Expanded nk cells

Abstract

The present invention relates to expanded NK cells. The NK cells have been expanded ex vivo, are activated and have a cytotoxic phenotype. The cytotoxicity against malignant cells is markedly increased compared to non-expanded NK cells. The invention also relates to a method of treatment.

1 . Natural killer (NK) cells produced by:
 (a) isolating NK cells from peripheral blood, bone marrow or cord blood of a patient suffering from multiple myeloma, and   (b) expanding the isolated NK cells ex vivo in the presence of autologous feeder cells for about 20 days, in a serum-free stem cell growth medium comprising human albumin, human recombinant insulin, L-glutamine and B-mercaptoethanol (CELLGRO SCGM), wherein said medium is supplemented with anti CD3 antibody, human serum, and IL-2 for about the first 5 days, and wherein said medium is supplemented with IL-2 and human serum for the remainder of the about 20 days whereby the expanded said NK cells have:
 (i) at least about a 100% increased cytotoxicity against multiple myeloma cells of said patient compared to freshly isolated non-expanded NK cells isolated from said patient, and 
 (ii) an upregulated expression of at least one natural cytotoxic receptor (NCR) compared to freshly isolated non-expanded NK cells isolated from said patient. 
   
     
     
         2 . The NK cells according to  claim 1 , wherein said natural cytotoxic receptor is upregulated by at least about 50% compared to freshly isolated non-expanded NK cells isolated from said patient. 
     
     
         3 . The NK cells according to  claim 1 , wherein said at least one natural cytotoxic receptor is selected from the group consisting of 2B4, CD8, CD16, CD27, CD226, NKG2D, NKp30, NKp44 and NKp46. 
     
     
         4 . The NK cells according to  claim 1 , wherein said NK cells exhibit higher degranulation activity compared to freshly isolated non-expanded NK cells isolated from said patient as determined by CD107a expression. 
     
     
         5 . A composition for treatment of multiple myeloma comprising NK cells according to  claim 1 . 
     
     
         6 . The NK cells according to  claim 3 , wherein said at least one natural cytotoxic receptor is 2B4. 
     
     
         7 . The NK cells according to  claim 6 , wherein said NK cells further have an upregulated expression of a second activating receptor compared to freshly isolated non-expanded NK cells isolated from said patient, wherein the second activating receptor is selected from the group consisting of CD8, CD16, CD27, CD226, NKG2D, NKp30, NKp44 and NKp46.