IgM Fc AND J-CHAIN MUTATIONS THAT AFFECT IgM SERUM HALF-LIFE

Abstract

This disclosure provides an IgM antibody or IgM-like antibody comprising a variant J-chain and/or variant IgM heavy chain constant regions that can confer increased serum half-life upon the antibody.

What is claimed is: 
     
         1 . A IgM antibody or IgM-like antibody with enhanced serum half-life comprising five bivalent antibody binding units or variants or fragments thereof and a J-chain or functional fragment thereof,
 wherein each binding unit comprises two IgM heavy chain constant regions or fragments or variants thereof, each associated with an antigen-binding domain or subunit thereof,   wherein the J-chain or functional fragment thereof comprises one or more single amino acid substitutions, deletions, or insertions relative to a wild-type J-chain that can affect serum half-life of the IgM antibody or IgM-like antibody; and   wherein the IgM antibody or IgM-like antibody exhibits an increased serum half-life upon administration to an animal relative to a reference IgM antibody or IgM-like antibody that is identical except for the one or more single amino acid substitutions, deletions, or insertions, and is administered in the same way to the same animal species.   
     
     
         2 . The IgM antibody or IgM-like antibody of  claim 1 , wherein the J-chain or functional fragment thereof comprises an amino acid substitution at the amino acid position corresponding to amino acid Y102 of the wild-type human J-chain (SEQ ID NO: 2). 
     
     
         3 . The IgM antibody or IgM-like antibody of  claim 2 , wherein the amino acid corresponding to Y102 of SEQ ID NO: 2 is substituted with alanine (A), serine (S) or arginine (R). 
     
     
         4 . The IgM antibody or IgM-like antibody of  claim 3 , wherein the amino acid corresponding to Y102 of SEQ ID NO: 2 is substituted with alanine (A). 
     
     
         5 . The IgM antibody or IgM-like antibody of  claim 4 , wherein the J-chain is a variant human J-chain and comprises the amino acid sequence SEQ ID NO: 3. 
     
     
         6 . The IgM antibody or IgM-like antibody of  claim 1 , wherein the J-chain or functional fragment thereof comprises an amino acid substitution at the amino acid position corresponding to amino acid N49 or amino acid S51 of the human J-chain (SEQ ID NO: 2), wherein S51 is not substituted with threonine (T), or wherein the J-chain comprises amino acid substitutions at the amino acid positions corresponding to both amino acids N49 and S51 of the human J-chain (SEQ ID NO: 2). 
     
     
         7 . The IgM antibody or IgM-like antibody of  claim 6 , wherein the position corresponding to N49 of SEQ ID NO: 2 is substituted with alanine (A), glycine (G), threonine (T), serine (S) or aspartic acid (D). 
     
     
         8 . The IgM antibody or IgM-like antibody of  claim 7 , wherein the position corresponding to N49 of SEQ ID NO: 2 is substituted with alanine (A). 
     
     
         9 . The IgM antibody or IgM-like antibody of  claim 8 , wherein the J-chain is a variant human J-chain and comprises the amino acid sequence SEQ ID NO: 4. 
     
     
         10 . The IgM antibody or IgM-like antibody of  claim 6 , wherein the position corresponding to S51 of SEQ ID NO: 2 is substituted with alanine (A) or glycine (G). 
     
     
         11 . The IgM antibody or IgM-like antibody of  claim 10 , wherein the position corresponding to S51 of SEQ ID NO: 2 is substituted with alanine (A). 
     
     
         12 . The IgM antibody or IgM-like antibody of  claim 11 , wherein the J-chain is a variant human J-chain and comprises the amino acid sequence SEQ ID NO: 5. 
     
     
         13 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  12 , which further exhibits an increased peak plasma concentration (Cmax), an increased area under the curve (AUC), a reduced clearance time, or any combination thereof relative to the reference antibody. 
     
     
         14 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  13 , wherein the IgM heavy chain constant regions or fragments or variants thereof each comprise a Cμ4 and an IgM tailpiece (tp) domain. 
     
     
         15 . The IgM antibody or IgM-like antibody of  claim 14 , wherein the IgM heavy chain constant regions or fragments or variants thereof further comprise a Cμ3 domain, a Cμ2 domain, a Cμ1 domain, or any combination thereof. 
     
     
         16 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  15 , wherein the antigen-binding domain comprises a single-chain Fv (ScFv) fragment, or a single domain variable region (VHH). 
     
     
         17 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  15 , wherein the antigen-binding domain subunit comprises a heavy chain variable region (VH). 
     
     
         18 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  17 , wherein each binding unit further comprises two light chain constant regions or fragments or variants thereof each associated with an antigen-binding domain or subunit thereof. 
     
     
         19 . The IgM antibody or IgM-like antibody of  claim 18 , wherein the light chain constant regions are kappa or lambda light chain constant regions or fragments or variants thereof, and wherein antigen binding domain comprises an ScFv fragment or the antigen binding domain subunit comprises a light chain variable region (VL). 
     
     
         20 . The IgM antibody or IgM-like antibody of any one of  claims 1  to  19 , wherein the J-chain or functional fragment thereof further comprises a heterologous polypeptide, wherein the heterologous polypeptide is directly or indirectly fused to the J-chain or functional fragment thereof. 
     
     
         21 . The IgM antibody or IgM-like antibody of  claim 20 , wherein the heterologous polypeptide is fused to the J-chain or fragment thereof via a peptide linker. 
     
     
         22 . The IgM antibody or IgM-like antibody of  claim 21 , wherein the peptide linker comprises at least 5 amino acids, but no more than 25 amino acids. 
     
     
         23 . The IgM antibody or IgM-like antibody of  claim 22 , wherein the peptide linker consists of GGGGS (SEQ ID NO: 10), GGGGSGGGGS (SEQ ID NO: 11), GGGGSGGGGSGGGGS (SEQ ID NO: 12), GGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 13), or GGGGSGGGGSGGGGSGGGGSGGGGS (SEQ ID NO: 14). 
     
     
         24 . The IgM antibody or IgM-like antibody of  claims 20  to  23 , wherein the heterologous polypeptide is fused to the N-terminus of the J-chain or fragment thereof, the C-terminus of the J-chain or fragment thereof, or to both the N-terminus and C-terminus of the J-chain or fragment thereof. 
     
     
         25 . The IgM antibody or IgM-like antibody of  claims 20  to  24 , wherein the heterologous polypeptide comprises a binding domain. 
     
     
         26 . The IgM antibody or IgM-like antibody of  claim 25 , wherein the binding domain of the heterologous polypeptide is an antibody or antigen-binding fragment thereof. 
     
     
         27 . The IgM antibody or IgM-like antibody of  claim 26 , wherein the antigen-binding fragment comprises an Fab fragment, an Fab′ fragment, an F(ab′)2 fragment, an Fd fragment, an Fv fragment, a single-chain Fv (scFv) fragment, a disulfide-linked Fv (sdFv) fragment, or any combination thereof. 
     
     
         28 . The IgM antibody or IgM-like antibody of  claim 27 , wherein the antigen-binding fragment is a scFv fragment. 
     
     
         29 . The IgM antibody or IgM-like antibody of any one of  claims 25  to  28  wherein the heterologous polypeptide can specifically bind to CD3ε. 
     
     
         30 . The IgM antibody or IgM-like antibody of  claim 29 , wherein the J-chain is a variant of the modified J-chain of SEQ ID NO: 6 (V15J), comprising the amino acid sequence of SEQ ID NO: 7 (V15J-Y102A) or SEQ ID NO: 8 (V15J-N49A). 
     
     
         31 . A composition comprising the IgM antibody or IgM-like antibody of any one of  claims 1  to  30 , and a pharmaceutically acceptable carrier. 
     
     
         32 . A J-chain or functional fragment thereof comprising one or more single amino acid substitutions, deletions, or insertions relative to a wild-type J-chain that can affect the serum half-life of an IgM antibody or IgM-like antibody comprising the J-chain. 
     
     
         33 . The J-chain of  claim 32 , comprising SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7, SEQ ID NO: 8, or any combination thereof. 
     
     
         34 . An isolated polynucleotide comprising a nucleic acid encoding the J-chain or functional fragment thereof of  claim 32  or  claim 33 . 
     
     
         35 . An expression vector comprising the polynucleotide of any one of  claims 32  to  34 . 
     
     
         36 . A host cell comprising the expression vector of  claim 35 . 
     
     
         37 . The host cell of  claim 36 , further comprising one or more expression vectors capable of expressing an IgM or IgM-like heavy chain and an antibody light chain or fragment, variant, or derivative thereof, wherein the host cell can express the IgM antibody or IgM-like antibody of any one of  claims 1  to  30 .