Single-cell transcriptomic analysis of B cells reveals new insights into atypical memory B cells in COVID-19.

Here, we performed single-cell RNA sequencing of S1 and receptor binding domain protein-specific B cells from convalescent COVID-19 patients with different clinical manifestations. This study aimed to evaluate the role and developmental pathway of atypical memory B cells (MBCs) in response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The results revealed a proinflammatory signature across B cell subsets associated with disease severity, as evidenced by the upregulation of genes such as GADD45B, MAP3K8, and NFKBIA in critical and severe individuals. Furthermore, the analysis of atypical MBCs suggested a developmental pathway similar to that of conventional MBCs through germinal centers, as indicated by the expression of several genes involved in germinal center processes, including CXCR4, CXCR5, BCL2, and MYC. Additionally, the upregulation of genes characteristic of the immune response in COVID-19, such as ZFP36 and DUSP1, suggested that the differentiation and activation of atypical MBCs may be influenced by exposure to SARS-CoV-2 and that these genes may contribute to the immune response for COVID-19 recovery. Our study contributes to a better understanding of atypical MBCs in COVID-19 and the role of other B cell subsets across different clinical manifestations.

Retroperitoneal adrenal neuroblastoma with bone marrow metastatic activity in a young adult.

A 31-year-old male came to emergency department with acute abdominal pain from the right flank, diaphoresis and, palpitations. Contrasted abdominal CT revealed a tumor dependent from right adrenal gland and kidney. A laparoscopic radical nephrectomy was made to resect the tumor and pain relief. Pathological analysis reported poorly differentiated neuroblastoma from the right adrenal gland without involvement to kidney and ureter. The patient was sent to oncology clinic to continue with chemotherapy treatment. This is the third case of adult neuroblastoma reported in South America. Adult neuroblastoma is an uncommon cause of malignant neoplasm with an exceptional incidence reported.

Pseudomixoma peritoneal: reporte de un caso / Peritoneal Pseudomyxoma: A Case Report

Resumen El pseudomixoma peritoneal (PMP) es una afección poco común, inicialmente descrita en 1884 por Werth en relación con la ascitis y tumores mucinosos de ovario, y posteriormente en 1901 por Frankel, asociado a tumores mucinosos apendiculares. Se ha observado una alta prevalencia de mutaciones en el gen K-RAS y TP53 en pacientes con PMP de bajo grado, lo que desencadena la proliferación y producción excesiva de moco. Los estudios han demostrado que la cavidad peritoneal, especialmente la superficie hepática, es el sitio principal de depósito de estos tumores. La tomografía computada se considera el estándar de oro para el diagnóstico, mientras que la resonancia magnética es más sensible para detectar el origen tumoral y evaluar la extensión de la enfermedad. Aunque la laparotomía exploratoria es el método tradicional para la toma de biopsias, se están explorando alternativas menos invasivas como la biopsia guiada por ultrasonido y tomografía computarizada, que han demostrado ser eficaces. El diagnóstico diferencial incluye la endometriosis y tumores mixoides, con énfasis en la invasión al mesenterio y las características quísticas. Es crucial reconocer las diferencias en etapas avanzadas, ya que el PMP tiende a invadir los órganos desde afuera, mientras que los tumores mixoides presentan metástasis sólidas a distancia.

Abstract Pseudomyxoma peritonei (PMP) is a rare condition, first described by Werth in 1884 in association with ascites and ovarian mucinous tumors, and later in 1901 by Frankel, associated with appendicular mucinous tumors. High prevalence of mutations in the K-RAS and TP53 genes has been observed in patients with low-grade PMP, triggering proliferation and excessive mucus production. Studies have shown that the peritoneal cavity, especially the hepatic surface, is the main site for deposition of these tumors. Computed tomography is considered the gold standard for diagnosis, while magnetic resonance imaging is more sensitive for detecting the tumor origin and assessing disease extent. Although exploratory laparotomy is the traditional method for biopsy, less invasive alternatives such as ultrasound-guided and computed tomography-guided biopsy are being explored, which have proven to be effective. The differential diagnosis includes endometriosis and mixoid tumors, with emphasis on mesentery invasion and cystic characteristics. Recognizing differences in advanced stages is crucial, as PMP tends to invade organs from the outside, while mixoid tumors present distant solid metastases.

Comparative single-cell transcriptomic profile of hybrid immunity induced by adenovirus vector-based COVID-19 vaccines.

In this study, antibody response and a single-cell RNA-seq analysis were conducted on peripheral blood mononuclear cells from five different groups: naïve subjects vaccinated with AZD1222 (AZ) or Ad5-nCoV (Cso), individuals previously infected and later vaccinated (hybrid) with AZD1222 (AZ-hb) or Ad5-nCoV (Cso-hb), and those who were infected and had recovered from COVID-19 (Inf). The results showed that AZ induced more robust neutralizing antibody responses than Cso. The single-cell RNA data revealed a high frequency of memory B cells in the Cso and Cso-hb. In contrast, AZ and AZ-hb groups exhibited the highest proportion of activated naïve B cells expressing CXCR4. Transcriptomic analysis of CD4+ and CD8+ T cells demonstrated a heterogeneous response following vaccination, hybrid immunity, or natural infection. However, a single dose of Ad5-nCoV was sufficient to strongly activate CD4+ T cells (naïve and memory) expressing ANX1 and FOS, similar to the hybrid response observed with AZ. An interesting finding was the robust activation of a subset of CD8+ T cells expressing GZMB, GZMH, and IFNG genes in the Cso-hb group. Our findings suggest that both vaccines effectively stimulated the cellular immune response; however, the Ad5-nCoV induced a more robust CD8+ T-cell response in previously infected individuals.

The type 2 inflammatory response favors recognition of tumor antigens by IgE in breast cancer.

BACKGROUND: Several studies describe an inverse statistical relationship between the presence of an allergy and development of cancer. However, the immunological mechanism involved in the relationship between these two degenerative diseases has not been explored. AIMS: The main objective of this study was to explore the possibility that the lymphocyte T helper (Th) 2 response, a characteristic of allergy, induces recognition of tumor antigens. METHODS AND RESULTS: Patients with a clinical diagnosis of breast ductal carcinoma were included. Histopathological markers related to proliferation of tumor cells were determined (Her-2-neu, Ki-67, estrogen receptor, and progesterone receptor). IHC was performed using IgE antibodies purified from an allergy patient and from each biopsy donor patient. Serum concentrations of cytokines representative of Th1 and Th2 inflammatory responses were determined. A total of 14 patients with a confirmed diagnosis of breast ductal carcinoma were included. IHC performed on biopsies showed a weak response when using purified IgE antibodies from an allergy patient; however, IHC using the IgE of each patient as the primary antibody showed an intense and highly specific signal. Serum concentrations of cytokines of the Th2 response, that is, IL-4 (130.5 pg/mL (116-135 pg/mL)), IL-5 (202 pg/mL (191-213 pg/mL)), and IL-13 (105.5 pg/mL (98-117 pg/mL)), were significantly higher than those of the Th1 response, that is, IL-6 (86 pg/mL (79-90 pg/mL)) and INF-γ (93 pg/mL (79-99 pg/mL)). CONCLUSION: Purified IgE antibodies specifically recognize tumor cells in breast ductal carcinoma.

Cultivable Microbiome Approach Applied to Cervical Cancer Exploration.

Traditional microbiological methodology is valuable and essential for microbiota composition description and microbe role assignations at different anatomical sites, including cervical and vaginal tissues; that, combined with molecular biology strategies and modern identification approaches, could give a better perspective of the microbiome under different circumstances. This pilot work aimed to describe the differences in microbiota composition in non-cancer women and women with cervical cancer through a culturomics approach combining culture techniques with Vitek mass spectrometry and 16S rDNA sequencing. To determine the possible differences, diverse statistical, diversity, and multivariate analyses were applied; the results indicated a different microbiota composition between non-cancer women and cervical cancer patients. The Firmicutes phylum dominated the non-cancer (NC) group, whereas the cervical cancer (CC) group was characterized by the predominance of Firmicutes and Proteobacteria phyla; there was a depletion of lactic acid bacteria, an increase in the diversity of anaerobes, and opportunistic and non-typical human microbiota isolates were present. In this context, we hypothesize and propose a model in which microbial composition and dynamics may be essential for maintaining the balance in the cervical microenvironment or can be pro-oncogenesis microenvironmental mediators in a process called Ying-Yang or have a protagonist/antagonist microbiota role.

Association Between Interleukin 6 and C-Reactive Protein Serum Levels and Body Composition Compartments and Components in Breast Cancer Survivors.

Obesity is highly prevalent in breast cancer (BC) survivors. Adipose tissue promotes inflammation, affecting recurrence, morbidity, and quality of life. This study aimed to determine the relationship of body composition parameters with the levels of C-reactive protein (CRP) and interleukin 6 (IL-6) in female BC survivors. Additionally, we evaluated the association of log-transformed serum concentrations of CRP and IL-6 with the appendicular skeletal lean mass index (ASMI). The results showed that CRP was positively associated with body fat percentage (BFP; ß adjusted = .08, 95% CI: .02-.14) in all participants, and with fat mass index (FMI; ß = .24, 95% CI: .08-.40) only in premenopausal women. IL-6 was positively associated with FMI (ß adjusted = .16, 95% CI: .03-.29), while ASMI decreased as CRP levels increased (ß adjusted = -.30, 95% CI: -.53 to -.06). Interventions to improve body composition in BC survivors should also consider the role of inflammatory markers in changes in body composition to avoid sarcopenic obesity (SO) and the risk of BC recurrence.

Incidencia del espectro de acretismo placentario en la unidad de cuidados intensivos obstétricos del Hospital de la Mujer de Sinaloa / Incidence of the placental accretism spectrum in the obstetric intensive care unit of the Hospital de la Mujer of Sinaloa

Resumen OBJETIVO: Determinar la incidencia del espectro del acretismo placentario en pacientes ingresadas a la unidad de cuidados intensivos obstétricos del Hospital de la Mujer, Culiacán, Sinaloa. MATERIALES Y MÉTODOS: Estudio retrospectivo, transversal y descriptivo fundamentado en el análisis de la base de datos del Hospital de la Mujer de pacientes internadas entre los años 2017 a 2020 con diagnóstico de espectro de placenta acreta, referidas o diagnosticadas en la institución e intervenidas para histerectomía por la complicación estudiada. RESULTADOS: Se analizaron 22 pacientes con diagnóstico de acretismo placentario que dieron una incidencia de 0.09%; de éstas, a 1 se le indicó cesárea; 19 de las 22 pacientes tenían antecedente de cicatriz uterina previa, todas con placenta previa. El promedio de edad fue de 30.86 ± 4 años. La cesárea se practicó, en promedio, a las 34 semanas de embarazo con dos técnicas quirúrgicas. El sangrado promedio estimado fue de 1.947 mL. Las complicaciones transoperatorias fueron las lesiones: ureteral (n = 2) y vesical (n = 1). La principal complicación posoperatoria fue la fístula vesicouterina (n = 1). El promedio de estancia fue de 2 días en 16 de las 22 pacientes y de 7 días en las 6 restantes. CONCLUSIONES: Lo importante del acretismo placentario es el diagnóstico oportuno que permita derivar a las pacientes a centros hospitalarios que cuenten con especialistas experimentados en la atención de estos casos.

Abstract OBJECTIVE: To determine the incidence of placental accretism spectrum in pregnant women admitted to the obstetric intensive care unit of the Hospital de la Mujer, Culiacán, Sinaloa. MATERIALS AND METHODS: Retrospective, cross-sectional, descriptive study based on the analysis of the database of the Hospital de la Mujer of patients admitted between 2017 and 2020 with a diagnosis of placenta accreta spectrum, referred or diagnosed at the institution and underwent hysterectomy for the complication studied. RESULTS: Twenty-two patients with a diagnosis of placenta accreta were analysed, giving a prevalence of 0.09%; of these, caesarean section was indicated in 0.2%. 19 of the 22 patients had a history of previous uterine scarring, all with placenta praevia. Mean age was 30.86 ± 4 years. Caesarean section was performed at a mean gestational age of 34 weeks using two surgical techniques. The mean estimated blood loss was 1,947 mL. The most common operative complications were ureteral (n = 2) and bladder (n = 1) injuries. The most common postoperative complication was vesico-uterine fistula (n = 1). The mean length of stay was 2 days in 16 of the 22 patients and 7 days in the remaining 6 patients. CONCLUSIONS: The most important aspect of placenta accreta is early diagnosis, which allows referral to hospital centres with specialists experienced in the management of these cases.

Unusual Manifestation of Membranous Dysmenorrhea: Case Report.

BACKGROUND In the 18th century, Morgagni described membranous dysmenorrhea as the sudden and complete detachment of the decidua during menstruation. This causes intense and painful contractions of the myometrium, aggravated by the expulsion of tissues produced by the decidualization of the endometrium. It is a rare pathology associated with oral contraceptives, ectopic pregnancies, abortions, and natural cycles, with consequent thickening and endometrial decidualization with molding of the tissue of the uterine cavity of membranous appearance. The definitive diagnosis is made by histopathological examination. CASE REPORT A 43-year-old female patient came for urgent consultation for an acute picture of severe pain in the lower abdomen, radiating to the genital area with transvaginal bleeding of 2 h of evolution. She had no significant past medical history. A transvaginal ultrasound was performed and showed an unchanged endometrial cavity. A vaginal examination revealed a foreign body of soft consistency; therefore, a speculum examination was performed, which showed tissue of endometrial origin located in the cervical canal of a reddish spongy texture. The tissue was removed, thus improving the symptomatology, and was sent to the pathological anatomy service for histopathologic diagnosis. CONCLUSIONS Membranous dysmenorrhea is a rare gynecologic disorder with only a few documented cases. According to other case reports, our patient's case, at age 43 years, was an atypical presentation. The clinical features and association with this pathology allowed the diagnosis and its confirmation by histopathological examination.

A Retrospective Analysis of Porcine Circovirus Type 3 in Samples Collected from 2008 to 2021 in Mexico.

Porcine circovirus type 3 (PCV3) is a nonenveloped virus of the Circoviridae family. This virus has been identified in pigs of different ages and pigs with several clinical manifestations of the disease or even in apparently healthy pigs. While PCV3 was first reported in 2015, several retrospective studies have reported the virus before that year. The earliest report indicates that PCV3 has been circulated in swine farms since 1996. In this study, we evaluated the presence of PCV3 in samples collected in Mexico in 2008, 2015, 2020, and 2021. This study assessed PCV3 DNA by qPCR and antibodies against CAP protein by indirect ELISA. The results showed that PCV3 (DNA and anti-CAP antibodies) was detected in the samples collected from 2008 to 2021. The highest prevalence was in 2008 (100%), and the lowest was in 2015 (negative). Genetic analysis of ORF2 showed that the virus identified belonged to genotype a, as most of the viruses identified thus far. PCV3 was detected in samples from piglets with respiratory signs and growth retardation, sows with reproductive failure, or asymptomatic piglets and sows. Pigs with respiratory signs, growth retardation, or reproductive failure had a higher prevalence of antibodies and qPCR-positive samples. In conclusion, this study showed that PCV3 has been circulating in Mexico since 2008 and that PCV3 DNA and antibodies were more prevalent in samples from pigs with clinical manifestations of diseases.

Development of a Multispecies Double-Antigen Sandwich ELISA Using N and RBD Proteins to Detect Antibodies against SARS-CoV-2.

SARS-CoV-2 infects humans and a broad spectrum of animal species, such as pets, zoo animals, and nondomestic animals. Monitoring infection in animals is important in terms of the risk of interspecies transmission and the emergence of new viral variants. Economical, fast, efficient, and sensitive diagnostic tests are needed to analyze animal infection. Double-antigen sandwich ELISA has the advantage of being multispecies and can be used for detecting infections caused by pathogens that infect several animal hosts. This study aimed to develop a double-antigen sandwich ELISA using two SARS-CoV-2 proteins, N and RBD. We compared its performance, when using these proteins separately, with an indirect ELISA and with a surrogate virus neutralization test. Positive and negative controls from a cat population (n = 31) were evaluated to compare all of the tests. After confirming that double-antigen sandwich ELISA with both RBD and N proteins had the best performance (AUC= 88%), the cutoff was adjusted using positive and negative samples from cats, humans (n = 32) and guinea pigs (n = 3). The use of samples from tigers (n = 2) and rats (n = 51) showed good agreement with the results previously obtained using the microneutralization test. Additionally, a cohort of samples from dogs with unknown infection status was evaluated. These results show that using two SARS-CoV-2 proteins in the double-antigen sandwich ELISA increases its performance and turns it into a valuable assay with which to monitor previous infection caused by SARS-CoV-2 in different animal species.

Autoantibody Diversity Is Augmented in Women with Breast Cancer and Is Related to the Stage of the Disease.

Breast cancer (BC) is the most frequent malignant neoplasia and leading cause of cancer mortality for women. A timely diagnosis of BC is crucial to ensure the best chances of survival. Among the various screening tools for BC, antibodies directed towards self-antigens or tumor-associated antigens (autoantibodies) have emerged as an alternative to image-based screening modalities. However, little attention has been paid to the global diversity of autoantibodies. This work aimed to analyze the diversity of autoantibodies reactive to antigens expressed by the BC cell line T47D in the sera of Mexican women with BC, benign breast pathology (BBP), or without breast pathology (WBP). We found that the diversity of antibodies in the sera was higher in the BC and BBP groups than in the WBP group. Likewise, the diversity changed with the progression of BC. Our results show and measure the complexity of the antibody response in breast health and disease.

First identification and characterization of ovine gammaherpesvirus type 2 in horses and artiodactyla from an outbreak of malignant catarrhal fever in Mexico.

Ovine gammaherpesvirus 2 (OvHV-2), a member of the genus Macavirus, causes sheep-associated malignant catarrhal fever (SA-MCF), a fatal lymphoproliferative disease affecting a wide variety of ungulates in addition to horses. This study described an outbreak of SA-MCF in Mexico and the identification of the OvHV-2 virus in primary rabbit testis cultures through the generation of intranuclear inclusion bodies, syncytia, immunofluorescence (IF), immunocytochemistry (ICC), immunohistochemistry (IHC), endpoint polymerase chain reaction (PCR), and partial sequencing of the ORF75 gene. The animals involved in this outbreak showed mucogingival ulcers in the vestibule of the mouth and tongue, hypersalivation, corneal opacity, reduced food consumption, and weight loss of variable severity. These clinical signs and the histopathological findings suggested the diagnosis of SA-MCF. Buffy coat fractions from the anticoagulated blood samples of ill animals were collected and analyzed by PCR. Positive buffy coats were used to inoculate the primary cell cultures of rabbit testis to identify the virus. Small clusters of refractile cytomegalic cells, characteristic of viral cytopathic effects, were observed between 48 and 72 h post-infection. Furthermore, intranuclear acidophilic inclusion bodies (IBs) were identified in the inoculated primary culture cells, and the cytoplasm showed immunoreactivity with hyperimmune rabbit serum against OvHV-2. Moreover, in the liver histological sections from sick deer, immunoreactive juxtanuclear IBs were identified with the same rabbit hyperimmune serum. The obtained sequences were aligned with the OvHV-2 sequences reported in GenBank and revealed a nucleotide identity higher than 98%. Based on the evidence provided in this study, we conclude that the outbreak of SA-MCF in the municipality of Tequisquiapan in the state of Queretaro, Mexico, was caused by OvHV-2. This is the second study reporting that horses are susceptible to OvHV-2 infection and can develop SA-MCF. We identified for the first time in Mexico, the presence of OvHV-2 in buffy coats from horses and Artiodactyla.

Pharmaceutical pollution fingerprinting and waterbodies remediation using waste-derived carbon dots as sustainable advanced nanomaterials.

The conversion of biomass waste into high-value nanomaterials such as carbon dots might represent a great advancement towards a circular economy system. Biomass wastes are an excellent choice as carbon precursors because of their wide availability, abundance, chemical composition, and eco-friendly nature. Moreover, their use as a raw material might decrease the total cost of the synthesis processes and reduce the environmental impacts. In addition, the complex composition of biomass leads to carbon dots with abundant functional groups, which in turn enhances water dispersibility and photoluminescence properties. In this manner, the effective transformation of biomass wastes into carbon dots reduces environmental pollution through the inadequate management of waste while producing carbon dots with enhanced performances. Therefore, this review describes biomass wastes as potential candidates for the synthesis of carbon dots through different synthesis methods. In addition, we have analyzed the great potential of biomass-derived carbon dots (CDs) for the degradation and detection of emerging pharmaceutical pollutants by promoting a circular economy approach. Finally, we identified current challenges to propose possible research directions for the large-scale and sustainable synthesis of high-quality biomass-derived CDs.

Neutralizing Antibodies against the SARS-CoV-2 Ancestral Strain and Omicron BA.1 Subvariant in Dogs and Cats in Mexico.

SARS-CoV-2 mainly affects humans; however, it is important to monitor the infection of companion and wild animals as possible reservoirs of this virus. In this sense, seroprevalence studies in companion animals, such as dogs and cats, provide important information about the epidemiology of SARS-CoV-2. This study aimed to evaluate the seroprevalence of neutralizing antibodies (nAbs) against the ancestral strain and the Omicron BA.1 subvariant in dogs and cats in Mexico. Six hundred and two samples were obtained from dogs (n = 574) and cats (n = 28). These samples were collected from the end of 2020 to December 2021 from different regions of Mexico. The presence of nAbs was evaluated using a plaque reduction neutralization test (PRNT) and microneutralization (MN) assays. The results showed that 14.2% of cats and 1.5% of dogs presented nAbs against the ancestral strain of SARS-CoV-2. The analysis of nAbs against Omicron BA.1 in cats showed the same percentage of positive animals but a reduced titer. In dogs, 1.2% showed nAbs against Omicron BA.1. These results indicate that nAbs were more frequent in cats than in dogs and that these nAbs have a lower capacity to neutralize the subvariant Omicron BA.1.

Corrigendum: Recent advances in antigen targeting to antigen-presenting cells in veterinary medicine.

[This corrects the article DOI: 10.3389/fimmu.2023.1080238.].

Environmental concerns and bioaccumulation of psychiatric drugs in water bodies - Conventional versus biocatalytic systems of mitigation.

The COVID-19 pandemic has brought increments in market sales and prescription of medicines commonly used to treat mental health disorders, such as depression, anxiety, stress, and related problems. The increasing use of these drugs, named psychiatric drugs, has led to their persistence in aquatic systems (bioaccumulation), since they are recalcitrant to conventional physical and chemical treatments typically used in wastewater treatment plants. An emerging environmental concern caused by the bioaccumulation of psychiatric drugs has been attributed to the potential ecological and toxicological risk that these medicines might have over human health, animals, and plants. Thus, by the application of biocatalysis-assisted techniques, it is possible to efficiently remove psychiatric drugs from water. Biocatalysis, is a widely employed and highly efficient process implemented in the biotransformation of a wide range of contaminants, since it has important differences in terms of catalytic behavior, compared to common treatment techniques, including photodegradation, Fenton, and thermal treatments, among others. Moreover, it is noticed the importance to monitor transformation products of degradation and biodegradation, since according to the applied removal technique, different toxic transformation products have been reported to appear after the application of physical and chemical procedures. In addition, this work deals with the discussion of differences existing between high- and low-income countries, according to their environmental regulations regarding waste management policies, especially waste of the drug industry.

Depression and opinion of dental students regarding the hybrid learning model during the COVID-19 pandemic.

BACKGROUND: The global spread of COVID-19 forced schools at all educational levels to close, which was repeated in more than 60 countries. In addition, the COVID-19 pandemic has affected the mental health of dental students world wide. This study hypothesizes that the prevalence of depression in dental students from El Salvador is higher than that reported in studies from Europe, Asia, and North America. METHODS: This study was an online cross-sectional survey performed at the Faculty of Dentistry of the University of Salvador. The PHQ-9 questionnaire was applied to know the level of depression of the students, and a questionnaire focused on learning the opinion of the students on the hybrid teaching model adopted. Approximately 450 students participated in both questionnaires. RESULTS: Regarding the levels of depression present in the students, 14% had minimal depression, 29% had medium depression, 23% had moderate depression and, 34% had severe depression. The students had an excellent opinion regarding the hybrid learning model. CONCLUSIONS: The prevalence of depression in dental students in El Salvador seems to be higher than that reported in studies in non-Latin American countries. Therefore, universities must generate care plans for mental health to avoid these harmful effects on students during future contingencies.

19n01, a broadly neutralizing antibody against omicron BA.1, BA.2, BA.4/5, and other SARS-CoV-2 variants of concern.

This study reports the isolation and characterization of a human monoclonal antibody (mAb) called 19n01. This mAb was isolated by using single-cell RNAseq of B cells from donors infected with the ancestral strain. This mAb possesses a potent and broad capacity to bind and neutralize all previously circulating variants of concern (VOCs), including Omicron sublineages BA.1, BA.2, and BA.4/5. The pseudovirus neutralization assay revealed robust neutralization capacity against the G614 strain, BA.1, BA.2, and BA.4/5, with inhibitory concentration (IC50) values ranging from 0.0035 to 0.0164 µg/mL. The microneutralization assay using the G614 strain and VOCs demonstrated IC50 values of 0.013-0.267 µg/mL. Biophysical and structural analysis showed that 19n01 cross-competes with ACE2 binding to the receptor-binding domain (RBD) and the kinetic parameters confirmed the high affinity against the Omicron sublineages (KD of 61 and 30 nM for BA.2 and BA.4/5, respectively). These results suggest that the 19n01 is a remarkably potent and broadly reactive mAb.