Novel anti cxcr4 antibodies and their use for the treatment of cancer

Abstract

The present invention relates to a novel isolated antibody, or the derived compounds or functional fragments of same, capable of binding to CXCR4 but also of inducing conformational changed of the CXCR4 homodimers and/or heterodimers. More particularly, the present invention relates to the 414H5 and 515H7 antibodies, specific to the CXCR4 protein, as well as their use for the treatment of cancer. Pharmaceutical compositions composed of such antibodies and a process for the selection of such antibodies are also covered.

1 . An isolated protein complex comprising a CXCR4/CXCR2 heterodimer, wherein:
 (a) the CXCR4 portion of the heterodimer comprises a polypeptide chosen from:
 (1) the amino acid sequence of SEQ ID No. 29 or the amino acid sequence of SEQ ID No. 30; 
 (2) an alternate transcriptional splice variant or a natural variant thereof having at least 95% identity with the amino acid sequence of SEQ ID No. 29 or 30; and 
 (3) a fragment of the amino acid sequence of SEQ ID No. 29 or SEQ ID No. 30 capable of being specifically recognized by SDF-1, wherein the fragment is at least 100 amino acids in length; and 
   (b) the CXCR2 portion of the heterodimer comprises a polypeptide chosen from:
 (4) the amino acid sequence of SEQ ID No. 31; 
 (5) an alternate transcriptional splice variant or a natural variant of the interleukin 8 receptor beta having at least 95% identity with SEQ ID No. 31; and 
 (6) a fragment of the amino acid sequence of SEQ ID No. 31 capable of being specifically recognized by IL-8, wherein the fragment is at least 100 amino acids in length. 
   
     
     
         2 . The isolated protein complex according to  claim 1 , wherein the CXCR4 portion of the heterodimer comprises the amino acid sequence of SEQ ID No. 29. 
     
     
         3 . The isolated protein complex according to  claim 1 , wherein the CXCR4 portion of the heterodimer comprises the amino acid sequence of SEQ ID No. 30. 
     
     
         4 . An isolated nucleic acid sequence encoding the CXCR4/CXCR2 heterodimer of  claim 1 . 
     
     
         5 . A vector comprising a nucleic acid sequence according to  claim 4 . 
     
     
         6 . A vector according to  claim 5  further comprising
 a first nucleic acid sequence encoding a first marker, wherein the first nucleic acid sequence is linked to the nucleic acid sequence encoding the CXCR4 portion of the CXCR4/CXCR2 heterodimer; and 
 a second nucleic acid sequence encoding a second marker, wherein the second nucleic acid sequence is linked to the nucleic acid sequence encoding the CXCR2 portion of the CXCR4/CXCR2 heterodimer. 
 
     
     
         7 . The vector according to  claim 6 , wherein the first nucleic acid sequence is directly linked to the sequence encoding the CXCR4 portion such that the CXCR4 portion and the first marker are encoded as a fusion protein. 
     
     
         8 . The vector according to  claim 6 , wherein the second nucleic acid sequence is directly linked to the sequence encoding the CXCR2 portion such that the CXCR2 portion and the second marker are encoded as a fusion protein. 
     
     
         9 . The vector according to  claim 6 , wherein the first marker is a luciferase marker. 
     
     
         10 . The vector according to  claim 6 , wherein the second marker is a Green Fluorescent Protein (GFP) marker or a Yellow Fluorescent Protein (YFP) marker. 
     
     
         11 . The protein complex according to  claim 1  further comprising a first marker associated with the CXCR4 portion of the heterodimer and a second marker associated with the CXCR2 portion of the heterodimer, such that the first marker and the CXCR4 portion form a fusion protein and the second marker and the CXCR2 portion form a fusion protein. 
     
     
         12 . The protein complex according to  claim 11 , wherein the first marker is a luciferase marker. 
     
     
         13 . The protein complex according to  claim 11 , wherein the second marker is a GFP marker or a YFP marker. 
     
     
         14 . The protein complex according to  claim 11 , wherein
 the CXCR4 portion of the heterodimer is a fusion protein of CXCR4 and a  Renilla  Luciferase marker; and   the CXCR2 portion of the heterodimer is a fusion protein of CXCR2 and a YFP marker.   
     
     
         15 . A method for the preparation of a recombinant host cell which expresses the CXCR4/CXCR2 heterodimer complex, wherein the method comprises the step of transforming or transfecting a host cell with the vector according to  claim 5 . 
     
     
         16 . A composition comprising a first polynucleotide encoding the CXCR4 portion of the CXCR4/CXCR2 heterodimer of  claim 1 , and a second polynucleotide encoding the CXCR2 portion of the CXCR4/CXCR2 heterodimer of  claim 1 . 
     
     
         17 . The composition according to  claim 16 , wherein at least one of the polynucleotides further comprises a vector sequence. 
     
     
         18 . The composition according to  claim 16 , wherein the first polynucleotide further comprises a nucleotide sequence encoding a first marker linked to the sequence encoding the CXCR4 portion of the heterodimer and the second polynucleotide further comprises a nucleotide sequence encoding a second marker linked to the sequence encoding the CXCR2 portion of the heterodimer. 
     
     
         19 . The composition according to  claim 18 , wherein the first nucleic acid sequence is directly linked to the sequence encoding the CXCR4 portion such that the CXCR4 portion and the first marker are encoded as a fusion protein. 
     
     
         20 . The composition according to  claim 18 , wherein the second nucleic acid sequence is directly linked to the sequence encoding the CXCR2 portion such that the CXCR2 portion and the second marker are encoded as a fusion protein. 
     
     
         21 . The composition according to  claim 18 , wherein the first marker is a luciferase marker. 
     
     
         22 . The composition according to  claim 18 , wherein the second marker is a GFP marker. 
     
     
         23 . A method for the preparation of a recombinant host cell which expresses the CXCR4/CXCR2 heterodimer complex, wherein the method comprises the step of transforming or transfecting a host cell with the composition according to  claim 16 . 
     
     
         24 . A recombinant host cell which expresses the CXCR4/CXCR2 heterodimer according to  claim 1 . 
     
     
         25 . A method for selecting a compound having anti-cancer activity, or selecting a compound that can be used for the preparation of a pharmaceutical composition for anti-cancer treatment, wherein the method comprises:
 a) contacting the recombinant host cell according to  claim 24  with the compound to be tested, and   b) determining whether the compound is capable of decreasing the activity of the CXCR4/CXCR2 heterodimer in the recombinant host cell.   
     
     
         26 . A method according to  claim 25 , wherein step b) is determining whether the test compound is capable of inhibiting the activity of the CXCR4/CXCR2 heterodimer.