Multispecific antibodies
The present invention relates to heterodimerically-tethered bispecific protein complexes (according to the general formula of (A-X) 2 :(Y-B) 2 ) and libraries/multiplexes thereof for use in research and therapy and in particular an in vitro/ex vivo method of detecting synergistic biological function of otherwise unknown pairs of targets. Such complexes may be used to capture soluble molecules secreted from a particular cell, in therapy, in research and for experimental purposes such as in assays to characterise patient populations by identifying cell populations relevant to a pathology or prognosis.
1. A multispecific protein complex having the formula (A-X) 2 :(Y-B) 2 wherein:
A-X is a first fusion protein;
Y-B is a second fusion protein;
X:Y is a heterodimeric-tether;
: is a binding interaction between X and Y;
A is a first protein component of the multispecific protein complex which is one half of a full length antibody comprising a light chain (VLCL) paired with a full length heavy chain (VHCH1CH2CH3);
B is a second protein component of the multispecific protein complex selected from a Fab or Fab′ fragment;
X is a first binding partner of a binding pair selected from the group consisting of:
i. an antigen appended to the C-terminal of the light chain or the heavy chain of A, and
ii. an antigen inserted between CH1 and CH2 of the heavy chain of A; and
Y is a second binding partner of the binding pair independently selected from a Fab fragment, a Fab′ fragment, or a scFv appended to the C-terminal of B;
wherein Y is a scFv specific to the peptide GCN4 having SEQ ID NO:1 or amino acids 1 to 38 of SEQ ID NO:1 and wherein the scFv is 52SR4 comprising SEQ ID NO:3 or amino acids 1 to 243 of SEQ ID NO:3 or wherein X is a peptide GCN4 having SEQ ID NO:1 or amino acids 1 to 38 of SEQ ID NO:1 and wherein A and B bind to different antigens.
2. The multispecific protein complex according to claim 1 wherein X is:
the peptide GCN4 comprising SEQ ID NO: 1.
3. The multispecific protein complex according to claim 1 , wherein B is a Fab fragment.
4. The multispecific protein complex according to claim 1 , wherein X is the peptide:
a. fused via a linker to the C-terminal of the heavy chain of A or
b. inserted between CH1 and CH2 of the heavy chain of A.
5. The multispecific protein complex according to claim 1 wherein Y is:
the scFv comprising SEQ ID NO: 3.
6. The multispecific protein complex according to claim 1 , wherein Y is specific to the peptide GCN4 consisitng of (SEQ ID NO:1 or amino acids 1 to 38 of SEQ ID NO:1).
7. The multispecific protein complex according to claim 6 , wherein Y is the scFv 52SR4 consisting of (SEQ ID NO:3 or amino acids 1 to 243 of SEQ ID NO:3).
8. The multispecific protein complex according to claim 1 , wherein X or Y is a peptide GCN4 consisting of (SEQ ID NO:1 or amino acids 1 to 38 of SEQ ID NO:1).
9. The multispecific protein complex according to claim 1 , wherein the scFv has a binding affinity for the peptide GCN4 is 5 nM or 5 pM.
10. A composition comprising one or more multispecific protein complexes defined in claim 1 .
11. The multispecific protein complex according to claim 9 , wherein the X and Y has a binding affinity of 800, 700, 600, 500, 400 or 300 pM.