Method for Preparing Cell Fraction Containing Hemangioblasts

Abstract

Mouse PCLP1 was identified by expression cloning with the use of a monoclonal antibody against a surface antigen of a cell line derived from mouse AGM. By fractionating PCLP1-positive/CD45-negative cells and culturing them in vitro, it was clarified that these cells differentiate into endothelial-like cells, angioblast-like cells, and hematopoietic cells. By transferring the PCLP1-positive/CD45-negative cells into a mouse defective in the hematopoietic function, the hematopoietic system was reconstructed over a long period of time. These facts indicate that the PCLP1-positive/CD45-negative cells contain mammalian hemangioblasts capable of expressing the activity as long-term repopulating hematopoietic stem cells (LTR-HSC). The present invention provides a method for preparing a cell fraction containing hemangioblasts, the cell fraction prepared by the method, and use of this cell fraction.

1 . A mouse-derived PCLP1 protein encoded by a DNA according to any one of the following (a) through (c):
 (a) a DNA comprising the coding region of the nucleotide sequence set forth in SEQ ID NO: 1,   (b) a DNA encoding a protein comprising the amino acid sequence set forth in SEQ ID NO: 2, or   (c) a DNA encoding a protein comprising the amino acid sequence set forth in SEQ ID NO: 2 in which one or more amino acids are substituted, deleted, inserted, and/or added.   
     
     
         2 . A polypeptide containing a partial sequence comprising at least seven or more consecutive amino acid residues at positions 1 to 405 in the amino acid sequence set forth in SEQ ID NO: 2.