Cell-free expression of antibodies, antigen-binding fragments thereof, and antibody derivatives
The present technology relates to cell-free systems, methods, and kits for expressing proteins in vitro and evaluating the expressed proteins. In particular, the technology relates to cell-free systems, methods, and kits for expressing antibodies, antigen-binding fragment thereof, and antibody derivatives in vitro and evaluating the expressed antibodies, antigen-binding fragment thereof, and antibody derivatives.
1 . A method comprising:
a) assembling a linear expression template (LET) from nucleic acid sequences, wherein assembling does not include the use of cells or cell culture; and wherein assembling comprises Golden Gate assembly or Gibson assembly;
b) amplifying the LET to generate amplification products;
c) contacting the amplification products of (b) with a cell-free protein expression system (CFPS) to produce protein products;
d) characterizing the protein products of (c), wherein characterization comprises Amplified Luminescent Proximity Homogeneous Linked Immunosorbent Assay (AlphaLISA).
2 . The method of claim 1 , wherein the CFPS comprises an Escherichia coli ( E. coli ) extract.
3 . The method of claim 2 , wherein the E. coli comprises a mutation in the trxB and gor E. coli reductase genes.
4 . The method of claim 1 , wherein the nucleic acid sequences of step (a) comprise one or more of:
(i) double-stranded linear DNA encoding a variable heavy (VH) chain sequence of a target antibody;
(ii) double-stranded linear DNA encoding a variable light (VL) chain sequence of a target antibody;
(iii) double-stranded linear DNA encoding a heavy chain constant (CH1) domain of a target antibody;
(iv) double-stranded linear DNA encoding a light chain constant (CL) domain of a target antibody;
(v) double-stranded linear DNA comprising an expression vector backbone or fragments thereof.
5 . The method of claim 4 , wherein the expression vector of (v) comprises a prokaryotic expression vector.
6 . The method of claim 4 , wherein the protein products of (c) comprise antigen-binding proteins.
7 . The method of claim 6 , wherein the antigen binding proteins comprise one or more of a full-length antibody, a Fab, and a scFV.
8 . The method of claim 7 , wherein the Fab comprises a sdFab.
9 . The method of claim 1 , wherein the AlphaLISA assay comprises donor and acceptor beads, wherein the donor beads comprise a first antigen, and wherein the acceptor beads comprise a second antigen, and wherein the protein products of (c) comprise antigen-binding proteins.
10 . The method of claim 9 , wherein the first and second antigens comprise the same protein.
11 . The method of claim 9 , wherein the first and second antigens comprise different proteins.
12 . The method of claim 9 , wherein the nucleic acid sequences of step (a) comprises:
(i) double-stranded linear DNA coding for variable heavy (VH) chain domain of a target antibody and a double-stranded linear DNA coding for heavy chain constant (CH1) domain of the target antibody; or
(ii) double-stranded linear DNA coding for variable light (VL) chain sequences of the target antibody and double-stranded linear DNA coding for light chain constant (CL) domain of the target antibody.
13 . The method of claim 4 , wherein the nucleic acid sequences of step (a) are from a B-cell isolated from an immunized animal.
14 . The method of claim 4 , wherein the nucleic acid sequences of step (a) are amplified via PCR from single cells after FACS sorting.
15 . The method of claim 4 , wherein the nucleic acid sequences of step (a) are identified via in vitro selection and individual sequences are recovered after cloning and transformation of the selected sequences.
16 . The method of claim 4 wherein the nucleic acid sequences of step (a) are identified via in vitro selection and individual sequences are identified via DNA sequencing.
17 . The method of claim 4 wherein the nucleic acid sequences of step (a) are identified via computational methods for predicting protein structure and function.
18 . The method of claim 4 wherein the nucleic acids of step (a) are produced via DNA synthesis.
19 . The method of claim 1 , wherein the AlphaLISA assay comprises donor beads and acceptor beads, wherein the donor beads comprise a first protein product of step (c), wherein the first protein product of (c) comprises a VL domain and a CL domain of a target antibody; and wherein the acceptor beads comprises a second protein product of step (c), wherein the second protein product of (c) comprises a VH and a CH1 of the target antibody.
20 . The method of claim 19 , wherein the AlphaLISA further comprises an antigen that binds the target antibody.