Mixture Of Antibodies Research Articles

A tool for evaluating heterogeneity in avidity of polyclonal antibodies.

Diversity in specificity of polyclonal antibody (pAb) responses is extensively investigated in vaccine efficacy or immunological evaluations, but the heterogeneity in antibody avidity is rarely probed as convenient tools are lacking. Here we have developed a polyclonal antibodies avidity resolution tool (PAART) for use with label-free techniques, such as surface plasmon resonance and biolayer interferometry, that can monitor pAb-antigen interactions in real time to measure dissociation rate constant (kd ) for defining avidity. PAART utilizes a sum of exponentials model to fit the dissociation time-courses of pAb-antigens interactions and resolve multiple kd contributing to the overall dissociation. Each kd value of pAb dissociation resolved by PAART corresponds to a group of antibodies with similar avidity. PAART is designed to identify the minimum number of exponentials required to explain the dissociation course and guards against overfitting of data by parsimony selection of best model using Akaike information criterion. Validation of PAART was performed using binary mixtures of monoclonal antibodies of same specificity but differing in kd of the interaction with their epitope. We applied PAART to examine the heterogeneity in avidities of pAb from malaria and typhoid vaccinees, and individuals living with HIV-1 that naturally control the viral load. In many cases, two to three kd were dissected indicating the heterogeneity of pAb avidities. We showcase examples of affinity maturation of vaccine induced pAb responses at component level and enhanced resolution of heterogeneity in avidity when antigen-binding fragments (Fab) are used instead of polyclonal IgG antibodies. The utility of PAART can be manifold in examining circulating pAb characteristics and could inform vaccine strategies aimed to guide the host humoral immune response.

Literature review on COVID-19 vaccine efficacy in the immunocompromised population, and possible implications to future vaccination in kidney transplant patients.

Since the emergence of the virulent coronavirus in 2019, efforts to tackle the coronavirus-disease-2019 (COVID-19) pandemic have been made globally. The development of the coronavirus disease (COVID) vaccine was a significant breakthrough in ways to tackle the virus. Various research studies have been conducted to identify how the virus works and ways to manage COVID, including the efficacy of the vaccines. However, there is limited data on how these measures work for the immunocompromised, despite the grave impact of these virulent strains in this population. Specifically, this review aims to focus on kidney transplant recipients (KTRs). Studies have suggested that there is significantly lower vaccine response in some immunocompromised groups despite additional booster doses, and hence warrants an augmented or alternative protection against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) for these patients. This suggests a need for alternative or more tailored approach in providing adequate protection against the COVID-19 in these cohorts. Some suggested ways include withholding immunosuppressants before and/or after vaccination, increasing the vaccine doses or reducing intervals and providing a mixture of monoclonal antibody (mAb) or antiviral therapy. However, the appropriate degree of alteration and augmentation, as well as its safety and effectiveness remains to be determined. Furthermore, continuous emergence of more virulent strains, such as the Omicron and its sub-lineages or the Deltacron, emphasises the need for ongoing research to assess the effectiveness of the current treatment against these new variants. Overall, active interest and appropriate updates to COVID-19 guidelines is necessary.

Protein association on multimodal chromatography media

The phenomenon of protein-protein association on multimodal chromatography resins was described for two different case study examples. The adsorption pattern of single-component solutions of calcium-rich alpha-lactalbumin (aLaCa) and calcium-depleted alpha-lactalbumin (aLa) and their mixtures with bovine serum albumin was determined on a multimodal anion-exchange chromatography medium. In single-component solutions, both aLaCa and aLa exhibited identical adsorption behavior at low resin loadings, whereas at high loadings the adsorption strength of aLa markedly exceeded that of alaCa. In binary mixtures, the adsorption of BSA enhanced at high concentrations of aLa or aLaCa in the adsorbed phase. The unusual adsorption patterns observed were attributed to the tendency of the proteins for molecular association in the adsorbed phase in single and binary solutions. The phenomena was examined for different pH of the solution: pH 6, 7, 8, and different solvent environments: phosphate buffer (PB), bis tris buffer (BT), 100 mM NaCl in BT and bis tris propane buffer (BTP). The strongest effect was observed for PB and for 100 mM NaCl in BT.Its occurrence was also evidenced for other case study example, i.e., adsorption of single-component solutions and binary mixtures of a monoclonal antibody (mAb) and lysozyme (LYZ) on a multimodal cation-exchange chromatography medium. The enhancement of adsorption of mAb was observed at high concentrations of LYZ in the adsorbed phase. To quantify the underlying effects, a mechanistic model was used, which accounted for both protein association and exclusion resulting from attractive and repulsive protein-protein iterations in the adsorbed phase.

Harnessing low dimensionality to visualize the antibody–virus landscape for influenza

Antibodies constitute a key line of defense against the diverse pathogens we encounter in our lives. Although the interactions between a single antibody and a single virus are routinely characterized in exquisite detail, the inherent tradeoffs between attributes such as potency and breadth remain unclear. Moreover, there is a wide gap between the discrete interactions of single antibodies and the collective behavior of antibody mixtures. Here we develop a form of antigenic cartography called a ‘neutralization landscape’ that visualizes and quantifies antibody–virus interactions for antibodies targeting the influenza hemagglutinin stem. This landscape transforms the potency–breadth tradeoff into a readily solvable geometry problem. With it, we decompose the collective neutralization from multiple antibodies to characterize the composition and functional properties of the stem antibodies within. Looking forward, this framework can leverage the serological assays routinely performed for influenza surveillance to analyze how an individual’s antibody repertoire evolves after vaccination or infection.

Nanobody-tethered transposition enables multifactorial chromatin profiling at single-cell resolution.

Chromatin states are functionally defined by a complex combination of histone modifications, transcription factor binding, DNA accessibility and other factors. Current methods for defining chromatin states cannot measure more than one aspect in a single experiment at single-cell resolution. Here we introduce nanobody-tethered transposition followed by sequencing (NTT-seq), an assay capable of measuring the genome-wide presence of up to three histone modifications and protein-DNA binding sites at single-cell resolution. NTT-seq uses recombinant Tn5 transposase fused to a set of secondary nanobodies (nb). Each nb-Tn5 fusion protein specifically binds to different immunoglobulin-G antibodies, enabling a mixture of primary antibodies binding different epitopes to be used in a single experiment. We apply bulk-cell and single-cell NTT-seq to generate high-resolution multimodal maps of chromatin states in cell culture and in human immune cells. We also extend NTT-seq to enable simultaneous profiling of cell surface protein expression and multimodal chromatin states to study cells of the immune system.

A biophysical model of viral escape from polyclonal antibodies.

A challenge in studying viral immune escape is determining how mutations combine to escape polyclonal antibodies, which can potentially target multiple distinct viral epitopes. Here we introduce a biophysical model of this process that partitions the total polyclonal antibody activity by epitope and then quantifies how each viral mutation affects the antibody activity against each epitope. We develop software that can use deep mutational scanning data to infer these properties for polyclonal antibody mixtures. We validate this software using a computationally simulated deep mutational scanning experiment and demonstrate that it enables the prediction of escape by arbitrary combinations of mutations. The software described in this paper is available at https://jbloomlab.github.io/polyclonal.

Severe hemolytic disease of a newborn due to anti-E combined with anti-Mia, anti-Mur and anti-Hil

Background: Common alloantibodies leading to severe hemolytic disease of the fetus and newborn (HDFN) could vary among different ethnic groups. The MNS blood group hybrid glycophorin GP.Mur distributes with a high frequency in the regions of Southeast Asia. Alloantibodies against GP.Mur (anti-‘Mia’) often present as mixture of antibodies against several low frequency antigens. In this study, we first described a case of severe HDFN in Guangzhou, China, which was caused by alloantibodies of anti-E in combination with specificities to the GP.Mur including Mia, Mur and Hil.

A protocol for setting-up robust hydrophobic interaction chromatography targeting the analysis of intact proteins and monoclonal antibodies.

Hydrophobic interaction chromatography (HIC) is a chromatographic technique that mainly targets the separation of biomolecules (intact proteins, monoclonal antibodies, etc.) based on the difference in surface hydrophobicity while applying non-denaturing conditions. This protocol paper provides guidelines for setting-up robust HIC analysis and considers the instrument configuration, mobile-phase and sample preparation, as well as chromatographic conditions and settings. The separation of a mixture of intact proteins and monoclonal antibodies is demonstrated by applying conventional HIC conditions, that is, using a mildly hydrophobic (C4) stationary phase in combination with an inverse ammonium sulphate gradient dissolved in aqueous phosphate buffer. The effect of sample-preparation conditions on sample breakthroughs is presented. Finally, good run-to-run repeatability (relative standard deviation<2%) is demonstrated for five different columns obtained from three different column lots, considering chromatographic retention, peak width, peak area and column pressure.

Parameter-by-parameter method for steric mass action model of ion exchange chromatography: Simplified estimation for steric shielding factor

Mechanistic models play a crucial role in the process development and optimization of ion-exchange chromatography (IEC). Recent researches in steric mass action (SMA) model have heightened the need for better estimation of nonlinear parameter, steric shielding factor σ. In this work, a straightforward approach combination of simplified linear approximation (SLA) and inverse method (IM) was proposed to initialize and further determine σ, respectively. An existed, unique, and positive σ can be derived from SLA. Compared with linear approximation (LA) developed in our previous study, σ of the multi-component system can be calculated easily without solving the complex system of linear equations, leading to a time complexity reduction from O(n3) to O(n). The proposed method was verified first in numerical experiments about the separation of three charge variants. The calculated σ was more reasonable than that of LA, and the error of elution profiles with the parameters estimated by SLA+IM was only one-sixth of that by LA in numerical experiments. Moreover, the error accumulation effect could also be reduced. The proposed method was further confirmed in real-world experiments about the separation of monomer-dimer mixtures of monoclonal antibody. The results gave a lower error and better physical understanding compared to LA. In conclusion, SLA+IM developed in the present work provides a novel and straightforward way to determine σ. This simplification would help to save the effort of calibration experiments and accelerate the process development for the multi-component IEC separation.

The agony of choice: Impact of the host animal species on the enzyme-linked immunosorbent assay performance for host cell protein quantification.

Host cell proteins (HCPs) are inevitable process-related impurities in biotherapeutics commonly monitored by enzyme-linked immunosorbent assays (ELISAs). Of particular importance for their reliable detection are the anti-HCP polyclonal antibodies (pAbs), supposed to detect a broad range of HCPs. The present study focuses on the identification of suitable host animal species for the development of high-performance CHO-HCP ELISAs, assuming the generation of pAbswith adequate coverage and specificity. Hence, antibodies derived from immunization of sheep, goats, donkeys, rabbits, and chickens were compared concerning their amount of HCP-specificantibodies, coverage, and performance in a sandwich ELISA. Immunization of sheep, goats, donkeys, and rabbits met all test criteria, whereas the antibodies from chickens cannot be recommended based on the results of this study. Additionally, a mixture of antibodies from the five host species was prepared to assess if coverage and ELISA performance can be improved by a multispecies approach. Comparable results were obtained for the single- and multispecies ELISAs in different in-process samples, indicating no substantial improvement for the latter in ELISA performance while raising ethical and financial concerns.

332P A phase II, open-label, single-center study of QL1706 plus platinum doublet chemotherapy with bevacizumab as first-line treatment in patients with advanced NSCLC: Data from EGFR mutant cohort

QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, showed promising antitumor efficacy in advanced solid tumors including NSCLC in a phase (Ph) I trial. Here, we report the efficacy and safety results from the EGFR mutant cohort of an ongoing Ph II study of QL1706+chemotherapy (chemo)+bevacizumab in patients (pts) with advanced NSCLC.

325P A phase II, open-label, single-center study of QL1706 plus platinum doublet chemotherapy with or without bevacizumab as first-line treatment in patients with advanced NSCLC: Data from EGFR wild-type cohort

Immunotherapy plus platinum doublet chemotherapy (chemo) as first-line therapy has shown survival benefit in patients (pts) with advanced NSCLC not harboring oncogenic driver alterations. QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, showed promising antitumor efficacy in advanced solid tumors including NSCLC in a phase (Ph) I trial. Here we report the efficacy and safety results from the EGFR wild-type (WT) cohort of an ongoing Ph II study of QL1706 plus chemo±bevacizumab in pts with advanced NSCLC.

Abstract CT520: The safety summary of the phase 1a/b trial of QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, for advanced malignant tumors

Abstract Background: Anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) antibody may enhance the efficacy of programmed cell death 1 (PD-1) inhibitor. QL1706 is a novel dual immune checkpoint blockade containing a mixture of anti-PD-1 IgG4 and anti-CTLA4 IgG1 antibodies produced by a single cell line. Here we reported the pooled data of the phase 1a/b trial. Methods: In the phase 1a dose escalation and expansion study (NCT04296994), dose escalation involved six levels (0.3, 1.0, 3.0, 5.0, 7.5, and 10.0 mg/kg, intravenously q3w) using an accelerated 3+3 design. The dose expansion cohorts received selected doses. In phase 1b (NCT05171790), patients with advanced solid tumors were given intravenous QL1706 5.0 mg/kg q3w according to the data in phase 1a. The primary objectives were to define the safety, tolerability, and recommended phase 2 dose (RP2D) of QL1706 in phase 1a, and to evaluate the preliminary efficacy in phase 1b. Results: As of Sept 30, 2021, totally 518 patients with multiple types of advanced cancer (99 in phase 1a and 419 in phase 1b) were enrolled, including lung cancer (175 [33.8%]), nasopharyngeal cancer (134 [25.9%]), cervical cancer (58 [11.2%]), liver cancer (34 [6.6%]), colorectal cancer (27 [5.2%]), and kidney cancer (18 [3.5%]), etc. 494 [95.4%] were previously treated, and 182 (35.1%) received previous immunotherapy. Two patients at 10 mg/kg suffered dose-limiting toxicity. The RP2D of QL1706 was defined as 5.0 mg/kg. After a median follow-up of 6.7 months, treatment-related adverse events (TRAEs) were observed in 374 patients (72.2%). 70 (13.5%) experienced grade ≥3 TRAEs. The most common TRAEs were rash (91 [17.6%]), pruritus (65 [12.5%]), hypothyroidism (60 [11.6%]), AST increased (48 [9.3%]), and hyperthyroidism (46 [8.9%]). The TRAEs that led to drug interruption and drug discontinuation were observed in 67 (12.9%) and 31 patients (6.0%), respectively. The immune-related TRAEs and treatment-related serious adverse events were observed in 223 (43.1%) and 59 patients (11.4%), respectively. 79 (16.9%) patients had a confirmed objective response, 237 (50.6%) patients had a confirmed disease control. Conclusion: QL1706 had a manageable safety profile. QL1706 still showed promising anti-tumor activity although over one-third of the patients received prior immunotherapy. These results supported further investigation of QL1706 for advanced solid tumors. Citation Format: Li Zhang, Hongyun Zhao, Yan Huang, Wenfeng Fang, Yuxiang Ma, Yang Zhang, Xiaoli Wei, Yanhua Yang, Wei Yang, Furong Liu, Zuan Lin, Jianing Li, Qianwen Liu, Benyan Zou, Kunlun Liao, qun Liu. The safety summary of the phase 1a/b trial of QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, for advanced malignant tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT520.

Routine flow cytometry approach for the evaluation of solid tumor neoplasms and immune cells in minimally invasive samples.

Multidimensional flow cytometry (MFC) is routinely used for the diagnosis and follow-up of hematolymphoid neoplasms but its contribution to the identification of non-hematolymphoid malignant tumors is limited. The presence of non-hematolymphoid cells in clinical samples obtained via minimally invasive methods was ascertained by using a panel of monoclonal antibodies previously developed in our laboratory comprising a mixture of antibodies: CD9-PacB/CD45-OC515/CD57-FITC/CD56-PE/CD3-PerCP-Cy5.5/CD117-PE-Cy7/CD326-APC/CD81-APC-C750. Histopathological studies were performed using standard techniques. 164 specimens of different origins were included. Malignancy was finally confirmed in 142 (86.5%), while 22 non neoplastic samples were identified. The most frequent diagnosis was small cell lung carcinoma (SCLC) (50%). High sensitivity (S=98.6%) was reached combining MFC and conventional pathology. Individual markers differed according to the cellular origin of the neoplasm, with neuroendocrine tumors showing a unique immunophenotypic profile (CD56+ CD326+ CD117-/+ and variable tetraspanins expression). Principal component analysis efficiently distinguished SCLC from other tumor samples. In immune cell populations, differences between reactive and malignant biopsies were found in different cell compartments, especially in B cells and Plasma cells. Differences also emerged in the percentage of CD4+ CD8- T cells, CD4-CD8+ T cells and NK cells and these were dependent on the origin of the tumor cells. These results support the use of MFC as a rapid and valuable technique to detect non-hematolymphoid tumoral cells in clinical specimens, providing an initial orientation to complement hystopathological studies and allow a more precise diagnosis, especially in neuroendocrine neoplasms. The impact of different immune cell patterns warrants further research.

Cascade-Enhanced Lateral Flow Immunoassay for Sensitive Detection of Okadaic Acid in Seawater, Fish, and Seafood.

In this investigation, a new approach for developing a sensitive lateral flow immunoassay (LFIA) was proposed for the detection of the hazardous marine toxin okadaic acid (OA). It is based on the indirect format with anti-species antibodies labeled by gold nanoparticles (AuNPs) and cascade signal amplification. The latter is performed by first passing a mixture of anti-OA antibodies and a tested sample along the immunochromatographic test strip and then performing several cycles of the interaction of anti-species antibodies conjugated with AuNPs with free antibodies, which bind to anti-species antibodies but are not specific to the target analyte. As a result, branched aggregates are formed, due to which the colorimetric signal intensification occurs. The developed test system enabled the detection of OA with an instrumental detection limit of 30 pg/mL and a cutoff of 1 ng/mL, which exceeds these characteristics in the LFIA without amplification by 7 and 2 times, respectively. The OA recoveries from seawater, fish, and seafood varied from 76.9% to 126%. The test system may be required for point-of-care monitoring of samples for phycotoxin contamination; the developed principle of signal amplification can be used in cases where highly sensitive detection of trace amounts of a contaminant is required.

Efficacy and safety of QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, for advanced nasopharyngeal carcinoma (NPC): Pooled cohort data from phase 1a/1b trials.

Efficacy and safety of QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, for advanced nasopharyngeal carcinoma (NPC): Pooled cohort data from phase 1a/1b trials.

Efficacy and safety of QL1706, a novel dual immune checkpoint blockade containing a mixture of anti-PD1 IgG4 and anti-CTLA4 IgG1 antibodies, for advanced cervical cancer: Cohort data from a phase 1b trial.

5535 Background: Anti-cytotoxic T lymphocyte antigen 4 (CTLA-4) and anti-programmed cell death 1 (PD-1) antibodies have synergistic effect. QL1706 is a novel dual immune checkpoint blockade containing a mixture of anti-PD-1 IgG4 and anti-CTLA4 IgG1 antibodies produced by a single cell line. QL1706 showed promising anti-tumor activity in multiple solid tumors. Here we reported the cervical cancer cohort data from the phase 1b trial of QL1706 (NCT05171790). Methods: Eligible patients had a pathologically confirmed diagnosis of squamous cell carcinoma, adenosquamous carcinoma, or adenocarcinoma of the cervix, with recurrent or metastatic, immunotherapy-naive disease at the time of enrollment. Patients were required to have ≥one lesion measurable by RECIST v1.1 and disease that had relapsed after a first-line, platinum-based regimen. Patients were included regardless of PD-L1 expression status at baseline. Patients received intravenous QL1706 5.0 mg/kg q3w (i.e., recommended phase 2 dose, defined in a phase 1a trial), for up to 24 months. The primary endpoint was confirmed overall response rate (ORR) per RECIST v1.1 by investigator. The secondary endpoints included disease control rate, duration of response (DoR), progression-free survival (PFS), overall survival (OS), safety, etc. Results: As of Dec 31, 2021, totally 53 patients with cervical cancer were enrolled (median age, 52 years [range 33-72]). Median follow-up was 5.6 months. Most patients (45 [85%]) had ECOG performance status of 1. Histological breakdown was squamous cell carcinoma (44 [83%]) and adenocarcinoma (nine [17%]). 33 (62%) patients had received one prior chemotherapy, 20(38%) patients had received ≥two prior chemotherapy. The confirmed ORR was 28% (95% CI 17%-42%; 15 patients), including one (2%) complete response and 14 (26%) partial response, with median duration of response not reached (95% CI 2.8 months-not estimable). Disease control was observed in 29 (55%; 95% CI 40%-68%) patients. Median PFS was 4.2 months (95% CI 1.7-6.9), and 6-month PFS rate was estimated as 37% (95% CI 24%-51%). Treatment-related adverse events (TRAE) were observed in 40 (75%) patients. Nine (17%) experienced grade ≥3 TRAE. The most common TRAE were rash (eight [15%]), hyperthyroidism (eight [15%]), and pyrexia (seven [13%]). Three (6%) patients suffered TRAE leading to dose discontinuation. The immune-related TRAE and serious TRAE were observed in 28 (53%) and eight (15%) patients, respectively. Conclusions: QL1706 demonstrated promising and durable clinical activity, with favorable tolerability in patients with recurrent and/or metastatic cervical cancer. Further investigations in this setting are continuing. Clinical trial information: NCT05171790.

Dual-color quantum dot-loaded nanoparticles based lateral flow biosensor for the simultaneous detection of gastric cancer markers in a single test line

A dual-color quantum dots-loaded nanoparticles (QPs) based lateral flow biosensor with single test line has been developed. Red and green emitted QPs were conjugated with antibodies and served as detecting probes in assays respectively, while the mixture of various antibodies were immobilized on nitrocellulose membranes as one detection line. Benefit from eliminating the heterogeneity caused by different position on the membrane, current biosensor achieved higher accuracy comparing with prevalent multi-lines or multi-strips lateral flow systems, which is of great significance for analyzing ratio-related diagnostics. The capability and reliability of the multiplex biosensor are also demonstrated by utilizing pepsinogen I (PG I) and pepsinogen II (PG II) as the model analytes. Under the optimal conditions, quantitative detection was achieved with ultra-low limits of detection at 6.9 pM (0.29 ng mL−1, PG I) and 15.7 pM (0.66 ng mL−1, PG II) respectively. The spectra crosstalk was negligible and no apparent cross-reaction was found in simultaneous detection. Furthermore, a good linear correlation of the QPs based lateral flow biosensor and commercial time-resolved fluoroimmunoassay was obtained in the detection of clinical samples, indicating the high reliability of the proposed biosensor.

First-in-Human Clinical Trial to Assess the Safety, Tolerability and Pharmacokinetics of Single Doses of NTM-1633, a Novel Mixture of Monoclonal Antibodies against Botulinum Toxin E.

Botulism is a rare, life-threatening paralytic disease caused by botulinum neurotoxin (BoNT). Available treatments including an equine antitoxin and human immune globulin are given postexposure and challenging to produce and administer. NTM-1633 is an equimolar mixture of 3 human IgG monoclonal antibodies, E1, E2, and E3, targeting BoNT serotype E (BoNT/E). This first-in-human study assessed the safety, tolerability, pharmacokinetics (PK), and immunogenicity of NTM-1633. This double-blind, single-center, placebo-controlled dose escalation study randomized 3 cohorts of healthy volunteers to receive a single intravenous dose of NTM-1633 (0.033, 0.165, or 0.330 mg/kg) or saline placebo. Safety monitoring included physical examinations, clinical laboratory studies, and vital signs. Blood sampling was performed at prespecified time points for PK and immunogenicity analyses. Twenty-four subjects received study product (18 NTM-1633; 6 placebo), and no deaths were reported. An unrelated serious adverse event was reported in a placebo subject. Adverse events in the NTM-1633 groups were generally mild and similar in frequency and severity to the placebo group, and no safety signal was identified. NTM-1633 has a favorable PK profile with a half-life >10 days for the 0.330 mg/kg dose and an approximately linear relationship with respect to maximum concentration and area under the concentration-time curve (AUC0→t). NTM-1633 also demonstrated low immunogenicity. NTM-1633 is well tolerated at the administered doses. The favorable safety, PK, and immunogenicity profile supports further development as a treatment for BoNT/E intoxication and postexposure prophylaxis.

The monitoring of plum pox virus in Bursa, Bilecik, and Bolu provinces of Turkey refined MIs status as a variant of strain M

A total of 486 symptomatic and asymptomatic peach leaf samples were collected from Bursa, Bilecik, and Bolu provinces and tested for plum pox virus (PPV, Potyvirus) in response to recent reports on the new divergent subgroup MIs in the nearby Istanbul province of Turkey. The phylogenetic analysis of newly sequenced isolates indicated that two isolates from Bolu belong to subgroup MIs, confirming the existence of its isolates beyond Istanbul. Both Bolu MIs isolates cross-reacted with a mixture of polyclonal antibodies and monoclonal 5B-IVIA in a commercial DAS-ELISA kit for universal detection of PPV strains, elucidating some of MIs serological characters. The identity percentage, and also the evolutionary distance and diversity analyses showed that M isolates shared high genetic identities among them, and that the diversity among its subgroups was also low. Therefore, the results showed that MIs is not a new distinct strain but a variant of strain M. Supplemental data for this article is available online at https://doi.org/10.1080/03235408.2022.2052523 .