perfusate cells and said stem cells from a second source are contained together in a bag. 
     
     
         38 . The composition of  claim 35 , wherein said placental perfusate cells and said stem cells from a second source are contained separately within a bag. 
     
     
         39 . The composition of  claim 35 , wherein said composition comprises one or more compounds that facilitate cryopreservation of the combined cell population. 
     
     
         40 . The composition of  claim 35 , wherein said combined stem cell population is contained within a physiologically-acceptable aqueous solution. 
     
     
         41 . The composition of  claim 40 , wherein said physiologically-acceptable aqueous solution is a 0.9% NaCl solution. 
     
     
         42 . The composition of  claim 36 , wherein said bag is a sterile plastic bag. 
     
     
         43 . The composition of  claim 42 , wherein said bag allows or facilitates intravenous administration of said combined cell population. 
     
     
         44 . The composition of  claim 35 , wherein said combined cell population comprises placental cells that are HLA-matched to said stem cells from a second source. 
     
     
         45 . The composition of  claim 35 , wherein said combined cell population comprises placental cells that are at least partially HLA-mismatched to said stem cells from a second source. 
     
     
         46 . The composition of  claim 35 , wherein said placental perfusate cells are derived from a plurality of donors. 
     
     
         47 . The composition of  claim 35 , wherein said stem cells from a second source are derived from a plurality of donors. 
     
     
         48 . The composition of  claim 35 , where said placental stem cells, said stem cells from a second source, or both have been passaged at least two times. 
     
     
         49 . The composition of  claim 35 , where said placental stem cells, said stem cells from a second source, or both have been passaged at least five times. 
     
     
         50 . The composition of  claim 35 , where said placental stem cells, said stem cells from a second source, or both have been passaged at least 10 times. 
     
     
         51 . The composition of  claim 35 , where said placental stem cells, said stem cells from a second source, or both have been passaged at least 15 times. 
     
     
         52 . The composition of  claim 35 , where said placental stem cells, said stem cells from a second source, or both have been passaged at least 20 times.