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Taha, Eskandari S, Slesarenko VA, Haselhorst T, Semchenko EA, Seib KL. Refinement and optimisation of Neisseria gonorrhoeae NHBA and MetQ vaccine candidates. Vaccine 2024; 42:126416. [PMID: 39368128 DOI: 10.1016/j.vaccine.2024.126416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2024] [Revised: 09/06/2024] [Accepted: 09/30/2024] [Indexed: 10/07/2024]
Abstract
Neisseria gonorrhoeae has a significant impact on reproductive health with an estimated 82 million new cases of infection per year worldwide. Due to the ongoing emergence of multidrug-resistant N. gonorrhoeae strains, the high number of asymptomatic cases, and the risk of disease sequelae, the development of a gonococcal vaccine is urgently needed. We have previously described two potential gonococcal vaccine antigens, cNHBA (C-terminal fragment of the Neisseria Heparin Binding Antigen) and MetQ (methionine-binding protein). This study aimed to optimise these antigens for improved immune responses and to facilitate vaccine production, by investigating cNHBA fusions with the full-length MetQ protein or N-terminal and C-terminal MetQ fragments (Met1 and Met2, respectively) adjuvanted with aluminium hydroxide. The cNHBA and MetQ fragments and fusion antigens were all immunogenic in mice, generating a predominantly IgG1 response. Antibodies mediated bacterial killing via both serum bactericidal activity (SBA) and opsonophagocytic activity (OPA), and reduced adherence to cervical and urethral epithelial cells. Among the antigen fusions tested, MetQ-cNHBA and cNHBA-Met2 generated the highest SBA, OPA and adherence blocking titres and are proposed as promising optimised antigens for N. gonorrhoeae vaccine development.
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Affiliation(s)
- Taha
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Sharareh Eskandari
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Valentin A Slesarenko
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Thomas Haselhorst
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia
| | - Evgeny A Semchenko
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia.
| | - Kate L Seib
- Institute for Biomedicine and Glycomics, Griffith University, Gold Coast, QLD, Australia.
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McConnell SA, Casadevall A. Immunoglobulin constant regions provide stabilization to the paratope and enforce epitope specificity. J Biol Chem 2024; 300:107397. [PMID: 38763332 PMCID: PMC11215335 DOI: 10.1016/j.jbc.2024.107397] [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] [Received: 04/11/2024] [Accepted: 05/09/2024] [Indexed: 05/21/2024] Open
Abstract
Constant domains in antibody molecules at the level of the Fab (CH1 and CL) have long been considered to be simple scaffolding elements that physically separate the paratope-defining variable (V) region from the effector function-mediating constant (C) regions. However, due to recent findings that C domains of different isotypes can modulate the fine specificity encoded in the V region, elucidating the role of C domains in shaping the paratope and influencing specificity is a critical area of interest. To dissect the relative contributions of each C domain to this phenomenon, we generated antibody fragments with different C regions omitted, using a set of antibodies targeting capsular polysaccharides from the fungal pathogen, Cryptococcus neoformans. Antigen specificity mapping and functional activity measurements revealed that V region-only antibody fragments exhibited poly-specificity to antigenic variants and extended to recognition of self-antigens, while measurable hydrolytic activity of the capsule was greatly attenuated. To better understand the mechanistic origins of the remarkable loss of specificity that accompanies the removal of C domains from identical paratopes, we performed molecular dynamics simulations which revealed increased paratope plasticity in the scFv relative to the corresponding Fab. Together, our results provide insight into how the remarkable specificity of immunoglobulins is governed and maintained at the level of the Fab through the enforcement of structural restrictions on the paratope by CH1 domains.
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Affiliation(s)
- Scott A McConnell
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Arturo Casadevall
- Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
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3
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Ge S, Dias ACP, Zhang X. Chimerism of avian IgY-scFv and truncated IgG-Fc: A novel strategy in cross-species antibody generation and enhancement. Immunology 2024; 172:46-60. [PMID: 38247105 DOI: 10.1111/imm.13752] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 12/15/2023] [Indexed: 01/23/2024] Open
Abstract
Chicken single-chain fragment variable (IgY-scFv) is a functional fragment and an emerging development in genetically engineered antibodies with a wide range of biomedical applications. However, scFvs have considerably shorter serum half-life due to the absence of antibody Fc region compared with the full-length antibody, and usually requires continuous intravenous administration for efficacy. A promising approach to overcome this limitation is to fuse scFv with immunoglobulin G (IgG) Fc region, for better recognition and mediation by the neonatal Fc receptor (FcRn) in the host. In this study, engineered mammalian ΔFc domains (CH2, CH3, and intact Fc region) were fused with anti-canine parvovirus-like particles avian IgY-scFv to produce chimeric antibodies and expressed in the HEK293 cell expression system. The obtained scFv-CH2, scFv-CH3, and scFv-Fc can bind with antigen specifically and dose-dependently. Surface plasmon resonance investigation confirmed that scFv-CH2, scFv-CH3, and scFv-Fc had different degrees of binding to FcRn, with scFv-Fc showing the highest affinity. scFv-Fc had a significantly longer half-life in mice compared with the unfused scFv. The identified ΔFcs are promising for the development of engineered Fc-based therapeutic antibodies and proteins with longer half-lives. The avian IgY-scFv-mammalian IgG Fc region opens up new avenues for antibody engineering, and it is a novel strategy to enhance the rapid development and screening of functional antibodies in veterinary and human medicine.
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Affiliation(s)
- Shikun Ge
- Department of Biology, Centre of Molecular and Environmental Biology, University of Minho, Braga, Portugal
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
| | - Alberto Carlos Pires Dias
- Department of Biology, Centre of Molecular and Environmental Biology, University of Minho, Braga, Portugal
| | - Xiaoying Zhang
- Department of Biology, Centre of Molecular and Environmental Biology, University of Minho, Braga, Portugal
- College of Biological Science and Engineering, Shaanxi University of Technology, Hanzhong, China
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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Brendle SA, Li JJ, Walter V, Schell TD, Kozak M, Balogh KK, Lu S, Christensen ND, Zhu Y, El-Bayoumy K, Hu J. Immune Responses in Oral Papillomavirus Clearance in the MmuPV1 Mouse Model. Pathogens 2023; 12:1452. [PMID: 38133335 PMCID: PMC10745854 DOI: 10.3390/pathogens12121452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/06/2023] [Accepted: 12/12/2023] [Indexed: 12/23/2023] Open
Abstract
Human papillomavirus (HPV)-induced oropharyngeal cancer now exceeds HPV-induced cervical cancer, with a noticeable sex bias. Although it is well established that women have a more proficient immune system, it remains unclear whether immune control of oral papillomavirus infections differs between sexes. In the current study, we use genetically modified mice to target CCR2 and Stat1 pathways, with the aim of investigating the role of both innate and adaptive immune responses in clearing oral papillomavirus, using our established papillomavirus (MmuPV1) infection model. Persistent oral MmuPV1 infection was detected in Rag1ko mice with T and B cell deficiencies. Meanwhile, other tested mice were susceptible to MmuPV1 infections but were able to clear the virus. We found sex differences in key myeloid cells, including macrophages, neutrophils, and dendritic cells in the infected tongues of wild type and Stat1ko mice but these differences were not observed in CCR2ko mice. Intriguingly, we also observed a sex difference in anti-MmuPV1 E4 antibody levels, especially for two IgG isotypes: IgG2b and IgG3. However, we found comparable numbers of interferon-gamma-producing CD8 T cells stimulated by E6 and E7 in both sexes. These findings suggest that males and females may use different components of innate and adaptive immune responses to control papillomavirus infections in the MmuPV1 mouse model. The observed sex difference in immune responses, especially in myeloid cells including dendritic cell (DC) subsets, may have potential diagnostic and prognostic values for HPV-associated oropharyngeal cancer.
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Affiliation(s)
- Sarah A. Brendle
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Jingwei J. Li
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Vonn Walter
- Department of Biochemistry & Molecular Biology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (V.W.); (K.E.-B.)
- Department of Public Health Sciences, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA
| | - Todd D. Schell
- Department of Microbiology and Immunology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA;
| | - Michael Kozak
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Karla K. Balogh
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Song Lu
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Neil D. Christensen
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
- Department of Microbiology and Immunology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA;
| | - Yusheng Zhu
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
| | - Karam El-Bayoumy
- Department of Biochemistry & Molecular Biology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (V.W.); (K.E.-B.)
| | - Jiafen Hu
- The Jake Gittlen Laboratories for Cancer Research, College of Medicine, Pennsylvania State University, Hershey, State College, PA 17033, USA; (S.A.B.); (J.J.L.); (M.K.); (K.K.B.); (N.D.C.)
- Department of Pathology, College of Medicine, Pennsylvania State University, Hershey, PA 17033, USA; (S.L.); (Y.Z.)
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Polmear J, Hailes L, Olshansky M, Rischmueller M, L'Estrange‐Stranieri E, Fletcher AL, Hibbs ML, Bryant VL, Good‐Jacobson KL. Targeting BMI-1 to deplete antibody-secreting cells in autoimmunity. Clin Transl Immunology 2023; 12:e1470. [PMID: 37799772 PMCID: PMC10550498 DOI: 10.1002/cti2.1470] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/13/2023] [Accepted: 09/22/2023] [Indexed: 10/07/2023] Open
Abstract
Objectives B cells drive the production of autoreactive antibody-secreting cells (ASCs) in autoimmune diseases such as Systemic Lupus Erythematosus (SLE) and Sjögren's syndrome, causing long-term organ damage. Current treatments for antibody-mediated autoimmune diseases target B cells or broadly suppress the immune system. However, pre-existing long-lived ASCs are often refractory to treatment, leaving a reservoir of autoreactive cells that continue to produce antibodies. Therefore, the development of novel treatment methods targeting ASCs is vital to improve patient outcomes. Our objective was to test whether targeting the epigenetic regulator BMI-1 could deplete ASCs in autoimmune conditions in vivo and in vitro. Methods Use of a BMI-1 inhibitor in both mouse and human autoimmune settings was investigated. Lyn -/- mice, a model of SLE, were treated with the BMI-1 small molecule inhibitor PTC-028, before assessment of ASCs, serum antibody and immune complexes. To examine human ASC survival, a novel human fibroblast-based assay was established, and the impact of PTC-028 on ASCs derived from Sjögren's syndrome patients was evaluated. Results BMI-1 inhibition significantly decreased splenic and bone marrow ASCs in Lyn -/- mice. The decline in ASCs was linked to aberrant cell cycle gene expression and led to a significant decrease in serum IgG3, immune complexes and anti-DNA IgG. PTC-028 was also efficacious in reducing ex vivo plasma cell survival from both Sjögren's syndrome patients and age-matched healthy donors. Conclusion These data provide evidence that inhibiting BMI-1 can deplete ASC in a variety of contexts and thus BMI-1 is a viable therapeutic target for antibody-mediated autoimmune diseases.
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Affiliation(s)
- Jack Polmear
- Department of Biochemistry and Molecular BiologyMonash UniversityClaytonVICAustralia
- Immunity Program, Biomedicine Discovery InstituteMonash UniversityClaytonVICAustralia
| | - Lauren Hailes
- Department of Biochemistry and Molecular BiologyMonash UniversityClaytonVICAustralia
- Immunity Program, Biomedicine Discovery InstituteMonash UniversityClaytonVICAustralia
| | - Moshe Olshansky
- Department of Biochemistry and Molecular BiologyMonash UniversityClaytonVICAustralia
- Immunity Program, Biomedicine Discovery InstituteMonash UniversityClaytonVICAustralia
| | - Maureen Rischmueller
- The Queen Elizabeth Hospital and Basil Hetzel InstituteWoodville SouthSAAustralia
- Adelaide Medical SchoolUniversity of AdelaideAdelaideSAAustralia
| | | | - Anne L Fletcher
- Department of Biochemistry and Molecular BiologyMonash UniversityClaytonVICAustralia
- Immunity Program, Biomedicine Discovery InstituteMonash UniversityClaytonVICAustralia
| | - Margaret L Hibbs
- Department of Immunology, Alfred Research AllianceMonash UniversityMelbourneVICAustralia
| | - Vanessa L Bryant
- Immunology DivisionWalter & Eliza Hall InstituteParkvilleVICAustralia
- Department of Medical BiologyUniversity of MelbourneParkvilleVICAustralia
- Department of Clinical Immunology & AllergyThe Royal Melbourne HospitalParkvilleVICAustralia
| | - Kim L Good‐Jacobson
- Department of Biochemistry and Molecular BiologyMonash UniversityClaytonVICAustralia
- Immunity Program, Biomedicine Discovery InstituteMonash UniversityClaytonVICAustralia
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Carreón-Talavera R, Santana-Sánchez P, Fuentes-Pananá EM, Legorreta-Haquet MV, Chávez-Sánchez L, Gorocica-Rosete PS, Chávez-Rueda AK. Prolactin promotes proliferation of germinal center B cells, formation of plasma cells, and elevated levels of IgG3 anti-dsDNA autoantibodies. Front Immunol 2022; 13:1017115. [DOI: 10.3389/fimmu.2022.1017115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Systemic lupus erythematosus (SLE) mainly affects females at reproductive age, which has been associated with hormones, such as prolactin (PRL). Different studies suggest that PRL exacerbates the clinical manifestations of SLE both in patients and in mouse models (e.g., the MRL/lpr strain), increasing the production of autoantibodies, which can be deposited as immune complexes and trigger inflammation and damage to different tissues. The objective of this work was to explore the potential mechanisms by which PRL increases the concentration of self-reactive antibodies in the MRL/lpr SLE model. To this end, we determined the role of PRL on the activation and proliferation of germinal center B cells (B-GCs) and their differentiation into antibody-secreting cells (ASCs). We show that the absolute number and percentage of B-GCs were significantly increased by PRL in vivo or upon in vitro treatment with anti-IgM and anti-CD40 antibodies and PRL. The augmented B-GC numbers correlated with enhanced proliferation, but we did not observe enhanced expression of CD80 and CD86 activation markers or the BCL6 transcription factor, arguing against a more effective differentiation. Nevertheless, we observed enhanced phosphorylation of STAT1, secretion of IL-6, expression of IRF4, numbers of ASCs, and levels of IgG3 antibodies directed against dsDNA. Altogether, these results support the hypothesis that a PRL-mediated expansion of B-GCs yields more self-reactive ASCs, potentially explaining the pathogenic immune complexes that steadily lead to tissue damage during SLE.
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High-valency Anti-CD99 Antibodies Toward the Treatment of T Cell Acute Lymphoblastic Leukemia. J Mol Biol 2022; 434:167402. [PMID: 34958778 PMCID: PMC8897262 DOI: 10.1016/j.jmb.2021.167402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 12/07/2021] [Indexed: 11/21/2022]
Abstract
T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive form of leukemia that currently requires intensive chemotherapy. While childhood T-ALL is associated with high cure rates, adult T-ALL is not, and both are associated with significant short- and long-term morbidities. Thus, less toxic and effective strategies to treat T-ALL are needed. CD99 is overexpressed on T-ALL blasts at diagnosis and at relapse. Although targeting CD99 with cytotoxic antibodies has been proposed, the molecular features required for their activity are undefined. We identified human antibodies that selectively bound to the extracellular domain of human CD99, and the most potent clone, 10A1, shared an epitope with a previously described cytotoxic IgM antibody. We engineered clone 10A1 in bivalent, trivalent, tetravalent, and dodecavalent formats. Increasing the antibody valency beyond two had no effects on binding to T-ALL cells. In contrast, a valency of ≥3 was required for cytotoxicity, suggesting a mechanism of action in which an antibody clusters ≥3 CD99 molecules to induce cytotoxicity. We developed a human IgG-based tetravalent version of 10A1 that exhibited cytotoxic activity to T-ALL cells but not to healthy peripheral blood cells. The crystal structure of the 10A1 Fab in complex with a CD99 fragment revealed that the antibody primarily recognizes a proline-rich motif (PRM) of CD99 in a manner reminiscent of SH3-PRM interactions. This work further validates CD99 as a promising therapeutic target in T-ALL and defines a pathway toward the development of a selective therapy against T-ALL.
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Liu XY, Zhu MH, Wang XY, Dong X, Liu HJ, Li RY, Jia SC, Lu Q, Zhao M, Sun P, Chen HZ, Fang C. A nano-innate immune system activator for cancer therapy in a 4T1 tumor-bearing mouse model. J Nanobiotechnology 2022; 20:54. [PMID: 35093074 PMCID: PMC8800325 DOI: 10.1186/s12951-022-01265-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2021] [Accepted: 01/14/2022] [Indexed: 11/25/2022] Open
Abstract
Background Harnessing the immune system to fight cancer has led to prominent clinical successes. Strategies to stimulate innate immune effectors are attracting considerable interest in cancer therapy. Here, through conjugating multivalent Fc fragments onto the surface of mesoporous silica nanoparticles (MSN), we developed a nanoparticle-based innate immune system activator (NISA) for breast cancer immunotherapy. Methods NISA was prepared through conjugating mouse IgG3 Fc to MSN surface. Then, long-chain PEG5000, which was used to shield Fc to confer nanoparticle colloidal stability, was linked to the MSN surface via matrix metalloprotease-2 (MMP-2)-cleavable peptide (GPLGIAGQC). The activation of multiple components of innate immune system, including complement and the innate cells (macrophages and dendritic cells) and the associated anticancer effect were investigated. Results Fc fragments of NISA can be exposed through hydrolysis of long-chain PEG5000 by highly expressed MMP-2 in tumor microenvironment. Then, effective stimulation and activation of multiple components of innate immune system, including complement, macrophages, and dendritic cells were obtained, leading to efficient antitumor effect in 4T1 breast cancer cells and orthotopic breast tumor model in mice. Conclusions The antitumor potency conferred by NISA highlights the significance of stimulating multiple innate immune elements in cancer immunotherapy. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12951-022-01265-4.
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Mouse IgG3 binding to macrophage-like cells is prevented by deglycosylation of the antibody or by Accutase treatment of the cells. Sci Rep 2021; 11:10295. [PMID: 33986441 PMCID: PMC8119965 DOI: 10.1038/s41598-021-89705-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 04/29/2021] [Indexed: 11/17/2022] Open
Abstract
The binding of mouse IgG3 to Fcγ receptors (FcγR) and the existence of a mouse IgG3-specific receptor have been discussed for 40 years. Recently, integrin beta-1 (ITGB1) was proposed to be a part of an IgG3 receptor involved in the phagocytosis of IgG3-coated pathogens. We investigated the interaction of mouse IgG3 with macrophage-like J774A.1 and P388D1 cells. The existence of an IgG3-specific receptor was verified using flow cytometry and a rosetting assay, in which erythrocytes clustered around the macrophage-like cells coated with an erythrocyte-specific IgG3. Our findings confirmed that receptors binding antigen-free IgG3 are present on J774A.1 and P388D1 cells. We demonstrated for the first time that the removal of N-glycans from IgG3 completely abolished its binding to the cells. Moreover, we discovered that the cells treated with Accutase did not bind IgG3, indicating that IgG3-specific receptors are substrates of this enzyme. The results of antibody-mediated blocking of putative IgG3 receptors suggested that apart from previously proposed ITGB1, FcγRII, FcγRIII, also additional, still unknown, receptor is involved in IgG3 binding. These findings indicate that there is a complex network of glycan-dependent interactions between mouse IgG3 and the surface of effector immune cells.
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10
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Molecular and structural basis for Lewis glycan recognition by a cancer-targeting antibody. Biochem J 2021; 477:3219-3235. [PMID: 32789497 DOI: 10.1042/bcj20200454] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 01/11/2023]
Abstract
Immunotherapy has been successful in treating many tumour types. The development of additional tumour-antigen binding monoclonal antibodies (mAbs) will help expand the range of immunotherapeutic targets. Lewis histo-blood group and related glycans are overexpressed on many carcinomas, including those of the colon, lung, breast, prostate and ovary, and can therefore be selectively targeted by mAbs. Here we examine the molecular and structural basis for recognition of extended Lea and Lex containing glycans by a chimeric mAb. Both the murine (FG88.2) IgG3 and a chimeric (ch88.2) IgG1 mAb variants showed reactivity to colorectal cancer cells leading to significantly reduced cell viability. We determined the X-ray structure of the unliganded ch88.2 fragment antigen-binding (Fab) containing two Fabs in the unit cell. A combination of molecular docking, glycan grafting and molecular dynamics simulations predicts two distinct subsites for recognition of Lea and Lex trisaccharides. While light chain residues were exclusively used for Lea binding, recognition of Lex involved both light and heavy chain residues. An extended groove is predicted to accommodate the Lea-Lex hexasaccharide with adjoining subsites for each trisaccharide. The molecular and structural details of the ch88.2 mAb presented here provide insight into its cross-reactivity for various Lea and Lex containing glycans. Furthermore, the predicted interactions with extended epitopes likely explains the selectivity of this antibody for targeting Lewis-positive tumours.
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The Role of IgG Subclass in Antibody-Mediated Protection against Carbapenem-Resistant Klebsiella pneumoniae. mBio 2020; 11:mBio.02059-20. [PMID: 32900809 PMCID: PMC7482069 DOI: 10.1128/mbio.02059-20] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Carbapenem-resistant Klebsiella pneumoniae is an urgent public health threat that causes life-threatening infections in immunocompromised hosts. Its resistance to nearly all antibiotics necessitates novel strategies to treat it, including the use of monoclonal antibodies. Monoclonal antibodies are emerging as important adjuncts to traditional pharmaceuticals, and studying how they protect against specific bacteria such as Klebsiella pneumoniae is crucial to their development as effective therapies. Antibody subclass is often overlooked but is a major factor in how an antibody interacts with other mediators of immunity. This paper is the first to examine how the subclass of anticapsular monoclonal antibodies can affect efficacy against CR-Kp. Additionally, this work sheds light on the viability of monoclonal antibody therapy in neutropenic patients, who are most vulnerable to CR-Kp infection. Monoclonal antibodies (MAbs) have the potential to assist in the battle against multidrug-resistant bacteria such as carbapenem-resistant Klebsiella pneumoniae (CR-Kp). However, the characteristics by which these antibodies (Abs) function, such as the role of antibody subclass, must be determined before such modalities can be carried from the bench to the bedside. We performed a subclass switch on anticapsular monoclonal murine IgG3 (mIgG3) hybridomas and identified and purified a murine IgG1 (mIgG1) hybridoma line through sib selection. We then compared the ability of the mIgG1 and mIgG3 antibodies to control CR-Kp sequence type 258 (ST258) infection both in vitro and in vivo. We found by enzyme-limited immunosorbent assay (ELISA) and flow cytometry that mIgG3 has superior binding to the CR-Kp capsular polysaccharide (CPS) and superior agglutinating ability compared to mIgG1. The mIgG3 also, predictably, had better complement-mediated serum bactericidal activity than the mIgG1 and also promoted neutrophil-mediated killing at concentrations lower than that of the mIgG1. In contrast, the mIgG1 had marginally better activity in improving macrophage-mediated phagocytosis. Comparing their activities in a pulmonary infection model with wild-type as well as neutropenic mice, both antibodies reduced organ burden in a nonlethal challenge, regardless of neutrophil status, with mIgG1 having the highest overall burden reduction in both scenarios. However, at a lethal inoculum, both antibodies showed reduced efficacy in neutropenic mice, with mIgG3 retaining the most activity. These findings suggest the viability of monoclonal Ab adjunctive therapy in neutropenic patients that cannot mount their own immune response, while also providing some insight into the relative contributions of immune mediators in CR-Kp protection.
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Vankemmelbeke M, McIntosh RS, Chua JX, Kirk T, Daniels I, Patsalidou M, Moss R, Parsons T, Scott D, Harris G, Ramage JM, Spendlove I, Durrant LG. Engineering the Human Fc Region Enables Direct Cell Killing by Cancer Glycan-Targeting Antibodies without the Need for Immune Effector Cells or Complement. Cancer Res 2020; 80:3399-3412. [PMID: 32532823 DOI: 10.1158/0008-5472.can-19-3599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 03/25/2020] [Accepted: 06/05/2020] [Indexed: 12/17/2022]
Abstract
Murine IgG3 glycan-targeting mAb often induces direct cell killing in the absence of immune effector cells or complement via a proinflammatory mechanism resembling oncotic necrosis. This cancer cell killing is due to noncovalent association between Fc regions of neighboring antibodies, resulting in enhanced avidity. Human isotypes do not contain the residues underlying this cooperative binding mode; consequently, the direct cell killing of mouse IgG3 mAb is lost upon chimerization or humanization. Using the Lewisa/c/x -targeting 88mAb, we identified the murine IgG3 residues underlying the direct cell killing and increased avidity via a series of constant region shuffling and subdomain swapping approaches to create improved ("i") chimeric mAb with enhanced tumor killing in vitro and in vivo. Constant region shuffling identified a major CH3 and a minor CH2 contribution, which was further mapped to discontinuous regions among residues 286-306 and 339-378 that, when introduced in 88hIgG1, recapitulated the direct cell killing and avidity of 88mIgG3. Of greater interest was the creation of a sialyl-di-Lewisa-targeting i129G1 mAb via introduction of these selected residues into 129hIgG1, converting it into a direct cell killing mAb with enhanced avidity and significant in vivo tumor control. The human iG1 mAb, termed Avidimabs, retained effector functions, paving the way for the proinflammatory direct cell killing to promote antibody-dependent cellular cytotoxicity and complement-dependent cytotoxicity through relief of immunosuppression. Ultimately, Fc engineering of human glycan-targeting IgG1 mAb confers proinflammatory direct cell killing and enhanced avidity, an approach that could be used to improve the avidity of other mAb with therapeutic potential. SIGNIFICANCE: Fc engineering enhances avidity and direct cell killing of cancer-targeting anti-glycan antibodies to create superior clinical candidates for cancer immunotherapy.
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Affiliation(s)
- Mireille Vankemmelbeke
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom.,Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Richard S McIntosh
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Jia Xin Chua
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom.,Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Thomas Kirk
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom.,Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Ian Daniels
- Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Marilena Patsalidou
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Robert Moss
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Tina Parsons
- Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - David Scott
- School of Biosciences, University of Nottingham, Sutton Bonington Campus, United Kingdom
| | - Gemma Harris
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot, United Kingdom
| | - Judith M Ramage
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Ian Spendlove
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
| | - Lindy G Durrant
- Academic Department of Clinical Oncology, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom. .,Scancell Limited, University of Nottingham Biodiscovery Institute, University Park, Nottingham, United Kingdom
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Recombinant Costimulatory Fusion Proteins as Functional Immunomodulators Enhance Antitumor Activity in Murine B16F10 Melanoma. Vaccines (Basel) 2020; 8:vaccines8020223. [PMID: 32423130 PMCID: PMC7349950 DOI: 10.3390/vaccines8020223] [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: 04/09/2020] [Revised: 05/04/2020] [Accepted: 05/12/2020] [Indexed: 11/23/2022] Open
Abstract
Blocking inhibitory signaling and engaging stimulatory signaling have emerged as important therapeutic modalities for cancer immunotherapy. This study aimed to investigate immunomodulatory features of three recombinant costimulatory ligand proteins in a mouse model, which are extracellular domains of OX40-ligand (OX40L), 4-1BB-ligand (4-1BBL), or two domains in tandem, fused with the transmembrane domain of diphtheria toxin (DTT), named DTT-COS1, DTT-COS2, and DTT-COS12, respectively. In vitro study showed that DTT-COS1 and DTT-COS12 had immunological activity increasing the ratio of CD8/CD4 T cells. Treatments with DTT-COS1 and DTT-COS12 dramatically generated immune protection against the B16F10 tumor challenge in both prophylactic and therapeutic efficacy. Furthermore, regarding tumor microenvironment (TME) immunomodulation, DTT-COS1 treatment increased the proportion of CD4+ effector T cells (Teff) and decreased the expression of a suppressive cytokine. Meanwhile, DTT-COS12 reduced regulatory T cells (Treg) and improved the level of stimulatory cytokines. In addition, endogenous antibodies against OX40L/4-1BBL were generated, which may help with antitumor responses. Unexpectedly, DTT-COS2 lacked antitumor effects in vitro and in vivo. Importantly, serum analysis of liver-function associated factors and pro-inflammatory cytokines demonstrated that treatments were safe formulations in mice without signs of systemic toxicity. Remarkably, DTT-COS1 and DTT-COS12 are functional immunomodulators for mouse B16F10 melanoma, creating practical preclinical value in cancer immunotherapy.
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14
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Abstract
PURPOSE OF REVIEW This review highlights recent developments in the development of monoclonal antibodies to treat bacterial disease, including preclinical advances and the status of current clinical trials. RECENT FINDINGS Monoclonal antibody (mAb) therapy is becoming increasingly promising in the infectious disease field. Though bacterial exotoxins continue to be a mainstay of mAb targets, searches for protein targets on the surface of bacteria have uncovered new mechanisms of antibody-mediated action against bacteria. Additionally, surveys of the polysaccharide serotype prevalence among antibiotic-resistant bacterial populations have yielded opportunities to leverage human selective pressures to our clinical advantage. Several mAb candidates are progressing through clinical development with great promise, especially those with structures altered to provide maximum benefit. Although other clinical trials have recently proved unsuccessful, these failures and lessons from immune profiling provide opportunities to understand how vulnerabilities of certain targets may change in different disease states. SUMMARY Despite the hurdles of identifying effective targets and understanding how mAbs provide protection within different infections, we show that the progress made in these fields is a positive indication of mAbs becoming more widely accepted as the future for treating bacterial infections.
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Affiliation(s)
- Michael P Motley
- Department of Medicine, Infectious Disease Division, Stony Brook University, Stony Brook, New York, USA
| | - Kasturi Banerjee
- Department of Medicine, Infectious Disease Division, Stony Brook University, Stony Brook, New York, USA
| | - Bettina C. Fries
- Department of Medicine, Infectious Disease Division, Stony Brook University, Stony Brook, New York, USA
- Department of Molecular Genetics and Microbiology, Stony Brook University, Stony Brook, New York, USA
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