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1.
bioRxiv ; 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-39005296

ABSTRACT

Staphylococcus aureus has evolved mechanisms to cope with low iron (Fe) availability in host tissues. S. aureus uses the ferric uptake transcriptional regulator (Fur) to sense titers of cytosolic Fe. Upon Fe depletion, apo-Fur relieves transcriptional repression of genes utilized for Fe uptake. We demonstrate that an S. aureus Δ fur mutant has decreased expression of acnA , which codes for the Fe-dependent enzyme aconitase. Decreased acnA expression prevented the Δ fur mutant from growing with amino acids as sole carbon and energy sources. Suppressor analysis determined that a mutation in isrR , which produces a regulatory RNA, permitted growth by decreasing isrR transcription. The decreased AcnA activity of the Δ fur mutant was partially relieved by an Δ isrR mutation. Directed mutation of bases predicted to facilitate the interaction between the acnA transcript and IsrR, decreased the ability of IsrR to control acnA expression in vivo and IsrR bound to the acnA transcript in vitro . IsrR also bound to the transcripts coding the alternate TCA cycle proteins sdhC , mqo , citZ , and citM . Whole cell metal analyses suggest that IsrR promotes Fe uptake and increases intracellular Fe not ligated by macromolecules. Lastly, we determined that Fur and IsrR promote infection using murine skin and acute pneumonia models.

2.
bioRxiv ; 2024 May 20.
Article in English | MEDLINE | ID: mdl-38826293

ABSTRACT

Gastrointestinal (GI) B cells and plasma cells (PCs), critical to mucosal homeostasis, play an important role in the host response to HIV-1 infection. Here, high resolution mapping of human B cells and PCs from colon and ileum during both viremic and suppressed HIV-1 infection identified a significant reduction in germinal center (GC) B cells and Follicular Dendritic Cells (FDCs) during HIV-1 viremia. Further, IgA + PCs, the major cellular output of intestinal GCs were significantly reduced during viremic HIV-1 infection. PC-associated transcriptional perturbations, including type I interferon signaling persisted in antiretroviral therapy (ART) treated individuals, suggesting ongoing disruption of the intestinal immune milieu during ART. GI humoral immune perturbations associated with changes in intestinal microbiome composition and systemic inflammation. Herein, we highlight a key immune defect in the GI mucosa due to HIV-1 viremia, with major implications. One Sentence Summary: Major perturbations in intestinal GC dynamics in viremic HIV-1 infection relate to reduced IgA + plasma cells, systemic inflammation and microbiota changes.

3.
Protein Sci ; 33(6): e5020, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38747397

ABSTRACT

Wheat germ agglutinin (WGA) demonstrates potential as an oral delivery agent owing to its selective binding to carbohydrates and its capacity to traverse biological membranes. In this study, we employed differential scanning calorimetry and molecular dynamics simulations to comprehensively characterize the thermal unfolding process of both the complete lectin and its four isolated domains. Furthermore, we present the nuclear magnetic resonance structures of three domains that were previously lacking experimental structures in their isolated forms. Our results provide a collective understanding of the energetic and structural factors governing the intricate unfolding mechanism of the complete agglutinin, shedding light on the specific role played by each domain in this process. The analysis revealed negligible interdomain cooperativity, highlighting instead significant coupling between dimer dissociation and the unfolding of the more labile domains. By comparing the dominant interactions, we rationalized the stability differences among the domains. Understanding the structural stability of WGA opens avenues for enhanced drug delivery strategies, underscoring its potential as a promising carrier throughout the gastrointestinal environment.


Subject(s)
Protein Stability , Wheat Germ Agglutinins , Calorimetry, Differential Scanning , Molecular Dynamics Simulation , Nuclear Magnetic Resonance, Biomolecular , Protein Domains , Wheat Germ Agglutinins/chemistry
5.
JAMA Netw Open ; 6(4): e239995, 2023 04 03.
Article in English | MEDLINE | ID: mdl-37099296

ABSTRACT

Importance: There were over 45 000 suicides in the US in 2020, making suicide the 12th leading cause of death. If social vulnerability is associated with suicide rates, targeted interventions for at-risk segments of the population may reduce US suicide rates. Objective: To determine the association between social vulnerability and suicide in adults. Design, Setting, and Participants: This cohort study analyzed 2 county-level social vulnerability measures (the Social Vulnerability Index [SVI] and the Social Vulnerability Metric [SVM]) and US Centers for Disease Control and Prevention-reported county-level suicides from 2016 to 2020. Data were analyzed November and December 2022. Exposures: County-level variability in social vulnerability. Main Outcomes and Measures: The primary outcome measure was number of county-level adult suicides from 2016 to 2020, offset by county adult population during those years. The association between social vulnerability (measured using the SVI and the newly created SVM for 2018) and suicide was modeled using a bayesian-censored Poisson regression model to account for the CDC's suppression of county-level suicide counts of less than 10, adjusted for age, racial and ethnic minority, and urban-rural county characteristics. Results: From 2016 to 2020, there were a total of 222 018 suicides in 3141 counties. Comparing the least socially vulnerable (0% to 10%) to the most socially vulnerable (90% to 100%) counties, there was a 56% increase in suicide rate (17.3 per 100 000 persons to 27.0 per 100 000 persons) as measured by the SVI (incidence rate ratio, 1.56; 95% credible interval, 1.51-1.60) and an 82% increase in suicide rate (13.8 per 100 000 persons to 25.1 per 100 000 persons) as measured by the SVM (incidence rate ratio, 1.82; 95% credible interval, 1.72-1.92). Conclusions and Relevance: This cohort study found that social vulnerability had a direct association with risk for adult suicide. Reducing social vulnerability may lead to life-saving reduction in the rate of suicide.


Subject(s)
Suicide , Humans , Adult , Ethnicity , Social Vulnerability , Cohort Studies , Bayes Theorem , Minority Groups
6.
J Biol Chem ; 299(4): 104568, 2023 04.
Article in English | MEDLINE | ID: mdl-36870681

ABSTRACT

The RIP homotypic interaction motif (RHIM) is an essential protein motif in inflammatory signaling and certain cell death pathways. RHIM signaling occurs following the assembly of functional amyloids, and while the structural biology of such higher-order RHIM complexes has started to emerge, the conformations and dynamics of nonassembled RHIMs remain unknown. Here, using solution NMR spectroscopy, we report the characterization of the monomeric form of the RHIM in receptor-interacting protein kinase 3 (RIPK3), a fundamental protein in human immunity. Our results establish that the RHIM of RIPK3 is an intrinsically disordered protein motif, contrary to prediction, and that exchange dynamics between free monomers and amyloid-bound RIPK3 monomers involve a 20-residue stretch outside the RHIM that is not incorporated within the structured cores of the RIPK3 assemblies determined by cryo-EM or solid-state NMR. Thus, our findings expand on the structural characterization of RHIM-containing proteins, specifically highlighting conformational dynamics involved in assembly processes.


Subject(s)
Amyloid , Amyloidogenic Proteins , Humans , Amyloid/chemistry , Cell Death , Amyloidogenic Proteins/metabolism , Signal Transduction , Magnetic Resonance Spectroscopy , Receptor-Interacting Protein Serine-Threonine Kinases/metabolism
7.
Biochim Biophys Acta Proteins Proteom ; 1871(4): 140906, 2023 07 01.
Article in English | MEDLINE | ID: mdl-36918120

ABSTRACT

Potassium channels play a key role in regulating many physiological processes, thus, alterations in their proper functioning can lead to the development of several diseases. Hence, the search for compounds capable of regulating the activity of these channels constitutes an intense field of investigation. Potassium scorpion toxins are grouped into six subfamilies (α, ß, γ, κ, δ, and λ). However, experimental structures and functional analyses of the long chain ß-KTx subfamily are lacking. In this study, we recombinantly produced the toxins TcoKIK and beta-KTx14.3 present in the venom of Tityus costatus and Lychas mucronatus scorpions, respectively. The 3D structures of these ß-KTx toxins were determined by nuclear magnetic resonance. In both toxins, the N-terminal region is unstructured, while the C-terminal possesses the classic CSα/ß motif. TcoKIK did not show any clear activity against frog Shaker and human KCNQ1 potassium channels; however, beta-KTx14.3 was able to block the KCNQ1 channel. The toxin-channel interaction mode was investigated using molecular dynamics simulations. The results showed that this toxin could form a stable network of polar-to-polar and hydrophobic interactions with KCNQ1, involving key conserved residues in both molecular partners. The discovery and characterization of a toxin capable of inhibiting KCNQ1 pave the way for the future development of novel drugs for the treatment of human diseases caused by the malfunction of this potassium channel. STATEMENT OF SIGNIFICANCE: Scorpion toxins have been shown to rarely block human KCNQ1 channels, which participate in the regulation of cardiac processes. In this study, we obtained recombinant beta-KTx14.3 and TcoKIK toxins and determined their 3D structures by nuclear magnetic resonance. Electrophysiological studies and molecular dynamics models were employed to examine the interactions between these two toxins and the human KCNQ1, which is the major driver channel of cardiac repolarization; beta-KTx14.3 was found to block effectively this channel. Our findings provide insights for the development of novel toxin-based drugs for the treatment of cardiac channelopathies involving KCNQ1-like channels.


Subject(s)
Potassium Channels , Scorpion Venoms , Humans , Potassium Channels/metabolism , Scorpion Venoms/pharmacology , Scorpion Venoms/chemistry , Amino Acid Sequence , KCNQ1 Potassium Channel/genetics , Molecular Dynamics Simulation
8.
Gastroenterology ; 164(4): 619-629, 2023 04.
Article in English | MEDLINE | ID: mdl-36634824

ABSTRACT

BACKGROUND & AIMS: Better biomarkers for prediction of ulcerative colitis (UC) development and prognostication are needed. Anti-integrin αvß6 (anti-αvß6) autoantibodies have been described in patients with UC. We tested for the presence of anti-αvß6 antibodies in the preclinical phase of UC and studied their association with disease-related outcomes after diagnosis. METHODS: Anti-αvß6 autoantibodies were measured in 4 longitudinal serum samples collected from 82 subjects who later developed UC and 82 matched controls from a Department of Defense preclinical cohort (PREDICTS [Proteomic Evaluation and Discovery in an IBD Cohort of Tri-service Subjects]). In a distinct, external validation cohort (Crohn's and Colitis Canada Genetic Environmental Microbial project cohort), we tested 12 pre-UC subjects and 49 matched controls. Furthermore, anti-αvß6 autoantibodies were measured in 2 incident UC cohorts (COMPASS [Comprehensive Care for the Recently Diagnosed IBD Patients], n = 55 and OSCCAR [Ocean State Crohn's and Colitis Area Registry], n = 104) and associations between anti-αvß6 autoantibodies and UC-related outcomes were defined using Cox proportional hazards model. RESULTS: Anti-αvß6 autoantibodies were significantly higher among individuals who developed UC compared with controls up to 10 years before diagnosis in PREDICTS. The anti-αvß6 autoantibody seropositivity was 12.2% 10 years before diagnosis and increased to 52.4% at the time of diagnosis in subjects who developed UC compared with 2.7% in controls across the 4 time points. Anti-αvß6 autoantibodies predicted UC development with an area under the curve of at least 0.8 up to 10 years before diagnosis. The presence of anti-αvß6 autoantibodies in preclinical UC samples was validated in the GEM cohort. Finally, high anti-αvß6 autoantibodies was associated with a composite of adverse UC outcomes, including hospitalization, disease extension, colectomy, systemic steroid use, and/or escalation to biologic therapy in recently diagnosed UC. CONCLUSIONS: Anti-integrin αvß6 autoantibodies precede the clinical diagnosis of UC by up to 10 years and are associated with adverse UC-related outcomes.


Subject(s)
Colitis, Ulcerative , Colitis , Crohn Disease , Humans , Colitis, Ulcerative/drug therapy , Autoantibodies , Proteomics , Crohn Disease/drug therapy , Biomarkers , Colitis/complications
9.
Eval Program Plann ; 97: 102207, 2023 04.
Article in English | MEDLINE | ID: mdl-36587432

ABSTRACT

Parenting programs are an increasingly used strategy to prevent family violence and promote gender equality in the household. Yet, there is limited understanding of the processes and pathways to change through such programs, especially from the Global South. This paper presents key findings of a qualitative evaluation of the parenting 'Program P', which was implemented in El Alto, Bolivia. The study complements and aims to provide additional insights to an experimental evaluation of this program, which found limited impact on the intended objectives, including a reduction in violence against children and women and more gender equitable attitudes among parents. Thirty-six qualitative interviews and 6 focus groups were conducted with men and women that attended Program P, and facilitators of the program. Findings were analyzed thematically and organized around key successes and challenges of the program including motivations and ability to engage with the program, opportunities for supportive group-based processes, addressing hegemonic gender and social norms, and learning and applying skills as a platform to change behaviours. We use these findings to offer implications for more effective design and implementation of gender transformative, parenting programs in Bolivia and globally.


Subject(s)
Domestic Violence , Parenting , Male , Child , Humans , Female , Bolivia , Program Evaluation , Parents , Domestic Violence/prevention & control
10.
Toxicon ; 222: 106985, 2023 Jan 15.
Article in English | MEDLINE | ID: mdl-36436588

ABSTRACT

Scorpine is an antimicrobial and antimalarial peptide isolated from Pandinus imperator scorpion venom. As there are few functional and structural studies reported on scorpine-like peptides, we investigated the recombinant truncated N- and C-terminal domains as well as complete scorpine using biological assays and determined the N- and C-terminal structures using solution nuclear magnetic resonance. The study was conducted using recombinant N- and C-terminal peptides and complete scorpine expressed in Escherichia coli. The results showed that N-scorpine presented a random coil structure in water and adopted α-helical folding in the presence of 50% trifluoroethanol (TFE). C-scorpine contains three disulfide bonds with two structural domains: an unstructured N-terminal domain in water that can form a typical secondary alpha-helix structure in 50% TFE and a C-terminal domain with the CS-αß motif. Our findings demonstrate cytolytic activity associated with C-scorpine, N-scorpine, and scorpine, as well as channel blocking activity associated with the C-scorpine domain.


Subject(s)
Anti-Infective Agents , Scorpion Venoms , Peptides/chemistry , Defensins/chemistry , Protein Domains , Scorpion Venoms/chemistry
11.
Front Physiol ; 12: 767684, 2021.
Article in English | MEDLINE | ID: mdl-34867473

ABSTRACT

Hypertension can be induced by the disruption of factors in blood pressure regulation. This includes several systems such as Neurohumoral, Renin-angiotensin-aldosterone, the Circadian clock, and melatonin production, which can induce elevation and non-dipping blood pressure. Melatonin has a supraphysiological role as a chronobiotic agent and modulates vascular system processes via pro/antiangiogenic factors, inflammation, the immune system, and oxidative stress regulation. An elevation of melatonin production is observed during pregnancy, modulating the placenta and fetus's physiological functions. Their impairment production can induce temporal desynchronization of cell proliferation, differentiation, or invasion from trophoblast cells results in vascular insufficiencies, elevating the risk of poor fetal/placental development. Several genes are associated with vascular disease and hypertension during pregnancy via impaired inflammatory response, hypoxia, and oxidative stress, such as cytokines/chemokines IL-1ß, IL-6, IL-8, and impairment expression in endothelial cells/VSMCs of HIF1α and eNOS genes. Pathological placentas showed differentially expressed genes (DEG), including vascular genes as CITED2, VEGF, PL-II, PIGF, sFLT-1, and sENG, oncogene JUNB, scaffolding protein CUL7, GPER1, and the pathways of SIRT/AMPK and MAPK/ERK. Additionally, we observed modification of subunits of NADPH oxidase and extracellular matrix elements, i.e., Glypican and Heparanase and KCa channel. Mothers with a low level of melatonin showed low production of proangiogenic factor VEGF, increasing the risk of preeclampsia, premature birth, and abortion. In contrast, melatonin supplementation can reduce systolic pressure, prevent oxidative stress, induce the activation of the antioxidants system, and lessen proteinuria and serum level of sFlt-1. Moreover, melatonin can repair the endothelial damage from preeclampsia at the placenta level, increasing PIGF, Nrf-2, HO-1 production and reducing critical markers of vascular injury during the pregnancy. Melatonin also restores the umbilical and uterine blood flow after oxidative stress and inhibits vascular inflammation and VCAM-1, Activin-A, and sEng production. The beneficial effects of melatonin over pathological pregnancies can be partially observed in normal pregnancies, suggesting the dual role of/over placental physiology could contribute to protection and have therapeutic applications in vascular pathologies of pregnancies in the future.

12.
Article in Spanish | IBECS | ID: ibc-230728

ABSTRACT

Introducción: Las enfermedades cardiovasculares, son la principal causa de muerte a nivel mundial, su aparición está influida por factores psicosociales uno de ellos es el estrés. Objetivo: Analizar la relación que existe entre el nivel de estrés laboral y la percepción de síntomas de enfermedades cardiovasculares en trabajadores de la Región de Ñuble, en Chile. Material y Métodos: Estudio analítico de corte transversal, desarrollado a través de encuestas on line (antecedentes sociodemográficos, laborales, de salud y nivel de estrés laboral) a trabajadores de la región de Ñuble. Resultados: De los 260 trabajadores evaluados, el 57,3% reportó síntomas de enfermedad cardiovascular, que se relacionan al nivel de estrés de los trabajadores y también al sexo, edad, nivel de estudios, rubro laboral y percepción de carga laboral excesiva. Conclusiones: Este estudio concluye que la percepción de síntomas de enfermedad cardiovascular, esta relacionada al nivel y gravedad del estrés laboral (AU)


Introduction: Cardiovascular diseases are the main cause of death worldwide, their appearance is influenced by psychosocial factors, one of them is stress. Objective: To analyze the relationship between the level of work stress and the perception of symptoms of cardiovascular diseases in workers in the Ñuble Region, in Chile. Material and Methods: Cross-sectional analytical study, developed through online surveys (sociodemographic, labor, health and level of work stress) to workers in the Ñuble region. Results: Of the 260 workers evaluated, 57.3% reported symptoms of cardiovascular disease, which are related to the stress level of the workers and also to sex, age, level of education, work category and perception of excessive workload. Conclusions: This study concludes that the perception of symptoms of cardiovascular disease is related to the level and severity of work stress (AU)


Subject(s)
Humans , Male , Female , Young Adult , Adult , Middle Aged , Burnout, Professional/epidemiology , Burnout, Professional/psychology , Cardiovascular Diseases/epidemiology , Cross-Sectional Studies , Peru/epidemiology
13.
Sci Rep ; 11(1): 13308, 2021 06 25.
Article in English | MEDLINE | ID: mdl-34172783

ABSTRACT

Gastrointestinal symptoms are common in COVID-19 patients but the nature of the gut immune response to SARS-CoV-2 remains poorly characterized, partly due to the difficulty of obtaining biopsy specimens from infected individuals. In lieu of tissue samples, we measured cytokines, inflammatory markers, viral RNA, microbiome composition, and antibody responses in stool samples from a cohort of 44 hospitalized COVID-19 patients. SARS-CoV-2 RNA was detected in stool of 41% of patients and more frequently in patients with diarrhea. Patients who survived had lower fecal viral RNA than those who died. Strains isolated from stool and nasopharynx of an individual were the same. Compared to uninfected controls, COVID-19 patients had higher fecal levels of IL-8 and lower levels of fecal IL-10. Stool IL-23 was higher in patients with more severe COVID-19 disease, and we found evidence of intestinal virus-specific IgA responses associated with more severe disease. We provide evidence for an ongoing humeral immune response to SARS-CoV-2 in the gastrointestinal tract, but little evidence of overt inflammation.


Subject(s)
COVID-19 , Feces , Gastrointestinal Microbiome , Nasopharynx/virology , RNA, Viral/isolation & purification , Aged , Biomarkers/metabolism , COVID-19/epidemiology , COVID-19/immunology , Cohort Studies , Cytokines/metabolism , Feces/virology , Female , Humans , Immunoglobulin A/blood , Immunoglobulin A/immunology , Male , Middle Aged , New York City/epidemiology , SARS-CoV-2/isolation & purification
14.
Gastroenterology ; 160(7): 2435-2450.e34, 2021 06.
Article in English | MEDLINE | ID: mdl-33676971

ABSTRACT

BACKGROUND & AIMS: Given that gastrointestinal (GI) symptoms are a prominent extrapulmonary manifestation of COVID-19, we investigated intestinal infection with SARS-CoV-2, its effect on pathogenesis, and clinical significance. METHODS: Human intestinal biopsy tissues were obtained from patients with COVID-19 (n = 19) and uninfected control individuals (n = 10) for microscopic examination, cytometry by time of flight analyses, and RNA sequencing. Additionally, disease severity and mortality were examined in patients with and without GI symptoms in 2 large, independent cohorts of hospitalized patients in the United States (N = 634) and Europe (N = 287) using multivariate logistic regressions. RESULTS: COVID-19 case patients and control individuals in the biopsy cohort were comparable for age, sex, rates of hospitalization, and relevant comorbid conditions. SARS-CoV-2 was detected in small intestinal epithelial cells by immunofluorescence staining or electron microscopy in 15 of 17 patients studied. High-dimensional analyses of GI tissues showed low levels of inflammation, including down-regulation of key inflammatory genes including IFNG, CXCL8, CXCL2, and IL1B and reduced frequencies of proinflammatory dendritic cells compared with control individuals. Consistent with these findings, we found a significant reduction in disease severity and mortality in patients presenting with GI symptoms that was independent of sex, age, and comorbid illnesses and despite similar nasopharyngeal SARS-CoV-2 viral loads. Furthermore, there was reduced levels of key inflammatory proteins in circulation in patients with GI symptoms. CONCLUSIONS: These data highlight the absence of a proinflammatory response in the GI tract despite detection of SARS-CoV-2. In parallel, reduced mortality in patients with COVID-19 presenting with GI symptoms was observed. A potential role of the GI tract in attenuating SARS-CoV-2-associated inflammation needs to be further examined.


Subject(s)
COVID-19/virology , Gastrointestinal Diseases/virology , Immunity, Mucosal , Intestinal Mucosa/virology , SARS-CoV-2/pathogenicity , Aged , Aged, 80 and over , COVID-19/diagnosis , COVID-19/immunology , COVID-19/mortality , Case-Control Studies , Cells, Cultured , Cytokines/blood , Female , Gastrointestinal Diseases/diagnosis , Gastrointestinal Diseases/immunology , Gastrointestinal Diseases/mortality , Host-Pathogen Interactions , Humans , Inflammation Mediators/blood , Intestinal Mucosa/immunology , Italy , Male , Middle Aged , New York City , Prognosis , Risk Assessment , Risk Factors , SARS-CoV-2/immunology , Viral Load
15.
Nature ; 591(7851): 639-644, 2021 03.
Article in English | MEDLINE | ID: mdl-33461210

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has infected 78 million individuals and is responsible for over 1.7 million deaths to date. Infection is associated with the development of variable levels of antibodies with neutralizing activity, which can protect against infection in animal models1,2. Antibody levels decrease with time, but, to our knowledge, the nature and quality of the memory B cells that would be required to produce antibodies upon reinfection has not been examined. Here we report on the humoral memory response in a cohort of 87 individuals assessed at 1.3 and 6.2 months after infection with SARS-CoV-2. We find that titres of IgM and IgG antibodies against the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 decrease significantly over this time period, with IgA being less affected. Concurrently, neutralizing activity in plasma decreases by fivefold in pseudotype virus assays. By contrast, the number of RBD-specific memory B cells remains unchanged at 6.2 months after infection. Memory B cells display clonal turnover after 6.2 months, and the antibodies that they express have greater somatic hypermutation, resistance to RBD mutations and increased potency, indicative of continued evolution of the humoral response. Immunofluorescence and PCR analyses of intestinal biopsies obtained from asymptomatic individuals at 4 months after the onset of coronavirus disease 2019 (COVID-19) revealed the persistence of SARS-CoV-2 nucleic acids and immunoreactivity in the small bowel of 7 out of 14 individuals. We conclude that the memory B cell response to SARS-CoV-2 evolves between 1.3 and 6.2 months after infection in a manner that is consistent with antigen persistence.


Subject(s)
Antibodies, Viral/immunology , COVID-19/immunology , Immunity, Humoral/immunology , SARS-CoV-2/immunology , Adolescent , Adult , Aged , Antibodies, Monoclonal/blood , Antibodies, Monoclonal/immunology , Antibodies, Neutralizing/blood , Antibodies, Neutralizing/genetics , Antibodies, Neutralizing/immunology , Antibodies, Viral/blood , Antibodies, Viral/genetics , Antigens, Viral/chemistry , Antigens, Viral/genetics , Antigens, Viral/immunology , B-Lymphocytes/cytology , B-Lymphocytes/immunology , Biopsy , COVID-19/blood , Cohort Studies , Fluorescent Antibody Technique , Humans , Immunity, Humoral/genetics , Immunoglobulin A/immunology , Immunoglobulin G/immunology , Immunoglobulin M/immunology , Immunologic Memory/immunology , Intestines/immunology , Middle Aged , Mutation , Somatic Hypermutation, Immunoglobulin , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology , Time Factors , Young Adult
16.
Biochim Biophys Acta Proteins Proteom ; 1869(4): 140601, 2021 04.
Article in English | MEDLINE | ID: mdl-33422669

ABSTRACT

Amoebiasis is the third leading cause of death among protozoon parasitic diseases in the lower-middle income countries. Understanding the molecular events that control gene expression such as transcription factors, their DNA binding mode and target sequences can help to develop new antiamoebic drugs against Entamoeba histolytica. In this paper we performed a genome and structural analysis of a specific transcription factor. The genome of E. histolytica codifies for 9 EhMybSHAQKYF proteins, which are a family within a large group of 34 Myb-DNA-binding domain (Myb-DBD) containing proteins. Here we compared Entamoeba Myb-SHAQKYF proteins with Myb-like proteins from the Reveille (RVE) family, important regulators of plant circadian networks. This comparison could lead to stablish their role in E. histolytica life cycle. We show that the ehmybshaqkyf genes are differentially expressed in trophozoites under basal cell culture conditions. An in-silico analysis predicts that members of this group harbor a highly conserved and structured Myb-DBD and a large portion of intrinsically disordered residues. As the Myb-DBD of these proteins harbors a distinctive Q[VI]R[ST]HAQK[YF]F sequence in its putative third α-helix, we consider relevant to determine the three-dimensional (3D) structure of one of them. An NMR structure of the Myb-DBD of EhMybS3 shows that this protein is composed of three α-helices stabilized by a hydrophobic core, similar to Myb proteins of different kingdoms. It is remarkable that despite not sharing similarities in their amino acid sequences, the structure of the Myb-DBD of the EhMybS3 is well conserved in this early branching eukaryote.


Subject(s)
Entamoeba histolytica/genetics , Gene Expression Regulation , Protozoan Proteins/genetics , Transcription Factors/genetics , Amino Acid Sequence , Helix-Turn-Helix Motifs , Hydrophobic and Hydrophilic Interactions , Phylogeny , Protein Conformation , Protozoan Proteins/chemistry , Sequence Homology, Amino Acid , Transcription Factors/chemistry
17.
bioRxiv ; 2021 Jan 04.
Article in English | MEDLINE | ID: mdl-33173867

ABSTRACT

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has infected 78 million individuals and is responsible for over 1.7 million deaths to date. Infection is associated with development of variable levels of antibodies with neutralizing activity that can protect against infection in animal models. Antibody levels decrease with time, but the nature and quality of the memory B cells that would be called upon to produce antibodies upon re-infection has not been examined. Here we report on the humoral memory response in a cohort of 87 individuals assessed at 1.3 and 6.2 months after infection. We find that IgM, and IgG anti-SARS-CoV-2 spike protein receptor binding domain (RBD) antibody titers decrease significantly with IgA being less affected. Concurrently, neutralizing activity in plasma decreases by five-fold in pseudotype virus assays. In contrast, the number of RBD-specific memory B cells is unchanged. Memory B cells display clonal turnover after 6.2 months, and the antibodies they express have greater somatic hypermutation, increased potency and resistance to RBD mutations, indicative of continued evolution of the humoral response. Analysis of intestinal biopsies obtained from asymptomatic individuals 4 months after coronavirus disease-2019 (COVID-19) onset, using immunofluorescence, or polymerase chain reaction, revealed persistence of SARS-CoV-2 nucleic acids and immunoreactivity in the small bowel of 7 out of 14 volunteers. We conclude that the memory B cell response to SARS-CoV-2 evolves between 1.3 and 6.2 months after infection in a manner that is consistent with antigen persistence.

18.
Gastroenterology ; 160(1): 287-301.e20, 2021 01.
Article in English | MEDLINE | ID: mdl-32980345

ABSTRACT

BACKGROUND AND AIMS: The presence of gastrointestinal symptoms and high levels of viral RNA in the stool suggest active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) replication within enterocytes. METHODS: Here, in multiple, large cohorts of patients with inflammatory bowel disease (IBD), we have studied the intersections between Coronavirus Disease 2019 (COVID-19), intestinal inflammation, and IBD treatment. RESULTS: A striking expression of ACE2 on the small bowel enterocyte brush border supports intestinal infectivity by SARS-CoV-2. Commonly used IBD medications, both biologic and nonbiologic, do not significantly impact ACE2 and TMPRSS2 receptor expression in the uninflamed intestines. In addition, we have defined molecular responses to COVID-19 infection that are also enriched in IBD, pointing to shared molecular networks between COVID-19 and IBD. CONCLUSIONS: These data generate a novel appreciation of the confluence of COVID-19- and IBD-associated inflammation and provide mechanistic insights supporting further investigation of specific IBD drugs in the treatment of COVID-19. Preprint doi: https://doi.org/10.1101/2020.05.21.109124.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/enzymology , Inflammatory Bowel Diseases/enzymology , Intestinal Mucosa/enzymology , SARS-CoV-2/pathogenicity , Serine Endopeptidases/metabolism , Angiotensin-Converting Enzyme 2/genetics , Animals , Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/therapeutic use , COVID-19/genetics , COVID-19/virology , Case-Control Studies , Clinical Trials as Topic , Cross-Sectional Studies , Disease Models, Animal , Female , Gene Regulatory Networks , Host-Pathogen Interactions , Humans , Inflammatory Bowel Diseases/drug therapy , Inflammatory Bowel Diseases/genetics , Intestinal Mucosa/drug effects , Intestinal Mucosa/virology , Longitudinal Studies , Male , Mice , SARS-CoV-2/drug effects , Serine Endopeptidases/genetics , Signal Transduction , COVID-19 Drug Treatment
19.
In. Castillo Pino, Edgardo A. Manual de ginecología y obstetricia para pregrados y médicos generales. Montevideo, Oficina del Libro-FEFMUR, 2 ed; 2021. p.213-218.
Monography in Spanish | LILACS, UY-BNMED, BNUY | ID: biblio-1372536
20.
Nat Rev Immunol ; 20(10): 593, 2020 10.
Article in English | MEDLINE | ID: mdl-32873887
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