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Two SARS-CoV-2 XBB sub-variants, FL.1 and GE.1, have been increasing in prevalence worldwide, but limited information is available about their ability to evade the immune system. FL.1 and GE.1 are emerging Omicron XBB variants possessing additional mutations in the spike RBD raising concerns of increased neutralization escape. In this study, we assessed the neutralizing ability of eleven FDA-approved monoclonal antibody combinations against different Omicron variants, including BA.2.75, BA.2.76, BA.4/5, XBB.1.5, and CH.1.1. Among the eleven antibodies, Sotrovimab was the only antibody to show broad neutralization ability against XBB.1.5. However, Sotrovimab showed attenuated neutralization efficiency against recently emerging XBB sub-lineages EG.5, FL.1, and GE.1 compared to XBB.1.5. Additionally, XBB.1.5 seropositive convalescent sera displayed lower neutralization activity against EG.5, FL.1, and GE.1. Overall, our findings present enhanced immune evasion capacity of emerging XBB variants and emphasize the importance of continued monitoring of novel variants., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Interleukin-17A (IL-17A) produced by Th17 cells, contributes to the pathogenesis of various autoimmune diseases by stimulating the release of cytokines and chemokines and its regulation. Anti-IL-17A antibody which blocks the function of IL-17A has been proved to be an effective treatment of autoimmune disease. The aim of our study was to generate a potential humanized anti-IL-17A therapeutic monoclonal antibody (mAb) through a comprehensive panel of in vitro and in vivo biological activity studies, as well as physicochemical characterization. HZD37-5, a humanized monoclonal antibody specifically recognizing N78 loci of IL-17A, binds to human and rhesus monkeys, blocks IL-17 induced signal transduction and the release of IL-6, IL-8, CXCL-1 and G-GSF. In an in vivo efficacy mouse model, HZD37-5 significantly inhibited human IL-17A induced-keratinocyte chemoattractant (KC) secretion in a dose-dependent manner. The pharmacokinetics (PK) study result of HZD37-5 in rhesus monkeys indicated that HZD37-5 had favorable PK characteristics with limited distribution (78.0-78.8 ml/kg), slow elimination (5.00-6.45 ml/day/kg), long half-life (9.1-10.7 days) and high bioavailability (103%) following a single IV or SC dose at 1.5 mg/kg. These findings provided a comprehensive preclinical characterization of HZD37-5 and supported that it may be developed as a potential therapeutic for the treatment of autoimmune diseases, including psoriasis, psoriatic arthritis, axial spondyloarthritis, etc., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Tumor-associated glycoprotein (TAG)-72 is a pancarcinoma antigen that is overexpressed in greater than 80% of colorectal adenocarcinomas. CC49 is a TAG-72-specific antibody. The aim of the present study was to demonstrate selective imaging of colon tumors and metastases with the humanized TAG-72 antibody (anti-huCC49) conjugated to a near-infrared fluorophore in orthotopic mouse models., Methods: Anti-huCC49 was conjugated to near-infrared dye IR800CW. Mouse imaging was performed with the Pearl Trilogy Small Animal and FLARE Imaging Systems. Subcutaneous mouse models of colon cancer cell line LS174T were used to determine the optimal dose of administration and timing of imaging. Orthotopic mouse models of LS174T were established by surgical orthotopic implantation of LS174T tumors onto the serosa of the cecum. Peritoneal carcinomatosis models were established by injection of LS174T cells into the peritoneum of nude mice. Mice were administered anti-huCC49-IR800 via tail vein injection. Mice were euthanized 72 h later and imaged after laparotomy., Results: Subcutaneous LS174T xenografts demonstrated optimal tumor detection 72 h after administration with 50 μg anti-huCC49-IR800CW. Tumors were visualized with fluorescence imaging with a mean tumor-to-liver ratio of 7.39 (standard deviation: 2.76). In the orthotopic model, metastases smaller than 1 mm were fluorescently visualized that were invisible with bright light., Conclusions: Anti-huCC49-IR800CW provides sensitive and specific imaging of colon cancer and metastases at a submillimeter resolution in metastatic nude mice models. This provides a promising near-infrared probe for the imaging of colon cancer and metastases for preoperative diagnosis and fluorescence-guided surgery., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Uterine serous carcinoma (USC) is an aggressive variant of endometrial cancer with poor prognosis. Sacituzumab govitecan (SG) is a novel antibody-drug-conjugate (ADC) targeting trophoblast cell-surface antigen 2 (Trop-2), a transmembrane-calcium-signal-transducer, to deliver SN-38, the active metabolite of irinotecan. The objective of this study was to evaluate the expression of Trop-2 in USC and the preclinical activity of SG against primary USC cell-lines and xenografts., Methods: We used immunohistochemistry (IHC) and flow-cytometry-based assays to evaluate Trop-2 expression and cell-viability in USC tissue and primary tumor-cell-lines after exposure to SG, non-targeting control ADC, and naked antibody hRS7-IgG. Antibody-dependent-cell-cytotoxicity (ADCC) against Trop-2+ and Trop-2- USC cell-lines was evaluated in vitro using 4-hr-Chromium-release-assays. In vivo activity of SG was tested against Trop-2+ USC xenografts by intravenous administration of SG, control ADC, and hRS7., Results: Trop-2 expression by IHC was detected in 95.1% of USC samples (99/104). Primary tumor cell-lines overexpressing Trop-2 were significantly more sensitive to SG when compared to control ADC (p <0.05). Both SG and hRS7 mediated ADCC in Trop2+ USC cell-lines while no cytotoxicity was detected against Trop-2- cells. SG induced significant bystander killing of Trop-2- tumors when admixed with Trop-2+ tumors. SG caused growth-inhibition and increased survival in SG treated mice harboring Trop-2+ xenografts when compared to controls (p <0.05)., Conclusions: SG is remarkably active against USC overexpressing Trop-2 in vitro and in vivo. Our results combined with SG clinical responses recently reported against multiple chemotherapy resistant human tumors further support clinical development of SG in USC patients with advanced/recurrent disease., (Copyright © 2019 Elsevier Inc. All rights reserved.)

An imbalance between production and clearance of soluble amyloid-β (Aβ) initiates the pathological process in sporadic Alzheimer's disease (AD). Aβ-specific antibodies seemed promising as therapeutic option in AD mouse models. In patients, however, vascular side-effects and Aβ-antibody complex-induced microglial and/or perivascular macrophage inflammatory responses were encountered. To prevent inflammatory reactions, we designed a single chain variable fragment (scFv-h3D6), based on monoclonal antibody bapineuzumab (mAb-h3D6), but lacking the Fc region. ScFv-h3D6 reduced Aβ-oligomer burden and prevented AD-associated behavioral and cellular changes in 3xTg-AD mice. As scFv-h3D6 lacks the Fc-tail, it cannot enhance Fc-receptor mediated Aβ clearance by microglia and probably exerts its beneficial effects in 3xTg-AD mice through other mechanisms. ScFv-h3D6 restored the increased apoE and apoJ levels in 3xTg-AD brains back to normal. ApoE and apoJ influence cholesterol transport, Aβ aggregation and clearance, and their genetic variants are risk factors for sporadic AD. Astrocytes are constitutive scavengers of soluble Aβ from the CNS. We previously found apoE and apoJ to inhibit Aβ uptake by adult human astrocytes, in vitro, and thus to potentially protect astrocytes from Aβ cytotoxicity. In the present study, scFv-h3D6 and mAb-h3D6 inhibited Aβ-oligomer uptake by adult human astrocytes. ApoE- and apoJ- mimetic peptides (MP) affected Aβ uptake as well as Aβ-induced cytokine release similar to intact apoE and apoJ, without interfering with the strong inhibitory effects of scFv-h3D6 on Aβ-oligomer uptake. These results suggest that combining Aβ-specific scFv and apoE-MP, that inhibits Aβ oligomer-induced cytokine release by astrocytes, could offer advantages over currently used therapeutics., (Copyright © 2018 The Authors. Published by Elsevier Inc. All rights reserved.)

Monoclonal antibody pharmaceuticals are the fastest-growing class of therapeutics, with a wide range of clinical applications. To assure their safety, these protein drugs must demonstrate highly consistent purity and stability. Key to these objectives is higher order structure measurements validated by calibration to reference materials. We describe preparation, characterization, and crystal structure of the Fab fragment prepared from the NIST Reference Antibody RM 8671 (NISTmAb). NISTmAb is a humanized IgG1κ antibody, produced in murine cell culture and purified by standard biopharmaceutical production methods, developed at the National Institute of Standards and Technology (NIST) to serve as a reference material. The Fab fragment was derived from NISTmAb through papain cleavage followed by protein A based purification. The purified Fab fragment was characterized by SDS-PAGE, capillary gel electrophoresis, multi-angle light scattering, size exclusion chromatography, mass spectrometry, and x-ray crystallography. The crystal structure at 0.2 nm resolution includes four independent Fab molecules with complete light chains and heavy chains through Cys 223, enabling assessment of conformational variability and providing a well-characterized reference structure for research and engineering applications. This nonproprietary, publically available reference material of known higher-order structure can support metrology in biopharmaceutical applications, and it is a suitable platform for validation of molecular modeling studies., (Published by Elsevier Ltd.)

A novel monoclonal antibody against human epidermal growth factor receptor 2 (HER2), i.e., pertuzumab (Perjeta®) developed by Genentech, has been verified to be effective in treating metastatic HER2-overexpressing breast cancer. The fact that the presence of the Fc region of the anti-HER2 is uncritical for growth inhibition of tumor cells suggests the potential biological activity of the associated antibody fragments. In the present study, we report functional expression of anti-HER2his-scFv, a single-chain variable fragment (scFv) derived from pertuzumab, in the periplasm of Escherichia coli and its purification. Biological activity of the soluble scFv produced in this manner was characterized using immunofluorescent staining, immunocytochemistry, flow cytometry and cytotoxicity assay. The effect of anti-HER2his-scFv on HER2 dimerization was also assessed by tyrosine kinase assay. It was observed that the purified scFv had a high specificity and affinity to HER2 receptors expressed on the surface of tumor cells with a selective cytotoxic effect on HER2-overexpressing SK-OV-3 cells. In addition, anti-HER2his-scFv was able to suppress phosphorylation of HER2 in the presence of heregulin. The results suggest that anti-HER2his-scFv can be a potential candidate for various therapeutic and diagnosis applications., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Around 350 million people worldwide suffer from rare diseases. These may have a genetic, infectious, or autoimmune basis, and several include an inflammatory component. Launching of effective treatments can be very challenging when there is a low disease prevalence and limited scientific insights into the disease mechanisms. As a key trigger of inflammatory processes, complement has been associated with a variety of diseases and has become an attractive therapeutic target for conditions involving inflammation. In view of the clinical experience acquired with drugs licensed for the treatment of rare diseases such as hereditary angioedema and paroxysmal nocturnal hemoglobinuria, growing evidence supports the safety and efficacy of complement therapeutics in restoring immune balance and preventing aggravation of clinical outcomes. This review provides an overview of the candidates currently in the pharmaceutical pipeline with potential to treat orphan diseases and discusses the molecular mechanisms triggered by complement involved with the disease pathogenesis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: The primary objective was to evaluate the clinical efficacy of hu3S193, a humanized monoclonal antibody against the Lewis-Y antigen, in patients with platinum resistant/refractory ovarian, fallopian tube and primary peritoneal carcinoma. Secondary objectives were safety and pharmacokinetics. In addition, we sought to determine the potential interaction of clinical benefit and patient characteristics., Methods: This two-stage, multicenter, single arm, phase II trial enrolled eligible patients to receive hu3S193 weekly at a dose of 20mg/m(2) intravenously for 8 weeks (1 cycle) to a maximum of 3 cycles. Efficacy was measured as clinical benefit rate (objective response or stable disease for at least 24 weeks)., Results: 26 of 31 patients were eligible for efficacy analysis. No complete/partial responses were observed. Six patients had stable disease for 24+weeks [clinical benefit rate 23% (95% CI=9.77%-46.71%)]. Median PFS was 8.4 weeks (95% CI=6.0 to 16.1). Median PFS differed between patients with no ascites and no visceral disease and patients with ascites and/or visceral disease [16.1 vs. 8.1 weeks (p=0.0058)]. The most commonly reported treatment-related adverse events were fatigue (19.3%) and nausea (16.2%). Allergic reactions occurred in 6 patients (5 with Grade 1/2; 1 with Grade 3)., Conclusions: Hu3S193 lacked sufficient activity in the first stage of the study to open enrollment to the second stage. However, based on the longer PFS in patients with no ascites and no visceral disease, consolidation strategies in platinum sensitive disease are currently being tested., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Interleukin 17 (IL-17) includes several cytokines among which IL-17A is considered as one of the major pro-inflammatory cytokine being central to the innate and adaptive immune responses. IL-17 is produced by unconventional T cells, members of innate lymphoid cells (ILCs), mast cells, as well as typical innate immune cells, such as neutrophils and macrophages located in the epithelial barriers and characterised by a rapid response to infectious agents by recruiting neutrophils as first line of defence and inducing the production of antimicrobial peptides. Th17 responses appear pivotal in chronic and acute infections by bacteria, parasites, and fungi, as well as in autoimmune and chronic inflammatory diseases, including rheumatoid arthritis, psoriasis, and psoriatic arthritis. The data discussed in this review cumulatively indicate that innate-derived IL-17 constitutes a major element in the altered immune response against self antigens or the perpetuation of inflammation, particularly at mucosal sites. New drugs targeting the IL17 pathway include brodalumab, ixekizumab, and secukinumab and their use in psoriatic disease is expected to dramatically impact our approach to this systemic condition., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

CD20 is a B cell lineage specific surface antigen involved in various B cell malignancies. So far, several murine and chimeric antibodies have been produced against this antigen among which Rituximab is a commercially approved antibody widely used in treatment of cancers associated with CD20 overexpression. The current study reports the production and characterization of a humanized single chain version of Rituximab through CDR grafting method. For either heavy or light chain variable domains, a human antibody with the highest sequence homology to Rituximab was selected from human germline sequences and used as framework donors. Vernier zone residues in framework regions were replaced with those of Rituximab to retain the antigen binding affinity of parental antibody. The reactivity of humanized single chain antibody with CD20 was examined by ELISA and dot blot assays. The ability of antibody to suppress the growth of CD20 overexpressing Raji cells was tested by MTT assay. Analysis of reactivity with CD20 antigen revealed that the humanized single chain antibody reacted to the target antigen with high affinity. Proliferation inhibition assay showed that humanized scFv could suppress the proliferation of Raji cells efficiently in a dose-dependent manner. This successful production of a humanized scFv with the ability to inhibit growth of CD20-expressing cancer cell may provide a promising alternative strategy for CD20 targeted therapy., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (Kon) for binding to RSV F protein, while alteration of dissociation rate (Koff) did not significantly affect neutralizing activity. Interestingly, linkage of reduced Kon with reduced potency mirrored the effect of increased Kon found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The nuclear autoantigen La can be detected on the surface of dying cells. Here we present an assay which enables us to show that La protein is not limited to the surface of dying cells but will be released upon stress-induced cell death. As released La protein tightly binds to the surface of neighboring intact cells we asked the question whether or not La protein could serve as a stress-inducible target e.g. for redirecting of regulatory T cells (Tregs) into damaged tissues to downregulate an immune response. In order to provide first proof of concept we developed a novel fully humanized single-chain bispecific antibody (bsAb) which on the one hand is directed to the La antigen and on the other hand to the CD3 complex of T cells. A cross-linkage of Tregs with La-decorated target cells mediated by this bsAb resulted indeed in the activation of the Tregs in a target-dependent manner. Moreover, such bsAb activated Tregs displayed a potent suppressive capacity and negatively influenced proliferation, expansion and cytokine production of autologous CD4(+) and CD8(+) Teff cells., (Copyright © 2013 Elsevier Ltd. All rights reserved.)

Unlabelled: The effect of an anti-human leukocyte antigen-DR (MHC class II) humanized monoclonal antibody, IMMU-114, against the human to bovine cellular response was investigated., Methods: Human peripheral mononuclear cells (PBMCs) were cocultured with inactivated self-PBMCs (Self), bovine PBMCs with control antibody (Xeno), or bovine PBMCs with IMMU-114 (IMMU-114). Cellular responses were investigated by thymidine incorporation assay, CFSE (carboxyfluorescein diacetate succinimidyl ester)-mixed lymphocyte reaction, and cytokine production in culture medium., Results: Thymidine incorporation rates at a 1:1 responder to stimulator ratio for Xeno + control antibody, Xeno + IMMU-114, Self + control antibody, and Self + IMMU-114 were 14201.3 ± 1968.4, 513.0 ± 49.5, 952.7 ± 128.7, and 423.3 ± 138.8 cpm, respectively (P = 0.032). Those at a 1:2 ratio were 6518.0 ± 690.1, 896.6 ± 92.9, 1051.0 ± 123.6, and 736.0 ± 35.6 cpm, respectively (P = 0.036). CFSE-mixed lymphocyte reaction demonstrated that the frequencies of CFSE-low, CD4(+), and CD25(+) activating T cells in Self, Xeno, and IMMU-114 were 0.27 ± 0.04%, 3.65 ± 0.53%, and 1.23 ± 0.15%, respectively (P = 0.027). Cytokine production in culture medium indicated that IMMU-114 decreased Th1-type cytokines, including interleukin-2, interferon-γ, and tumor necrosis factor-α., Conclusion: IMMU-114 effectively suppresses human to bovine cellular responses. The mechanism involves direct inhibition of the interaction between class II human leukocyte antigen-DR-positive cells and CD4(+) T cells, and indirect suppression of Th1 cytokine production., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Currently there are no licensed antiviral treatments for the Alphaviruses Venezuelan equine encephalitis virus (VEEV), Everglades virus and Mucambo virus. We previously developed a humanised version of the mouse monoclonal antibody 1A3B-7 (Hu1A3B-7) which exhibited a wide range of reactivity in vitro and was able to protect mice from infection with VEEV. Continued work with the humanised antibody has now demonstrated that it has the potential to be a new human therapeutic. Hu1A3B-7 successfully protected mice from infection with multiple Alphaviruses. The effectiveness of the humanisation process was determined by assessing proliferation responses in human T-cells to peptides derived from the murine and humanised versions of the V(H) and V(L) domains. This analysis showed that the number of human T-cell epitopes within the humanised antibody had been substantially reduced, indicating that Hu1A3B-7 may have reduced immunogenicity in vivo., (Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.)

The recently successful targeting of B cells in patients with multiple sclerosis (MS) using monoclonal antibodies (mAbs) targeting CD20 has established that it is no longer a question of whether B cells contribute, but how they contribute, to MS disease activity. Here, the focus will be to review results that have emerged over the last few years from clinical trials of different anti-CD20 mAbs in patients with MS. We will also consider the biological basis underlying the apparent therapeutic efficacy of B cell depletion in MS. To this end, we will draw on several instructive observations made in MS patients who were treated with the anti-CD20 mAb rituximab. While the initial application of rituximab to patients with MS was based on the concept that B cell depletion may translate into decreases in potentially pathogenic CNS-autoreactive antibodies, insights from these studies have underscored the importance of non-antibody mediated functions of B cells., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Alemtuzumab is a humanized monoclonal antibody targeting CD52, a broadly expressed cell surface molecule on immune cells. Application results in a rapid and long-lasting removal of lymphocyte populations from the circulation. Alemtuzumab-treatment of MS patients with relapsing-remitting forms of the disease significantly reduced the risk of relapse and accumulation of disability compared to interferon β-1a treatment in a phase II trial. Interestingly, further analysis together with parallel experimental studies suggested that alemtuzumab not only reduces disease activity due to its immune cell-depleting effect, but also confers neuroprotective effects, presumably by inducing production of neurotrophic factors in autoreactive T cells. However, alemtuzumab-treated MS patients experienced increased rates of novel autoimmunity and a slight increase in infections, demonstrating that alemtuzumab-mediated skewing of the immune cell compartment has a broad influence on immune functions. This review discusses the current concepts about the underlying mechanisms causing these altered immune responses in alemtuzumab-treated MS patients., (Copyright © 2011 Elsevier Inc. All rights reserved.)