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Wu H, Zhou Z, Xie S, Yan R, Gong M, Tian X, Wang Z. Similarity measurements of B cell receptor repertoire in baseline mice showed spectrum convergence of IgM. BMC Immunol 2022; 23:11. [PMID: 35246036 PMCID: PMC8895918 DOI: 10.1186/s12865-022-00482-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Accepted: 02/18/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The B cell receptor (BCR) repertoire is highly diverse among individuals. Poor similarity of the spectrum among inbred baseline mice may limit the ability to discriminate true signals from those involving specific experimental factors. The repertoire similarity of the baseline status lacks intensive measurements. RESULTS We measured the repertoire similarity of IgH in blood and spleen samples from untreated BALB/c and C57BL/6J mice to investigate the baseline status of the two inbred strains. The antibody pool was stratified by the isotype of IgA, IgG and IgM. Between individuals, the results showed better convergence of CDR3 and clonal lineage profiles in IgM than in IgA and IgG, and better robustness of somatic mutation networks in IgM than in IgA and IgG. It also showed that the CDR3 clonotypes and clonal lineages shared better in the spleen samples than in the blood samples. The animal batch differences were detected in CDR3 evenness, mutated clonotype proportions, and maximal network degrees. A cut-off of 95% identity in the CDR3 nucleotide sequences was suitable for clonal lineage establishment. CONCLUSIONS Our findings reveal a natural landscape of BCR repertoire similarities between baseline mice and provide a solid reference for designing studies of mouse BCR repertoires.
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Affiliation(s)
- Hongkai Wu
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
| | - Zhichao Zhou
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China
| | - Shi Xie
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Rong Yan
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Mingxing Gong
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China
| | - Xingui Tian
- State Key Laboratory of Respiratory Disease, National Clinical Research Center for Respiratory Disease, The First Affiliated Hospital of Guangzhou Medical University, Guangzhou Medical University, Guangzhou, China.
| | - Zhanhui Wang
- State Key Laboratory of Organ Failure Research, Guangdong Provincial Key Laboratory of Viral Hepatitis Research, Department of Infectious Diseases and Hepatology Unit, Nanfang Hospital, Southern Medical University, Guangzhou, China.
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Li M, Wan L, Law MK, Meng L, Jia Y, Mak PI, Martins RP. One-shot high-resolution melting curve analysis for KRAS point-mutation discrimination on a digital microfluidics platform. LAB ON A CHIP 2022; 22:537-549. [PMID: 34904611 DOI: 10.1039/d1lc00564b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Single-nucleotide polymorphism (SNP) plays a critical role in personalized medicine, forensics, pharmacogenetics, and disease diagnostics. Among different existing SNP genotyping techniques, melting curve analysis (MCA) becomes increasingly popular due to its high accuracy and straightforward procedures in extracting the melting temperature (Tm). Yet, its study on existing digital microfluidic (DMF) platforms has intrinsic limitations due to the temperature inhomogeneity within a thickened droplet during the on-chip rapid heating process. Although the utilization of an on-chip thermostat can regulate and monitor the dynamic melting process in real time, the limited Tm accuracy resulting from the insufficient system response time to accommodate the fast-melting evolution still poses a great challenge for precise MCA with high throughput. This work proposes a one-shot MCA on a DMF platform. The tailoring of a functional substrate with hierarchical micro/nano structure enables high-resolution patterning of pL-scale droplets. Specifically, the hydrothermal and photocatalysis treatment allows the functional substrate to exhibit a superwettability contrast of >170°, facilitating passive isolation of the pL-scale DNA sample into highly-resolved pL droplets above the 200 μm superhydrophilic patterns. This high-resolution MCA technique can successfully discriminate KRAS gene targets with single-nucleotide mutations in 3 seconds. The high accuracy and consistency in the acquired Tm when compared with off-chip results demonstrate its opportunities for near-patient diagnostics, precision medicines, genetic counseling, and prevention strategies on DMF platforms.
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Affiliation(s)
- Mingzhong Li
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
| | - Liang Wan
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
| | - Man-Kay Law
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
| | - Li Meng
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
| | - Yanwei Jia
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
| | - Pui-In Mak
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
| | - Rui P Martins
- State Key Laboratory of Analog and Mixed-Signal VLSI, Institute of Microelectronics, University of Macau, Taipa, Macao, China.
- Faculty of Science and Technology - Electrical and Computer Engineering, University of Macau, Macao, China
- On leave from Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
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Mullen TE, Abdullah R, Boucher J, Brousseau AS, Dasuri NK, Ditto NT, Doucette AM, Emery C, Gabriel J, Greamo B, Patil KS, Rothenberger K, Stolte J, Souders CA. Accelerated antibody discovery targeting the SARS-CoV-2 spike protein for COVID-19 therapeutic potential. Antib Ther 2021; 4:185-196. [PMID: 34541454 PMCID: PMC8444149 DOI: 10.1093/abt/tbab018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/18/2021] [Accepted: 08/20/2021] [Indexed: 11/13/2022] Open
Abstract
Background Rapid deployment of technologies capable of high-throughput and high-resolution screening is imperative for timely response to viral outbreaks. Risk mitigation in the form of leveraging multiple advanced technologies further increases the likelihood of identifying efficacious treatments in aggressive timelines. Methods In this study, we describe two parallel, yet distinct, in vivo approaches for accelerated discovery of antibodies targeting the severe acute respiratory syndrome coronavirus-2 spike protein. Working with human transgenic Alloy-GK mice, we detail a single B-cell discovery workflow to directly interrogate antibodies secreted from plasma cells for binding specificity and ACE2 receptor blocking activity. Additionally, we describe a concurrent accelerated hybridoma-based workflow utilizing a DiversimAb™ mouse model for increased diversity. Results The panel of antibodies isolated from both workflows revealed binding to distinct epitopes with both blocking and non-blocking profiles. Sequence analysis of the resulting lead candidates uncovered additional diversity with the opportunity for straightforward engineering and affinity maturation. Conclusions By combining in vivo models with advanced integration of screening and selection platforms, lead antibody candidates can be sequenced and fully characterized within one to three months.
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Affiliation(s)
- Tracey E Mullen
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Rashed Abdullah
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Jacqueline Boucher
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Anna Susi Brousseau
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Narayan K Dasuri
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Noah T Ditto
- Product Development, Carterra, 825 N 300 W c309, Salt Lake City, UT 84103, USA
| | - Andrew M Doucette
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Chloe Emery
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Justin Gabriel
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Brendan Greamo
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Ketan S Patil
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Kelly Rothenberger
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Justin Stolte
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
| | - Colby A Souders
- Antibody Discovery, Abveris Inc., 480 Neponset St, Ste 10B, Canton, MA 02021, USA
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Identification of Two Critical Neutralizing Epitopes in the Receptor Binding Domain of Hepatitis B Virus preS1. J Virol 2021; 95:JVI.01680-20. [PMID: 33298539 PMCID: PMC8092832 DOI: 10.1128/jvi.01680-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Hepatitis B virus (HBV) infection is a major public health problem. Human hepatocytes are infected with HBV via binding between the preS1 region in the large envelope protein of HBV and sodium taurocholate cotransporting polypeptide. Although several monoclonal antibodies (MAbs) that recognize the receptor binding domain in preS1 and neutralize HBV infection have been isolated, details of neutralizing epitopes are not understood. In this study, we generated 13 MAbs targeting the preS1 receptor binding domain from preS1-specific memory B cells derived from DNA immunized mice. The MAbs were classified into three groups according to the epitope regions, designated epitopes I-III. A virus neutralization assay revealed that MAbs recognizing epitopes I and III neutralized HBV infection, suggesting that these domains are critical epitopes for viral neutralization. In addition, a neutralization assay against multiple genotypes of HBV revealed that epitope I is a semi-pangenotypic neutralizing epitope, whereas epitope III is a genotype-specific epitope. We also showed that neutralizing MAbs against preS1 could neutralize HBV bearing vaccine-induced escape mutation. These findings provide insight into novel immunoprophylaxis for the prevention and treatment of HBV infection.IMPORTANCE The HBV preS1 2-47 aa region (preS1/2-47) is essential for virus binding with sodium taurocholate cotransporting polypeptide. Several MAbs targeting preS1/2-47 have been reported to neutralize HBV infection; however, which region in preS1/2-47 contains the critical neutralizing epitope for HBV infection is unclear. Here, we generated several MAbs targeting preS1/2-47 and found that MAbs recognizing the N- or C-terminus of preS1/2-47 remarkably neutralized HBV infection. We further confirmed the neutralizing activity of anti-preS1 MAbs against HBV with vaccine escape mutation. These data clarified the relationship between the antibody epitope and the virus neutralizing activity and also suggested the potential ability of a vaccine antigen containing the preS1 region to overcome the weakness of current HB vaccines comprising the small S protein.
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Szikora B, Marx A, Jani PK, Pipek O, Müller V, Csabai I, Kacskovics I. FcRn Overexpression Expands Diversity of the Humoral Immune Response in bFcRn Transgenic Mice. Front Immunol 2020; 11:1887. [PMID: 32973781 PMCID: PMC7472951 DOI: 10.3389/fimmu.2020.01887] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 07/13/2020] [Indexed: 11/30/2022] Open
Abstract
The neonatal Fc receptor (FcRn) plays key roles in IgG and albumin homeostasis, maternal IgG transport, and antigen presentation of IgG-opsonized antigens. Previously, we reported that transgenic (Tg) mice that overexpress bovine FcRn (bFcRn) have augmented T-dependent humoral immune response with increased IgG protection, higher level of antigen-specific antibodies, greater number of antigen-specific B cells, and effective immune response even against weakly immunogenic epitopes. In this study we analyzed the diversity of the humoral immune response of bFcRn Tg mice, using a length distribution analysis (spectratyping) and next generation sequencing (NGS) of the immunoglobulin heavy chain variable regions. Our analysis showed that in response to immunization with ovalbumin or transfected cells that expressed a unique membrane protein, our Tg animals developed a more diverse plasma cell repertoire than controls, which manifested in greater numbers of different clones, and clusters with fewer highly expanded large clones, as identified by the variable region (CDR3) of the immunoglobulin heavy chain. The increased antibody diversity in Tg mice after immunization was observed at both IgM and IgG levels, indicating that the increased humoral immune diversity in Tg mice is due to a higher number of both activated, antigen-specific naïve and isotype switched B cells. We thus demonstrated that the BCR repertoire of the immunized bFcRn Tg animals is more diverse compared to wild type mice, which likely makes these Tg mice a better choice for monoclonal antibody production against challenging antigens, including the extracellular regions of cell membrane proteins.
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Affiliation(s)
- Bence Szikora
- Department of Immunology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - Anita Marx
- Department of Immunology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | | | - Orsolya Pipek
- Department of Physics of Complex Systems, Institute of Physics, Eötvös Loránd University, Budapest, Hungary
| | - Viktor Müller
- Department of Plant Systematics, Ecology and Theoretical Biology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary
| | - István Csabai
- Department of Physics of Complex Systems, Institute of Physics, Eötvös Loránd University, Budapest, Hungary
| | - Imre Kacskovics
- Department of Immunology, Institute of Biology, Eötvös Loránd University, Budapest, Hungary.,ImmunoGenes Ltd., Budakeszi, Hungary
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