Novel antibody composition for isolating human cells from human-murine chimeric hematopoietic cell suspensions

Abstract

The present invention relates to an antibody composition which contains antibodies directed to murine leukocyte and murine erythroid cells. This composition is used in a novel negative selection process to enrich for human hematopoietic cells from a sample from human-murine chimeric mice. The invention also relates to kits for carrying out this process.

We claim:  
     
         1 . A negative selection process for enriching and recovering human cells in a sample containing human cells and murine cells comprising: 
 (a) reacting the sample with an antibody composition containing antibodies capable of binding to murine leukocytes under conditions such that conjugates are formed between the antibodies and murine leukocytes;    (b) removing the conjugates; and    (c) recovering a cell population which is enriched in human cells and depleted of murine leukocytes.    
     
     
         2 . A process according to  claim 1  further comprising adding antibodies capable of binding to murine erythroid cells in step (a) and recovering a cell population which is enriched in human cells and depleted of murine hematopoietic cells in step (c).  
     
     
         3 . A process according to  claim 1  wherein the antibody capable of binding to murine leukocytes is a murine anti-CD45 antibody.  
     
     
         4 . A process according to  claim 2  wherein the antibody capable of binding to murine erythroid cells is TER119.  
     
     
         5 . A process according to  claim 2  wherein the antibodies are monoclonal antibodies.  
     
     
         6 . A process as claimed in  claim 5  wherein the antibodies are labelled with a marker or they are conjugated to a matrix.  
     
     
         7 . A process as claimed in  claim 5  wherein the antibodies are labelled with biotin or fluorochrome.  
     
     
         8 . A process as claimed in  claim 6  wherein the matrix is magnetic beads, a panning surface, dense particles for density centrifugation, an adsorption column, or an adsorption membrane.  
     
     
         9 . A process as claimed in  claim 8 , wherein each of the monoclonal antibodies to the murine leukocytes and murine erythroid cells is incorporated in a tetrameric antibody complex wherein each tetrameric antibody complex comprises a first monoclonal antibody of a first animal species can bind either leukocytes or erythroid cells, and a second monoclonal antibody of the first animal species which is capable of binding to at least one antigen on the surface of a matrix, which have been conjugated to form a cyclic tetramer with two monoclonal antibodies of a second animal species directed against the Fc-fragments of the antibodies of the first animal species.  
     
     
         10 . A process as claimed in  claim 9  wherein each of the monoclonal antibodies is biotinylated and coupled to a separation matrix via a tetrameric antibody complex which recognises biotin and the matrix.  
     
     
         11 . An antibody composition comprising an antibody specific for murine leukocytes and an antibody specific for murein erythroid cells.  
     
     
         12 . An antibody composition according to  claim 11  wherein the antibody specific for the murine leukocytes is murine anti-CD45.  
     
     
         13 . An antibody composition according to  claim 11  wherein the antibody specific for the murine leukocytes is an anti-MHC-I antibody.  
     
     
         14 . An antibody composition according to  claim 11  wherein the antibody capable of binding the murine erythroid cells is TER119.