Antibodies最新文献

Background/objectives: Tumor-associated antigens are not tumor-specific antigens but proteins that are overexpressed by tumor cells and also weakly expressed at the surface of healthy tissues. Therefore, some side effects are observed when targeted by therapeutic antibodies, a phenomenon named "on-target, off-tumor toxicity". As tumors generate an acidic microenvironment, we investigated whether we could generate pH-dependent antibodies to increase their tumor specificity. For this proof-of-concept study, we selected the tyrosine kinase receptor AXL because we already developed several antibodies against this target.

Methods: To generate a pH-dependent anti-AXL antibody, we performed classical panning of a single-chain variable fragment (scFv) library using phage display at an acidic pH throughout the process.

Results: After the third round of panning, 9 scFvs, among the 96 picked clones, bound to AXL at acidic pH and showed very low binding at a neutral pH. After reformatting them into IgG, two clones were selected for further study due to their strong pH-sensitive binding. Using molecular docking and alanine scanning, we found that their binding strongly depended on two histidine residues present on AXL at positions 61 and 116.

Conclusions: To conclude, we set-up an easy process to generate pH-dependent antibodies that may increase their tumor-binding specificity and potentially decrease toxicity towards healthy tissues.

Primary podocytopathies, including minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), are caused by a circulating factor or factors injurious to the podocyte. An immunologic origin seems likely based on responsiveness to corticosteroids or other immunosuppressive agents, including calcineurin inhibitors targeting T-cells and rituximab targeting B-cells. Potential non-antibody-mediated circulating factors have been identified, including cardiotrophin-like cytokine 1, soluble urokinase plasminogen activator receptor, and angiopoietin-like 4, among others. More recent research supports a primary antibody pathogenesis, with anti-nephrin antibodies found in a significant percentage of cases. Such antibodies also predict recurrence after transplantation. Other potential antigenic targets besides nephrin include annexin, the proteosome, podocin, and CD40. Additionally, high-resolution confocal microscopy has identified punctate immunoglobulin deposits along the slit diaphragm and podocyte cell body that may or may not colocalize with abnormal punctate nephrin staining and may correlate with detectable circulating antibodies. The success of rituximab in observational studies in both native kidneys and transplants supports a primary role for autoantibodies. We discuss in detail the data supporting putative non-antibody circulating factors, as well as the recent data supporting antibody pathogenesis, which may provide some clues on treating the individual patient.

Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite responsible for toxoplasmosis, a disease with significant health implications for humans and animals. The surface antigen 1 (SAG1) of T. gondii is a major immunodominant protein that facilitates host cell invasion, making it an ideal target for diagnostic and therapeutic interventions. Immunoglobulin Y (IgY), the primary antibody in avian species, offers unique advantages over mammalian IgG, including easier animal care, lower costs, high-yield production, and potential passive immunization.

Objectives: This study aimed to induce, purify, and characterize IgY antibodies targeting T. gondii SAG1 from hen egg yolks.

Methods: The coding region of the mature portion of T. gondii SAG1 was amplified by PCR, cloned into the pET32a(+) vector for heterologous expression in E. coli. The recombinant SAG1 (rSAG1) was purified by affinity chromatography and used to immunize hens. IgY was extracted from egg yolks using PEG. SDS-PAGE and spectrophotometry were used to evaluate purity and concentration. By ELISA, Western blot, and flow cytometry, the specificity of IgY was assessed against recombinant and endogenous, native, and denatured SAG1.

Results: Purified IgY demonstrated strong recognition of both recombinant and native SAG1 in ELISA and Western blot, and against T. gondii tachyzoites by flow cytometry.

Conclusions: SAG1-specific IgY was produced in a pure form; it could be helpful in research, diagnosis, and treatment at low costs on a larger production scale, with minimal animal harm.

Background/Objectives: Calsequestrin (CSQ) is a calcium-binding protein that is highly soluble and can serve as a solubility-enhancing fusion tag in recombinant protein expression. Its unique property of calcium-induced precipitation followed by EDTA-mediated resolubilization enables efficient purification. However, the broader application of CSQ-tagged proteins in research have been hampered by the lack of reliable anti-CSQ detection reagents. This study aimed to develop single-domain antibodies (sdAbs) against CSQ for use in diverse immunoassays and cell-based analyses. Methods: Single-domain antibodies were selected from phage-displayed chicken VH libraries generated from CSQ-immunized chickens. After biopanning, CSQ-specific VH sdAb clones were isolated and expressed as VH-human kappa light chain constant region (VH-Cκ) fusion proteins in E. coli. The PE06 clone was chosen for further characterization and conjugated to horseradish peroxidase (HRP) and Alexa Fluor 647 for assay applications. Results: PE06 VH-Cκ fusion protein demonstrated specific binding to CSQ-tagged proteins and enabled reliable detection in enzyme-linked immunosorbent assay (ELISA), immunoblotting, and flow cytometry. These results validated its utility as a chemically defined detection reagent for CSQ fusion proteins expressed in E. coli. Conclusions: This study establishes a CSQ-specific chicken VH sdAb as a versatile detection tool for CSQ-tagged proteins. The approach expands the utility of CSQ as a protein fusion tag and enables the development of recombinant antibodies fused with CSQ, such as scFv-CSQ constructs, for broad application in research and assay systems.

Background/Objectives: Lichen planus (LP) is a chronic inflammatory disease of autoimmune origin, affecting the skin and mucous membranes. While corticosteroids and immunosuppressants are traditionally used, many cases remain refractory or intolerant to standard therapies. Recent advances in immunopathogenesis have led to the exploration of targeted therapies, including biologic agents and small-molecule inhibitors. Methods: This review synthesizes current evidence from case reports, case series, and observational studies on the use of monoclonal antibodies (anti-TNF-α, anti-IL-17, anti-IL-23, anti-IL-6) and JAK inhibitors in LP. A structured literature search was conducted across PubMed, Scopus, and Web of Science, focusing on studies published between 2010 and 2025. Data on mechanisms, clinical efficacy, safety, and research limitations were extracted and summarized. Results: Promising therapeutic responses were reported for IL-17 inhibitors (secukinumab, ixekizumab) and JAK inhibitors (tofacitinib, baricitinib) in mucosal and recalcitrant LP. Anti-TNF agents showed variable efficacy, while emerging targets such as BTK and IFN-γ are under investigation. Adverse events were generally mild to moderate, but long-term safety data are lacking. The absence of randomized controlled trials and standardized outcome measures limits generalizability. Conclusions: Biologic and small-molecule therapies represent a potential paradigm shift in the treatment of LP, offering targeted immunomodulation with promising efficacy in refractory cases. Further collaborative research, including randomized studies and biomarker-driven approaches, is urgently needed to validate these treatments and establish personalized care strategies.

Background: The accurate evaluation of anti-ABO antibodies is essential for risk stratification in ABO-incompatible (ABOi) transplantation. Historically, hemagglutination-based titration has been the cornerstone of such an assessment; however, different tools are being evaluated in this context. In recent years, several novel methods have been reported. Methods: A narrative review was conducted using PubMed, Scopus, and Google Scholar, focusing on recent studies evaluating anti-ABO antibody measurement techniques in the context of ABOi organ transplantation. Results: In addition to the conventional tube method, techniques such as column agglutination technology, flow cytometry, and enzyme-linked immunosorbent assay are utilized for anti-ABO antibody assessment. However, any particular technique, significant interinstitutional and interoperator variabilities have been reported due to differences in the detailed protocols and the inherently subjective nature of some techniques. Moreover, these assays are based on the antibody binding to ABO antigens expressed on red blood cells, which might not accurately reflect the clinical context of organ transplantation. In recent years, technological advances have enabled the development of novel assays evaluating antibody responses specifically against the ABO antigens expressed on vascular endothelial cells. These include glycan microarrays, which differentiate responses by ABO antigen subtypes, and CD31-based microarrays, wherein recombinant CD31 proteins expressing ABO antigens are immobilized. These approaches are applied to assess clinically relevant anti-ABO antibodies in the context of ABOi organ transplantation. Conclusions: The objective evaluation of antibody titers against ABO antigens on vascular endothelial cells might not only enable a more accurate risk assessment but also facilitate meaningful comparisons between institutions.

Infertility is a multifactorial condition with a wide range of potential causes, including anatomical, hormonal, genetic, and lifestyle-related factors. Among these, immunological mechanisms have increasingly been recognized as important contributors. The immune system plays a critical role in maintaining reproductive health, and its dysregulation can impair fertility in both men and women. Recent scientific studies suggest that altered immune responses, particularly those involving autoimmune reactions, may negatively affect fertility by disrupting the complex immunological balance required for successful conception and pregnancy maintenance. This review focuses on the most common autoantibodies, such as antinuclear, antisperm, antiendometrial, antiovarian, antiphospholipid, and antithyroid antibodies. Treatment options, including immunomodulatory therapy, hormone replacement therapy, and lifestyle interventions, are also reviewed.

Background: p16 immunohistochemistry (IHC) serves as a surrogate marker for high-risk human papillomavirus (hrHPV) and is widely used in gynecologic pathology. However, few studies have directly compared the staining performance and reproducibility of different p16 antibody clones in this context.

Methods: We retrospectively evaluated 176 gynecologic tumor specimens including 42 whole slide sections and 134 tissue microarray cores from the cervix, endometrium, vulva, and ovary using three fully automated p16 IHC assays: E6H4 (Ventana/Roche), JC8 (Agilent/Dako), and 6H12 (Leica). Two pathologists independently reviewed each case, and concordance and interobserver agreement were analyzed. Sensitivity, specificity, and Cohen's κ statistics were calculated, with E6H4 serving as the reference.

Results: All three antibody clones demonstrated excellent staining performance with preserved tissue morphology and minimal background artifacts. Concordance for p16 positivity/negativity was 100% across all clone pairings (95% CI: 97.9-100%). Interobserver reproducibility was also perfect, with a κ coefficient of 1.00 (95% CI: 0.94-1.00). Minor non-block staining patterns did not impair interpretability.

Conclusions: Our findings indicate that E6H4, JC8, and 6H12 clones yield comparable staining results when used in conjunction with standardized automated protocols. These results support the practical interchangeability of these clones in clinical and research settings, particularly when cost, availability, or risk management require substitution. Laboratories should continue to perform internal validation and utilize external quality assurance programs when implementing p16 IHC.

Background: Dupilumab, a monoclonal antibody targeting the interleukin-4 receptor α, is approved for moderate-to-severe atopic dermatitis (AD). However, its safety profile in patients with concomitant hematologic disorders remains unclear, as such populations were excluded from pivotal trials.

Objective: To evaluate the safety and effectiveness of dupilumab in adolescents and adults with AD and underlying hematologic comorbidities.

Methods: This retrospective, multicenter study included 139 patients aged ≥15 years with moderate-to-severe AD and at least one hematologic disorder, treated with dupilumab across 21 dermatology centers. Data on disease severity, laboratory markers, and hematologic outcomes were collected over a median follow-up of 52 weeks (range 4-156).

Results: The most common hematologic conditions included monoclonal gammopathies, leukemias, lymphomas, myeloproliferative neoplasms, and immune cytopenias. Clinical response to dupilumab was sustained across all endpoints, with median EASI scores decreasing from 26.0 at the baseline to 1.0 at week 52. NRS pruritus and sleep scores similarly declined to 0.0 by week 52. Serum IgE levels and eosinophil counts progressively decreased. The clinical response to dupilumab was sustained across all endpoints, with significant and progressive improvements in EASI, pruritus NRS, and sleep NRS observed up to week 52, followed by long-term stability through week 156. Serum IgE levels decreased steadily at all timepoints, while eosinophil counts declined after week 4 and stabilized beyond week 52. Hematologic conditions remained stable in 82.7% of patients, resolved in 16.5%, and progressed in only one case. Twelve patients (8.6%) received a new hematologic diagnosis during follow-up; no causal relationship could be established due to the retrospective design and absence of systematic screening, and these findings should be interpreted as descriptive associations only.

Conclusions: Dupilumab appears to be safe and effective in AD patients with a broad range of hematologic comorbidities, including malignancies. These findings support its use in real-world settings, though prospective studies are warranted to further assess long-term safety in this population.

Background: Bispecific antibodies have emerged as a promising class of therapeutics, enabling simultaneous targeting of two distinct antigens. Single-domain antibodies (sdAbs) comprising camelid variable heavy chains (VHHs) provide a compact and adaptable platform for bispecific antibody design due to their small size and ease of linkage.

Methods: Here we investigate structure-activity relationship of VHH-based cytokine surrogates by combining cell signaling and functional assays with x-ray crystallography and other biophysical techniques.

Results: We describe crystal structures of four unique bispecific VHHs that engage and activate the cytokine receptor pairs IL-18Rα/IL-18Rβ and IL-2Rβ/IL-2Rγ. These bispecific VHH molecules, referred to as surrogate cytokine agonists (SCAs), create unique cytokine signals that can be tuned by linker engineering. Our structural analysis reveals multiple dimeric conformations for these bispecific SCAs, where the two VHH domains can interact to form a compact structure. We demonstrate that the dimeric conformation can be enforced via engineering of a non-native disulfide bond between the VHH subunits, thus enhancing molecular thermostability.

Conclusion: Our findings have important implications for the design and engineering of bispecific VHHs or sdAbs, offering a novel strategy for tuning their activity and increasing their stability.