FcgammaRIIB-specific Fc region variant
An objective of the present invention is to provide an Fc region variant with enhanced FcγRIIb-binding activity, and/or enhanced binding selectivity to FcγRIIb compared to FcγRIIa (type R), as compared to those of a polypeptide containing an Fe region to which an amino acid alteration(s) has not been introduced; a polypeptide which includes the Fc region variant; a pharmaceutical composition containing the polypeptide; preventing therapeutic or preventive agent for immunological inflammatory diseases that includes the pharmaceutical composition; a production method thereof; and a method of enhancing FcγRIIb-binding activity and also enhancing binding selectivity to FcγRIIb compared to FcγRIIa (type R). It was found that a polypeptide containing an antibody Fc region variant that contains an amino acid sequence in which an amino-acid alteration at position 238 (EU numbering) is combined with other specific amino-acid alterations enhances FcγRIIb-binding activity, and/or enhances binding selectivity to FcγRIIb compared to FcγRIIa (type R).
1. A protein comprising an IgG Fc region variant in which the amino acid at position 238 (EU numbering) is Asp, wherein the IgG Fc region variant further comprises one of the following combinations (i) to (xxiv) (all positions by EU numbering):
(i) Asp at position 233, Asp at position 237, Asp at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(ii) Asp at position 237, Asp or Glu at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(iii) Asp at position 233, Asp at position 237, Asp at position 268, Gly at position 271, Asp at position 296, Arg at position 330, and Thr at position 332;
(iv) Asp at position 233, Asp at position 237, Ile at position 264, Gly or Ala at position 267, Glu at position 268, Gly at position 271, and Arg at position 330;
(v) Asp at position 233, Asp at position 237, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, Arg at position 330, and Thr at position 332;
(vi) Asp at position 237, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, Arg at position 330, and Thr at position 332;
(vii) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, and Gly at position 271;
(viii) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(ix) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, Arg at position 330, and Met or Leu at position 396;
(x) Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, and Arg at position 330;
(xi) Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(xii) Ile at position 264, Ala at position 267, Glu at position 268, and Gly at position 271;
(xiii) Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, and Asp at position 296;
(xiv) Asp at position 237, Ala or Gly at position 267, Glu at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(xv) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Arg at position 330, and Met or Leu at position 396;
(xvi) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 296, Gly at position 327, Arg at position 330, and Met at position 396;
(xvii) Asp at position 233, Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 272, and Asp at position 296;
(xviii) Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Pro at position 272, and Arg at position 330;
(xix) Asp at position 237, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Pro at position 272, Asp at position 296, and Arg at position 330;
(xx) Asp at position 233, Ile at position 264, Ala at position 267, Glu at position 268, and Gly at position 271;
(xxi) Asp at position 237, Gly at position 267, Asp at position 268, Gly at position 271, Asp at position 296, and Arg at position 330;
(xxii) Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, Asp at position 272, Asp at position 296;
(xxiii) Asp at position 233, Ile at position 264, Ala at position 267, Glu at position 268, Gly at position 271, and Asp at position 296; or
(xxiv) Asp at position 233, Tyr at position 234, Phe at position 235, Asp at position 237, Ile at position 264, Glu at position 265, Phe at position 266, Ala at position 267, Asp at position 268, Asp at position 269, Gly at position 271, Asp at position 272, Gln at position 274, Asp at position 296, Ala at position 326, Gly at position 327, Lys at position 330, Ser at position 331, Lys at position 332, Lys at position 333, Arg at position 334, Ala at position 355, Glu at position 356, Met at position 358, Ala at position 396, Arg at position 409, and Glu at position 419.
2. The protein of claim 1 , wherein the ratio of [KD value for FcγRIIa (type R) of a polypeptide comprising the Fc region variant]/[KD value for FcγRIIb of the polypeptide comprising the Fc region variant] is 10.0 or more, and wherein the respective KD values are determined using a surface plasmon resonance technique in which the polypeptide comprising the Fc region variant is immobilized, an extracellular domain of the respective Fcγ receptor serves as analyte, and the following conditions are used: 0.01 M HEPES pH 7.4, 0.15 M NaCl, 3 mM ethylene diamine tetraacetic acid (EDTA), 0.05% polysorbate 20, at 25° C.
3. The protein of claim 2 , wherein the ratio of [KD value for FcγRIIa (type R) of the polypeptide comprising the Fc region variant]/[KD value for FcγRIIb of the polypeptide comprising the Fc region variant] is 20.0 or more.
4. The protein of claim 1 , wherein the ratio of [KD value for FcγRIIb of a first polypeptide comprising an Fc region of SEQ ID NO: 11/[KD value for FcγRIIb of a second polypeptide comprising the Fc region variant] is 15.0 or more, wherein the first and second polypeptides are identical to each other except in their Fc regions, and wherein the respective KD values are determined using a surface plasmon resonance technique in which the first or second polypeptide, respectively, is immobilized, an extracellular domain of the respective Fcγ receptor serves as analyte, and the following conditions are used: 0.01 M HEPES pH 7.4, 0.15 M NaCl, 3 mM ethylene diamine tetraacetic acid (EDTA), 0.05% polysorbate 20, at 25° C.
5. The protein of claim 4 , wherein the ratio of [KD value for FcγRIIb of the first polypeptide/[KD value for FcγRIIb of the second polypeptide] is 50.0 or more.
6. The protein of claim 4 , wherein the ratio of [KD value for FcγRIIb of the first polypeptide/[KD value for FcγRIIb of the second polypeptide] is 100.0 or more.
7. The protein of any of claims 1 to 6 , wherein the protein comprises an IgG antibody.
8. A pharmaceutical composition comprising the protein of claim 7 .