Antibodies comprising modified heavy constant regions
Provided herein are heavy chain constant regions (referred to as “modified heavy chain constant regions”), or functionally equivalent fragments thereof, that enhance biological properties of antibodies relative to the same antibodies in unmodified form. An exemplary modified heavy chain constant region includes an IgG2 hinge and three constant domains (i.e., CH1, CH2, and CH3 domains), wherein one or more of the constant region domains are of a non-IgG2 isotype (e.g., IgG1, IgG3 or IgG4). The heavy chain constant region may comprise wildtype human IgG domain sequences, or variants of these sequences. Also provided herein are methods for enhancing certain biological properties of antibodies that comprise a non-IgG2 hinge, such as internalization, agonism and antagonism, wherein the method comprises replacing the non-IgG2 hinge of the antibody with an IgG2 hinge.
1. A method of preparing an antibody comprising a modified heavy chain constant region, comprising the steps of:
(a) providing an antibody comprising a hinge and/or a CH1 domain that is not an IgG2 hinge and/or IgG2 CH1 domain;
(b) replacing the hinge and/or the CH1 domain with an IgG2 hinge and/or IgG2 CH1 domain, respectively, wherein the modified heavy chain constant region comprises a CH1 domain, a hinge, a CH2 domain, and a CH3 domain in order from N- to C-terminus, wherein:
(i) the hinge comprises the amino acid sequence of SEQ ID NO: 129, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 130, or SEQ ID NO: 127;
(ii) the CH1 domain comprises the amino acid sequence of SEQ ID NO: 7;
(iii) the CH2 domain comprises the amino acid sequence of SEQ ID NO: 4 or the amino acid sequence of SEQ ID NO: 24; and
(iv) the CH3 domain comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 5 with the amino acid substitutions E356D and M358L according to the EU index as in Kabat;
or wherein the modified heavy chain constant region comprising the CH1 domain, the hinge, the CH2 domain, and the CH3 domain as defined in (i), (ii), (iii) and (iv) lacks the C-terminal GK or K.
2. A method of increasing internalization of an antibody by a cell, comprising:
(a) providing an antibody comprising a hinge and/or a CH1 domain that is not an IgG2 hinge and/or IgG2 CH1 domain;
(b) replacing the hinge and/or the CH1 domain with an IgG2 hinge and/or IgG2 CH1 domain, respectively, thereby modifying the heavy chain constant region of the antibody so that it comprises a CH1 domain, a hinge, a CH2 domain, and a CH3 domain in order from N- to C-terminus, wherein:
(i) the hinge comprises the amino acid sequence of SEQ ID NO: 129, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 130, or SEQ ID NO: 127;
(ii) the CH1 domain comprises the amino acid sequence of SEQ ID NO: 7;
(iii) the CH2 domain comprises the amino acid sequence of SEQ ID NO: 4 or the amino acid sequence of SEQ ID NO: 24; and
(iv) the CH3 domain comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 5 with the amino acid substitutions E356D and M358L according to the EU index as in Kabat;
or wherein the modified heavy chain constant region comprising the CH1 domain, the hinge, the CH2 domain, and the CH3 domain as defined in (i), (ii), (iii) and (iv) lacks the C-terminal GK or K.
3. A method of increasing the agonist activity of an antibody, comprising:
(a) providing an antibody comprising a hinge and/or a CH1 domain that is not an IgG2 hinge and/or IgG2 CH1 domain;
(b) replacing the hinge and/or the CH1 domain with an IgG2 hinge and/or IgG2 CH1 domain, respectively, thereby modifying the heavy chain constant region of the antibody so that it comprises a CH1 domain, a hinge, a CH2 domain, and a CH3 domain in order from N- to C-terminus, wherein:
(i) the hinge comprises the amino acid sequence of SEQ ID NO: 129, SEQ ID NO: 21, SEQ ID NO: 23, SEQ ID NO: 130, or SEQ ID NO: 127;
(ii) the CH1 domain comprises the amino acid sequence of SEQ ID NO: 7;
(iii) the CH2 domain comprises the amino acid sequence of SEQ ID NO: 4 or the amino acid sequence of SEQ ID NO: 24; and
(iv) the CH3 domain comprises the amino acid sequence of SEQ ID NO: 5 or SEQ ID NO: 5 with the amino acid substitutions E356D and M358L according to the EU index as in Kabat;
or wherein the modified heavy chain constant region comprising the CH1 domain, the hinge, the CH2 domain, and the CH3 domain as defined in (i), (ii), (iii) and (iv) lacks the C-terminal GK or K.
4. The method of claim 1 , wherein the antibody comprises a modified heavy chain constant region selected from the group consisting of SEQ ID NOs: 34, 35, 37, 80, 81, 84 and 159.
5. The method of claim 2 , wherein the antibody comprises a modified heavy chain constant region selected from the group consisting of SEQ ID NOs: 34, 35, 37, 80, 81, 84 and 159.
6. The method of claim 3 , wherein the antibody comprises a modified heavy chain constant region selected from the group consisting of SEQ ID NOs: 34, 35, 37, 80, 81, 84 and 159.