A5056144704- COVID-19 Clinical Research Studies
- Respiratory viral infections research
- Immune Cell Function and Interaction
- SARS-CoV-2 and COVID-19 Research
- Immunotherapy and Immune Responses
- Neonatal Respiratory Health Research
- Long-Term Effects of COVID-19
- Immune Response and Inflammation
- COVID-19 Impact on Reproduction
- T-cell and B-cell Immunology
- Neutrophil, Myeloperoxidase and Oxidative Mechanisms
- Immunodeficiency and Autoimmune Disorders
- Inflammasome and immune disorders
- Monoclonal and Polyclonal Antibodies Research
- HIV Research and Treatment
- Immune cells in cancer
- Asthma and respiratory diseases
- Neuropeptides and Animal Physiology
- Sepsis Diagnosis and Treatment
- Kawasaki Disease and Coronary Complications
- Receptor Mechanisms and Signaling
- Respiratory Support and Mechanisms
- Complement system in diseases
- Renin-Angiotensin System Studies
- Proteoglycans and glycosaminoglycans research
Hospital Pedro de Elizalde
2014-2025
Centro Científico Tecnológico - San Juan
2020
University of Buenos Aires
1995-2018
Hospital de Clínicas "José de San Martín"
2014
Academia Nacional de Medicina
1997-2011
Academy of Medicine
2004
New York Academy of Medicine
2002
Institute for Medical Research
1995
In recent years it has become clear that the therapeutic properties of bone marrow-derived mesenchymal stromal cells (MSC) are related not only to their ability differentiate into different lineages but also capacity suppress immune response. We here studied influence MSC on macrophage function. Using mouse thioglycolate-elicited peritoneal macrophages (M) stimulated with LPS, we found markedly suppressed production inflammatory cytokines TNF-alpha, IL-6, IL-12p70 and interferon-gamma while...
Abstract It is widely appreciated that inflammatory responses in peripheral tissues are usually associated to the development of acidic microenvironments. Despite this, there few studies aimed analyze effect extracellular pH on immune cell functions. We analyzed impact acidosis behavior dendritic cells (DCs) derived from murine bone marrow. found (pH 6.5) markedly stimulated uptake FITC-OVA, FITC-dextran, and HRP by DCs. In fact, reach similar levels endocytosis, DCs cultured at 7.3 required...
Semen is the main vector for HIV-1 dissemination worldwide. It contains three major sources of infectious virus: free virions, infected leukocytes, and spermatozoa-associated virions. We focused on interaction with human spermatozoa dendritic cells (DCs). report that heparan sulfate expressed in plays an important role capture HIV-1. Spermatozoa-attached virus efficiently transmitted to DCs, macrophages, T cells. Interaction DCs not only leads transmission internalization but also results...
Abstract Bacterial DNA stimulates macrophages, monocytes, B lymphocytes, NK cells, and dendritic cells in a CpG‐dependent manner. In this work we demonstrate that bacterial DNA, but not mammalian induces human neutrophil activation as assessed by L‐selectin shedding, CD11b upregulation, stimulation of cellular shape change, IL‐8 secretion, cell migration. Induction these responsesis dependent on the presence unmethylated CpG motifs, stimulatory properties were neither modified...
BackgroundPerhaps reflecting that children with COVID-19 rarely exhibit severe respiratory symptoms and often remain asymptomatic, little attention has been paid to explore the immune response in pediatric COVID-19. Here, we analyzed phenotype function of circulating neutrophils from COVID-19.MethodsAn observational study including 182 COVID-19, 21 multisystem inflammatory syndrome (MIS-C), 40 healthy was performed Buenos Aires, Argentina. Neutrophil by flow cytometry blood samples. Cytokine...
Background Most children in Argentina received only the initial COVID-19 vaccine series, with presumed hybrid immunity after multiple Omicron waves. However, durability of immune memory, particularly immunocompromised (IC) children, remains poorly studied. Methods A cohort IC (n=45) and healthy (HC, n=79) was assessed between 13 to 17 months receiving two or three doses BBIBP-CorV and/or BNT162b2. Plasma anti-spike IgG, neutralizing activity antigen-specific CD4+ CD8+ T cells against Wuhan...
ABSTRACT Dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin (DC-SIGN) is expressed by dendritic cells (DCs) at mucosal surfaces and appears to play an important role in the dissemination of human immunodeficiency virus type 1 (HIV-1) infection. DC-SIGN binds HIV-1 gp120 efficiently transmits T CD4 + cells, which become center viral replication. Semen represents main vector for worldwide. In present study we show that seminal plasma (SP), even when used very high...
Low affinity receptors for the Fc portion of IgG (FcγRs) represent a critical link between innate and adaptive immunity. Immune complexes (ICs) are natural ligands low FcγRs, high levels ICs usually detected in both, chronic viral infections autoimmune diseases. The expression function FcγRs myeloid cells, NK cells B have been well characterized. By contrast, there controversial reports about T cells. Here, we demonstrated that ~2% resting CD4+ express cell surface FcγRII (CD32). Analysis...
Although human airway epithelial cells are the main target of respiratory syncytial virus (RSV), it also infects immune cells, such as macrophages and B cells. Whether T permissive to RSV infection is unknown. We sought analyze permissiveness CD4+ infection. CD8+ from cord blood, healthy young children, adults were challenged by or cocultured with infected HEp-2 Infection, phenotype, cytokine production analyzed flow cytometry enzyme-linked immunosorbent assay. Expression antigens...
BackgroundMost children and youth develop mild or asymptomatic disease during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, a very small number of patients suffer Coronavirus induced 2019 (COVID-19). The reasons underlying these different outcomes remain unknown.MethodsWe analyzed three cohorts: with infection (n=550), convalescent (n=138), MIS-C (multisystem inflammatory in children, n=42). IgG IgM antibodies to the spike protein SARS-CoV-2,...
We have previously reported that losartan, a selective antagonist of AT1 receptors for angiotensin II (AII), strongly suppresses the activation neutrophils by<i>N</i>-formylmethionyl-leucyl-phenylalanine (fMLP) through mechanism does not involve inhibition receptors. Herein, we analyze whether losartan would prevent development acute respiratory distress syndrome (ARDS) triggered by lung bacterial infection. found (0.2–200 μg/kg/min) delays onset ARDS in Wistar rats challenged i.t....
In the absence of appropriate stimuli, polymorphonuclear neutrophils rapidly undergo characteristic changes indicative programmed cell death or apoptosis. We report here that cultured in presence platelets (neutrophil:platelet ratios 1:50, 1:25, and 1:10) show a dramatic inhibition apoptosis compared with alone. Similar degrees delay were induced by viable unstimulated platelets, fixed activated (1 U/ml thrombin) platelets. Inhibition was associated prolongation functional lifespan...
Although long COVID-19 is widely recognized in adults, less information available about this condition children, especially developing countries. Here, we studied the long-term symptoms of SARS-CoV-2 infection beyond 3 months and associated risk factors a pediatric population.This observational study included 639 Argentinian children adolescents with previously confirmed from June 2020-June 2021 577 without previous COVID-19. Parents completed survey that their child had for >3 after...
Severe COVID-19 in children is rare, but the reasons underlying are unclear. Profound alterations T cell responses have been well characterized course of adult severe COVID-19, little known about function with COVID-19. Here, we made three major observations a cohort symptomatic acute COVID-19: 1) reduced frequency circulating FoxP3+ regulatory cells, 2) prevalence TH17 polarizing microenvironment by high plasma levels IL-6, IL-23, and IL17A, an increased CD4+ cells expressing ROR-γt, master...
FOXP3+ regulatory T cells (Tregs) restrain the destructive potential of immune system. We have previously reported a pronounced reduction in circulating Tregs infants with severe respiratory syncytial virus (RSV) disease. Because interleukin-2 (IL-2) is critical for Treg growth, survival, and activity, we here analyzed IL-2 production function RSV-infected infants.Phenotype, proliferation, production, signaling CD4+ were by flow cytometry. Serum soluble CD25 levels quantified ELISA.CD4+ from...
Losartan, a selective antagonist of AT1 receptors for angiotensin II, is widely used clinically to manage hypertension. We report here that losartan markedly inhibits neutrophil shape change, adherence and chemiluminescence responses triggered by N-formylmethionyl-leucyl-phenylalanine (fMLP), without affecting induced immune complexes, zymosan or concanavalin A. Neither saralasin, another II receptors, nor captopril, an angiotensin-converting enzyme inhibitor, reproduced the effects...
Summary We have previously reported that human neutrophils pretreated with tumour necrosis factor‐α (TNF‐α) and then exposed to a variety of agents such as immune complexes, zymosan, phorbol 12‐myristate 13‐acetate (PMA), C5a, fMLP, or granulocyte–macrophage colony‐stimulating factor (GM‐CSF), undergo dramatic stimulation apoptosis, suggesting TNF‐α is able prime an apoptotic death programme which can be rapidly triggered by different stimuli. report here this response involves the...
Introduction.Despite the magnitude of COVID-19 pandemic, information about its development in pediatrics is still limited.This report describes characteristics patients admitted to a children's hospital due during first three months pandemic.Method.Descriptive study including all hospitalized between 4/1/2020 and 6/30/2020.Results.A total 191 were COVID-19; their median age was 7.7 years; 89 % had history close contact.Of them, 35.6 considered asymptomatic; 61.2 %, mild cases; 3.2 moderate...
We have shown that losartan, a selective inhibitor of AT1 receptors for angiotensin II (AII), inhibits the binding [3H]fMLP to neutrophil (FPR). Here, we analyze, in Wistar rats, effect losartan on recruitment lung triggered by fMLP. found i.v. infusion (0.4-20.0 microg/kg/min) induced i.t. instillation fMLP, without affecting responses other stimuli, such as aggregated human IgG (aIgG), precipitating immune complexes (IC), or zymosan. Histological evaluation lungs well analysis hemorrhage...
Abstract In the current study, we analyzed whether immunoglobulin A (IgA) is able to modulate neutrophil apoptosis. We found that culture of neutrophils on immobilized plasma IgA (iIgAp) or secretory (iIgAs) induced a marked increase in apoptotic rates. By contrast, soluble IgAp, IgAs, aggregated IgAp exerted no effect. Promotion apoptosis by iIgA was almost completely prevented blocking antibodies directed CD18 CD11b and shown be dependent activation respiratory burst as suggested ability...