Revisions to the requirement of the Japanese clinical study data for biosimilar developments in Japan.

BACKGROUND: The 'Questions and Answers (Q&A)' document regarding Japanese biosimilar guideline elucidated that Japanese participant enrollment in at least one comparative clinical study was required for the marketing authorization application (MAA) of biosimilars in Japan. RESEARCH DESIGN AND METHODS: To discuss the requirement of Japanese clinical study data for biosimilar development, the trend in comparative clinical studies conducted for approved biosimilars of monoclonal antibodies and fusion proteins was analyzed, and the consistency of the results between the overall population and the Japanese population according to the publicly available information was reviewed. RESULTS: The number of comparative clinical studies enrolling Japanese participants was 25 cases, and the type and percentage were 13 (52%) and 12 (48%) cases of comparative pharmacokinetic study and comparative efficacy study, respectively. In all comparative clinical studies, consistent results between the overall population and the Japanese population were shown. CONCLUSIONS: Our study indicated that Japanese participant enrollment in comparative clinical studies may not always be necessary for biosimilar development when certain conditions are satisfied. This has been described in the revised Q&A document published by the Ministry of Health, Labour and Welfare in January 2024.

KLHL17 differentially controls the expression of AMPA- and KA-type glutamate receptors to regulate dendritic spine enlargement.

Kelch-like family member 17 (KLHL17), an actin-associated adaptor protein, is linked to neurological disorders, including infantile spasms and autism spectrum disorders. The key morphological feature of Klhl17-deficient neurons is impaired dendritic spine enlargement, resulting in the amplitude of calcium events being increased. Our previous studies have indicated an involvement of F-actin and the spine apparatus in KLHL17-mediated dendritic spine enlargement. Here, we show that KLHL17 further employs different mechanisms to control the expression of two types of glutamate receptors, that is, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) and kainate receptors (KARs), to regulate dendritic spine enlargement and calcium influx. We deployed proteomics to reveal that KLHL17 interacts with N-ethylmaleimide-sensitive fusion protein (NSF) in neurons, with this interaction of KLHL17 and NSF enhancing NSF protein levels. Consistent with the function of NSF in regulating the surface expression of AMPAR, Klhl17 deficiency limits the surface expression of AMPAR, but not its total protein levels. The NSF pathway also contributes to synaptic F-actin distribution and the dendritic spine enlargement mediated by KLHL17. KLHL17 is known to act as an adaptor mediating degradation of the KAR subunit GluK2 by the CUL3 ubiquitin ligase complex, and Klhl17 deficiency impairs activity-dependent degradation of GluK2. Herein, we further demonstrate that GluK2 is critical to the increased amplitude of calcium influx in Klhl17-deficient neurons. Moreover, GluK2 is also involved in KLHL17-regulated dendritic spine enlargement. Thus, our study reveals that KLHL17 controls AMPAR and KAR expression via at least two mechanisms, consequently regulating dendritic spine enlargement. The regulatory effects of KLHL17 on these two glutamate receptors likely contribute to neuronal features in patients suffering from certain neurological disorders.

Enhancing immunogenicity and antiviral protection of inactivated porcine reproductive and respiratory syndrome virus vaccine in piglets.

OBJECTIVE: Porcine interferon-γ (poIFN-γ) and porcine granulocyte-macrophage colony-stimulating factor (poGM-CSF) are multifunctional cytokines that exhibit robust antiviral activity against porcine reproductive and respiratory syndrome virus (PRRSV). In this study, the immunoadjuvant effects of recombinant poIFN-γ-poGM-CSF fusion protein in inactivated PRRSV vaccine administered to piglets were assessed. ANIMALS: Twenty-eight 4-week-old specific pathogen-free piglets. METHODS: The experimental piglets were divided into control, highly pathologic PRRSV, PRRSV killed virus vaccine (KV), poIFN-γ-poGM-CSF, KV + 1.0 mg poIFN-γ-poGM-CSF, KV + 2.0 mg poIFN-γ-poGM-CSF, and KV + 4.0 mg poIFN-γ-poGM-CSF groups. A recombinant poIFN-γ-linker-poGM-CSF fusion gene was constructed via splicing by overlap extension PCR and prepared using an Escherichia coli expression system, after which its adjuvant activity in the context of PRRSV KV administration was assessed. RESULTS: This analysis revealed the successful construction of the poIFN-γ-linker-poGM-CSF fusion gene via splicing by overlap extension PCR, with recombinant poIFN-γ-linker-poGM-CSF successfully being prepared in E coli with a plasmid vector for expressing thioredoxin fusion proteins with an enterokinase site. Importantly, the coadministration of poIFN-γ-linker-poGM-CSF and PRRSV KV significantly increased neutralizing antibody titers, accelerated viral clearance, reduced clinical symptoms, and prevented highly pathogenic PRRSV infection. CLINICAL RELEVANCE: The recombinant poIFN-γ-poGM-CSF fusion protein is a promising candidate adjuvant for use in the context of swine immunization and viral challenge.

Prediction of Pesticide Interactions with Proteins Involved in Human Reproduction by Using a Virtual Screening Approach: A Case Study of Famoxadone Binding CRBP-III and Izumo.

In recent years, the awareness that pesticides can have other effects apart from generic toxicity is growing. In particular, several pieces of evidence highlight their influence on human fertility. In this study, we investigated, by a virtual screening approach, the binding between pesticides and proteins present in human gametes or associated with reproduction, in order to identify new interactions that could affect human fertility. To this aim, we prepared ligand (pesticides) and receptor (proteins) 3D structure datasets from online structural databases (such as PubChem and RCSB), and performed a virtual screening analysis using Autodock Vina. In the comparison of the predicted interactions, we found that famoxadone was predicted to bind Cellular Retinol Binding Protein-III in the retinol-binding site with a better minimum energy value of -10.4 Kcal/mol and an RMSD of 3.77 with respect to retinol (-7.1 Kcal/mol). In addition to a similar network of interactions, famoxadone binding is more stabilized by additional hydrophobic patches including L20, V29, A33, F57, L117, and L118 amino acid residues and hydrogen bonds with Y19 and K40. These results support a possible competitive effect of famoxadone on retinol binding with impacts on the ability of developing the cardiac tissue, in accordance with the literature data on zebrafish embryos. Moreover, famoxadone binds, with a minimum energy value between -8.3 and -8.0 Kcal/mol, to the IZUMO Sperm-Egg Fusion Protein, interacting with a network of polar and hydrophobic amino acid residues in the cavity between the 4HB and Ig-like domains. This binding is more stabilized by a predicted hydrogen bond with the N185 residue of the protein. A hindrance in this position can probably affect the conformational change for JUNO binding, avoiding the gamete membrane fusion to form the zygote. This work opens new interesting perspectives of study on the effects of pesticides on fertility, extending the knowledge to other typologies of interaction which can affect different steps of the reproductive process.

Generation of novel respiratory syncytial virus vaccine candidate antigens that can induce high levels of prefusion-specific antibodies.

Respiratory syncytial virus (RSV) infection is an acute respiratory infection caused by RSV. It occurs worldwide, and for over 50 years, several attempts have been made to research and develop vaccines to prevent RSV infection; effective preventive vaccines are eagerly awaited. The RSV fusion (F) protein, which has gained attention as a vaccine antigen, causes a dynamic structural change from the preF to postF state. Therefore, the structural changes in proteins must be regulated to produce a vaccine antigen that can efficiently induce antibodies with high virus-neutralizing activity. We successfully discovered several mutations that stabilized the antigen site Ø in the preF state, trimerized it, and improved the level of protein expression through observation and computational analysis of the RSV-F protein structure and amino acid mutation analysis of RSV strains. The four RSV-F protein mutants that resulted from the combination of these effective mutations stably conserved a wide range of preF- and trimeric preF-specific epitopes with high virus-neutralizing activity. Absorption assay using human serum revealed that mutants constructed bound to antibodies with virus-neutralizing activity that were induced by natural RSV infection, whereas they hardly bound to anti-postF antibodies without virus-neutralizing activity. Furthermore, mouse immunization demonstrated that our constructed mutants induced a high percentage of antibodies that bind to the preF-specific antigen site. These characteristics suggest that the mutants constructed can be superior vaccine antigens from the viewpoint of RSV infection prevention effect and safety.

A fusion protein approach to integrate antiviral and anti-inflammatory activities for developing new therapeutics against influenza A virus infection.

Human interferon α2 (IFNα2) is a cytokine with broad-spectrum antiviral activity, and its engineered forms are widely used to treat viral infections. However, IFNα2 may trigger proinflammatory responses and underlying side effects during treatment. Trefoil factor 2 (TFF2) is a secreted protein with anti-inflammatory properties. Here, we explored whether coupling IFNα2 to TFF2 in a two-in-one fusion form could combine the beneficial effects of both molecules on viral infections toward a more desirable treatment outcome. We engineered two forms of human IFNα2 and TFF2 fusion proteins, IFNα2-TFF2-Fc (ITF) and TFF2-IFNα2-Fc (TIF), and examined their properties in vitro in comparison to IFNα2 and TFF2 alone. RNA-Seq was further used to explore such comparison on dynamic gene regulation at transriptomic level. These in vitro assessments collectively indicated that TIF largely retained the antiviral activity of IFNα2 while being a weaker inflammation inducer, consistent with the presence of TFF2 activity. We further demonstrated the superiority of TIF over IFNα2 or TFF2 alone in treating influenza infection using a mouse infection model. Together, our study provided evidence supporting that, by possessing antiviral activity conferred by IFNα2 with complementation from TFF2 in suppressing the inflammatory side effects, the fusion proteins, particularly TIF, represent more effective agents against influenza and other respiratory viral infections than IFNα2 or TFF2 alone. It implies that merging two molecules with complementary functions holds potential for developing novel therapeutics against viral infections.

Discovery and preclinical evaluation of KYS202004A, a novel bispecific fusion protein targeting TNF-α and IL-17A, in autoimmune disease models.

The treatment of autoimmune and inflammatory diseases often requires targeting multiple pathogenic pathways. KYS202004A is a novel bispecific fusion protein designed to antagonize TNF-α and IL-17A, pivotal in the pathophysiology of autoimmune and inflammatory diseases. Our initial efforts focused on screening for optimal structure by analyzing expression levels, purity, and binding capabilities. The binding affinity of KYS202004A to TNF-α and IL-17A was evaluated using SPR. In vitro, we assessed the inhibitory capacity of KYS202004A on cytokine-induced CXCL1 expression in HT29 cells. In vivo, its efficacy was tested using a Collagen-Induced Arthritis (CIA) model in transgenic human-IL-17A mice and an imiquimod-induced psoriasis model in cynomolgus monkeys. KYS202004A demonstrated significant inhibition of IL-17A and TNF-α signaling pathways, outperforming the efficacy of monotherapeutic agents ixekizumab and etanercept in reducing CXCL1 expression in vitro and ameliorating disease markers in vivo. In the CIA model, KYS202004A significantly reduced clinical symptoms, joint destruction, and serum IL-6 concentrations. The psoriasis model revealed that KYS202004A, particularly at a 2  mg/kg dose, was as effective as the combination of ixekizumab and etanercept. This discovery represents a significant advancement in treating autoimmune and inflammatory diseases, offering a dual-targeted therapeutic approach with enhanced efficacy over current monotherapies.

Implementation of a LC-MS based multi-attribute method (MAM) and intact multi-attribute method (iMAM) workflow for the characterisation of a GLP-Fc fusion protein.

Over the past few years, the implementation of mass spectrometry (MS) in QC laboratories has become a more common occurrence. The multi-attribute method (MAM), and emerging intact multi-attribute method (iMAM), are powerful analytical tools utilising liquid chromatography-mass spectrometry (LC-MS) methods that enable the monitoring of critical quality attributes (CQAs) in biotherapeutic proteins in compliant settings. Both MAM and iMAM are intended to replace or supplement several conventional assays with a single LC-MS method utilising MS data in combination with robust, semi-automated data processing workflows. MAM and iMAM workflows can also be implemented into current Good Manufacturing Practices environments due to the availability of CFR 11 compliant chromatography data system software. In this study, MAM and iMAM are employed for the analysis of 4 batches of a glucagon-like peptide-Fc fusion protein. MAM approach involved a first the discovery phase for the identification of CQAs and second, the target monitoring phase of the selected CQAs in other samples. New peak detection was performed on the data set to determine the appearance, absence or change of any peak. For native iMAM workflow both size exclusion and strong cation exchange chromatography were optimized for the identification and monitoring of CQAs at the intact level.

Elucidation of the Reversible Self-Association Interface of a Diabody-Interleukin Fusion Protein Using Hydrogen-Exchange Mass Spectrometry and In Silico Modeling.

Reversible self-association (RSA) of therapeutic proteins presents major challenges in the development of high-concentration formulations, especially those intended for subcutaneous administration. Understanding self-association mechanisms is therefore critical to the design and selection of candidates with acceptable developability to advance to clinical trials. The combination of experiments and in silico modeling presents a powerful tool to elucidate the interface of self-association. RSA of monoclonal antibodies has been studied extensively under different solution conditions and have been shown to involve interactions for both the antigen-binding fragment and the crystallizable fragment. Novel modalities such as bispecific antibodies, antigen-binding fragments, single-chain-variable fragments, and diabodies constitute a fast-growing class of antibody-based therapeutics that have unique physiochemical properties compared to monoclonal antibodies. In this study, the RSA interface of a diabody-interleukin 22 fusion protein (FP-1) was studied using hydrogen-deuterium exchange coupled with mass spectrometry (HDX-MS) in combination with in silico modeling. Taken together, the results show that a complex solution behavior underlies the self-association of FP-1 and that the interface thereof can be attributed to a specific segment in the variable light chain of the diabody. These findings also demonstrate that the combination of HDX-MS with in silico modeling is a powerful tool to guide the design and candidate selection of novel biotherapeutic modalities.

Functional studies on tandem carbohydrate-binding modules of a multimodular enzyme possessing two catalytic domains.

Although functional studies on carbohydrate-binding module (CBM) have been carried out extensively, the role of tandem CBMs in the enzyme containing multiple catalytic domains (CDs) is unclear. Here, we identified a multidomain enzyme (Lc25986) with a novel modular structure from lignocellulolytic bacterial consortium. It consists of a mannanase domain, two CBM65 domains (LcCBM65-1/LcCBM65-2), and an esterase domain. To investigate CBM function and domain interactions, full-length Lc25986 and its variants were constructed and used for enzymatic activity, binding, and bioinformatic analyses. The results showed that LcCBM65-1 and LcCBM65-2 both bind mannan and xyloglucan but not cellulose or ß-1,3-1,4-glucan, which differs from the ligand specificity of reported CBM65s. Compared to LcCBM65-2, LcCBM65-1 showed a stronger ligand affinity and a preference for acetylation sites. Both CBM65s stimulated the enzymatic activities of their respective neighboring CDs against acetylated mannan, but did not contribute to the activities of the distal CDs. The time course of mannan hydrolysis indicated that the full-length Lc25986 was more effective in the complete degradation of mixed acetyl/non-acetyl substrates than the mixture of single-CD mutants. When acting on complex substrates, LcCBM65-1 not only improved the enzymatic activity of the mannanase domain, but also directed the esterase domain to the acetylated polysaccharides. LcCBM65-2 adopted a low affinity to reduce interference with the catalysis of the mannanase domain. These results demonstrate the importance of CBMs for the synergism between the two CDs of a multidomain enzyme and suggest that they contribute to the adequate degradation of complex substrates such as plant cell walls. IMPORTANCE: Lignocellulolytic enzymes, particularly those of bacterial origin, often harbor multiple carbohydrate-binding modules (CBMs). However, the function of CBM multivalency remains poorly understood. This is especially true for enzymes that contain more than one catalytic domain (CD), as the interactions between CDs, CBMs, and CDs and CBMs can be complex. Our research demonstrates that homogeneous CBMs can have distinct functions in a multimodular enzyme. The tandem CBMs coordinate the CDs in catalytic conflict through their differences in binding affinity, ligand preference, and arrangement within the full-length enzyme. Additionally, although the synergism between mannanase and esterase is widely acknowledged, our study highlights the benefits of integrating the two enzymes into a single entity for the degradation of complex substrates. In summary, these findings enhance our understanding of the intra-synergism of a multimodular enzyme and emphasize the significance of multiple CBMs in this context.

Optimizing the Amino Acid Sequence Enhances the Productivity and Bioefficacy of the RBP-Albumin Fusion Protein.

The significant growth of the global protein drug market, including fusion proteins, emphasizes the crucial role of optimizing amino acid sequences to enhance the productivity and bioefficacy. Among these fusion proteins, RBP-IIIA-IB, comprising retinol-binding protein in conjunction with the albumin domains, IIIA and IB, has displayed efficacy in alleviating liver fibrosis by inhibiting the activation of hepatic stellate cells (HSCs). This study aimed to address the issue of the low productivity in RBP-IIIA-IB. To induce structural changes, the linking sequence, EVDD, between domain IIIA and IB in RBP-IIIA-IB was modified to DGPG, AAAA, and GGPA. Among these, RBP-IIIA-AAAA-IB demonstrated an increase in yield (>4-fold) and a heightened inhibition of HSC activation. Furthermore, we identified amino acid residues that could form disulfide bonds when substituted with cysteine. Through the mutation of N453S-V480S in RBP-IIIA-AAAA-IB, the productivity further increased by over 9-fold, accompanied by an increase in anti-fibrotic activity. Overall, there was a more than 30-fold increase in the fusion protein's yield. These findings demonstrate the effectiveness of modifying linker sequences and introducing extra disulfide bonds to improve both the production yield and biological efficacy of fusion proteins.

Intestinal Clear Cell Sarcoma-A Case Presentation of an Extremely Rare Tumor and Literature Review.

Background: Clear cell sarcoma (CCS) is an extremely rare form of sarcoma representing less than 1% of all soft-tissue sarcomas. It has morphological, structural, and immunohistochemical similarities to malignant melanoma, affecting young adults and equally affecting both sexes, and is usually located in the tendinous sheaths and aponeuroses of the limbs. Gastrointestinal localization is exceptional, with less than 100 cases reported thus far. The gene fusion of activating transcription factor 1 (ATF1) and the Ewing sarcoma breakpoint region 1 (EWSR1) are pathognomonic for clear cell sarcoma, representing the key to the diagnosis. CCS is an extremely aggressive tumor, with >30% having distant or lymphatic metastasis at the time of diagnostic, and it has a high recurrence rate of over 80% in the first year after diagnosis and a high tendency for metastatic dissemination. Given the rarity of this tumor, there is no standardized treatment. Early diagnosis and radical surgery are essential in the treatment of CCS both for the primary tumor and for recurrence or metastasis. Chemo-radiotherapy has very little effect and is rarely indicated, and the role of targeted therapies is still under investigation. Case presentation: We present an extremely rare case of intestinal CSS in a 44-year-old Caucasian female. The patient, asymptomatic, first presented for a routine checkup and was diagnosed with mild iron-deficiency anemia. Given her family history of multiple digestive cancers, additional investigations were requested (gastroscopy, colonoscopy, tumoral markers and imaging) and the results were all within normal limits. In the subsequent period, the patient experienced mild diffuse recurrent abdominal pain, which occurred every 2-3 months. Two years later, the patient presented with symptoms of intestinal obstruction and underwent an emergency laparotomy followed by segmental enterectomy and regional lymphadenectomy for stenotic tumor of the jejunum. Histology, immunohistochemistry, and genetic testing established the diagnosis of CCS. No adjuvant therapy was indicated. Initially, no signs of recurrence or metastasis were detected, but after 30 and 46 months, respectively, from the primary treatment, the patient developed liver metastasis and pericolic peritoneal implants treated by atypical hepatic resections and right hemicolectomy. The patient remains under observation.

Identification of CT Features to Differentiate Pulmonary Sarcoma from Carcinoma.

Background Primary lung sarcoma (PLS) differs in management protocols and prognosis from the more common primary lung carcinoma (PLC). It becomes imperative to raise a high index of suspicion on radiological and pathological features. Purpose The aim of this study is to highlight the variable imaging appearances of PLS compared with PLC, which impacts radiologic - pathologic correlation. Materials and Methods A retrospective observational study of 68 patients with biopsy-proven lung tumors who underwent baseline imaging at our tertiary care cancer hospital was conducted between January 2018 and March 2022. The patient details and imaging parameters of the mass on contrast-enhanced computed tomography (CECT) were recorded and analyzed for patients with PLS and compared with PLC. Follow-up imaging was available in 9/12 PLS and 52/56 PLC patients. Results Among 12 patients with PLS, 5 patients had synovial sarcoma on histopathology. PLS was seen in patients with a mean age of 40.8 years; the mass showed a mean size of 13.2 cm, lower lobe (75%), parahilar (75%), hilar involvement (41.7%), oval shape (41.7%), circumscribed (25%) or lobulated (75%) margins, lower mean postcontrast attenuation of 57.3 HU, fissural extension (50%), calcification (50%), and no organ metastasis other than to the lung. PLC (56 patients) was seen in the elderly with a mean age of 54.8 years; the mass showed a mean size of 5.7 cm, irregular shape (83.9%), spiculated margins (73.2%), higher mean postcontrast attenuation (77.3 HU), chest wall infiltration (30.4%), and distant metastasis (58.9%) at baseline imaging. A statistically significant difference ( p < 0.05) was seen between sarcoma and carcinoma in the mean age, size, site, shape, margins, postcontrast attenuation, presence of calcifications, fissural extension, and distant metastasis. Conclusion The distinct imaging features of sarcoma help in differentiating it from carcinoma. This can also be used to corroborate with histopathology to achieve concordance and guide clinicians on further approach.

High-Affinity Superantigen-Based Trifunctional Immune Cell Engager Synergizes NK and T Cell Activation for Tumor Suppression.

The development of immune cell engagers (ICEs) can be limited by logistical and functional restrictions associated with fusion protein designs, thus limiting immune cell recruitment to solid tumors. Herein, a high affinity superantigen-based multivalent ICE is developed for simultaneous activation and recruitment of NK and T cells for tumor treatment. Yeast library-based directed evolution is adopted to identify superantigen variants possessing enhanced binding affinity to immunoreceptors expressed on human T cells and NK cells. High-affinity superantigens exhibiting improved immune-stimulatory activities are then incorporated into a superantigen-based tri-functional yeast-display-enhanced multivalent immune cell engager (STYMIE), which is functionalized with a nanobody, a Neo-2/15 cytokine, and an Fc domain for tumor targeting, immune stimulation, and prolonged circulation, respectively. Intravenous administration of STYMIE enhances NK and T cell recruitment into solid tumors, leading to enhanced inhibition in multiple tumor models. The study offers design principles for multifunctional ICEs.

Respiratory Syncytial Virus in Adult Patients at a Tertiary Care Hospital in Germany: Clinical Features and Molecular Epidemiology of the Fusion Protein in the Severe Respiratory Season of 2022/2023.

Following an interseasonal rise in mainly pediatric respiratory syncytial virus (RSV) cases in Germany in 2021, an exceptionally high number of adult cases was observed in the subsequent respiratory season of 2022/2023. The aim of this study was to compare the clinical presentation of RSV infections in the pre- and post-SARS-CoV-2 pandemic periods. Additionally, the local epidemiology of the RSV fusion protein was analyzed at a molecular genetic and amino acid level. RSV detections in adults peaked in calendar week 1 of 2023, 8 weeks earlier than the earliest peak observed in the three pre-pandemic seasons. Although the median age of the adult patients was not different (66.5 vs. 65 years), subtle differences between both periods regarding comorbidities and the clinical presentation of RSV cases were noted. High rates of comorbidities prevailed; however, significantly lower numbers of patients with a history of lung transplantation (p = 0.009), chronic kidney disease (p = 0.013), and immunosuppression (p = 0.038) were observed in the 2022/2023 season. In contrast, significantly more lower respiratory tract infections (p < 0.001), in particular in the form of pneumonia (p = 0.015) and exacerbations of obstructive lung diseases (p = 0.008), were detected. An ICU admission was noted for 23.7% of all patients throughout the study period. Sequence analysis of the fusion protein gene revealed a close phylogenetic relatedness, regardless of the season of origin. However, especially for RSV-B, an accumulation of amino acid point substitutions was noted, including in antigenic site Ø. The SARS-CoV-2 pandemic had a tremendous impact on the seasonality of RSV, and the introduction of new vaccination and immunization strategies against RSV warrants further epidemiologic studies of this important pathogen.

Transport of Zinc-Phthalocyanine to Cancer Cells using Myoglobin-Albumin Fusion Protein for Photodynamic Therapy.

Photodynamic therapy (PDT) is a noninvasive approach to cancer treatment, wherein cell death is initiated by singlet oxygen (1O2) production via energy transfer from excited photosensitizers to ground-state O2. Effective clinical photosensitizers necessitate water solubility for in vivo administration. Hydrophobic dyes, such as phthalocyanines, cannot be used directly as photosensitizers. Herein, we synthesized a myoglobin-(human serum albumin) fusion protein reconstituted with zinc-phthalocyanine (ZnPc), termed ZnPcMb-HSA. The photophysical properties of ZnPcMb-HSA closely resemble those of ZnPc-substituted Mb. Notably, ZnPc dissociates from ZnPcMb-HSA and selectively accumulates within cancer cells, while the protein components remain extracellular. Treatment of four distinct cell lines with ZnPcMb-HSA, followed by red-light irradiation, effectively induced apoptosis. The half-maximal inhibitory concentrations (IC50) against these cancer cell lines ranged between 0.1-0.5 µM. Reconstituted Mb-HSA emerges as a promising carrier for transporting various water-insoluble porphyrinoid photosensitizer to target cancer cells in PDT applications.

Genetically Programmed Temperature-Responsive Barnacle-Derived Protein with an Enhanced Adhesion Ability.

There is an emerging strong demand for smart environmentally responsive protein-based biomaterials with improved adhesion properties, especially underwater adhesion for potential environmental and medical applications. Based on the fusion of elastin-like polypeptides (ELPs), SpyCatcher and SpyTag modules, biosynthetic barnacle-derived protein was genetically engineered and self-assembled with an enhanced adhesion ability and temperature response. The water resistance ability of the synthetic protein biopolymer with a network structure increased to 98.8 from 58.5% of the original Cp19k, and the nonaqueous adhesion strength enhanced to 1.26 from 0.68 MPa of Cp19k. The biopolymer showed an improved adhesion ability toward hydrophilic and hydrophobic surfaces as well as diatomite powders. The combination of functional module ELPs and SpyTag/SpyCatcher could endow the biosynthetic protein with temperature response, an insoluble form above 42 °C and a soluble form at 4 °C. The combinational advantages including temperature response and adhesion performance make the self-assembled protein an excellent candidate in surgical adhesion, underwater repair, and surface modification of various coatings. Distinct from the traditional approach of utilizing solely ELPs, the integration of short ELPs with Spy partners exhibited a synergistic enhancement in the temperature response. The synergistic effects of two functional modules provide a technical method and insight for designing smart self-assembled protein-based biopolymers.

MB2033, an anti-PD-L1 × IL-2 variant fusion protein, demonstrates robust anti-tumor efficacy with minimal peripheral toxicity.

Interleukin-2 (IL-2), a cytokine with pleiotropic immune effects, was the first approved cancer immunotherapy agent. However, IL-2 is associated with systemic toxicity due to binding with its ligand IL-2Rα, such as vascular leakage syndrome, limiting its clinical applications. Despite efforts to extend the half-life of IL-2 and abolish IL-2Rα interactions, the risk of toxicity remains unresolved. In this study, we developed the bispecific fusion protein MB2033, comprising a novel IL-2 variant (IL-2v) connected to anti-programmed death ligand 1 (PD-L1) via a silenced Fc domain. The IL-2v of MB2033 exhibits attenuated affinity for IL-2Rßγ without binding to IL-2Rα. The binding affinity of MB2033 for PD-L1 is greater than that for IL-2Rßγ, indicating its preferential targeting of PD-L1+ tumor cells to induce tumor-specific immune activation. Accordingly, MB2033 exhibited significantly reduced regulatory T cell activation, while inducing comparable CD8+ T cell activation to recombinant human IL-2 (rhIL-2). MB2033 induced lower immune cell expansion and reduced cytokine levels compared with rhIL-2 in human peripheral blood mononuclear cells, indicating a decreased risk of peripheral toxicity. MB2033 exhibited superior anti-tumor efficacy, including tumor growth inhibition and complete responses, compared with avelumab monotherapy in an MC38 syngeneic mouse model. In normal mice, MB2033 was safer than non-α IL-2v and tolerable up to 30 mg/kg. These preclinical results provide evidence of the dual advantages of MB2033 with an enhanced safety and potent clinical efficacy for cancer treatment.

Receptor binding and immunogenic properties of the receptor binding domain of influenza D virus hemagglutinin-esterase-fusion protein expressed from Escherichia coli.

The hemagglutinin-esterase-fusion (HEF) protein binds 9-O-acetylated sialic acids-containing glycans on the cell surface and drives influenza D virus (IDV) entry. The HEF is a primary determinant of the exceptional thermal and acid stability observed in IDV infection biology. Here, we expressed and purified the receptor binding domain (RBD) of the IDV HEF protein in Escherichia coli and characterized its receptor binding and antigenic properties. The data from these experiments indicate that (i) the RBD can bind with specificity to turkey red blood cells (RBC), and its binding can be specifically inhibited by IDV antibody; (ii) the RBD efficiently binds to the cell surface of MDCK cells expressing the receptor of IDV; and (iii) anti-RBD antibodies are capable of blocking RBD attachment to MDCK cells as well as of inhibiting the virus from agglutinating RBCs. These observations support the utility of this RBD in future receptor and entry studies of IDV.

Prophylaxis with recombinant factor IX Fc fusion protein reduces the risk of bleeding and delays time to first spontaneous bleed event in previously untreated patients with haemophilia B: A post hoc analysis of the PUPs B-LONG study.

OBJECTIVES: Haemophilia B (HB), characterised by deficient factor IX (FIX), leads to spontaneous bleeds. Severe cases require prophylactic FIX replacement. This post hoc analysis assessed the first spontaneous bleeds among previously untreated patients (PUPs) with HB treated with recombinant FIX Fc fusion protein (rFIXFc) (NCT02234310) to identify factors influencing bleeds. METHODS: Subjects included paediatric PUPs with HB (≤2 IU/dL endogenous FIX). Analyses described treatment patterns (on demand [OD] vs. prophylaxis) and prophylaxis type (started on vs. switched to prophylaxis). Kaplan-Meier analyses assessed the time to first spontaneous bleed, including median time to event and fitting models with predictors for treatment regimen and/or baseline age. RESULTS: PUPs B-LONG enrolled 33 subjects. Baseline age did not influence the time to first spontaneous bleed for any rFIXFc regimen. Those who started on prophylaxis with rFIXFc (n = 11), compared with those treated OD (n = 22), had an extended time to first spontaneous bleed. Starting prophylaxis afforded a 93% reduced risk of first spontaneous bleed versus starting OD (hazard ratio [95% confidence interval]: 0.071 [0.009-0.592]) (p = .015). CONCLUSION: rFIXFc prophylaxis, particularly starting early, reduced the risk of bleeding and delayed time to first spontaneous bleed compared with rFIXFc OD. Hence, initial treatment regimens impact bleed patterns in paediatric PUPs.