Altered antibodies and their preparation

Abstract

An altered antibody chain is produced in which the CDR's of the variable domain of the chain are derived from a first mammalian species. The framework-encoding regions of DNA encoding the variable domain of the first species are mutated so that the mutated framework-encoding regions encode a framework derived from a second different mammalian species. The or each constant domain of the antibody chain, if present, are also derived from the second mammalian species.

1. An antibody which is capable of binding to human CD4 antigen, in which the CDRs of the light chain of the antibody have the amino acid sequences:
 CDR1: LASEDIYSDLA (SEQ ID NO:13) 
 CDR2: NTDTLQN (SEQ ID NO:14) 
 CDR3: QQYNNYPWT (SEQ ID NO:15) 
 
       in which the CDRs of the heavy chain of the antibody have the amino acid sequences:
 CDR1: NYGMA (SEQ ID NO:16) 
 CDR2: TISHDGSDTYFRDSVKG (SEQ ID NO:17) 
 CDR3: QGTIAGIRH (SEQ ID NO:18), and 
 
       in which the framework of the variable domain of each chain and any constant domain present in said chain are derived from a mammalian non-rat species. 
     
     
       2. An antibody according to  claim 1 , in which the mammalian non-rat species is human. 
     
     
       3. An antibody according to  claim 2 , in which the variable domain framework region of the heavy chain consists essentially of the heavy chain variable domain framework region of the protein KOL. 
     
     
       4. An antibody according to  claim 3 , in which the heavy chain variable domain has the amino acid sequence shown in the upper line in  FIG. 10  (SEQ ID NO:39) or 12 (SEQ ID NO:40). 
     
     
       5. An antibody according to  claim 2 , in which the variable domain framework region of the heavy chain consists essentially of the heavy chain variable domain framework region of the protein NEW. 
     
     
       6. An antibody according to  claim 5 , in which the heavy chain variable domain has the amino acid sequence shown in the upper line of  FIG. 6  (SEQ ID NO:41) or 7 (SEQ ID NO:42). 
     
     
       7. An antibody according to  claims 2 ,  3 ,  4 ,  5  or  6 , in which the variable domain framework of the light chain consists essentially of the variable domain framework of the protein REI. 
     
     
       8. An antibody according to  claim 7 , in which the light chain has the amino acid sequence shown in the upper line of  FIG. 3  (SEQ ID NO:43). 
     
     
       9. A pharmaceutical composition comprising a pharmaceutically acceptable carrier or diluent and, as active ingredient, an antibody as claimed in  claim 1 . 
     
     
       10. An antibody which is capable of binding to human CD4 antigen, in which the CDRs of the light chain of the antibody have the amino acid sequences:
 CDR1: LASEDIYSDLA (SEQ ID NO:13) 
 CDR2: NTDTLQN (SEQ ID NO:14) 
 CDR3: QQYNNYPWT (SEQ ID NO:15), and 
 
       in which the CDRs of the heavy chain of the antibody have the amino acid sequences:
 CDR1: NYGMA (SEQ ID NO:16) 
 CDR2: TISHDGSDTYFRDSVKG (SEQ ID NO:17) 
 CDR3: QCTIAGIRH (SEQ ID NO:18), and 
 
       in which the framework of the variable domain of each chain and the constant region of said chain are derived from a human. 
     
     
       11. An antibody according to  claim 1 , wherein the antibody has glycosylation characteristic of CHO cells. 
     
     
       12. A humanized antibody, or an antigen-binding fragment of said humanized antibody, wherein the humanized antibody comprises a light chain variable domain comprising a framework and three complementarity determining regions (CDRs) and a heavy chain variable domain comprising a framework and three CDRs, wherein:
 the amino acid sequence of the CDRs consists of the amino acid sequence of the CDRs of an antibody of a first species that is capable of binding to a human cluster of differentiation (CD) antigen, wherein the first species is a non-human mammal;   the amino acid sequence of the light chain framework, of the heavy chain framework, or of both the light and the heavy chain frameworks consists of the amino acid sequence of a selected human antibody variable region, wherein the light chain framework consists of four framework regions and the heavy chain framework consists of four framework regions;   wherein the humanized antibody differs from the antibody of a first species at least in that, for the humanized antibody:
 i.) the sequence of all four framework regions of the light chain is identical to the sequence of all four framework regions of a single selected human antibody variable region; or 
 ii.) the sequence of all four framework regions of the heavy chain is identical to the sequence of all four framework regions of a single selected human antibody variable region; or 
 iii.) both i.) and ii); and 
 wherein: 
 iv.) the selected human antibody variable region of i.) is selected from the human light chain antibody variable regions with the most overall homology to the light chain variable region of the antibody of the first species; or 
 v.) the selected human antibody variable region of ii.) is selected from the human heavy chain antibody variable regions with the most overall homology to the heavy chain variable region of the antibody of the first species; or 
 vi.) both iv.) and v.); and 
 vii.) wherein the most overall homology is determined on the basis of the respective variable domains, including at least CDR1 and CDR2; and 
   wherein the humanized antibody is capable of binding the same human CD antigen as the antibody of the first species.   
     
     
       13. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, wherein the non-human mammal is rat. 
     
     
       14. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, wherein the non-human mammal is mouse. 
     
     
       15. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, wherein the humanized antibody or fragment thereof is a (Fab′) 2  fragment. 
     
     
       16. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, wherein the humanized antibody or fragment thereof is a Fab fragment. 
     
     
       17. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, wherein the antibody has glycosylation characteristic of CHO cells. 
     
     
       18. A humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, further comprising a human light chain constant region and a human heavy chain constant region. 
     
     
       19. A pharmaceutical composition comprising a humanized antibody according to claim 12, or an antigen-binding fragment of said humanized antibody, and a pharmaceutically acceptable carrier or diluent.