Antibodies最新文献

Background/objectives: The increasing prevalence of human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) has necessitated a revaluation of therapeutic strategies. HPV-driven OPSCC differs from HPV-negative OPSCC due to its distinct molecular signatures, increased radiosensitivity, and better prognoses. However, despite these differences, treatment strategies have remained largely uniform, resulting in minimal reductions in morbidity and exposing HPV-positive patients to unnecessary toxicity. Monoclonal antibodies (mAbs) have become a promising therapeutic option due to their ability to target treatment with fewer systemic side effects. Immune checkpoint inhibitors (ICIs) such as pembrolizumab have shown efficacy in enhancing the immune response against tumors, while EGFR inhibitors like cetuximab offer an alternative modality. Current clinical trials aim to refine dosing regimens and identify combination strategies that may enhance therapeutic outcomes.

Results: Despite promising evidence, several challenges hinder the widespread adoption of mAbs as a standard treatment for HPV-positive OPSCC in clinical practice. This review examines the current role of mAbs in HPV-positive OPSCC treatment, highlighting their limitations and future research directions.

Conclusions: Further studies are needed to optimize patient selection, establish standardized treatment protocols, and investigate the long-term benefits of mAb-based therapies in this patient population.

Background: Triple-negative breast cancer (TNBC) is an aggressive subtype with high metastatic potential, poor prognosis, and the absence of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2 (HER2). The lack of these receptors limits the standard treatments, such as hormone therapies and HER2-targeted antibodies like trastuzumab. These challenges highlight the critical need for novel therapeutic strategies. CD147, a transmembrane glycoprotein overexpressed in TNBC, promotes tumor progression, metastasis, and chemoresistance, making it a promising therapeutic target. This study evaluates the antibody-dependent cellular cytotoxicity (ADCC) of HuM6-1B9, a humanized anti-CD147 antibody, against MDA-MB-231 cells, a TNBC model.

Methods: CFSE-labelled MDA-MB-231 cells were co-cultured with PBMCs as effector cells (E:T ratio 80:1) in the presence of HuM6-1B9 and incubated for 4 h. Cells were then collected and stained with PI, and CFSE+/PI+ dead target cells were analyzed by flow cytometry.

Results: Co-culturing MDA-MB-231 cells with peripheral blood mononuclear cells (PBMCs) in the presence of HuM6-1B9 demonstrated effective ADCC induction without direct cytotoxicity. HuM6-1B9 induced 54.01% cancer cell death via ADCC, significantly outperforming trastuzumab (26.14%) while sparing PBMCs.

Conclusion: These findings support HuM6-1B9 as a prospective TNBC therapeutic and warrant further investigation into its clinical potential.

Monoclonal antibodies (mAbs) targeting various pathways in cancer therapy play crucial roles in enhancing the immune system's ability to recognise and eliminate tumour cells. These therapies are designed to either block inhibitory immune checkpoint pathways or to target specific tumour cell markers for direct destruction. Additionally, mAbs can modulate the tumour microenvironment, enhance antibody-dependent cellular cytotoxicity, and inhibit angiogenesis, further amplifying their therapeutic impact. Below is a summary of monoclonal antibodies targeting key pathways, along with their indications and mechanisms of action, which are reviewed based on therapeutic mechanisms.

Introduction: Epidermolysis bullosa acquisita (EBA) is a rare autoimmune disease causing subepithelial blistering due to autoantibodies against type VII collagen. While mechanobullous EBA predominantly affects adults, our report presents an exceedingly rare case in an 11-year-old football player.

Case report: The patient reported a one-year history of blistering and scarring on the knees and scrotum. The diagnosis was established with direct immunofluorescence (DIF), mosaic indirect immunofluorescence (IIF) showing IgG antibodies reacting with the dermal side of salt-split primate skin, and multiplex ELISA revealing an elevated level of IgG antibodies against type VII collagen. Treatment with a superpotent topical glucocorticosteroid and activity modifications improved his condition.

Review: This case highlights the importance of considering EBA in differential diagnoses of pediatric blistering diseases and suggests that conservative management may be effective in mild cases. We also review clinical and laboratory considerations on the topic of childhood EBA.

Conclusions: Further studies are essential to develop evidence-based guidelines for pediatric EBA.

Objective: To investigate the effect of Lipopolysaccharide (LPS)-induced acute lung injury (ALI) on the pulmonary pharmacokinetics (PK) of a systemically administered antibody in mice.

Method: The PK of a non-target-binding antibody was evaluated in healthy mice and mice with intratracheal instillation of 5 mg/kg LPS. The plasma, bronchoalveolar lavage (BAL), trachea, bronchi, and lung homogenate PK of the antibody were measured following intravenous administration of 5 mg/kg antibody dose. Noncompartmental analysis was performed to determine AUC values. Antibody concentrations in all biological matrices were quantified using qualified ELISA. The effect of ALI on BAL albumin and total protein concentrations was also determined. BAL protein concentrations were corrected for dilution using plasma urea concentrations.

Results: Intratracheal instillation of LPS and the resultant ALI led to ~2-4-fold higher concentrations of albumin and proteins in the BAL. LPS-induced ALI also notably altered the pulmonary PK of the antibody. The effect of ALI on the antibody PK was time and tissue dependent. The trachea and bronchi showed ~1.7-fold and ~1.4-fold lower antibody exposure compared with the control group, but the BAL fluid exhibited ~4-fold increase in antibody exposure following LPS treatment. Most noticeable changes in antibody PK occurred 24 h after LPS administration, and the effect was temporary for the bronchi and trachea. However, the changes in lung homogenate and, more notably, in BAL persisted until the end of the experiment. Thus, our investigation suggests that due to the acute nature of ALI-induced pathophysiology and the changing severity of the disease, the dose and timing of antibody administration following ALI may need to be optimized based on the target site of action (e.g., bronchi, trachea, BAL, lung parenchyma, etc.) to maximize the therapeutic effect of the antibody.

Conclusions: ALI may significantly affect pulmonary PK of systemically administered antibodies. Changes caused by ALI are time and tissue dependent, and hence, the timing and dose of antibody following ALI may need to be optimized to maximize the therapeutic effect of the antibody at the site of action.

Background/Objectives: Romania remains endemic for measles due to suboptimal vaccine coverage rates. During the last three epidemics, the highest incidence of measles was recorded in children younger than 1 year, who should have been partially protected by maternal antibodies. A nationwide cross-sectional seroprevalence study was conducted on persons of fertile age, to evaluate potential immunity gaps in the population. Methods: Between June and October 2020, 959 serum samples were collected from individuals aged 25-44 years (46.5% females) from all the geographic regions in Romania. Measles IgG antibodies were assessed using an enzyme-linked immune assay (DIA.PRO-Diagnostic Bioprobes Srl, Italy). Statistical analysis was performed in IBM SPSS Statistics 27.0, using Fisher's exact and chi-squared tests to test for associations between seropositivity and demographic factors, with p < 0.05 considered statistically significant. Results: The overall measles seroprevalence was 77%, without gender- or geographic region-related differences. Both the seropositivity rate and the measles antibodies titers increased with age, with the highest difference between the oldest and the youngest age group (p = 0.057), suggesting persistent immunity after natural infection in older individuals or anamnestic responses in vaccinated persons, caused by repeated exposures to the circulating virus. An additional confirmatory pilot study on 444 pregnant women confirmed the low level of measles seroprevalence (68.4%), with a significant upward trend in older ages (75% in those aged >40 years old vs. 65% in those aged 25-29 years, p = 0.018 and mean reactivity of measles antibodies 3.05 ± 1.75 in those aged >40 years vs. 2.28 ± 1.39 in those aged 25-29 years, p = 0.037). Conclusions: This study signals critical immunity gaps in the population that contribute to the accumulation of susceptible individuals and recurrent measles outbreaks. The absence of measles antibodies in women of childbearing age increases the newborn's susceptibility to infection, with potentially severe complications.

Background/objectives: Monoclonal antibodies have successfully been used for a variety of indications. Many therapeutic antibodies are IgG1 and elicit effector functions as part of their mechanism of action. It is well known that aggregate levels should be controlled for therapeutic antibodies. Although there are several reports describing the impact of antibody aggregates on FcγR binding, most of these have been performed with surface plasmon resonance in an avidity-based format. What is less well known is which Fcγ receptor is most impacted by antibody aggregation and how antibody aggregates impact binding to Fcγ receptors in solution-based formats and in cell-based assays.

Methods: An effector-competent IgG1 (mAb1) was forcibly degraded and fractionated by size exclusion chromatography to enrich for aggregates. The fractions were examined for FcγR binding by SPR with different formats and in solution. The fractions were also analyzed with cell-based FcγR reporter assays.

Results: All Fcγ receptors displayed increased binding to enriched mAb1 aggregates in the avidity-based SPR methods and in solution, with FcγRIIa impacted the most. When examined with an antibody-down SPR format that is not usually susceptible to avidity, FcγRIIa did not show increased binding with mAb1 aggregation. Although activity for mAb1 aggregates increased slightly in an FcγRIIa cell-based reporter assay, it decreased in the FcγRIIIa reporter assay (most likely due to differences in fucosylation from the reference standard).

Conclusions: Monoclonal antibody aggregation can impact FcγR binding for avidity-based binding formats. Even at low levels of antibody aggregation, FcγRII binding increases substantially.

Background: Monoclonal antibodies against the sodium-dependent phosphate transporter NaPi2b (SLC34A2) represent a promising approach in the treatment of ovarian and lung cancer. Of particular interest is the potential cancer-specific MX35 epitope of NaPi2b, as it serves as a target for monoclonal antibodies studied at various stages of preclinical and clinical trials. However, variations in the NaPi2b protein structure may limit the efficacy of therapeutic antibodies by affecting the accessibility of the MX35 epitope. Methods: An in silico analysis was performed using data from 101,562 tumor samples. Genomic DNA sequencing was conducted on blood samples from patients with ovarian carcinoma, breast cancer, and renal carcinoma to access the frequency of germline mutations in the SLC34A2 gene region encoding the MX35 epitope. To assess the impact of the selected mutation, we generated a model cell line through site-directed mutagenesis carrying the mutant NaPi2b variant. Results: Using in silico analysis, we identified 17 unique variants in the SLC34A2 gene leading to amino acid substitutions within the MX35 epitope of the NaPi2b. Among these, the most prevalent mutation, c.989C>T, resulting in p.T330M substitution, was detected in 5 out of 64 patients through genomic DNA sequencing. Using site-directed mutagenesis, we created the OVCAR-8/NaPi2b^p.T330M model cell line. L3 (28/1) monoclonal antibodies specific to the MX35 epitope failed to recognize the mutant NaPi2b^p.T330M variant compared to the wild-type of the NaPi2b in both Western blot and confocal microscopy experiments. Conclusions: The obtained data may serve as a basis for predicting the efficacy of monoclonal antibody-based targeted therapy binding to the MX35 epitope of NaPi2b in the treatment of oncological diseases.

Background: The preparation of antibodies in powder form without changing their physicochemical properties may enable their use in new drug delivery system therapies or non-refrigerated storage. The variable domain of heavy-chain antibodies (VHHs) is more suited for this purpose than that of conventional antibodies because of VHHs' high thermal stability and ability to refold.

Methods: In this report, the fine droplet drying (FDD) process was selected as the powderization technique because of its favorable features, such as mild drying conditions and the generation of uniform particle sizes. The aggregation, binding, particle, and in vitro inhalation properties of the prepared VHH powders (VHHps) were evaluated.

Results: The amount of aggregated VHHs present in the VHHps depended on the flow temperature during the FDD process, with higher temperatures yielding a higher aggregation ratio. In contrast, no significant difference in binding activity was observed between each VHHp preparation and the native VHHs. However, this process degraded VHHs or inactivated their function, and ultimately, only about 30% of the original VHHs were functional, whereas the remaining VHHs that were not degraded showed little loss of functionality, even after storage at room temperature for more than two years. Analysis of the VHHp samples revealed that the particles were uniformly spherical with a single-micron size. The VHHps showed fine inhalation properties in the inhalation property test.

Conclusions: These findings suggest that the FDD process affords various VHH powder formulations, including pharmaceutical formulations.

Background: There is an unmet medical need to develop a vaccine targeting endemic coronaviruses. Antigen-specific monoclonal antibodies (mAbs) are crucial for many assays to support vaccine development. Objective: In this study, we used the HuCal Fab phage display library with a diversity of 4.5 × 10¹⁰ to identify antibodies specific to the spike proteins of the four endemic coronaviruses: OC43, NL63, 229E, and HKU1. Methods: As proof of concept, we established a newly designed platform using a long-read NGS workflow for antibody discovery and compared the results against the traditional workflow using Sanger sequencing consisting of lengthy and laborious benchwork. Results: The long-read NGS workflow identified most of the antibodies seen from the Sanger sequencing workflow, and many more additional antigen-specific antibodies against the endemic coronaviruses. Overall efficiency improved up to three times, comparing the traditional workflow with the NGS workflow. Of the 113 NGS-derived mAbs isolated to bind the four endemic coronavirus spike proteins, 107/113 (94.7%) had potent ELISA binding affinities (EC50 < 150 ng/mL, or <1 nM), and 61/113 (54%) had extremely potent ELISA binding affinities (EC50 of <15 ng/mL, or <0.1 nM). Conclusions: We successfully developed and incorporated the long-read NGS workflow to generate target-specific antibodies with many antibodies at sub-nanomolar affinities that are likely missed by a traditional workflow. We identified strong neutralizing antibodies, proving that our endemic spike proteins are capable of generating antibodies that could offer protection against the endemic HCoVs.