1
|
Segaliny AI, Jayaraman J, Chen X, Chong J, Luxon R, Fung A, Fu Q, Jiang X, Rivera R, Ma X, Ren C, Zimak J, Hedde PN, Shang Y, Wu G, Zhao W. A high throughput bispecific antibody discovery pipeline. Commun Biol 2023; 6:380. [PMID: 37029216 PMCID: PMC10082157 DOI: 10.1038/s42003-023-04746-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/22/2023] [Indexed: 04/09/2023] Open
Abstract
Bispecific antibodies (BsAbs) represent an emerging class of immunotherapy, but inefficiency in the current discovery has limited their broad clinical availability. Here we report a high throughput, agnostic, single-cell-based functional screening pipeline, comprising molecular and cell engineering for efficient generation of BsAb library cells, followed by functional interrogation at the single-cell level to identify and sort positive clones and downstream sequence identification and functionality characterization. Using a CD19xCD3 bispecific T cell engager (BiTE) as a model, we demonstrate that our single-cell platform possesses a high throughput screening efficiency of up to one and a half million variant library cells per run and can isolate rare functional clones at a low abundance of 0.008%. Using a complex CD19xCD3 BiTE-expressing cell library with approximately 22,300 unique variants comprising combinatorially varied scFvs, connecting linkers and VL/VH orientations, we have identified 98 unique clones, including extremely rare ones (~ 0.001% abundance). We also discovered BiTEs that exhibit novel properties and insights to design variable preferences for functionality. We expect our single-cell platform to not only increase the discovery efficiency of new immunotherapeutics, but also enable identifying generalizable design principles based on an in-depth understanding of the inter-relationships between sequence, structure, and function.
Collapse
Affiliation(s)
| | - Jayapriya Jayaraman
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Xiaoming Chen
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | | | - Ryan Luxon
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - Audrey Fung
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - Qiwei Fu
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - Xianzhi Jiang
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | | | - Xiaoya Ma
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - Ci Ren
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - Jan Zimak
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, 92697, USA
| | - Per Niklas Hedde
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92697, USA
| | - Yonglei Shang
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA
| | - George Wu
- Amberstone Biosciences, Inc., Irvine, CA, 92618, USA.
| | - Weian Zhao
- Department of Biomedical Engineering, University of California, Irvine, Irvine, CA, 92697, USA.
- Department of Pharmaceutical Sciences, University of California, Irvine, Irvine, CA, 92697, USA.
- Sue and Bill Gross Stem Cell Research Center, University of California, Irvine, Irvine, CA, 92697, USA.
- Chao Family Comprehensive Cancer Center, University of California, Irvine, Irvine, CA, 92697, USA.
- Edwards Life Sciences Center for Advanced Cardiovascular Technology, University of California, Irvine, Irvine, CA, 92697, USA.
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92697, USA.
- Institute for Immunology, University of California, Irvine, Irvine, CA, 92697, USA.
| |
Collapse
|
2
|
Kiguchi Y, Morita I, Yamaki K, Takegami S, Kobayashi N. Framework-Directed Amino-Acid Insertions Generated over 55-Fold Affinity-Matured Antibody Fragments That Enabled Sensitive Luminescent Immunoassays of Cortisol. Biol Pharm Bull 2023; 46:1661-1665. [PMID: 38044090 DOI: 10.1248/bpb.b23-00656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2023]
Abstract
We generated three single-chain Fv fragments (scFvs) specific to cortisol according to our original affinity-maturation strategy and verified their utility in developing immunoassays. These scFv mutants (m-scFvs) had insertion of one, four, or six amino acid(s) in the framework region 1 of the VH-domain and showed >55-fold higher affinity (Ka, 2.0 - 2.2 × 1010 M-1) than the unmodified scFv (wt-scFv). Each m-scFv was fused with NanoLuc luciferase (NLuc) for the use in enzyme-linked immunosorbent assays (ELISAs). In these ELISA, the m-scFv-NLuc fusions were competitively reacted with immobilized cortisol residues and cortisol standards, and then the bound NLuc activity was monitored luminometrically. The luminescent ELISAs generated dose-response curves with extremely low midpoints (approx. 3 pg/assay) and were >150-fold more sensitive than the colorimetric ELISAs using wt-scFv and >8000-fold more sensitive than the ELISA using the parental native antibody. The luminescent ELISAs showed acceptable cross-reactivity patterns with related steroids, and the determination of control sera afforded cortisol levels in the reference range with satisfactory parallelism.
Collapse
Affiliation(s)
- Yuki Kiguchi
- Kobe Pharmaceutical University
- Kyoto Pharmaceutical University
| | | | | | | | | |
Collapse
|
3
|
Kiguchi Y. A Novel System for Discovering High-affinity Antibody Mutants That Enables Immunoassays with Higher Sensitivities —Development and Application of Clonal Array Profiling (CAP)—. YAKUGAKU ZASSHI 2022; 142:1153-1159. [DOI: 10.1248/yakushi.22-00141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
4
|
Antoine D, Mohammadi M, McDermott CE, Walsh E, Johnson PA, Wawrousek KE, Wall JG. Isolation of SARS-CoV-2-blocking recombinant antibody fragments and characterisation of their binding to variant spike proteins. FRONTIERS IN NANOTECHNOLOGY 2022. [DOI: 10.3389/fnano.2022.1028186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
COVID-19 is a severe acute respiratory disease caused by SARS-CoV-2. From its initial appearance in Wuhan, China in 2019, it developed rapidly into a global pandemic. In addition to vaccines, therapeutic antibodies play an important role in immediately treating susceptible individuals to lessen severity of the disease. In this study, phage display technology was utilised to isolate human scFv antibody fragments that bind the receptor-binding domain (RBD) of SARS-CoV-2 Wuhan-Hu-1 spike protein. Of eight RBD-binding scFvs isolated, two inhibited interaction of RBD with ACE2 protein on VeroE6 cells. Both scFvs also exhibited binding to SARS-CoV-2 Delta variant spike protein but not to Omicron variant spike protein in a Raman spectroscopy immunotest. The study demonstrates the potential of recombinant antibody approaches to rapidly isolate antibody moieties with virus neutralisation potential.
Collapse
|
5
|
Kiguchi Y, Morita I, Tsuruno A, Kobayashi N. Retrieving Dissociation-Resistant Antibody Mutants: An Efficient Strategy for Developing Immunoassays with Improved Sensitivities. Biol Pharm Bull 2022; 45:1432-1437. [PMID: 36184500 DOI: 10.1248/bpb.b22-00454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously, we generated high-affinity antibody mutants that enabled sensitive immunoassays by exploring diverse libraries of single-chain Fv fragments (scFvs) displayed on bacteriophage. To isolate rarely-occurring desirable clones, "panning" has commonly been performed but is often unsuccessful. Therefore, we previously developed a clonal array profiling (CAP) method, wherein scFv-displaying phage (scFv-Ph) clones in a library were examined individually regarding their ability to target antigens immobilized on microwells. Clones that showed strong reactivity were recovered via dissociation using an acidic treatment. The CAP successfully discovered cortisol-specific scFvs showing 17-31-fold improved Ka from libraries generated via site-directed insertions in a prototype anti-cortisol scFv (wt-scFv; Ka, 3.6 × 108 M-1), but their Ka did not exceed 1.1 × 1010 M-1. In this study, to break this possible affinity ceiling, we devised a new system employing a dissociation-independent recovery. scFv-Phs were individually reacted to target antigen (cortisol) immobilized on microwells via a linker containing a disulfide bond. Following acidic and basic treatments to eliminate scFv-Phs with "ordinary affinities," dissociation-resistant scFv-Phs remaining on the microwells were retrieved via reductive cleavage of the disulfide bonds. This system allowed for a straightforward and efficient discovery of scFv mutants with 33-56-fold increased Ka (1.2-2.0 × 1010 M-1), exceeding the previous affinity ceiling. These scFvs enabled an enzyme-linked immunosorbent assay for cortisol with 18-51-fold higher sensitivity than the assay performed using wt-scFv.
Collapse
|
6
|
Morita I, Kiguchi Y, Oyama H, Yamaki K, Sakio N, Kashiwabara K, Kuroda Y, Ito A, Yokota A, Ikeda N, Kikura-Hanajiri R, Ueda H, Numazawa S, Yoshida T, Kobayashi N. Derivatization-assisted immunoassays: application for group-specific detection of potent methamphetamine and amphetamine enantiomers. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2022; 14:2745-2753. [PMID: 35785801 DOI: 10.1039/d2ay00940d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Reliable and feasible tools for detecting (S)-methamphetamine [(S)-MAP] and (S)-amphetamine [(S)-AP] are required for regulating their illicit circulation. Antibodies that react equally to these stimulants are desirable for this purpose, but have been difficult to generate because of the crucial difference between their characteristic structures: i.e., N-methylamino (MAP) and amino (AP) groups. Furthermore, their small molecular masses (Mr < 150) have hampered the generation of high-affinity antibodies. To overcome these problems, we converted (S)-MAP and -AP into their 2-(trimethylsilyl)ethyl carbamate forms, Teoc-(S)-MAP and -AP, respectively, as surrogate analytes. The Teoc-derivatization not only increases their molecular masses, but also masks their structural differences. We generated a novel monoclonal antibody that showed a satisfactory affinity to Teoc-(S)-MAP residues (Kd = 13 nM as the IgG form) and developed a competitive enzyme-linked immunosorbent assay (ELISA) using microplates containing immobilized Teoc-(S)-MAP residues. Almost overlapping dose-response curves were obtained for Teoc-(S)-MAP and -AP, with the limit of detection of 0.078 and 0.10 ng per assay, respectively. A fixed amount of test powder sample (1 mg) was derivatized with Teoc-O-succinimidyl for 5 min, and subjected to ELISA using Teoc-(S)-MAP as the calibration standard. Under this protocol, (S)-MAP and -AP were converted to their Teoc derivatives with 30% and 34% yield, respectively, determined using ELISA as "Teoc-(S)-MAP equivalent," being distinguished from the derivatization products of (R)-MAP, (R)-AP, ephedrine, (S)-methylenedioxymethamphetamine, tyramine, dopamine, and β-alanine. This ELISA detected as little as 10 μg of (S)-MAP and -AP, and (S)-MAP in urine obtained from (S)-MAP-administered rats. Immunochromatography devices were also developed using gold nanoparticles coated with the monoclonal antibody, with which 0.10 mg of (S)-MAP and -AP was detected by the naked eye. We conclude that the present derivatization-assisted immunoassays may be useful for the detection of (S)-MAP and/or -AP in early stage screening of suspicious substances.
Collapse
Affiliation(s)
- Izumi Morita
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Yuki Kiguchi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Hiroyuki Oyama
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Kouya Yamaki
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Nami Sakio
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Keisuke Kashiwabara
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Yumi Kuroda
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Aya Ito
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Asaka Yokota
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Natsumi Ikeda
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Ruri Kikura-Hanajiri
- National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan
| | - Hiroshi Ueda
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8503, Japan
| | - Satoshi Numazawa
- Department of Pharmacology, Toxicology, and Therapeutics, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
| | - Takemi Yoshida
- Department of Pharmacology, Toxicology, and Therapeutics, Showa University School of Pharmacy, 1-5-8 Hatanodai, Shinagawa-ku, Tokyo 142-8555, Japan
- Council on Pharmacists Credentials, 1-9-2 Nishi-shinbashi, Minato-ku, Tokyo 105-0003, Japan
| | - Norihiro Kobayashi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| |
Collapse
|
7
|
Morita I, Kiguchi Y, Nakamura S, Yoshida A, Kubo H, Ishida M, Oyama H, Kobayashi N. More than 370-Fold Increase in Antibody Affinity to Estradiol-17β by Exploring Substitutions in the V H-CDR3. Biol Pharm Bull 2022; 45:851-855. [PMID: 35786593 DOI: 10.1248/bpb.b22-00187] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Antibodies that specifically target biomarkers are essential in clinical diagnosis. Genetic engineering has assisted in designing novel antibodies that offer greater antigen-binding affinities, thus providing more sensitive immunoassays. We have succeeded in generating a single-chain Fv fragment (scFv) targeted estradiol-17β (E2) with more than 370-fold improved affinity, based on a strategy focusing the complementarity-determining region 3 in the VH domain (VH-CDR3). Systematic exploration of amino acid substitutions therein, using a clonal array profiling, revealed a cluster of four substitutions, containing H99P and a serial substitution E100eN-I100fA-L100gQ that lead to a 90-fold increase in E2-binding affinity. This substitution quartet in the VH-CDR3, combined with the substitution cluster I29V/L36M/S77G in the VL domain, resulted in a scFv fragment with a further increase in the affinity (Ka, 3.2 × 1010 M-1). This enabled a highly sensitive enzyme-linked immunosorbent assay capable of detecting up to 0.78 pg/assay. The current study has, thus, focused on the significance of reevaluating the potential of mutagenesis targeting the VH-CDR3, and encouraging the production and use of engineered antibodies that enable enhanced sensitivities as next-generation diagnostic tools.
Collapse
|
8
|
Morita I, Kiguchi Y, Oyama H, Takeuchi A, Tode C, Tanaka R, Ogata J, Kikura-Hanajiri R, Kobayashi N. Derivatization-assisted enzyme-linked immunosorbent assay for identifying hallucinogenic mushrooms with enhanced sensitivity. ANALYTICAL METHODS : ADVANCING METHODS AND APPLICATIONS 2021; 13:3954-3962. [PMID: 34528944 DOI: 10.1039/d1ay01157j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
A sensitive immunochemical method for identifying hallucinogenic mushrooms (magic mushrooms) is required for regulating their illicit use. We have previously generated a monoclonal antibody (mAb) that targets psilocin (Psi), the major psychoactive compound in hallucinogenic mushrooms, and developed an enzyme-linked immunosorbent assay (ELISA). However, this ELISA failed to achieve the expected low-picomole-range sensitivity, as a result of insufficient affinity of the mAb to Psi. It is recognized that haptenic antigens with a larger molecular mass tend to induce antibodies with higher affinities. Thus, we herein report a "derivatization-assisted ELISA," in which the "real analyte" Psi was determined as a "surrogate analyte," the tert-butyldimethylsilyl ether analog thereof (TBS/Psi) having a 1.6-fold greater molecular mass (Mr 318.53) than Psi. A novel mAb against TBS/Psi, prepared by immunizing mice with a TBS/Psi-albumin conjugate showed a 69-fold higher affinity to TBS/Psi residues (Ka = 3.6 × 107 M-1 as IgG) than that of our previous mAb against Psi. This mAb consequently enabled a competitive ELISA for measuring TBS/Psi with the desired sensitivity: the dose-response curve midpoint (12.1 pmol per assay) was >100-fold lower than that of the previous ELISA for determining Psi. Extracts of dried mushroom powders were mixed with TBS triflate for 30 min at room temperature, converting Psi into TBS/Psi in approximately 50% yield. The reaction mixture was then subjected to an ELISA using the anti-TBS/Psi mAb to determine TBS/Psi. Psilocybe cubensis, a species of hallucinogenic mushrooms, gave rise to positive signals, indicating the presence of Psi therein in the expected quantity, while no detectable response was observed for four kinds of edible mushrooms available in the markets.
Collapse
Affiliation(s)
- Izumi Morita
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Yuki Kiguchi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Hiroyuki Oyama
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Atsuko Takeuchi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Chisato Tode
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| | - Rie Tanaka
- National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan
| | - Jun Ogata
- National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan
| | - Ruri Kikura-Hanajiri
- National Institute of Health Sciences, 3-25-26, Tonomachi, Kawasaki-ku, Kawasaki 210-9501, Japan
| | - Norihiro Kobayashi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe 658-8558, Japan.
| |
Collapse
|
9
|
Yeoh SG, Sum JS, Lai JY, W Isa WYH, Lim TS. Potential of Phage Display Antibody Technology for Cardiovascular Disease Immunotherapy. J Cardiovasc Transl Res 2021; 15:360-380. [PMID: 34467463 DOI: 10.1007/s12265-021-10169-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 08/22/2021] [Indexed: 11/26/2022]
Abstract
Cardiovascular disease (CVD) is one of the leading causes of death worldwide. CVD includes coronary artery diseases such as angina, myocardial infarction, and stroke. "Lipid hypothesis" which is also known as the cholesterol hypothesis proposes the linkage of plasma cholesterol level with the risk of developing CVD. Conventional management involves the use of statins to reduce the serum cholesterol levels as means for CVD prevention or treatment. The regulation of serum cholesterol levels can potentially be regulated with biological interventions like monoclonal antibodies. Phage display is a powerful tool for the development of therapeutic antibodies with successes over the recent decade. Although mainly for oncology, the application of monoclonal antibodies as immunotherapeutic agents could potentially be expanded to CVD. This review focuses on the concept of phage display for antibody development and discusses the potential target antigens that could potentially be beneficial for serum cholesterol management.
Collapse
Affiliation(s)
- Soo Ghee Yeoh
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Jia Siang Sum
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - Jing Yi Lai
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia
| | - W Y Haniff W Isa
- School of Medical Sciences, Department of Medicine, Universiti Sains Malaysia, Kubang Kerian, 16150, Kelantan, Malaysia
| | - Theam Soon Lim
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, 11800, Penang, Malaysia.
- Analytical Biochemistry Research Centre, Universiti Sains Malaysia, 11800, Penang, Malaysia.
| |
Collapse
|
10
|
Kiguchi Y, Oyama H, Morita I, Nagata Y, Umezawa N, Kobayashi N. The V H framework region 1 as a target of efficient mutagenesis for generating a variety of affinity-matured scFv mutants. Sci Rep 2021; 11:8201. [PMID: 33859250 PMCID: PMC8050046 DOI: 10.1038/s41598-021-87501-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/30/2021] [Indexed: 11/30/2022] Open
Abstract
In vitro affinity-maturation potentially generates antibody fragments with enhanced antigen-binding affinities that allow for developing more sensitive diagnostic systems and more effective therapeutic agents. Site-directed mutagenesis targeting “hot regions,” i.e., amino acid substitutions therein frequently increase the affinities, is desirable for straightforward discovery of valuable mutants. We here report two “designed” site-directed mutagenesis (A and B) targeted the N-terminal 1–10 positions of the VH framework region 1 that successfully improved an anti-cortisol single-chain Fv fragment (Ka, 3.6 × 108 M−1). Mutagenesis A substituted the amino acids at the position 1–3, 5–7, 9 and 10 with a limited set of substitutions to generate only 1,536 different members, while mutagenesis B inserted 1–6 random residues between the positions 6 and 7. Screening the resulting bacterial libraries as scFv-phage clones with a clonal array profiling system provided 21 genetically unique scFv mutants showing 17–31-fold increased affinity with > 109 M−1Ka values. Among the mutants selected from the library A and B, scFv mA#18 (with five-residue substitutions) and mB1-3#130 (with a single residue insertion) showed the greatest Ka value, 1.1 × 1010 M−1.
Collapse
Affiliation(s)
- Yuki Kiguchi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Hiroyuki Oyama
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Izumi Morita
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Yasuhiro Nagata
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Naoko Umezawa
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Norihiro Kobayashi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan.
| |
Collapse
|
11
|
Oyama H, Kiguchi Y, Morita I, Miyashita T, Ichimura A, Miyaoka H, Izumi A, Terasawa S, Osumi N, Tanaka H, Niwa T, Kobayashi N. NanoLuc luciferase as a suitable fusion partner of recombinant antibody fragments for developing sensitive luminescent immunoassays. Anal Chim Acta 2021; 1161:238180. [PMID: 33896564 DOI: 10.1016/j.aca.2020.12.055] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 12/22/2020] [Accepted: 12/24/2020] [Indexed: 11/27/2022]
Abstract
Enzyme-linked immunosorbent assays (ELISAs) are essential for monitoring various biomarkers. Competitive and noncompetitive (sandwich) assay formats are used to determine hapten and macromolecule levels, respectively. Both formats require more sensitive detection of reporter enzymes for greater assay sensitivities. We previously reported the utility of wild-type Gaussia luciferase (wtGLuc) as a fusion partner with antibody single-chain Fv fragments (scFvs) for developing sensitive luminescent ELISAs. Here, we evaluated utility of NanoLuc luciferase (NLuc), a recently developed luciferase, as fusion partner with scFvs from the view of comparison with wtGLuc and a mutant of alkaline phosphatase (ALP'). Thyroxine (T4) and T4-labeled albumin were chosen as model haptenic and macromolecular antigens, respectively. An in-house-prepared anti-T4 scFv was fused with NLuc, wtGLuc, or ALP'. The scFv-NLuc fusion protein showed 47-fold and 29-fold lower limit of detection [LOD; 59 zmol (per assay)] than the wtGLuc- and ALP'-fusions, respectively. In a competitive T4 ELISA, the NLuc-fusion showed 9.3- and 6.3-fold lower LOD, (0.67 pg) than the wtGLuc- and ALP'-fusions, respectively, with a higher specificity in clinical applications. A typical colorimetric ELISA using a peroxidase-labeled second antibody showed 70-fold higher LOD than NLuc-based ELISA. Another advantage of the NLuc-fusion was shown in the sandwich assays; the LOD of T4-labeled albumin (5.0 fmol) was >6-fold lower than that of the other luminescent ELISAs. In an additional sandwich assay developed to count bacteriophage particles, NLuc enabled more sensitive determination than wtGLuc, whereas ALP' showed nearly equivalent performance. Its slowest alteration rate for light intensity after starting the enzyme reaction should enable robust batch-by-batch assay operations. Thus, we concluded that scFv-NLuc fusions serve as suitable probes in various types of immunoassays and may facilitate higher sensitivities with practical specificities.
Collapse
Affiliation(s)
- Hiroyuki Oyama
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Yuki Kiguchi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Izumi Morita
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Takayuki Miyashita
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Akiyoshi Ichimura
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Hiroko Miyaoka
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Aki Izumi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Sayaka Terasawa
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Natsumi Osumi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Hiroki Tanaka
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan
| | - Toshifumi Niwa
- Department of Medical Technology, School of Health Sciences, Tohoku University, 2-1, Seiryo-machi, Aoba-ku, Sendai, 980-8575, Japan
| | - Norihiro Kobayashi
- Kobe Pharmaceutical University, 4-19-1, Motoyama-Kitamachi, Higashinada-ku, Kobe, 658-8558, Japan.
| |
Collapse
|