Efficacy of Rituximab Versus Cyclophosphamide and Mycophenolate for the Treatment of Interstitial Lung Disease in Systemic Sclerosis: A Systematic Review.

Interstitial lung disease (ILD) is a common complication of systemic sclerosis (SSc), contributing to significant morbidity and mortality in affected individuals. The optimal treatment approach for SSc-associated ILD remains uncertain, with rituximab, cyclophosphamide, and mycophenolate among potential therapeutic options. This systematic review aims to evaluate and synthesize the existing evidence on the efficacy of rituximab compared to cyclophosphamide and mycophenolate for the treatment of ILD in patients with systemic sclerosis. A comprehensive search of the following electronic databases, PubMed, Science Direct, Google Scholar, and Cochrane Library, has been conducted to identify relevant studies, including randomized controlled trials, systematic review and meta-analysis, prospective cohort studies, and retrospective cohort studies. Data on study characteristics, participant demographics, interventions, outcomes, and key findings have been extracted and synthesized. The risk of bias in the included studies has been assessed using appropriate tools such as the Cochrane Bias assessment tool for randomized controlled trials, the New Castle Ottawa tool for cohort studies, and the AMSTAR checklist for systematic reviews and meta-analysis. The research team ultimately selected 15 high-quality studies for review. Rituximab demonstrated similar efficacy to cyclophosphamide and mycophenolate in improving lung function (forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO)), with fewer severe adverse events. Cyclophosphamide, while effective, had higher toxicity, leading to more frequent adverse events such as leukopenia and infections. Mycophenolate showed comparable efficacy to cyclophosphamide but with fewer side effects, making it a well-tolerated alternative. The findings of this systematic review will provide valuable insights into the comparative efficacy of rituximab, cyclophosphamide, and mycophenolate in the management of ILD in systemic sclerosis, informing clinical decision-making and guiding future research in this area.

Curcumin and Cognitive Function: A Systematic Review of the Effects of Curcumin on Adults With and Without Neurocognitive Disorders.

This systematic review investigates the effect of curcumin on neurocognitive exams and inflammatory serum biomarkers in adults 18 years and older. We search PubMed, Science Direct, Google Scholar, Cochrane Library, and Multidisciplinary Digital Publishing Institute. Modeling the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (PRISMA), we screened 1,284 studies with the keywords "neurocognitive disorders," "dementia," "cognitive health," "serum biomarkers," and "curcumin." We use the revised Cochrane Risk-of-Bias tool (RoB2) and the Newcastle-Ottawa Scale to select 12 open-access full-text articles published within 20 years. We include clinical trials, randomized controlled trials (RCTs), cohort studies, and human studies, excluding nonhumans, other design types, and schizophrenia. Despite gastrointestinal side effects, studies found curcumin significantly improves working memory in the following adult groups: non-demented, metabolically impaired, cognitively impaired, mood impaired, and chemotherapy impaired. Study limitations include variable population characteristics and few trials employing intention-to-treat analysis, emphasizing the need for shared clinical decision-making before curcumin therapy.

Effectiveness of High-Fiber, Plant-Based Diets in Reducing Cardiovascular Risk Factors Among Middle-Aged and Older Adults: A Systematic Review.

Cardiovascular disease (CVD) is a prominent contributor to morbidity and mortality, particularly in the middle-aged and elderly population. Plant-based, high-fiber diets high in fruits, vegetables, whole grains, legumes, and nuts can significantly lower CVD risk factors. This systematic review aims to assess how effectively diet improves cardiovascular health in this demographic. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria, we thoroughly searched PubMed, Google Scholar, ScienceDirect, Cochrane Library, and ClinicalTrials.gov, explicitly focusing on papers published in English. The review identified 10 pertinent papers, including three systematic reviews, one randomized-controlled trial (RCT), two observational studies, and four review articles demonstrating significant improvements in blood pressure, cholesterol levels, and glycemic management associated with high-fiber plant-based diets (PBDs). The research specifically emphasized the significance of dietary fiber in decreasing low-density lipoprotein (LDL) cholesterol, enhancing insulin sensitivity, and reducing systemic inflammation. These data support the concept that PBDs high in fiber can effectively lower CVD risk factors. However, limitations such as self-reported dietary intake and variability in adherence were noted. In conclusion, high-fiber PBDs are a viable strategy for managing and preventing CVD in middle-aged and older adults. Future research should focus on long-term adherence, the comparative benefits of different plant-based foods, and developing personalized dietary recommendations to optimize cardiovascular health outcomes in this population.

Evaluating Cardiovascular Benefits of Glucagon-Like Peptide-1 Receptor Agonists (GLP-1 RAs) in Type 2 Diabetes Mellitus: A Systematic Review.

Cardiovascular risks and complications remain elevated in patients with type 2 diabetes even after appropriate control of contributing factors like glycemic control, hypertension, and lipid profile. More efficient methods are needed to address this issue in type 2 diabetics. Newer drugs like glucagon-like peptide-1 receptor agonists (GLP-1 RAs) have shown a cardioprotective effect in addition to glycemic control. This systematic review aims to study the latest literature findings on the cardiovascular effects of GLP-1 RAs in patients with type 2 diabetes. We used PubMed, Google Scholar, Science Direct, and Biomed Central databases for our data collection. Our review adheres to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The outcomes evaluated in the review include major adverse cardiovascular events (MACE), heart failure, stroke, all-cause mortality, and effects on cardiovascular risk factors. After careful inspection and quality check, we included 14 articles in the systematic review. GLP-1 RAs were associated with a significant reduction in cardiovascular mortality, all-cause mortality, nonfatal myocardial infarction (MI), and nonfatal stroke, especially in patients with existing cardiovascular risk factors. However, more evidence is required to determine if these benefits extend to those without such risk factors. Limited data suggest that GLP-1 RAs might have a protective effect on arrhythmias, but this area needs further investigation. Despite their potential, several barriers hinder the widespread use of GLP-1 RAs. In conclusion, GLP-1 RAs significantly reduce cardiovascular mortality, all-cause mortality, nonfatal MI, and stroke, with minor effects on hospitalization due to heart failure. Benefits are greater in patients with cardiovascular risk factors. A comprehensive, multilevel approach to policy development and implementation is necessary to optimize the use of these medications in eligible populations.

The Impact of Exercise on C-reactive Protein Levels in Hypertensive Patients: A Systematic Review.

Hypertension, defined as persistently elevated blood pressure, is a prevalent chronic condition and a significant global health issue, closely linked to cardiovascular complications, with inflammation being one of the underlying mechanisms. In hypertensive patients, C-reactive protein (CRP), an inflammatory marker, is often elevated and associated with increased cardiovascular risk. Alongside pharmacotherapy, exercise is recommended as a non-pharmacological approach to managing hypertension, with evidence suggesting that exercise can also reduce inflammation. This study examines the impact of exercise on CRP levels in hypertensive patients. Fourteen studies focusing on exercise interventions and physical fitness related to CRP in individuals with high blood pressure were identified through an extensive search of PubMed, PubMed Central, ScienceDirect, Cochrane Library, and Google Scholar. The findings indicated that most studies involving aerobic exercise consistently demonstrated reductions in CRP levels among hypertensive patients, with significant effects observed under supervised conditions, and additional benefits seen when combined with dietary control. Resistance training showed mixed results, with significant reductions in CRP observed primarily in longer-term interventions. Combined exercise training, incorporating both aerobic and resistance elements, effectively reduced CRP levels and improved cardiovascular health markers. Physical fitness assessments, such as a bicycle exercise test to exhaustion, revealed a relationship between physical fitness and decreased CRP levels. Therefore, regular, consistent aerobic and combined training, as well as prolonged resistance exercise, significantly reduce CRP levels in hypertensive patients, highlighting exercise's role as a non-pharmacological strategy for managing hypertension through the reduction of inflammation. Further research is essential to validate these findings and investigate the underlying mechanisms and differential effects of various exercise modalities.

Genetic and antigenic characterization of two diarrhoeicdominant rotavirus A genotypes G3P[12] and G14P[12] circulating in the global equine population.

Equine rotavirus species A (ERVA) G3P[12] and G14P[12] are two dominant genotypes that cause foal diarrhoea with a significant economic impact on the global equine industry. ERVA can also serve as a source of novel (equine-like) rotavirus species A (RVA) reassortants with zoonotic potential as those identified previously in 2013-2019 when equine G3-like RVA was responsible for worldwide outbreaks of severe gastroenteritis and hospitalizations in children. One hurdle to ERVA research is that the standard cell culture system optimized for human rotavirus replication is not efficient for isolating ERVA. Here, using an engineered cell line defective in antiviral innate immunity, we showed that both equine G3P[12] and G14P[12] strains can be rapidly isolated from diarrhoeic foals. The genome sequence analysis revealed that both G3P[12] and G14P[12] strains share the identical genotypic constellation except for VP7 and VP6 segments in which G3P[12] possessed VP7 of genotype G3 and VP6 of genotype I6 and G14P[12] had the combination of VP7 of genotype G14 and VP6 of genotype I2. Further characterization demonstrated that two ERVA genotypes have a limited cross-neutralization. The lack of an in vitro broad cross-protection between both genotypes supported the increased recent diarrhoea outbreaks due to equine G14P[12] in foals born to dams immunized with the inactivated monovalent equine G3P[12] vaccine. Finally, using the structural modelling approach, we provided the genetic basis of the antigenic divergence between ERVA G3P[12] and G14P[12] strains. The results of this study will provide a framework for further investigation of infection biology, pathogenesis and cross-protection of equine rotaviruses.

Evaluating the Impact of Telemedicine on Diabetes Management in Rural Communities: A Systematic Review.

Telemedicine is the delivery of healthcare services using information and communication technologies to diagnose, treat, and prevent diseases. The COVID-19 pandemic has accelerated the adoption of telemedicine, transforming how healthcare is delivered, especially in remote and underserved areas. Despite its potential, no systematic reviews have been conducted in the last five years to assess the effectiveness of telemedicine for managing diabetes in rural populations. This review addresses this gap by evaluating studies on telemedicine's impact on glycemic control among diabetic patients in these settings. We searched five databases: PubMed, Google Scholar, ClinicalTrials.gov, ScienceDirect, and Science.gov, covering studies published in the last five years. Of the 331 articles identified, 10 met our inclusion criteria: English-language studies from the past five years involving adults in rural areas or comparing rural and urban settings, focusing on telemedicine's impact on glycemic control in diabetic patients. In many studies, the findings revealed that telemedicine interventions integrated into structured programs significantly improved HbA1c levels. Successful implementation requires local infrastructure and consistent patient-provider interactions, although increased healthcare provider workloads may affect sustainability. Telemedicine alone was less effective for patients with complex comorbidities, suggesting that a combined approach with in-person visits may be more effective. This review highlights telemedicine's potential to replace routine in-person visits for diabetes management in rural areas, demonstrating significant improvements in HbA1c levels, medication adherence, and timely care management support. Future research should focus on randomized controlled trials in rural settings, hybrid care models that optimize in-person visit frequency and remote monitoring, and addressing technological challenges such as broadband access and platform usability to ensure sustainable telehealth interventions.

RETRACTED: Skelton et al. Contribution of Host Immune Responses against Influenza D Virus Infection toward Secondary Bacterial Infection in a Mouse Model. Viruses 2019, 11, 994.

The Viruses Editorial Office retracts the article, "Contribution of Host Immune Responses Against Influenza D Virus Infection Toward Secondary Bacterial Infection in a Mouse Model" [...].

A recombinant chimeric influenza virus vaccine expressing the consensus H3 hemagglutinin elicits broad hemagglutination inhibition antibodies against divergent swine H3N2 influenza viruses.

The global distribution and ongoing evolution of type A swine influenza virus (IAV-S) continue to pose significant challenges against developing broadly protective vaccines to control swine influenza. This study focuses on the hemagglutinin (HA) consensus-based approach towards developing a more broadly protective swine influenza vaccine against various H3 strains circulating in domestic pig populations. By computationally analyzing >1000 swine H3 full-length HA sequences, we generated a consensus H3 and expressed it in the context of influenza A WSN/33 reverse genetics system. The derived recombinant chimeric swine influenza virus with the consensus H3 was inactivated and further evaluated as a potential universal vaccine in pigs. The consensus H3 vaccine elicited broadly active hemagglutination inhibition (HI) antibodies against divergent swine H3N2 influenza viruses including human H3N2 variant of concern, and strains belong to genetic clusters IV, IV-A, IV-B, IV-C, IV-D and IV-F. Importantly, vaccinated pigs were completely protected against challenge with a clinical swine H3N2 isolate in that neither viral shedding nor replication in lungs of vaccinated pigs were observed. These findings warrant further study of the consensus H3 vaccine platform for broad protection against diverse swine influenza viruses.

Prevalence and characterization of seven-segmented influenza viruses in bovine respiratory disease complex.

Bovine respiratory disease (BRD) complex is a multifactorial respiratory disease of cattle. Seven-segmented influenza C (ICV) and D (IDV) viruses have been identified in cattle with BRD, however, molecular epidemiology and prevalence of IDV and ICV in the diseased population remain poorly characterized. Here, we conducted a molecular screening of 208 lung samples of bovine pneumonia cases for the presence of IDV and ICV. Our results demonstrated that both viruses were prevalent in BRD cases and the overall positivity rates of IDV and ICV were 20.88% and 5.99% respectively. Further analysis of three IDV strains isolated from lungs of cattle with BRD showed that these lung-tropic strains belonged to D/Michigan/2019 clade and diverged antigenically from the circulating dominant IDV clades D/OK and D/660. Our results reveal that IDV and ICV are associated with BRD complex and support a role for IDV and ICV in the etiology of BRD.

A fully human monoclonal antibody possesses antibody-dependent cellular cytotoxicity (ADCC) activity against the H1 subtype of influenza A virus by targeting a conserved epitope at the HA1 protomer interface.

The DiversitabTM system produces target specific high titer fully human polyclonal IgG immunoglobulins from transchromosomic (Tc) bovines shown to be safe and effective against multiple virulent pathogens in animal studies and Phase 1, 2 and 3 human clinical trials. We describe the functional properties of a human monoclonal antibody (mAb), 38C2, identified from this platform, which recognizes recombinant H1 hemagglutinins (HAs) and induces appreciable antibody-dependent cellular cytotoxicity (ADCC) activity in vitro. Interestingly, 38C2 monoclonal antibody demonstrated no detectable neutralizing activity against H1N1 virus in both hemagglutination inhibition and virus neutralization assays. Nevertheless, this human monoclonal antibody induced appreciable ADCC against cells infected with multiple H1N1 strains. The HA-binding activity of 38C2 was also demonstrated in flow cytometry using Madin-Darby canine kidney cells infected with multiple influenza A H1N1 viruses. Through further investigation with the enzyme-linked immunosorbent assay involving the HA peptide array and 3-dimensional structural modeling, we demonstrated that 38C2 appears to target a conserved epitope located at the HA1 protomer interface of H1N1 influenza viruses. A novel mode of HA-binding and in vitro ADCC activity pave the way for further evaluation of 38C2 as a potential therapeutic agent to treat influenza virus infections in humans.

Influenza C and D Viruses Demonstrated a Differential Respiratory Tissue Tropism in a Comparative Pathogenesis Study in Guinea Pigs.

Influenza C virus (ICV) is increasingly associated with community-acquired pneumonia (CAP) in children and its disease severity is worse than the influenza B virus, but similar to influenza A virus associated CAP. Despite the ubiquitous infection landscape of ICV in humans, little is known about its replication and pathobiology in animals. The goal of this study was to understand the replication kinetics, tissue tropism, and pathogenesis of human ICV (huICV) in comparison to the swine influenza D virus (swIDV) in guinea pigs. Intranasal inoculation of both viruses did not cause clinical signs, however, the infected animals shed virus in nasal washes. The huICV replicated in the nasal turbinates, soft palate, and trachea but not in the lungs while swIDV replicated in all four tissues. A comparative analysis of tropism and pathogenesis of these two related seven-segmented influenza viruses revealed that swIDV-infected animals exhibited broad tissue tropism with an increased rate of shedding on 3, 5, and 7 dpi and high viral loads in the lungs compared to huICV. Seroconversion occurred late in the huICV group at 14 dpi, while swIDV-infected animals seroconverted at 7 dpi. Guinea pigs infected with huICV exhibited mild to moderate inflammatory changes in the epithelium of the soft palate and trachea, along with mucosal damage and multifocal alveolitis in the lungs. In summary, the replication kinetics and pathobiological characteristics of ICV in guinea pigs agree with the clinical manifestation of ICV infection in humans, and hence guinea pigs could be used to study these distantly related influenza viruses. IMPORTANCE Similar to influenza A and B, ICV infections are seen associated with bacterial and viral co-infections which complicates the assessment of its real clinical significance. Further, the antivirals against influenza A and B viruses are ineffective against ICV which mandates the need to study the pathobiological aspects of this virus. Here we demonstrated that the respiratory tract of guinea pigs possesses specific viral receptors for ICV. We also compared the replication kinetics and pathogenesis of huICV and swIDV, as these viruses share 50% sequence identity. The tissue tropism and pathology associated with huICV in guinea pigs are analogous to the mild respiratory disease caused by ICV in humans, thereby demonstrating the suitability of guinea pigs to study ICV. Our comparative analysis revealed that huICV and swIDV replicated differentially in the guinea pigs suggesting that the type-specific genetic differences can result in the disparity of the viral shedding and tissue tropism.

Experimental Infection of Horses with Influenza D Virus.

Antibodies to influenza D virus (IDV) have been detected in horses, but no evidence of disease in the field has been reported. To determine whether IDV is infectious, immunogenic, and pathogenic in horses, four 2-year-old horses seronegative for both influenza A (H3N8) and D viruses were intranasally inoculated with 6.25 × 107 TCID50/animal of D/bovine/California/0363/2019 (D/CA2019) virus, using a portable equine nebulizer system. Horses were observed daily for clinical signs including rectal temperature, nasal discharge, coughing, lung sounds, tachycardia, and tachypnea. No horses exhibited clinical signs of disease. Nasopharyngeal swabs collected from 1-8 days post-infection demonstrated virus shedding by qRT-PCR. The horses showed evidence of seroconversion as early as 13 days post-infection (dpi) and the geometric mean of the antibody titers (GMT) of all four horses ranged from 16.82-160 as demonstrated by the microneutralization assay. Further, deep RNA sequencing of the virus isolated in embryonated chicken eggs revealed no adaptive mutations indicating that IDV can replicate in horses, suggesting the possibility of interspecies transmission of IDV with bovine reservoir into equids in nature.

Host Range, Biology, and Species Specificity of Seven-Segmented Influenza Viruses-A Comparative Review on Influenza C and D.

Other than genome structure, influenza C (ICV), and D (IDV) viruses with seven-segmented genomes are biologically different from the eight-segmented influenza A (IAV), and B (IBV) viruses concerning the presence of hemagglutinin-esterase fusion protein, which combines the function of hemagglutinin and neuraminidase responsible for receptor-binding, fusion, and receptor-destroying enzymatic activities, respectively. Whereas ICV with humans as primary hosts emerged nearly 74 years ago, IDV, a distant relative of ICV, was isolated in 2011, with bovines as the primary host. Despite its initial emergence in swine, IDV has turned out to be a transboundary bovine pathogen and a broader host range, similar to influenza A viruses (IAV). The receptor specificities of ICV and IDV determine the host range and the species specificity. The recent findings of the presence of the IDV genome in the human respiratory sample, and high traffic human environments indicate its public health significance. Conversely, the presence of ICV in pigs and cattle also raises the possibility of gene segment interactions/virus reassortment between ICV and IDV where these viruses co-exist. This review is a holistic approach to discuss the ecology of seven-segmented influenza viruses by focusing on what is known so far on the host range, seroepidemiology, biology, receptor, phylodynamics, species specificity, and cross-species transmission of the ICV and IDV.

Identification of a Ruminant Origin Group B Rotavirus Associated with Diarrhea Outbreaks in Foals.

Equine rotavirus group A (ERVA) is one of the most common causes of foal diarrhea. Starting in February 2021, there was an increase in the frequency of severe watery to hemorrhagic diarrhea cases in neonatal foals in Central Kentucky. Diagnostic investigation of fecal samples failed to detect evidence of diarrhea-causing pathogens including ERVA. Based on Illumina-based metagenomic sequencing, we identified a novel equine rotavirus group B (ERVB) in fecal specimens from the affected foals in the absence of any other known enteric pathogens. Interestingly, the protein sequence of all 11 segments had greater than 96% identity with group B rotaviruses previously found in ruminants. Furthermore, phylogenetic analysis demonstrated clustering of the ERVB with group B rotaviruses of caprine and bovine strains from the USA. Subsequent analysis of 33 foal diarrheic samples by RT-qPCR identified 23 rotavirus B-positive cases (69.69%). These observations suggest that the ERVB originated from ruminants and was associated with outbreaks of neonatal foal diarrhea in the 2021 foaling season in Kentucky. Emergence of the ruminant-like group B rotavirus in foals clearly warrants further investigation due to the significant impact of the disease in neonatal foals and its economic impact on the equine industry.

Isolation and development of bovine primary respiratory cells as model to study influenza D virus infection.

Influenza D virus (IDV) is a novel type of influenza virus that infects and causes respiratory illness in bovines. Lack of host-specific in vitro model that can recapitulate morphology and physiology of in vivo airway epithelial cells has impeded the study of IDV infection. Here, we established and characterized bovine primary respiratory epithelial cells from nasal turbinate, soft palate, and trachea of the same calf. All three cell types showed characteristics peculiar of epithelial cells, polarized into apical-basolateral membrane, and formed tight junctions. Furthermore, these cells expressed both α-2,3- and α-2,6-linked sialic acids with α-2,3 linkage being more abundant. IDV strains replicated to high titers in these cells, while influenza A and B viruses exhibited moderate to low titers, with influenza C virus replication not detected. These findings suggest that bovine primary airway epithelial cells can be utilized to model infection biology and pathophysiology of IDV and other respiratory pathogens.

Emergence of new phylogenetic lineage of Influenza D virus with broad antigenicity in California, United States.

Influenza D virus (IDV), with bovines as a primary host, circulates widely in cattle populations across North America and Eurasia. Here we report the identification of a novel IDV group with broad antigenicity in U.S. bovine herds, which is genetically different from previously known lineages of IDV.

Piglet immunization with a spike subunit vaccine enhances disease by porcine epidemic diarrhea virus.

Immunization with an insect cell lysate/baculovirus mixture containing recombinant porcine epidemic diarrhea virus (PEDV) spike protein induced high levels of neutralizing antibodies in both mice and piglets. However, immunization of piglets with this vaccine resulted in enhancement of disease symptoms and virus replication in vaccine recipients exposed to PEDV challenge. Thus, these observations demonstrate a previously unrecognized challenge of PEDV vaccine research, which has important implications for coronavirus vaccine development.

Susceptibility of livestock and companion animals to COVID-19.

While the coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to wreak havoc, there is little known about the susceptibility of the livestock and companion animals relative to humans. Here, we explore the susceptibility of companion and agricultural animals, in light of the existing information on natural infections, experimental infections, serosurveillance, and in vitro protein-homology binding interaction studies of the SARS-CoV-2 with the proposed receptor angiotensin-converting enzyme 2 from diverse animal species.

Human Monoclonal Antibody Derived from Transchromosomic Cattle Neutralizes Multiple H1 Clades of Influenza A Virus by Recognizing a Novel Conformational Epitope in the Hemagglutinin Head Domain.

Influenza remains a global health risk and challenge. Currently, neuraminidase (NA) inhibitors are extensively used to treat influenza, but their efficacy is compromised by the emergence of drug-resistant variants. Neutralizing antibodies targeting influenza A virus surface glycoproteins are critical components of influenza therapeutic agents and may provide alternative strategies to the existing countermeasures. However, the major hurdle for the extensive application of antibody therapies lies in the difficulty of generating nonimmunogenic antibodies in large quantities rapidly. Here, we report that one human monoclonal antibody (MAb), 53C10, isolated from transchromosomic (Tc) cattle exhibits potent neutralization and hemagglutination inhibition titers against different clades of H1N1 subtype influenza A viruses. In vitro selection of antibody escape mutants revealed that 53C10 recognizes a novel noncontinuous epitope in the hemagglutinin (HA) head domain involving three amino acid residues, glycine (G), serine (S), and glutamic acid (E) at positions 172, 207, and 212, respectively. The results of our experiments supported a critical role for substitution of arginine at position 207 (S207R) in mediating resistance to 53C10, while substitutions at either G172E or E212A did not alter antibody recognition and neutralization. The E212A mutation may provide structural stability for the epitope, while the substitution G172E probably compensates for loss of fitness introduced by S207R. Our results offer novel insights into the mechanism of action of MAb 53C10 and indicate its potential role in therapeutic treatment of H1 influenza virus infection in humans.IMPORTANCE Respiratory diseases caused by influenza viruses still pose a serious concern to global health, and neutralizing antibodies constitute a promising area of antiviral therapeutics. However, the potential application of antibodies is often hampered by the challenge in generating nonimmunogenic antibodies in large scale. In the present study, transchromosomic (Tc) cattle were used for the generation of nonimmunogenic monoclonal antibodies (MAbs), and characterization of such MAbs revealed one monoclonal antibody, 53C10, exhibiting a potent neutralization activity against H1N1 influenza viruses. Further characterization of the neutralization escape mutant generated using this MAb showed that three amino acid substitutions in the HA head domain contributed to the resistance. These findings emphasize the importance of Tc cattle in the production of nonimmunogenic MAbs and highlight the potential of MAb 53C10 in the therapeutic application against H1 influenza virus infection in humans.