Humanized anti-ccr2 antibodies and methods of use therefor

This application is a divisional of U.S. application Ser. No. 09/497,625, filed Feb. 3, 2000, which is a continuation-in-part of U.S. application Ser. No. 09/359,193, filed Jul. 22, 1999, which is a continuation-in-part of U.S. application Ser. No. 09/121,781, filed Jul. 23, 1998, the entire teachings of all of which are incorporated herein by reference.

Over the past several years a growing family of leukocyte chemoattractant/activating factors, termed chemokines, has been described (Oppenheim, J. J. et al., Annu. Rev. Immunol., 9:617-648 (1991); Schall and Bacon, Curr. Opin. Immunol, 6:865-873 (1994); Baggiolini, M., et al., Adv. Immunol., 55:97-179 (1994)). Members of this family are produced and secreted by many cell types in response to early inflammatory mediators such as L-1β or TNFα. The chemokine superfamily comprises two main branches: the α-chemokines (or CXC chemokines) and the β-chemokines (CC chemokines). The α-chemokine branch includes proteins such as IL-8, neutrophil activating peptide-2 (NAP-2), melanoma growth stimulatory activity (MGSA/gro or GROα), and ENA-78, each of which have attracting and activating effects predominantly on neutrophils. The members of the β-chemokine branch affect other cell types such as monocytes, lymphocytes, basophils, and eosinophils (Oppenheim, J. J. et al., Annu. Rev. Immunol., 9:617-648 (1991); Baggiolini, M., et al., Adv. Immunol., 55:97-179 (1994); Miller and Krangel, Crit. Rev. Immunol., 12:17-46 (1992); Jose, P. J., et al., J. Exp. Med., 179:881-118 (1994); Ponath, P. D., et al., J. Clin. Invest., 97:604-612 (1996)), and include proteins such as monocyte chemotactic proteins 1-4 (MCP-1, MCP-2, MCP-3, and MCP-4), RANTES, and macrophage inflammatory proteins (MIP-1α, MIP-1β). Recently a new class of membrane-bound chemokines designated CX3C chemokines has been identified (Bazan, J. F., et al., Nature 385:640-644 (1997)). Chemokines can mediate a range of pro-inflammatory effects on leukocytes, such as triggering of chemotaxis, degranulation, synthesis of lipid mediators, and integrin activation (Oppenheim, J. J. et al., Annu. Rev. Immunol., 9:617-648 (1991); Baggiolini, M., et al., Adv. Immunol., 55:97-179 (1994); Miller, M. D. and Krangel, M. S., Crit. Rev. Immunol., 12:17-46 (1992)). Lately, certain β-chemokines have been shown to suppress HIV-1 infection of human T cell lines in vitro (Cocchi, F., et al., Science (Wash. D.C.), 270:1811-1815 (1995)).

Chemokines bind to 7 transmembrane spanning (7TMS) G protein-coupled receptors (Murphy, P. M., Annu. Rev. Immunol., 12:593-633 (1994)). Some known receptors for the CC or β chemokines include CCR1, which binds MIP-1α and RANTES (Neote, K., et al., Cell, 72:415-425 (1993); Gao, J. L., J. Exp. Med., 177:1421-1427 (1993)); CCR2, which binds chemokines including MCP-1, MCP-2, MCP-3 and MCP-4 (Charo, I. F., et al., Proc. Natl. Acad. Sci. USA, 91:2752-2756 (1994); Myers, S. J., et al., J. Biol. Chem., 270:5786-5792 (1995); Gong et al., J. Biol Chem 272:11682-11685 (1997); Garcia-Zepeda et al., J. Immunol. 157:5613-5626 (1996)); CCR3, which binds chemokines including eotaxin, RANTES and MCP-3 (Ponath, P. D., et al., J. Exp. Med., 183:2437-2448 (1996)); CCR4, which has been found to signal in response to MCP-1, MIP-1α, and RANTES (Power, C. A., et al., J. Biol. Chem., 270:19495-19500 (1995)); and CCR5, which has been shown to signal in response to MIP-1α, MIP-1β, and RANTES (Boring, L., et al., J. Biol. Chem., 271 (13):7551-7558 (1996); Raport, C. J., J. Biol. Chem., 271:17161-17166 (1996); and Samson, M. et al., Biochemistry, 35:3362-3367 (1996)).

CCR2 is expressed on the surface of several leukocyte subsets, and appears to be expressed in two slightly different forms (CCR2a and CCR2b) due to alternative splicing of the mRNA encoding the carboxy-terminal region (Charo et al., Proc. Natl. Acad. Sci. USA 91:2752-2756 (1994)). MCP-1 acts upon monocytes, lymphocytes and basophils, inducing chemotaxis, granule release, respiratory burst and histamine and cytokine release. Studies have suggested that MCP-1 is implicated in the pathology of diseases such as rheumatoid arthritis, atherosclerosis, granulomatous diseases and multiple sclerosis (Koch, J. Clin. Invest. 90:772-79 (1992); Hosaka et al., Clin. Exp. Immunol. 97:451-457 (1994); Schwartz et al., Am. J. Cardiol. 71(6):9B-14B (1993); Schimmer et al., J. Immunol. 160:1466-1471 (1998); Flory et al., Lab. Invest. 69:396-404 (1993); Gong et al., J. Exp. Med. 186:131-137 (1997)). Additionally, CCR2 can act as a co-receptor for HIV (Connor et al., J. Exp. Med. 185:621-628 (1997)). Thus, CCR2 receptor antagonists may represent a new class of important therapeutic agents.

The present invention relates to an antibody (immunoglobulin) or functional fragment thereof (e.g., an antigen-binding fragment) which binds to a mammalian CC-chemokine receptor 2 (also referred to as CCR2, CKR-2, MCP-1RA or MCP-1RB) or portion of the receptor (anti-CCR2). In one embodiment, the antibody of the present invention or fragment thereof has specificity for human or rhesus CCR2 or a portion thereof. In another embodiment, the antibody or fragment of the invention blocks binding of a ligand (e.g., MCP-1, MCP-2, MCP-3, MCP-4) to the receptor and inhibits function associated with binding of the ligand to the receptor (e.g., leukocyte trafficking). For example, as described herein, antibodies and fragments thereof of the present invention which bind human or rhesus CCR2 or a portion thereof, can block binding of a chemokine (e.g., MCP-1, MCP-2, MCP-3, MCP-4) to the receptor and inhibit function associated with binding of the chemokine to the receptor. In one embodiment, the antibody is monoclonal antibody (mAb) LS132.1D9 (1D9) or an antibody which can compete with 1D9 for binding to human CCR2 or a portion of human CCR2. Functional fragments of the foregoing antibodies are also envisioned.

In another embodiment, the antibody or functional fragment of the present invention binds human CCR2 or a portion thereof, and inhibits human immunodeficiency virus (HIV) binding to the receptor, thereby inhibiting function associated with binding of HIV to the receptor (e.g., HIV antigen release and infectivity). In one embodiment, the antibody is monoclonal antibody 1D9 or an antibody which can compete with 1D9 for binding to human CCR2 or a portion of human CCR2.

The present invention also relates to an antibody or functional fragment thereof (e.g., an antigen-binding fragment) which binds to a mammalian CCR2 or portion of the receptor and provides increased fluorescent staining intensity of CCR2 or compositions comprising CCR2 relative to other anti-CCR2 antibodies. In one embodiment, the antibody is monoclonal antibody 1D9 or LS132.8G2 (8G2) or an antibody which can compete with 1D9 or 8G2 for binding to human CCR2 or a portion of human CCR2.

The present invention also relates to a humanized immunoglobulin or antigen-biding fragment thereof having binding specificity for CCR2, said immunoglobulin comprising an antigen binding region of nonhuman origin (e.g., rodent) and at least a portion of an immunoglobulin of human origin (e.g., a human framework region, a human constant region of the gamma type). In one embodiment, the humanized immunoglobulin or fragment thereof described herein can compete with 1D9 for binding to CCR2. In a preferred embodiment, the antigen binding region of the humanized immunoglobulin is derived from monoclonal antibody 1D9 (e.g., an immunoglobulin comprising the variable regions of the light and heavy chains as shown in FIG. 7 (SEQ ID NO: 9) and FIG. 8 (SEQ ID NO: 10), respectively).

For example, the humanized immunoglobulin or antigen-binding fragment thereof can comprise an antigen binding region comprising at least one complementarity determining region (CDR) of nonhuman origin, and a framework region (FR) derived from a human framework region. In one aspect, the humanized immunoglobulin having binding specificity for CCR2 comprises a light chain comprising at least one CDR derived from an antibody of nonhuman origin which binds CCR2 and a FR derived from a light chain of human origin (e.g., from HF-21/28), and a heavy chain comprising a CDR derived from an antibody of nonhuman origin which binds CCR2 and a FR derived from a heavy chain of human origin (e.g., from 4B4′CL). In another aspect, the light chain comprises three CDRs derived from the light chain of the 1D9 antibody, and the heavy chain comprises three CDRs derived from the heavy chain of the 1D9 antibody.

The present invention also relates to humanized immunoglobulin light chains and antigen-binding fragments thereof (e.g., comprising CDR1, CDR2 and CDR3 of the light chain of the 1D9 antibody, and a human light chain FR), and to humanized immunoglobulin heavy chains and antigen-binding fragments thereof (e.g., comprising CDR1, CDR2 and CDR3 of the heavy chain of the 1D9 antibody, and a human heavy chain FR). In a preferred embodiment, the invention relates to humanized heavy and light chains described herein (e.g., a humanized light chain comprising the variable region of the light chain shown in FIG. 7 (SEQ ID NO: 9), a humanized heavy chain comprising the variable region of the heavy chain shown in FIG. 8 (SEQ ID NO: 10). Also encompassed are humanized immunoglobulins comprising one or more humanized light and/or heavy chains.

The invention further relates to isolated nucleic acid molecules comprising a nucleic acid sequence which encodes a humanized immunoglobulin of the present invention (e.g., a single chain antibody), as well as to isolated nucleic acid molecules comprising a sequence which encodes a humanized immunoglobulin light chain (e.g., comprising nucleotides 52-390 of SEQ ID NO: 95) or heavy chain (e.g., comprising nucleotides 58-411 of SEQ ID NO: 96) of the present invention. For example, the present invention provides a gene (e.g., a fused gene) encoding a humanized immunoglobulin light or heavy chain comprising a first nucleic acid sequence encoding an antigen binding region derived from murine 1D9 monoclonal antibody; and a second nucleic acid sequence encoding at least a portion of a constant region of an immunoglobulin of human origin.

The present invention further relates to a construct comprising a nucleic acid molecule encoding a humanized immunoglobulin having binding specificity for CCR2 or a chain of such an immunoglobulin. For example, an expression vector comprising a gene (e.g., a fused gene) encoding a humanized immunoglobulin light chain, comprising a nucleotide sequence encoding a CDR derived from a light chain of a nonhuman antibody having binding specificity for CCR2, and a framework region derived from a light chain of human origin, is provided. An expression vector comprising a gene encoding a humanized immunoglobulin heavy chain, comprising a nucleotide sequence encoding a CDR derived from a heavy chain of a nonhuman antibody having binding specificity for CCR2, and a framework region derived from a heavy chain of human origin is another example of such a construct.

The present invention also relates to a host cell comprising a nucleic acid molecule of the present invention, including one or more constructs comprising a nucleic acid molecule of the present invention. In one embodiment, the invention relates to a host cell comprising a first recombinant nucleic acid encoding a humanized immunoglobulin light chain, and a second recombinant nucleic acid encoding a humanized immunoglobulin heavy chain, said first nucleic acid comprising a nucleotide sequence encoding a CDR derived from the light chain of murine 1D9 antibody and a framework region derived from a light chain of human origin; and said second nucleic acid comprising a nucleotide sequence encoding a CDR derived from the heavy chain of murine 1D9 antibody and a framework region derived from a heavy chain of human origin.

The present invention also provides a method of preparing a humanized immunoglobulin comprising maintaining a host cell of the present invention under conditions appropriate for expression of a humanized immunoglobulin, whereby a humanized immunoglobulin chain(s) is expressed and a humanized immunoglobulin is produced. The method can further comprise the step of isolating the humanized immunoglobulin.

The humanized immunoglobulins of the present invention can be less immunogenic than their murine or other nonhuman counterparts. Thus, the humanized immunoglobulins described herein can be used as therapeutic agents in humans, for example to control lymphocyte homing to mucosal lymphoid tissue, thereby, reducing inflammatory responses.

The invention further relates to a humanized immunoglobulin of the present invention for use in diagnosis or therapy (including prophylaxis). In one embodiment, the invention relates to a humanized immunoglobulin of the present invention for use in the treatment of diseases associated with leukocyte infiltration of tissues, for example, in the treatment of inflammatory diseases, autoimmune diseases, graft rejection, HIV infection and monocyte-mediated disorders such as atherosclerosis.

In another aspect, the invention relates to use of a humanized immunoglobulin of the present invention for the manufacture of a medicament for the treatment of diseases associated with leukocyte infiltration of tissues, for example, in the treatment of inflammatory diseases, autoimmune diseases, monocyte-mediated disorders such as atherosclerosis, graft rejection, or HIV infection.

The present invention further relates to a method of inhibiting the interaction of a cell bearing mammalian (e.g., human, non-human primate or murine) CCR2 with a ligand thereof, comprising contacting the cell with an effective amount of an antibody or functional fragment thereof which binds to a mammalian CCR2 or a portion of CCR2. Suitable cells include granulocytes, leukocytes, such as monocytes, macrophages, basophils and eosinophils, mast cells, and lymphocytes including T cells (e.g., CD8+ cells, CD4+ cells, CD25+ cells, CD45RO+ cells), and other cells expressing CCR2 such as a recombinant cell expressing CCR2 (e.g., transfected cells). In a particular embodiment, the antibody is 1D9 or an antibody which can compete with 1D9 for binding to human CCR2 or a portion of human CCR2.