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PURPOSE: Common Variable Immunodeficiency (CVID) is characterized by hypogammaglobulinemia and failure of specific antibody production due to B-cell defects. However, studies have documented various T-cell abnormalities, potentially linked to viral complications. The frequency of Cytomegalovirus (CMV) replication in CVID cohorts is poorly studied. To address this gap in knowledge, we set up an observational study with the objectives of identifying CVID patients with active viraemia (CMV, Epstein-Barr virus (EBV)), evaluating potential correlations with immunophenotypic characteristics, clinical outcome, and the dynamic progression of clinical phenotypes over time. METHODS: 31 CVID patients were retrospectively analysed according to viraemia, clinical and immunologic characteristics. 21 patients with non CVID humoral immunodeficiency were also evaluated as control. RESULTS: Active viral replication of CMV and/or EBV was observed in 25% of all patients. CMV replication was detected only in CVID patients (16%). CVID patients with active viral replication showed reduced HLA-DR+ NK counts when compared with CMV-DNA negative CVID patients. Viraemic patients had lower counts of LIN-DNAMbright and LIN-CD16+ inflammatory lymphoid precursors which correlated with NK-cell subsets. Analysis of the dynamic progression of CVID clinical phenotypes over time, showed that the initial infectious phenotype progressed to complicated phenotypes with time. All CMV viraemic patients had complicated disease. CONCLUSION: Taken together, an impaired production of inflammatory precursors and NK activation is present in CVID patients with active viraemia. Since "Complicated" CVID occurs as a function of disease duration, there is need for an accurate evaluation of this aspect to improve classification and clinical management of CVID patients.
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Inmunodeficiencia Variable Común , Infecciones por Citomegalovirus , Citomegalovirus , Herpesvirus Humano 4 , Replicación Viral , Humanos , Inmunodeficiencia Variable Común/inmunología , Inmunodeficiencia Variable Común/complicaciones , Masculino , Femenino , Infecciones por Citomegalovirus/inmunología , Citomegalovirus/inmunología , Citomegalovirus/fisiología , Adulto , Persona de Mediana Edad , Herpesvirus Humano 4/fisiología , Herpesvirus Humano 4/inmunología , Estudios Retrospectivos , Células Asesinas Naturales/inmunología , Adulto Joven , Viremia/inmunología , Infecciones por Virus de Epstein-Barr/inmunología , Inmunofenotipificación , Anciano , AdolescenteRESUMEN
Background: There is little information on the trajectory and developmental fate of Lin-CD34+DNAM-1bright CXCR4+ progenitors exiting bone marrow during systemic inflammation. Objective: To study Lin-CD34+DNAM-1bright CXCR4+ cell circulation in cancer patients, to characterize their entry into involved lung tissue and to characterize their progenies. Methods: Flow cytometric analysis of PBMC from 18 patients with lung cancer on samples collected immediately before the first and the second treatment was performed to study Lin-CD34+DNAM-1bright CXCR4+ precursors. Precursors were purified (>99%) and cultured in vitro from all patients. Paired PBMC and tissue samples from patients undergoing tumor resection were analyzed by flow cytometry to assess tissue entry and compare phenotype and developmental potential of Lin-CD34+DNAM-1bright CXCR4+ cells in both compartments. Results: Significant circulation of Lin-CD34+DNAM-1bright CXCR4+ precursors was observed 20d after the first treatment. Precursors express CXC3CR1, CXCR3, CXCR1 consistent with travel towards inflamed tissues. Flowcytometric analysis of lung tissue samples showed precursor presence in all patients in tumor and neighboring uninvolved areas. Successful purification and in vitro culture from both blood and lung tissue generates a minor proportion of maturing NK cells (<10%) and a predominant proportion (>85%) of α/ß T-progenies with innate-like phenotype expressing NKG2D,NKp30,DNAM-1. Innate-like maturing T-cells in vitro are cytotoxic, can be triggered via NKR/TCR co-stimulation and display broad spectrum Th1,Th2 and Th1/Th17 cytokine production. Conclusion: In advanced stage lung cancer CD34+DNAM-1brightCXCR4+ inflammatory precursors increase upon treatment, enter involved tissues, generate functional progenies and may thus represent an additional player contributing to immune balance in the highly SDF-1/CXCR4-biased pro-metastatic tumor microenvironment.
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Leucocitos Mononucleares , Neoplasias Pulmonares , Humanos , Células Asesinas Naturales , Médula Ósea , Pulmón , Neoplasias Pulmonares/tratamiento farmacológico , Microambiente Tumoral , Receptores CXCR4RESUMEN
Polyvalent mechanical bacterial lysate is effective in the prevention of respiratory tract infections, although its mechanism of action is not entirely elucidated. Because epithelial cells constitute the frontline defense against infections, we investigated the molecular mechanisms of innate response exerted by bronchial epithelial cells in the presence of polyvalent mechanical bacterial lysate. By using primary human bronchial epithelial cells, we observed that polyvalent mechanical bacterial lysate was able to increase the expression of cellular adhesion molecules such as ICAM-1 and E-cadherin, as well as the expression of amphiregulin, a growth factor able to support human bronchial epithelial cell proliferation. Remarkably, polyvalent mechanical bacterial lysate promoted in human bronchial epithelial cells the de novo expression of human ß-defensin-2, a major antimicrobial peptide, conferring them a direct antimicrobial activity. Moreover, polyvalent mechanical bacterial lysate-stimulated human bronchial epithelial cells provided signals for increased IL-22 production by innate lymphoid cells via IL-23, which could further contribute to the release of antimicrobial peptides by epithelial cells. In agreement with these in vitro data, the concentration of both IL-23 and antimicrobial peptides (human ß-defensin-2 and LL-37) increased in the saliva of healthy volunteers after sublingual administration of polyvalent mechanical bacterial lysate. Altogether, these results indicate that polyvalent mechanical bacterial lysate administration might support mucosal barrier integrity and promote mechanisms of antimicrobial activity in airway epithelial cells.
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Antiinfecciosos , beta-Defensinas , Humanos , Inmunidad Innata , Linfocitos/metabolismo , Antiinfecciosos/metabolismo , Células Epiteliales/metabolismo , Interleucina-23RESUMEN
Water buffalo (Bubalus bubalis) has a prominent position in the livestock industry worldwide but still suffers from limited knowledge on the mechanisms regulating the immune against infections, including brucellosis (BRC), one of the most significant neglected zoonotic diseases of livestock. Seventy-three buffalo were recruited for the study. Thirty-five were naturally infected with Brucella spp. The aims of the study were to (i) verify the cross-reactivity of 16 monoclonal antibodies (mAbs) developed against human, bovine, and ovine antigens; (ii) evaluate lymphocyte subset alterations in BRC positive buffalo; (iii) evaluate the use of the canonical discriminant analysis (CDA), with flow cytometric data, to discriminate BRC positive from negative animals. A new set of eight mAbs (anti CD3e, CD16, CD18, CD45R0, CD79a; CD172a) were shown to cross-react with water buffalo orthologous molecules. BRC positive animals presented a significant (p < 0.0001) decrease in the percentage of PBMC (29.5 vs. 40.3), total, T and B lymphocytes (23.0 vs. 35.5, 19.2 vs. 28.9, 2.6 vs. 5.7, respectively). In contrast, they showed an increase in percentage of granulocytes (65.2 vs. 55.1; p < 0.0001) and B lymphocytes CD21neg (22.9 vs. 16.1; p = 0.0067), a higher T/B lymphocyte ratio (10.3 vs. 6.4; p = 0.0011) and CD3+ /CD21+ (14.7 vs. 8.3; p = 0.0005) ratio. The CDA, applied to 33 different flow cytometric traits, allowed the discrimination of all BRC positive from negative buffalo. Although this is a preliminary study, our results show that flow cytometry can be used in a wide range of applications in livestock diseases, including in support of uncertain BRC diagnoses.
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Brucelosis , Búfalos , Animales , Ovinos , Bovinos , Humanos , Inmunofenotipificación , Leucocitos Mononucleares , Brucelosis/diagnóstico , Subgrupos LinfocitariosRESUMEN
Innate lymphoid cells (ILCs) comprise cytotoxic NK cells and helper-ILCs, which are further divided in ILC1, ILC2, and ILC3. Helper-ILCs mirror the effector functions of helper T-cell subsets and contribute to host immune defense, tissue homeostasis and repair through cytokine secretion. Although they are mainly tissue-resident, helper ILCs are also found in the peripheral blood (PB). In the human setting, it may be needed to analyze circulating helper ILCs to compare pathological to physiological conditions. In this review, we provide simple guidelines and a list of markers useful to study human PB helper ILCs phenotype and function by flow cytometry.
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Inmunidad Innata , Linfocitos , Humanos , Citometría de Flujo , Células Asesinas NaturalesRESUMEN
BACKGROUND: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection may result in a severe pneumonia associated with elevation of blood inflammatory parameters, reminiscent of cytokine storm syndrome. Steroidal anti-inflammatory therapies have shown efficacy in reducing mortality in critically ill patients; however, the mechanisms by which SARS-CoV-2 triggers such an extensive inflammation remain unexplained. OBJECTIVES: To dissect the mechanisms underlying SARS-CoV-2-associated inflammation in patients with severe coronavirus disease 2019 (COVID-19), we studied the role of IL-1ß, a pivotal cytokine driving inflammatory phenotypes, whose maturation and secretion are regulated by inflammasomes. METHODS: We analyzed nod-like receptor protein 3 pathway activation by means of confocal microscopy, plasma cytokine measurement, cytokine secretion following in vitro stimulation of blood circulating monocytes, and whole-blood RNA sequencing. The role of open reading frame 3a SARS-CoV-2 protein was assessed by confocal microscopy analysis following nucleofection of a monocytic cell line. RESULTS: We found that circulating monocytes from patients with COVID-19 display ASC (adaptor molecule apoptotic speck like protein-containing a CARD) specks that colocalize with nod-like receptor protein 3 inflammasome and spontaneously secrete IL-1ß in vitro. This spontaneous activation reverts following patient's treatment with the IL-1 receptor antagonist anakinra. Transfection of a monocytic cell line with cDNA coding for the ORF3a SARS-CoV-2 protein resulted in ASC speck formation. CONCLUSIONS: These results provide further evidence that IL-1ß targeting could represent an effective strategy in this disease and suggest a mechanistic explanation for the strong inflammatory manifestations associated with COVID-19.
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Tratamiento Farmacológico de COVID-19 , Inflamasomas , Antiinflamatorios , Síndrome de Liberación de Citoquinas/tratamiento farmacológico , Citocinas/metabolismo , ADN Complementario , Humanos , Inflamasomas/metabolismo , Proteína Antagonista del Receptor de Interleucina 1/uso terapéutico , Interleucina-1beta/metabolismo , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Proteínas NLR , Receptores de Interleucina-1 , SARS-CoV-2RESUMEN
Limb-girdle muscular dystrophy R3, a rare genetic disorder affecting the limb proximal muscles, is caused by mutations in the α-sarcoglycan gene (Sgca) and aggravated by an immune-mediated damage, finely modulated by the extracellular (e)ATP/purinoceptors axis. Currently, no specific drugs are available. The aim of this study was to evaluate the therapeutic effectiveness of a selective P2X7 purinoreceptor antagonist, A438079. Sgca knockout mice were treated with A438079 every two days at 3 mg/Kg for 24 weeks. The P2X7 antagonist improved clinical parameters by ameliorating mice motor function and decreasing serum creatine kinase levels. Histological analysis of muscle morphology indicated a significant reduction of the percentage of central nuclei, of fiber size variability and of the extent of local fibrosis and inflammation. A cytometric characterization of the muscle inflammatory infiltrates showed that A438079 significantly decreased innate immune cells and upregulated the immunosuppressive regulatory T cell subpopulation. In α-sarcoglycan null mice, the selective P2X7 antagonist A438079 has been shown to be effective to counteract the progression of the dystrophic phenotype and to reduce the inflammatory response. P2X7 antagonism via selective inhibitors could be included in the immunosuppressant strategies aimed to dampen the basal immune-mediated damage and to favor a better engraftment of gene-cell therapies.
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The characterization of frequency and phenotypes of natural killer (NK) cells and T cells in BAL and peripheral blood of patients with sarcoidosis was evaluated, to discriminate the differential status of these cells in these two compartments. The analysis revealed that CD56brightCD16neg resulted higher in BAL than PB of sarcoidosis and healthy subjects, while CD56dimCD16+ showed a different proportion between BAL and PB of both Sarcoidosis patients and HC. Moreover, in comparison with autologous PB, BAL was characterized by a higher expression of activated NK cell markers NKp44, CD69 and CD25. Significantly increased levels of PD-1+ NK cells in the BAL of patients were detected. Regarding the maturation of CD4 and CD8, an increase of Effector Memory T cells (TEM) was reported in BAL compared to PB. A better characterization of NK and T cells may lead to an improvement of the pathogenetic mechanisms in sarcoidosis.
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Sarcoidosis , Humanos , Sarcoidosis/metabolismo , Células Asesinas Naturales/metabolismo , Lavado Broncoalveolar , Líquido del Lavado Bronquioalveolar , FenotipoRESUMEN
The third edition of Flow Cytometry Guidelines provides the key aspects to consider when performing flow cytometry experiments and includes comprehensive sections describing phenotypes and functional assays of all major human and murine immune cell subsets. Notably, the Guidelines contain helpful tables highlighting phenotypes and key differences between human and murine cells. Another useful feature of this edition is the flow cytometry analysis of clinical samples with examples of flow cytometry applications in the context of autoimmune diseases, cancers as well as acute and chronic infectious diseases. Furthermore, there are sections detailing tips, tricks and pitfalls to avoid. All sections are written and peer-reviewed by leading flow cytometry experts and immunologists, making this edition an essential and state-of-the-art handbook for basic and clinical researchers.
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Enfermedades Autoinmunes/inmunología , Citometría de Flujo , Infecciones/inmunología , Neoplasias/inmunología , Animales , Enfermedad Crónica , Humanos , Ratones , Guías de Práctica Clínica como AsuntoRESUMEN
Immune checkpoint inhibitors (CI) have demonstrated clinical activity in Hodgkin Lymphoma (HL) patients relapsing after autologous stem cell transplantation (ASCT), although only 20% complete response (CR) rate was observed. The efficacy of CI is strictly related to the host immune competence, which is impaired in heavily pre-treated HL patients. Here, we aimed to enhance the activity of early post-ASCT CI (nivolumab) administration with the infusion of autologous lymphocytes (ALI). Twelve patients with relapse/refractory (R/R) HL (median age 28.5 years; range 18-65), underwent lymphocyte apheresis after first line chemotherapy and then proceeded to salvage therapy. Subsequently, 9 patients with progressive disease at ASCT received early post-transplant CI supported with four ALI, whereas 3 responding patients received ALI alone, as a control cohort. No severe adverse events were recorded. HL-treated patients achieved negative PET scan CR and 8 are alive and disease-free after a median follow-up of 28 months. Four patients underwent subsequent allogeneic SCT. Phenotypic analysis of circulating cells showed a faster expansion of highly differentiated NK cells in ALI plus nivolumab-treated patients as compared to control patients. Our data show anti-tumor activity with good tolerability of ALI + CI for R/R HL and suggest that this setting may accelerate NK cell development/maturation and favor the expansion of the "adaptive" NK cell compartment in patients with HCMV seropositivity, in the absence of HCMV reactivation.
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Traslado Adoptivo , Trasplante de Células Madre Hematopoyéticas , Enfermedad de Hodgkin/terapia , Inhibidores de Puntos de Control Inmunológico/uso terapéutico , Células Asesinas Naturales/inmunología , Transfusión de Linfocitos , Terapia Recuperativa , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Diferenciación Celular , Infecciones por Citomegalovirus/complicaciones , Supervivencia sin Enfermedad , Estudios de Factibilidad , Femenino , Enfermedad de Hodgkin/complicaciones , Enfermedad de Hodgkin/tratamiento farmacológico , Humanos , Masculino , Persona de Mediana Edad , Nivolumab/uso terapéutico , Recurrencia , Trasplante Autólogo , Adulto JovenRESUMEN
BACKGROUND: Neuroblastoma (NB) represents the most frequent and aggressive form of extracranial solid tumor of infants. Nucleolin (NCL) is a protein overexpressed and partially localized on the cell surface of tumor cells of adult cancers. Little is known about NCL and pediatric tumors and nothing is reported about cell surface NCL and NB. METHODS: NB cell lines, Schwannian stroma-poor NB tumors and bone marrow (BM)-infiltrating NB cells were evaluated for the expression of cell surface NCL by Flow Cytometry, Imaging Flow Cytometry and Immunohistochemistry analyses. The cytotoxic activity of doxorubicin (DXR)-loaded nanocarriers decorated with the NCL-recognizing F3 peptide (T-DXR) was evaluated in terms of inhibition of NB cell proliferation and induction of cell death in vitro, whereas metastatic and orthotopic animal models of NB were used to examine their in vivo anti-tumor potential. RESULTS: NB cell lines, NB tumor cells (including patient-derived and Patient-Derived Xenografts-PDX) and 70% of BM-infiltrating NB cells show cell surface NCL expression. NCL staining was evident on both tumor and endothelial tumor cells in NB xenografts. F3 peptide-targeted nanoparticles, co-localizing with cell surface NCL, strongly associates with NB cells showing selective tumor cell internalization. T-DXR result significantly more effective, in terms of inhibition of cell proliferation and reduction of cell viability in vitro, and in terms of delay of tumor growth in all NB animal model tested, when compared to both control mice and those treated with the untargeted formulation. CONCLUSIONS: Our findings demonstrate that NCL could represent an innovative therapeutic cellular target for NB.
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Proliferación Celular/efectos de los fármacos , Doxorrubicina/farmacología , Neuroblastoma/tratamiento farmacológico , Fosfoproteínas/genética , Proteínas de Unión al ARN/genética , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Células de la Médula Ósea/efectos de los fármacos , Línea Celular Tumoral , Membrana Celular/genética , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Xenoinjertos , Humanos , Liposomas/química , Liposomas/farmacología , Ratones , Nanopartículas/química , Neuroblastoma/genética , Neuroblastoma/patología , Péptidos/química , Péptidos/genética , Péptidos/farmacología , NucleolinaRESUMEN
A cardinal feature of COVID-19 is lung inflammation and respiratory failure. In a prospective multi-country cohort of COVID-19 patients, we found that increased Notch4 expression on circulating regulatory T (Treg) cells was associated with disease severity, predicted mortality, and declined upon recovery. Deletion of Notch4 in Treg cells or therapy with anti-Notch4 antibodies in conventional and humanized mice normalized the dysregulated innate immunity and rescued disease morbidity and mortality induced by a synthetic analog of viral RNA or by influenza H1N1 virus. Mechanistically, Notch4 suppressed the induction by interleukin-18 of amphiregulin, a cytokine necessary for tissue repair. Protection by Notch4 inhibition was recapitulated by therapy with Amphiregulin and, reciprocally, abrogated by its antagonism. Amphiregulin declined in COVID-19 subjects as a function of disease severity and Notch4 expression. Thus, Notch4 expression on Treg cells dynamically restrains amphiregulin-dependent tissue repair to promote severe lung inflammation, with therapeutic implications for COVID-19 and related infections.
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Interacciones Huésped-Patógeno , Inmunidad Celular , Neumonía Viral/etiología , Neumonía Viral/metabolismo , Receptor Notch4/metabolismo , Transducción de Señal , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/metabolismo , Anfirregulina/farmacología , Animales , Biomarcadores , Citocinas/metabolismo , Modelos Animales de Enfermedad , Susceptibilidad a Enfermedades , Interacciones Huésped-Patógeno/inmunología , Humanos , Inmunohistoquímica , Inmunomodulación/efectos de los fármacos , Mediadores de Inflamación/metabolismo , Virus de la Influenza A/fisiología , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Pulmón/virología , Ratones , Ratones Transgénicos , Neumonía Viral/patología , Receptor Notch4/antagonistas & inhibidores , Receptor Notch4/genética , Índice de Severidad de la EnfermedadRESUMEN
BACKGROUND: There is limited knowledge on the origin and development from CD34+ precursors of the ample spectrum of human natural killer (NK) cells, particularly of specialized NK subsets. OBJECTIVE: This study sought to characterize the NK-cell progeny of CD34+DNAM-1brightCXCR4+ and of other precursors circulating in the peripheral blood of patients with chronic viral infections (eg, HIV, hepatitis C virus, cytomegalovirus reactivation). METHODS: Highly purified precursors were obtained by flow cytometric sorting and cultured in standard NK-cell differentiation media (ie, SCF, FLT3, IL-7, IL-15). Phenotypic and functional analyses on progenies were performed by multiparametric cytofluorimetric assays. Transcriptional signatures of NK-cell progenies were studied by microarray analysis. Inhibition of cytomegalovirus replication was studied by PCR. RESULTS: Unlike conventional CD34+ precursors, Lin-CD34+DNAM-1brightCXCR4+ precursors from patients with chronic infection, rapidly differentiate into cytotoxic, IFN-γ-secreting CD94/NKG2C+KIR+CD57+ NK-cell progenies. An additional novel subset of common lymphocyte precursors was identified among Lin-CD34-CD56-CD16+ cells and characterized by expression of CXCR4 and lack of perforin and CD94. Lin-CD34-CD56-CD16+Perf-CD94-CXCR4+ precursors are also endowed with generation potential toward memory-like NKG2C+NK cells. Maturing NK-cell progenies mediated strong human cytomegalovirus-inhibiting activity. Microarray analysis confirmed a transcriptional signature compatible with NK-cell progenies and with maturing adaptive NK cells. CONCLUSIONS: During viral infections, precursors of adaptive NK cells are released and circulate in the peripheral blood.
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Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/metabolismo , Citomegalovirus/inmunología , Interacciones Huésped-Patógeno/inmunología , Células Asesinas Naturales/inmunología , Células Asesinas Naturales/metabolismo , Subfamília C de Receptores Similares a Lectina de Células NK/metabolismo , Biomarcadores , Diferenciación Celular , Citocinas/metabolismo , Infecciones por Citomegalovirus/virología , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Humanos , Inmunofenotipificación , Mediadores de Inflamación/metabolismo , Activación de Linfocitos/inmunologíaRESUMEN
T lymphocytes play a central role in antigen-specific immune responses. They modulate the function of different immune cells both through a direct contact (receptor binding) and through the secretion of cytokines. At the same time, they are deeply involved in the direct killing of aberrant target cells. T lymphocytes derive from a bone marrow precursor that migrates in the thymus where the main differentiation steps take place. Mature CD4 and CD8 single-positive cells, then, leave the thymus to reach the secondary lymphoid organs. T-cell subsets and their maturation steps can be identified mainly based on the expression of extracellular markers, intracellular transcription factors and cytokine production profiles. In this review, we report, from a cytometric point of view, an overview of the most important T-cell subpopulations and their differentiation state. © 2020 International Society for Advancement of Cytometry.
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Linfocitos T CD8-positivos , Subgrupos de Linfocitos T , Animales , Antígenos , Linfocitos T CD4-Positivos , Diferenciación Celular , Citocinas , Citometría de Flujo , RatonesRESUMEN
Extracellular vesicles (EVs) are released by shedding during different physiological processes and are increasingly thought to be new potential biomarkers. However, the impact of pre-analytical processing phases on the final measurement is not predictable and for this reason, the translation of basic research into clinical practice has been precluded. Here we have optimized a simple procedure in combination with polychromatic flow cytometry (PFC), to identify, classify, enumerate, and separate circulating EVs from different cell origins. This protocol takes advantage of a lipophilic cationic dye (LCD) able to probe EVs. Moreover, the application of the newly optimized PFC protocol here described allowed the obtainment of repeatable EVs counts. The translation of this PFC protocol to fluorescence-activated cell sorting allowed us to separate EVs from fresh peripheral blood samples. Sorted EVs preparations resulted particularly suitable for proteomic analyses, which we applied to study their protein cargo. Here we show that LCD staining allowed PFC detection and sorting of EVs from fresh body fluids, avoiding pre-analytical steps of enrichment that could impact final results. Therefore, LCD staining is an essential step towards the assessment of EVs clinical significance.
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Biomarcadores , Vesículas Extracelulares/metabolismo , Citometría de Flujo , Biopsia Líquida , Animales , Citometría de Flujo/métodos , Humanos , Biopsia Líquida/métodos , Tamaño de la Partícula , Plasma , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
The NK cell compartment provides powerful innate defenses against virus-infected and tumor cells. Specific NK cell receptors control this process and maintain the immune system homeostasis and prevent autoimmunity. A wide variety of NK cell subsets with different functional capabilities exist and this reflects not only the different maturation stages of NK cells but also different microenvironments in which they can operate. In this review, we will give an overview on the various NK cell subsets present in peripheral blood of healthy donors in order to clearly and univocally identify them on the basis of their phenotypic traits using flow cytometry. © 2020 International Society for Advancement of Cytometry.