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1.
Methods Mol Biol ; 2414: 433-447, 2022.
Article in English | MEDLINE | ID: covidwho-1588848

ABSTRACT

Vaccines induce a highly complex immune reaction in secondary lymphoid organs to generate immunological memory against an antigen or antigens of interest. Measurement of post immunization immune responses generated by specialized lymphocyte subsets requires time-dependent sampling, usually of the blood. Several T and B cell subsets are involved in the reaction, including CD4 and CD8 T cells, T follicular helper cells (Tfh), and germinal center B cells alongside their circulating (c) counterparts; cTfh and antibody secreting cells. Multicolor flow cytometry of peripheral blood mononuclear cells (PBMC) coupled with high-dimensional analysis offers an opportunity to study these cells in detail. Here we demonstrate a method by which such data can be generated and analysed using software that renders multidimensional data on a two dimensional map to identify rare vaccine-induced T and B cell subsets.


Subject(s)
Flow Cytometry , Leukocytes, Mononuclear , Data Analysis , T-Lymphocytes, Helper-Inducer , Vaccinology
2.
Methods Mol Biol ; 2386: 43-60, 2022.
Article in English | MEDLINE | ID: covidwho-1513947

ABSTRACT

A comprehensive study of the cellular components of the immune system demands both deep and broad immunophenotyping of numerous cell subsets in an effective and practical way. Novel full-spectrum technology reveals the complete emission spectrum of each dye maximizing the amount of information that can be obtained on a single sample regarding conventional flow cytometry and provide an expanded knowledge of biological processes. In this chapter, we describe a 37-color protocol that allows to identify more than 45 different cell populations on whole blood samples of SARS-CoV-2-infected patients.


Subject(s)
COVID-19 , Flow Cytometry , Immunophenotyping/methods , COVID-19/blood , Color , Humans , Immune System
3.
Eur J Immunol ; 51(11): 2665-2676, 2021 11.
Article in English | MEDLINE | ID: covidwho-1482126

ABSTRACT

To monitor infection by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and successful vaccination against coronavirus disease 2019 (COVID-19), the kinetics of neutralizing or blocking anti-SARS-CoV-2 antibody titers need to be assessed. Here, we report the development of a quick and inexpensive surrogate SARS-CoV-2 blocking assay (SUBA) using immobilized recombinant human angiotensin-converting enzyme 2 (hACE2) and human cells expressing the native form of surface SARS-CoV-2 spike protein. Spike protein-expressing cells bound to hACE2 in the absence or presence of blocking antibodies were quantified by measuring the optical density of cell-associated crystal violet in a spectrophotometer. The advantages are that SUBA is a fast and inexpensive assay, which does not require biosafety level 2- or 3-approved laboratories. Most importantly, SUBA detects blocking antibodies against the native trimeric cell-bound SARS-CoV-2 spike protein and can be rapidly adjusted to quickly pre-screen already approved therapeutic antibodies or sera from vaccinated individuals for their ACE2 blocking activities against any emerging SARS-CoV-2 variants.


Subject(s)
Antibodies, Blocking/blood , Antibodies, Neutralizing/blood , Antibodies, Viral/analysis , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Flow Cytometry/methods , Antibodies, Blocking/immunology , Antibodies, Neutralizing/immunology , COVID-19/immunology , Humans , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/immunology
4.
Front Immunol ; 12: 730766, 2021.
Article in English | MEDLINE | ID: covidwho-1463473

ABSTRACT

The SARS-CoV-2 pandemic has spread to all parts of the world and can cause life-threatening pneumonia and other severe disease manifestations known as COVID-19. This health crisis has resulted in a significant effort to stop the spread of this new coronavirus. However, while propagating itself in the human population, the virus accumulates mutations and generates new variants with increased fitness and the ability to escape the human immune response. Here we describe a color-based barcoded spike flow cytometric assay (BSFA) that is particularly useful to evaluate and directly compare the humoral immune response directed against either wild type (WT) or mutant spike (S) proteins or the receptor-binding domains (RBD) of SARS-CoV-2. This assay employs the human B lymphoma cell line Ramos, transfected for stable expression of WT or mutant S proteins or a chimeric RBD-CD8 fusion protein. We find that the alpha and beta mutants are more stably expressed than the WT S protein on the Ramos B cell surface and/or bind with higher affinity to the viral entry receptor ACE2. However, we find a reduce expression of the chimeric RBD-CD8 carrying the point mutation N501Y and E484K characteristic for the alpha and beta variant, respectively. The comparison of the humoral immune response of 12 vaccinated probands with 12 COVID-19 patients shows that after the boost, the S-specific IgG class immune response in the vaccinated group is similar to that of the patient group. However, in comparison to WT the specific IgG serum antibodies bind less well to the alpha variant and only poorly to the beta variant S protein. This is in line with the notion that the beta variant is an immune escape variant of SARS-CoV-2. The IgA class immune response was more variable than the IgG response and higher in the COVID-19 patients than in the vaccinated group. In summary, we think that our BSFA represents a useful tool to evaluate the humoral immunity against emerging variants of SARS-CoV-2 and to analyze new vaccination protocols against these variants.


Subject(s)
COVID-19/immunology , Cell Separation/methods , Flow Cytometry/methods , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , Angiotensin-Converting Enzyme 2/metabolism , Antibodies, Viral/metabolism , Antibody Formation , Female , Humans , Immunization, Secondary , Immunoglobulin A/metabolism , Immunoglobulin G/metabolism , Male , Middle Aged , Mutation/genetics , Spike Glycoprotein, Coronavirus/genetics , Vaccination
5.
Viruses ; 13(10)2021 09 30.
Article in English | MEDLINE | ID: covidwho-1444330

ABSTRACT

BACKGROUND: The immunological changes associated with COVID-19 are largely unknown. METHODS: Patients with COVID-19 showing moderate (n = 18; SpO2 > 93%, respiratory rate > 22 per minute, CRP > 10 mg/L) and severe (n = 23; SpO2 < 93%, respiratory rate >30 per minute, PaO2/FiO2 ≤ 300 mmHg, permanent oxygen therapy, qSOFA > 2) infection, and 37 healthy donors (HD) were enrolled. Circulating T- and B-cell subsets were analyzed by flow cytometry. RESULTS: CD4+Th cells were skewed toward Th2-like phenotypes within CD45RA+CD62L- (CM) and CD45RA-CD62L- (EM) cells in patients with severe COVID-19, while CM CCR6+ Th17-like cells were decreased if compared with HD. Within CM Th17-like cells "classical" Th17-like cells were increased and Th17.1-like cells were decreased in severe COVID-19 cases. Circulating CM follicular Th-like (Tfh) cells were decreased in all COVID-19 patients, and Tfh17-like cells represented the most predominant subset in severe COVID-19 cases. Both groups of patients showed increased levels of IgD-CD38++ B cells, while the levels of IgD+CD38- and IgD-CD38- were decreased. The frequency of IgD+CD27+ and IgD-CD27+ B cells was significantly reduced in severe COVID-19 cases. CONCLUSIONS: We showed an imbalance within almost all circulating memory Th subsets during acute COVID-19 and showed that altered Tfh polarization led to a dysregulated humoral immune response.


Subject(s)
B-Lymphocyte Subsets/immunology , COVID-19/immunology , Immunity , SARS-CoV-2 , ADP-ribosyl Cyclase 1 , Adult , Aged , B-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/immunology , Female , Flow Cytometry , Humans , Immunoglobulin D , Male , Middle Aged , Oxygen , Receptors, CCR6 , T-Lymphocytes/metabolism , Th17 Cells/immunology
6.
J Immunol Methods ; 499: 113159, 2021 12.
Article in English | MEDLINE | ID: covidwho-1440195

ABSTRACT

In general, the method of choice for evaluating immunity against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) is detection of antibodies against the virus in patient sera. However, this is not feasible in patients who do not produce antibodies, either due to a primary immunodeficiency or secondary to treatment with immunosuppressive drugs. Assessment of the antiviral T cell response is an alternative to serological tests, but most T cell assays are labor-intensive and unsuitable for a clinical routine laboratory. We developed a flow cytometry-based assay for T cell proliferative responses against SARS-CoV-2, based on the detection of blast transformation of activated cells. The assay was validated on previously SARS-CoV-2 infected individuals and healthy seronegative blood donors, displaying 74% sensitivity and 96% specificity for previous infection with SARS-CoV-2. The usefulness of the assay was demonstrated in a patient with common variable immunodeficiency with a history of COVID-19. The described T-cell assay is a clinically relevant complement to serology in the evaluation of cellular immunity against SARS-CoV-2, which can be emulated by any routine lab with flow cytometric competence.


Subject(s)
Flow Cytometry , Immunologic Memory/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Aged , Cell Proliferation , Female , Humans , Male , Middle Aged , Young Adult
7.
Cells ; 10(10)2021 09 26.
Article in English | MEDLINE | ID: covidwho-1438528

ABSTRACT

The coronavirus disease 2019 (COVID-19) is related to enhanced production of NETs, and autoimmune/autoinflammatory phenomena. We evaluated the proportion of low-density granulocytes (LDG) by flow cytometry, and their capacity to produce NETs was compared with that of conventional neutrophils. NETs and their protein cargo were quantified by confocal microscopy and ELISA. Antinuclear antibodies (ANA), anti-neutrophil cytoplasmic antibodies (ANCA) and the degradation capacity of NETs were addressed in serum. MILLIPLEX assay was used to assess the cytokine levels in macrophages' supernatant and serum. We found a higher proportion of LDG in severe and critical COVID-19 which correlated with severity and inflammatory markers. Severe/critical COVID-19 patients had higher plasmatic NE, LL-37 and HMGB1-DNA complexes, whilst ISG-15-DNA complexes were lower in severe patients. Sera from severe/critical COVID-19 patients had lower degradation capacity of NETs, which was reverted after adding hrDNase. Anti-NET antibodies were found in COVID-19, which correlated with ANA and ANCA positivity. NET stimuli enhanced the secretion of cytokines in macrophages. This study unveils the role of COVID-19 NETs as inducers of pro-inflammatory and autoimmune responses. The deficient degradation capacity of NETs may contribute to the accumulation of these structures and anti-NET antibodies are related to the presence of autoantibodies.


Subject(s)
Autoimmunity , COVID-19/blood , COVID-19/immunology , Extracellular Traps/immunology , Immunity, Humoral , Inflammation , Neutrophils/immunology , Antibodies, Antinuclear , Antimicrobial Cationic Peptides/blood , Autoantibodies/metabolism , Cross-Sectional Studies , Cytokines/metabolism , Cytokines/pharmacology , Flow Cytometry , Granulocytes/metabolism , HMGB1 Protein/blood , Healthy Volunteers , Humans , Microscopy, Confocal , Monocytes/cytology , Neutrophils/cytology , SARS-CoV-2 , Ubiquitins/pharmacology
8.
Am J Clin Pathol ; 156(4): 634-643, 2021 Sep 08.
Article in English | MEDLINE | ID: covidwho-1408305

ABSTRACT

OBJECTIVES: Myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are a group of rare and heterogeneous hematopoietic disorders that frequently present a diagnostic challenge. Here we present our institutional experience with next-generation sequencing (NGS), together with morphologic, flow cytometric, and cytogenetic evaluation, in the diagnosis of MDS/MPN, with particular emphasis on MDS/MPN unclassifiable (MPN-U). METHODS: We evaluated the morphologic, flow cytometric, cytogenetic, and molecular characteristics of all MDS/MPN cases that underwent NGS at our institution between April 2016 and February 2019. RESULTS: Thirty-seven cases of MDS/MPN were identified, including 14 cases of MDS/MPN-U. Ninety-seven percent harbored mutations and immunophenotypic aberrancies (36/37), while only 38% had cytogenetic abnormalities (12/32). The MDS/MPN-U group had the highest rate of myeloblast phenotypic abnormalities and had a high mutation rate of approximately 2.7 mutated genes per case, most commonly in JAK2, SRSF2, and ASXL1. CONCLUSIONS: No single ancillary study was abnormal in every case, but all cases had at least one abnormal finding, demonstrating the usefulness of a multiparameter approach to the diagnosis of MDS/MPN. Although a few specific mutations were found exclusively in MDS/MPN-U and JAK2 mutations were most prevalent, larger studies are needed to determine whether MDS/MPN-U has a mutational "fingerprint," which may aid in diagnosis and targeted therapy.


Subject(s)
Myelodysplastic-Myeloproliferative Diseases/diagnosis , Myeloproliferative Disorders/diagnosis , Adult , Aged , Aged, 80 and over , Cytogenetics , Female , Flow Cytometry , Granulocyte Precursor Cells/pathology , High-Throughput Nucleotide Sequencing , Humans , Immunophenotyping , Male , Middle Aged , Mutation , Mutation Rate , Myelodysplastic-Myeloproliferative Diseases/classification , Myelodysplastic-Myeloproliferative Diseases/genetics , Myelodysplastic-Myeloproliferative Diseases/pathology , Myeloproliferative Disorders/classification , Myeloproliferative Disorders/genetics , Myeloproliferative Disorders/pathology , Sequence Analysis, DNA , Young Adult
10.
Cytometry A ; 99(1): 60-67, 2021 01.
Article in English | MEDLINE | ID: covidwho-1384157

ABSTRACT

Data management is essential in a flow cytometry (FCM) shared resource laboratory (SRL) for the integrity of collected data and its long-term preservation, as described in the Cytometry publication from 2016, ISAC Flow Cytometry Shared Resource Laboratory (SRL) Best Practices (Barsky et al.: Cytometry Part A 89A(2016): 1017-1030). The SARS-CoV-2 pandemic introduced an array of challenges in the operation of SRLs. The subsequent laboratory shutdowns and access restrictions brought to the forefront well-established practices that withstood the impact of a sudden change in operations and illuminated areas that need improvement. The most significant challenges from a data management perspective were data access for remote analysis and workstation management. Notably, lessons learned from this challenge emphasize the importance of safeguarding collected data from loss in various emergencies such as fire or natural disasters where the physical hardware storing data could be directly affected. Here, we describe two data management systems that have been successful during the current emergency created by the pandemic, specifically remote access and automated data transfer. We will discuss other situations that could arise and lead to data loss or challenges in interpreting data. © 2020 International Society for Advancement of Cytometry.


Subject(s)
COVID-19/epidemiology , Data Management/trends , Flow Cytometry/trends , Laboratories/trends , Teleworking/trends , COVID-19/prevention & control , Data Management/standards , Flow Cytometry/standards , Humans , Laboratories/standards , Teleworking/standards
11.
Cell Mol Immunol ; 18(8): 1847-1860, 2021 08.
Article in English | MEDLINE | ID: covidwho-1387308

ABSTRACT

CD4+ T cells orchestrate adaptive immune responses via binding of antigens to their receptors through specific peptide/MHC-II complexes. To study these responses, it is essential to identify protein-derived MHC-II peptide ligands that constitute epitopes for T cell recognition. However, generating cells expressing single MHC-II alleles and isolating these proteins for use in peptide elution or binding studies is time consuming. Here, we express human MHC alleles (HLA-DR4 and HLA-DQ6) as native, noncovalent αß dimers on yeast cells for direct flow cytometry-based screening of peptide ligands from selected antigens. We demonstrate rapid, accurate identification of DQ6 ligands from pre-pro-hypocretin, a narcolepsy-related immunogenic target. We also identify 20 DR4-binding SARS-CoV-2 spike peptides homologous to SARS-CoV-1 epitopes, and one spike peptide overlapping with the reported SARS-CoV-2 epitope recognized by CD4+ T cells from unexposed individuals carrying DR4 subtypes. Our method is optimized for immediate application upon the emergence of novel pathogens.


Subject(s)
CD4-Positive T-Lymphocytes/metabolism , COVID-19/metabolism , Epitopes, T-Lymphocyte/metabolism , HLA-DQ Antigens/metabolism , HLA-DR4 Antigen/metabolism , Saccharomyces cerevisiae/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Two-Hybrid System Techniques , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , COVID-19/genetics , COVID-19/immunology , Epitopes, T-Lymphocyte/genetics , Epitopes, T-Lymphocyte/immunology , Flow Cytometry , HLA-DQ Antigens/genetics , HLA-DQ Antigens/immunology , HLA-DR4 Antigen/genetics , HLA-DR4 Antigen/immunology , Ligands , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae/immunology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
12.
Cytometry A ; 97(9): 887-890, 2020 09.
Article in English | MEDLINE | ID: covidwho-1384155

ABSTRACT

In patients with severe SARS-CoV-2 infection, the development of cytokine storm induces extensive lung damage, and monocytes play a role in this pathological process. Non-classical (NC) and intermediate (INT) monocytes are known to be involved during viral and bacterial infections. In this study, 30 patients with different manifestations of acute SARS-CoV-2 infection were investigated with a flow cytometric study of NC, INT, and classical (CL) monocytes. Significantly reduced NC and INT monocytes and a downregulated HLA-DR were found in acute patients with severe SARS-CoV-2 symptoms. Conversely in patients with moderate symptoms NC and INT monocytes and CD11b expression were increased. © 2020 International Society for Advancement of Cytometry.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Monocytes/immunology , Pneumonia, Viral/immunology , Aged , Betacoronavirus/pathogenicity , Biomarkers/analysis , CD11b Antigen/analysis , COVID-19 , Cell Separation , Coronavirus Infections/diagnosis , Coronavirus Infections/virology , Female , Flow Cytometry , Host Microbial Interactions , Humans , Leukocytes , Male , Middle Aged , Monocytes/virology , Pandemics , Phenotype , Pneumonia, Viral/diagnosis , Pneumonia, Viral/virology , SARS-CoV-2 , Severity of Illness Index
13.
J Ethnopharmacol ; 282: 114574, 2022 Jan 10.
Article in English | MEDLINE | ID: covidwho-1373117

ABSTRACT

ETHNOPHARMACOLOGICAL RELEVANCE: Gekko gecko is used as a traditional medicine for various diseases including respiratory disorders in northeast Asian countries, mainly Korea, Japan, and China. AIM OF THE STUDY: Allergic asthma is a chronic respiratory disease caused by an inappropriate immune response. Due to the recent spread of coronavirus disease 2019, interest in the treatment of pulmonary disorders has rapidly increased. In this study, we investigated the anti-asthmatic effects of G. gecko extract (GGE) using an established mouse model of ovalbumin-induced asthma. MATERIALS AND METHODS: To evaluate the anti-asthmatic effects of GGE, we evaluated histological changes and the responses of inflammatory mediators related to allergic airway inflammation. Furthermore, we investigated the regulatory effects of GGE on type 2 helper T (Th2) cell activation. RESULTS: Administration of GGE attenuated asthmatic phenotypes, including inflammatory cell infiltration, mucus production, and expression of Th2 cytokines. Furthermore, GGE treatment reduced Th2 cell activation and differentiation. CONCLUSIONS: These results indicate that GGE alleviates allergic airway inflammation by regulating Th2 cell activation and differentiation.


Subject(s)
Anti-Asthmatic Agents/therapeutic use , Asthma/drug therapy , Medicine, East Asian Traditional , Mucus/metabolism , Ovalbumin , Plant Extracts/therapeutic use , Animals , Asthma/chemically induced , Asthma/pathology , Bronchoalveolar Lavage Fluid , COVID-19 , Cytokines/metabolism , Female , Flow Cytometry , Immunoglobulin E/immunology , Inflammation Mediators/metabolism , Lung/pathology , Mice , Mice, Inbred BALB C , Pandemics , Th2 Cells/drug effects , Th2 Cells/immunology , Tryptamines/pharmacology
14.
Front Immunol ; 12: 692729, 2021.
Article in English | MEDLINE | ID: covidwho-1369667

ABSTRACT

Epidemiological studies and clinical trials suggest Bacillus Calmette-Guérin (BCG) vaccine has protective effects against coronavirus disease 2019 (COVID-19). There are now over 30 clinical trials evaluating if BCG vaccination can prevent or reduce the severity of COVID-19. However, the mechanism by which BCG vaccination can induce severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific T cell responses is unknown. Here, we identify 8 novel BCG-derived peptides with significant sequence homology to either SARS-CoV-2 NSP3 or NSP13-derived peptides. Using an in vitro co-culture system, we show that human CD4+ and CD8+ T cells primed with a BCG-derived peptide developed enhanced reactivity to its corresponding homologous SARS-CoV-2-derived peptide. As expected, HLA differences between individuals meant that not all persons developed immunogenic responses to all 8 BCG-derived peptides. Nevertheless, all of the 20 individuals that were primed with BCG-derived peptides developed enhanced T cell reactivity to at least 7 of 8 SARS-CoV-2-derived peptides. These findings provide an in vitro mechanism that may account, in part, for the epidemiologic observation that BCG vaccination confers some protection from COVID-19.


Subject(s)
BCG Vaccine/immunology , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cross Reactions , SARS-CoV-2/immunology , Adult , COVID-19/immunology , COVID-19/prevention & control , Cells, Cultured , Coculture Techniques , Female , Flow Cytometry , Humans , Male , Sequence Analysis, Protein , Sequence Homology , Vaccines, Subunit/immunology , Young Adult
15.
Front Immunol ; 12: 697840, 2021.
Article in English | MEDLINE | ID: covidwho-1359188

ABSTRACT

Monocytes are antigen-presenting cells (APCs) that play diverse roles in promoting or regulating inflammatory responses, but their role in T cell stimulation is not well defined. In inflammatory conditions, monocytes frequently show increased expression of CD169/Siglec-1, a type-I interferon (IFN-I)-regulated protein. However, little is known about the phenotype and function of these CD169+ monocytes. Here, we have investigated the phenotype of human CD169+ monocytes in different diseases, their capacity to activate CD8+ T cells, and the potential for a targeted-vaccination approach. Using spectral flow cytometry, we detected CD169 expression by CD14+ CD16- classical and CD14+ CD16+ intermediate monocytes and unbiased analysis showed that they were distinct from dendritic cells, including the recently described CD14-expressing DC3. CD169+ monocytes expressed higher levels of co-stimulatory and HLA molecules, suggesting an increased activation state. IFNα treatment highly upregulated CD169 expression on CD14+ monocytes and boosted their capacity to cross-present antigen to CD8+ T cells. Furthermore, we observed CD169+ monocytes in virally-infected patients, including in the blood and bronchoalveolar lavage fluid of COVID-19 patients, as well as in the blood of patients with different types of cancers. Finally, we evaluated two CD169-targeting nanovaccine platforms, antibody-based and liposome-based, and we showed that CD169+ monocytes efficiently presented tumor-associated peptides gp100 and WT1 to antigen-specific CD8+ T cells. In conclusion, our data indicate that CD169+ monocytes are activated monocytes with enhanced CD8+ T cell stimulatory capacity and that they emerge as an interesting target in nanovaccine strategies, because of their presence in health and different diseases.


Subject(s)
Antigen Presentation/immunology , CD8-Positive T-Lymphocytes/immunology , Lymphocyte Activation/immunology , Monocytes/immunology , Sialic Acid Binding Ig-like Lectin 1/metabolism , COVID-19/immunology , Carcinoma, Pancreatic Ductal/immunology , Cells, Cultured , Flow Cytometry , Humans , Influenza, Human/immunology , Interferon-alpha/pharmacology , Lipopolysaccharide Receptors/metabolism , Lung Neoplasms/immunology , Pancreatic Neoplasms/immunology , SARS-CoV-2/immunology
16.
Eur J Immunol ; 51(11): 2633-2640, 2021 11.
Article in English | MEDLINE | ID: covidwho-1344986

ABSTRACT

Here, we describe a new, simple, highly multiplexed serological test that generates a more complete picture of seroconversion than single antigen-based assays. Flow cytometry is used to detect multiple Ig isotypes binding to four SARS-CoV-2 antigens: the Spike glycoprotein, its RBD fragment (the main target for neutralizing antibodies), the nucleocapsid protein, and the main cysteine-like protease in a single reaction. Until now, most diagnostic serological tests measured antibodies to only one antigen and in some laboratory-confirmed patients no SARS-CoV-2-specific antibodies could be detected. Our data reveal that while most patients respond against all the viral antigens tested, others show a marked bias to make antibodies against either proteins exposed on the viral particle or those released after cellular infection. With this assay, it was possible to discriminate between patients and healthy controls with 100% confidence. Analysing the response of multiple Ig isotypes to the four antigens in combination may also help to establish a correlation with the severity degree of disease. A more detailed description of the immune responses of different patients to SARS-CoV-2 virus might provide insight into the wide array of clinical presentations of COVID-19.


Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Flow Cytometry/methods , Antigens, Viral/immunology , COVID-19/immunology , High-Throughput Screening Assays , Humans , SARS-CoV-2 , Sensitivity and Specificity , Serologic Tests
17.
Viral Immunol ; 34(5): 342-351, 2021 06.
Article in English | MEDLINE | ID: covidwho-1343608

ABSTRACT

The spectrum of coronavirus disease 2019 (COVID-19) severity, related to cellular immune functions, has not been fully clarified yet. Therefore, this study aimed to investigate the alteration of peripheral blood cells in patients with COVID-19. The flow cytometric characterization of immune cell subset was performed on 69 COVID-19 patients and 21 healthy controls. These data were evaluated based on the disease severity. A total of 69 patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were classified as asymptomatic infection (n = 14), nonsevere (n = 39), and severe (n = 16) groups. Decreased lymphocytes and increased CD14 + 4- monocytes are found in patients with severe COVID-19. Decreased CD4 expression level was observed in the monocytes of patients with severe COVID-19. The total lymphocytes, B and T lymphocytes, CD4+ cells and CD8+ cells, and natural killer (NK) and natural killer T (NKT) cells were found to be decreased in patients with severe COVID-19. The CD4+/CD8+ ratio was not significantly different between patients with COVID-19 and healthy controls. The percentage of activated T cells (CD3+HLA-DR+) and B cells (CD19+CD38+) was lower in patients with severe COVID-19. Age and CD4- monocytes were independent predictors of disease severity. The SARS-CoV-2 infection may affect lymphocyte subsets, resulting in decreased T and B cells, monocytes, and NK and NKT cells. Decreased CD4 expression level by monocytes was significantly correlated with disease severity. Further studies on the host immune response to SARS-CoV-2 infection are necessary to predict the disease severity and protect against the virus.


Subject(s)
CD4 Antigens/genetics , COVID-19/immunology , Immunity, Cellular , Lymphocyte Subsets/immunology , Monocytes/immunology , Severity of Illness Index , Adolescent , Adult , Aged , Aged, 80 and over , COVID-19/pathology , Female , Flow Cytometry , Hospitalization/statistics & numerical data , Humans , Lymphocyte Activation , Lymphocyte Count , Male , Middle Aged , Young Adult
18.
J Infect Dis ; 224(3): 395-406, 2021 08 02.
Article in English | MEDLINE | ID: covidwho-1338702

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) clinical expression is pleiomorphic, severity is related to age and comorbidities such as diabetes and hypertension, and pathophysiology involves aberrant immune activation and lymphopenia. We wondered if the myeloid compartment was affected during COVID-19 and if monocytes and macrophages could be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). METHODS: Monocytes and monocyte-derived macrophages (MDMs) from COVID-19 patients and controls were infected with SARS-CoV-2 and extensively investigated with immunofluorescence, viral RNA extraction and quantification, and total RNA extraction followed by reverse-transcription quantitative polymerase chain reaction using specific primers, supernatant cytokines (interleukins 6, 10, and 1ß; interferon-ß; transforming growth factor-ß1, and tumor necrosis factor-α), and flow cytometry. The effect of M1- vs M2-type or no polarization prior to infection was assessed. RESULTS: SARS-CoV-2 efficiently infected monocytes and MDMs, but their infection is abortive. Infection was associated with immunoregulatory cytokines secretion and the induction of a macrophagic specific transcriptional program characterized by the upregulation of M2-type molecules. In vitro polarization did not account for permissivity to SARS-CoV-2, since M1- and M2-type MDMs were similarly infected. In COVID-19 patients, monocytes exhibited lower counts affecting all subsets, decreased expression of HLA-DR, and increased expression of CD163, irrespective of severity. CONCLUSIONS: SARS-CoV-2 drives monocytes and macrophages to induce host immunoparalysis for the benefit of COVID-19 progression.SARS-CoV-2 infection of macrophages induces a specific M2 transcriptional program. In Covid-19 patients, monocyte subsets were decreased associated with up-expression of the immunoregulatory molecule CD163 suggesting that SARS-CoV-2 drives immune system for the benefit of Covid-19 disease progression.


Subject(s)
COVID-19/immunology , Macrophages/virology , Monocytes/virology , Respiratory Distress Syndrome/virology , SARS-CoV-2 , Adolescent , Adult , Aged , Aged, 80 and over , Cytokines/metabolism , Female , Flow Cytometry , Fluorescent Antibody Technique , Humans , Male , Middle Aged , Respiratory Distress Syndrome/immunology , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/immunology , Severity of Illness Index , Young Adult
19.
Adv Sci (Weinh) ; 8(18): e2100323, 2021 09.
Article in English | MEDLINE | ID: covidwho-1316190

ABSTRACT

Blood cell analysis is a major pillar of biomedical research and healthcare. These analyses are performed in central laboratories. Rapid shipment from collection site to the central laboratories is currently needed because cells and biomarkers degrade rapidly. The dried blood spot from a fingerstick allows the preservation of cellular molecules for months but entire cells are never recovered. Here leucocyte elution is optimized from dried blood spots. Flow cytometry and mRNA expression profiling are used to analyze the recovered cells. 50-70% of the leucocytes that are dried on a polyester solid support via elution after shaking the support with buffer are recovered. While red blood cells lyse upon drying, it is found that the majority of leucocytes are preserved. Leucocytes have an altered structure that is improved by adding fixative in the elution buffer. Leucocytes are permeabilized, allowing an easy staining of all cellular compartments. Common immunophenotyping and mRNAs are preserved. The ability of a new biomarker (CD169) to discriminate between patients with and without Severe Acute Respiratory Syndrome induced by Coronavirus 2 (SARS-CoV-2) infections is also preserved. Leucocytes from blood can be dried, shipped, and/or stored for at least 1 month, then recovered for a wide variety of analyses, potentially facilitating biomedical applications worldwide.


Subject(s)
Communicable Diseases/diagnosis , Diagnostic Tests, Routine/methods , Dried Blood Spot Testing/methods , Hematology/methods , Immunophenotyping/methods , Antibodies, Viral/blood , Biomarkers/blood , Blood Specimen Collection/methods , COVID-19/diagnosis , Cell Separation/methods , Communicable Diseases/virology , Erythrocytes/virology , Flow Cytometry/methods , Humans , Leukocytes/virology , RNA, Messenger/blood , SARS-CoV-2/genetics
20.
J Immunol ; 207(2): 720-734, 2021 07 15.
Article in English | MEDLINE | ID: covidwho-1311404

ABSTRACT

Most shared resource flow cytometry facilities do not permit analysis of radioactive samples. We are investigating low-dose molecular targeted radionuclide therapy (MTRT) as an immunomodulator in combination with in situ tumor vaccines and need to analyze radioactive samples from MTRT-treated mice using flow cytometry. Further, the sudden shutdown of core facilities in response to the COVID-19 pandemic has created an unprecedented work stoppage. In these and other research settings, a robust and reliable means of cryopreservation of immune samples is required. We evaluated different fixation and cryopreservation protocols of disaggregated tumor cells with the aim of identifying a protocol for subsequent flow cytometry of the thawed sample, which most accurately reflects the flow cytometric analysis of the tumor immune microenvironment of a freshly disaggregated and analyzed sample. Cohorts of C57BL/6 mice bearing B78 melanoma tumors were evaluated using dual lymphoid and myeloid immunophenotyping panels involving fixation and cryopreservation at three distinct points during the workflow. Results demonstrate that freezing samples after all staining and fixation are completed most accurately matches the results from noncryopreserved equivalent samples. We observed that cryopreservation of living, unfixed cells introduces a nonuniform alteration to PD1 expression. We confirm the utility of our cryopreservation protocol by comparing tumors treated with in situ tumor vaccines, analyzing both fresh and cryopreserved tumor samples with similar results. Last, we use this cryopreservation protocol with radioactive specimens to demonstrate potentially beneficial effector cell changes to the tumor immune microenvironment following administration of a novel MTRT in a dose- and time-dependent manner.


Subject(s)
Cryopreservation/methods , Flow Cytometry/methods , Leukocytes, Mononuclear/immunology , Melanoma, Experimental/pathology , Myeloid Cells/immunology , Animals , CD4-Positive T-Lymphocytes/immunology , CD8-Positive T-Lymphocytes/immunology , Cell Line, Tumor , Immunophenotyping/methods , Mice , Mice, Inbred C57BL , Natural Killer T-Cells/immunology , Pandemics , Signal Transduction/immunology , Tumor Microenvironment/immunology
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