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1.
Emerg Microbes Infect ; 10(1): 2141-2150, 2021 Dec.
Article in English | MEDLINE | ID: covidwho-1532382

ABSTRACT

BACKGROUND: We studied humoral and cellular responses against SARS-CoV-2 longitudinally in a homogeneous population of healthy young/middle-aged men of South Asian ethnicity with mild COVID-19. METHODS: In total, we recruited 994 men (median age: 34 years) post-COVID-19 diagnosis. Repeated cross-sectional surveys were conducted between May 2020 and January 2021 at six time points - day 28 (n = 327), day 80 (n = 202), day 105 (n = 294), day 140 (n = 172), day 180 (n = 758), and day 280 (n = 311). Three commercial assays were used to detect anti-nucleoprotein (NP) and neutralizing antibodies. T cell response specific for Spike, Membrane and NP SARS-CoV-2 proteins was tested in 85 patients at day 105, 180, and 280. RESULTS: All serological tests displayed different kinetics of progressive antibody reduction while the frequency of T cells specific for different structural SARS-CoV-2 proteins was stable over time. Both showed a marked heterogeneity of magnitude among the studied cohort. Comparatively, cellular responses lasted longer than humoral responses and were still detectable nine months after infection in the individuals who lost antibody detection. Correlation between T cell frequencies and all antibodies was lost over time. CONCLUSION: Humoral and cellular immunity against SARS-CoV-2 is induced with differing kinetics of persistence in those with mild disease. The magnitude of T cells and antibodies is highly heterogeneous in a homogeneous study population. These observations have implications for COVID-19 surveillance, vaccination strategies, and post-pandemic planning.


Subject(s)
Antibodies, Viral/blood , COVID-19/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Antibodies, Neutralizing/blood , Cross-Sectional Studies , Humans , Male , Nucleocapsid Proteins/immunology
2.
Biomedica ; 41(Sp. 2): 86-102, 2021 10 15.
Article in English, Spanish | MEDLINE | ID: covidwho-1529016

ABSTRACT

INTRODUCTION: Immunological markers have been described during COVID-19 and persist after recovery. These immune markers are associated with clinical features among SARSCoV-2 infected individuals. Nevertheless, studies reporting a comprehensive analysis of the immune changes occurring during SARS-CoV-2 infection are still limited. OBJECTIVE: To evaluate the production of proinflammatory cytokines, the antibody response, and the phenotype and function of NK cells and T cells in a Colombian family cluster with SARS-CoV-2 infection. MATERIALS AND METHODS: Proinflammatory cytokines were evaluated by RT-PCR and ELISA. The frequency, phenotype, and function of NK cells (cocultures with K562 cells) and T-cells (stimulated with spike/RdRp peptides) were assessed by flow cytometry. Anti-SARS-CoV-2 antibodies were determined using indirect immunofluorescence and plaque reduction neutralization assay. RESULTS: During COVID-19, we observed a high proinflammatory-cytokine production and a reduced CD56bright-NK cell and cytotoxic response. Compared with healthy controls, infected individuals had a higher frequency of dysfunctional CD8+ T cells CD38+HLA-DR-. During the acute phase, CD8+ T cells stimulated with viral peptides exhibited a monofunctional response characterized by high IL-10 production. However, during recovery, we observed a bifunctional response characterized by the co-expression of CD107a and granzyme B or perforin. CONCLUSION: Although the proinflammatory response is a hallmark of SARS-CoV-2 infection, other phenotypic and functional alterations in NK cells and CD8+ T cells could be associated with the outcome of COVID-19. However, additional studies are required to understand these alterations and to guide future immunotherapy strategies.


Subject(s)
COVID-19/immunology , Killer Cells, Natural , SARS-CoV-2/immunology , T-Lymphocytes , Adult , Antibodies, Viral/analysis , CD56 Antigen/immunology , Case-Control Studies , Colombia , Family Health , Granzymes/metabolism , Humans , Interleukin-10/metabolism , Interleukin-1beta/blood , Interleukin-6/blood , Interleukin-8/blood , K562 Cells , Killer Cells, Natural/cytology , Killer Cells, Natural/immunology , Lymphocyte Activation , Male , Middle Aged , Perforin/metabolism , Phenotype , Receptors, CCR7/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology , Tumor Necrosis Factor-alpha/blood , Young Adult
4.
Front Immunol ; 12: 697622, 2021.
Article in English | MEDLINE | ID: covidwho-1518482

ABSTRACT

Objectives: The longitudinal and systematic evaluation of immunity in coronavirus disease 2019 (COVID-19) patients is rarely reported. Methods: Parameters involved in innate, adaptive, and humoral immunity were continuously monitored in COVID-19 patients from onset of illness until 45 days after symptom onset. Results: This study enrolled 27 mild, 47 severe, and 46 deceased COVID-19 patients. Generally, deceased patients demonstrated a gradual increase of neutrophils and IL-6 but a decrease of lymphocytes and platelets after the onset of illness. Specifically, sustained low numbers of CD8+ T cells, NK cells, and dendritic cells were noted in deceased patients, while these cells gradually restored in mild and severe patients. Furthermore, deceased patients displayed a rapid increase of HLA-DR expression on CD4+ T cells in the early phase, but with a low level of overall CD45RO and HLA-DR expressions on CD4+ and CD8+ T cells, respectively. Notably, in the early phase, deceased patients showed a lower level of plasma cells and antigen-specific IgG, but higher expansion of CD16+CD14+ proinflammatory monocytes and HLA-DR-CD14+ monocytic-myeloid-derived suppressor cells (M-MDSCs) than mild or severe patients. Among these immunological parameters, M-MDSCs showed the best performance in predicting COVID-19 mortality, when using a cutoff value of ≥10%. Cluster analysis found a typical immunological pattern in deceased patients on day 9 after onset, which was characterized as the increase of inflammatory markers (M-MDSCs, neutrophils, CD16+CD14+ monocytes, and IL-6) but a decrease of host immunity markers. Conclusions: This study systemically characterizes the kinetics of immunity of COVID-19, highlighting the importance of immunity in patient prognosis.


Subject(s)
COVID-19/immunology , SARS-CoV-2 , Adaptive Immunity , Aged , Aged, 80 and over , Antibodies, Viral/blood , B-Lymphocytes/immunology , COVID-19/blood , COVID-19/classification , COVID-19/physiopathology , Cytokines/blood , Dendritic Cells/immunology , Female , Humans , Immunity, Innate , Immunoglobulin G/blood , Killer Cells, Natural/immunology , Lymphocyte Count , Male , Middle Aged , SARS-CoV-2/immunology , Severity of Illness Index , T-Lymphocytes/immunology
5.
Elife ; 102021 07 22.
Article in English | MEDLINE | ID: covidwho-1513065

ABSTRACT

Immature neutrophils and HLA-DRneg/low monocytes expand in cancer, autoimmune diseases and viral infections, but their appearance and immunoregulatory effects on T-cells after acute myocardial infarction (AMI) remain underexplored. We found an expansion of circulating immature CD16+CD66b+CD10neg neutrophils and CD14+HLA-DRneg/low monocytes in AMI patients, correlating with cardiac damage, function and levels of immune-inflammation markers. Immature CD10neg neutrophils expressed high amounts of MMP-9 and S100A9, and displayed resistance to apoptosis. Moreover, we found that increased frequency of CD10neg neutrophils and elevated circulating IFN-γ levels were linked, mainly in patients with expanded CD4+CD28null T-cells. Notably, the expansion of circulating CD4+CD28null T-cells was associated with cytomegalovirus (CMV) seropositivity. Using bioinformatic tools, we identified a tight relationship among the peripheral expansion of immature CD10neg neutrophils, CMV IgG titers, and circulating levels of IFN-γ and IL-12 in patients with AMI. At a mechanistic level, CD10neg neutrophils enhanced IFN-γ production by CD4+ T-cells through a contact-independent mechanism involving IL-12. In vitro experiments also highlighted that HLA-DRneg/low monocytes do not suppress T-cell proliferation but secrete high levels of pro-inflammatory cytokines after differentiation to macrophages and IFN-γ stimulation. Lastly, using a mouse model of AMI, we showed that immature neutrophils (CD11bposLy6GposCD101neg cells) are recruited to the injured myocardium and migrate to mediastinal lymph nodes shortly after reperfusion. In conclusion, immunoregulatory functions of CD10neg neutrophils play a dynamic role in mechanisms linking myeloid cell compartment dysregulation, Th1-type immune responses and inflammation after AMI.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , HLA-DR Antigens/immunology , Monocytes/immunology , Myocardial Infarction/immunology , Neprilysin/immunology , Neutrophils/immunology , Aged , Animals , Biomarkers , Cell Differentiation , Cell Proliferation , Cytokines , Female , Humans , Inflammation , Lymphocyte Activation , Male , Mice , Middle Aged , Myocardial Infarction/pathology , T-Lymphocytes/immunology
6.
Biomolecules ; 11(10)2021 09 29.
Article in English | MEDLINE | ID: covidwho-1512106

ABSTRACT

Coronavirus disease 2019 (COVID-19), a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes infectious disease, and manifests in a wide range of symptoms from asymptomatic to severe illness and even death. Severity of infection is related to many risk factors, including aging and an array of underlying conditions, such as diabetes, hypertension, chronic obstructive pulmonary disease (COPD), and cancer. It remains poorly understood how these conditions influence the severity of COVID-19. Expansion of the CD28null senescent T-cell populations, a common phenomenon in aging and several chronic inflammatory conditions, is associated with higher morbidity and mortality rates in COVID-19. Here, we summarize the potential mechanisms whereby CD28null cells drive adverse outcomes in disease and predispose patients to devastating COVID-19, and discuss possible treatments for individuals with high counts of CD28null senescent T-cells.


Subject(s)
CD28 Antigens/immunology , COVID-19/immunology , T-Lymphocytes/immunology , Humans
7.
Front Immunol ; 12: 738073, 2021.
Article in English | MEDLINE | ID: covidwho-1497076

ABSTRACT

The mechanisms underlying the immune remodeling and severity response in coronavirus disease 2019 (COVID-19) are yet to be fully elucidated. Our comprehensive integrative analyses of single-cell RNA sequencing (scRNAseq) data from four published studies, in patients with mild/moderate and severe infections, indicate a robust expansion and mobilization of the innate immune response and highlight mechanisms by which low-density neutrophils and megakaryocytes play a crucial role in the cross talk between lymphoid and myeloid lineages. We also document a marked reduction of several lymphoid cell types, particularly natural killer cells, mucosal-associated invariant T (MAIT) cells, and gamma-delta T (γδT) cells, and a robust expansion and extensive heterogeneity within plasmablasts, especially in severe COVID-19 patients. We confirm the changes in cellular abundances for certain immune cell types within a new patient cohort. While the cellular heterogeneity in COVID-19 extends across cells in both lineages, we consistently observe certain subsets respond more potently to interferon type I (IFN-I) and display increased cellular abundances across the spectrum of severity, as compared with healthy subjects. However, we identify these expanded subsets to have a more muted response to IFN-I within severe disease compared to non-severe disease. Our analyses further highlight an increased aggregation potential of the myeloid subsets, particularly monocytes, in COVID-19. Finally, we provide detailed mechanistic insights into the interaction between lymphoid and myeloid lineages, which contributes to the multisystemic phenotype of COVID-19, distinguishing severe from non-severe responses.


Subject(s)
COVID-19/immunology , Killer Cells, Natural/immunology , Mucosal-Associated Invariant T Cells/immunology , Neutrophils/immunology , SARS-CoV-2/physiology , Systemic Inflammatory Response Syndrome/immunology , T-Lymphocytes/immunology , COVID-19/diagnosis , Cell Differentiation , Cell Proliferation , Humans , Immunity, Innate , Interferon Type I/metabolism , Lymphopoiesis , Receptors, Antigen, T-Cell, gamma-delta/metabolism , Sequence Analysis, RNA , Single-Cell Analysis , Systemic Inflammatory Response Syndrome/diagnosis , T-Lymphocytes/metabolism , Thrombopoiesis
8.
J Infect Dis ; 224(8): 1333-1344, 2021 10 28.
Article in English | MEDLINE | ID: covidwho-1493827

ABSTRACT

BACKGROUND: Lymphopenia is a key feature for adult patients with coronavirus disease 2019 (COVID-19), although it is rarely observed in children. The underlying mechanism remains unclear. METHODS: Immunohistochemical and flow cytometric analyses were used to compare the apoptotic rate of T cells from COVID-19 adults and children and apoptotic responses of adult and child T cells to COVID-19 pooled plasma. Biological properties of caspases and reactive oxygen species were assessed in T cells treated by COVID-19 pooled plasma. RESULTS: Mitochondria apoptosis of peripheral T cells were identified in COVID-19 adult patient samples but not in the children. Furthermore, increased tumor necrosis factor-α and interleukin-6 in COVID-19 plasma induced mitochondria apoptosis and caused deoxyribonucleic acid damage by elevating reactive oxygen species levels of the adult T cells. However, the child T cells showed tolerance to mitochondrial apoptosis due to mitochondria autophagy. Activation of autophagy could decrease apoptotic sensitivity of the adult T cells to plasma from COVID-19 patients. CONCLUSIONS: Our results indicated that the mitochondrial apoptosis pathway was activated in T cells of COVID-19 adult patients specifically, which may shed light on the pathophysiological difference between adults and children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 ).


Subject(s)
COVID-19/complications , Lymphopenia/blood , SARS-CoV-2/immunology , T-Lymphocytes/pathology , Adolescent , Adult , Age Factors , Aged , Apoptosis/immunology , Autophagy , COVID-19/blood , COVID-19/immunology , COVID-19/virology , Child , Child, Preschool , Humans , Infant , Lymphopenia/immunology , Lymphopenia/pathology , Lymphopenia/virology , Male , Middle Aged , Mitochondria/immunology , Mitochondria/pathology , Reactive Oxygen Species/metabolism , T-Lymphocytes/cytology , T-Lymphocytes/immunology
9.
Proc Natl Acad Sci U S A ; 118(39)2021 09 28.
Article in English | MEDLINE | ID: covidwho-1493337

ABSTRACT

The COVID-19 pandemic highlights the importance of efficient and safe vaccine development. Vaccine adjuvants are essential to boost and tailor the immune response to the corresponding pathogen. To allow for an educated selection, we assessed the effect of different adjuvants on human monocyte-derived dendritic cells (DCs) and their ability to polarize innate and adaptive immune responses. In contrast to commonly used adjuvants, such as aluminum hydroxide, Toll-like receptor (TLR) agonists induced robust phenotypic and functional DC maturation. In a DC-lymphocyte coculture system, we investigated the ensuing immune reactions. While monophosphoryl lipid A synthetic, a TLR4 ligand, induced checkpoint inhibitors indicative for immune exhaustion, the TLR7/8 agonist Resiquimod (R848) induced prominent type-1 interferon and interleukin 6 responses and robust CTL, B-cell, and NK-cell proliferation, which is particularly suited for antiviral immune responses. The recently licensed COVID-19 vaccines, BNT162b and mRNA-1273, are both based on single-stranded RNA. Indeed, we could confirm that the cytokine profile induced by lipid-complexed RNA was almost identical to the pattern induced by R848. Although this awaits further investigation, our results suggest that their efficacy involves the highly efficient antiviral response pattern stimulated by the RNAs' TLR7/8 activation.


Subject(s)
Adjuvants, Immunologic/pharmacology , COVID-19/immunology , Dendritic Cells/immunology , Immunity, Cellular/drug effects , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adolescent , Adult , Aged , Female , Humans , Imidazoles/pharmacology , Lipid A/analogs & derivatives , Lipid A/pharmacology , Male , Middle Aged , Toll-Like Receptors/immunology
10.
Cell Res ; 31(11): 1148-1162, 2021 11.
Article in English | MEDLINE | ID: covidwho-1493088

ABSTRACT

Increasing numbers of SARS-CoV-2-positive (SARS-CoV-2pos) subjects are detected at silent SARS-CoV-2 infection stage (SSIS). Yet, SSIS represents a poorly examined time-window wherein unknown immunity patterns may contribute to the fate determination towards persistently asymptomatic or overt disease. Here, we retrieved blood samples from 19 asymptomatic and 12 presymptomatic SARS-CoV-2pos subjects, 47 age/gender-matched patients with mild or moderate COVID-19 and 27 normal subjects, and interrogated them with combined assays of 44-plex CyTOF, RNA-seq and Olink. Notably, both asymptomatic and presymptomatic subjects exhibited numerous readily detectable immunological alterations, while certain parameters including more severely decreased frequencies of CD107alow classical monocytes, intermediate monocytes, non-classical monocytes and CD62Lhi CD8+ Tnaïve cells, reduced plasma STC1 level but an increased frequency of CD4+ NKT cells combined to distinguish the latter. Intercorrelation analyses revealed a particular presymptomatic immunotype mainly manifesting as monocytic overactivation and differentiation blockage, a likely lymphocyte exhaustion and immunosuppression, yielding mechanistic insights into SSIS fate determination, which could potentially improve SARS-CoV-2 management.


Subject(s)
Asymptomatic Infections , COVID-19/immunology , Carrier State/immunology , Adult , B-Lymphocytes/immunology , COVID-19/pathology , Female , Humans , Leukocytes, Mononuclear/immunology , Male , Natural Killer T-Cells/immunology , SARS-CoV-2/physiology , T-Lymphocytes/immunology
13.
Front Immunol ; 12: 726960, 2021.
Article in English | MEDLINE | ID: covidwho-1477820

ABSTRACT

Objectives: In the context of the Covid-19 pandemic, the fast development of vaccines with efficacy of around 95% preventing Covid-19 illness provides a unique opportunity to reduce the mortality associated with the pandemic. However, in the absence of efficacious prophylactic medications and few treatments for this infection, the induction of a fast and robust protective immunity is required for effective disease control, not only to prevent the disease but also the infection and shedding/transmission. The objective of our study was to analyze the level of specific humoral and cellular T-cell responses against the spike protein of SARS-CoV-2 induced by two mRNA-based vaccines (BNT162b2 and mRNA-1273), but also how long it takes after vaccination to induce these protective humoral and cellular immune responses. Methods: We studied in 40 healthy (not previously infected) volunteers vaccinated with BNT162b2 or mRNA-1273 vaccines the presence of spike-specific IgG antibodies and SARS-CoV-2-specific T cells at 3, 7 and 14 days after receiving the second dose of the vaccine. The specific T-cell response was analyzed stimulating fresh whole blood from vaccinated volunteers with SARS-CoV-2 peptides and measuring the release of cytokines secreted by T cells in response to SARS-CoV-2 stimulation. Results: Our results indicate that the immunization capacity of both vaccines is comparable. However, although both BNT162b2 and mRNA-1273 vaccines can induce early B-cell and T-cell responses, these vaccine-mediated immune responses do not reach their maximum values until 14 days after completing the vaccination schedule. Conclusion: This refractory period in the induction of specific immunity observed after completing the vaccination could constitute a window of higher infection risk, which could explain some emerging cases of SARS-CoV-2 infection in vaccinated people.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/immunology , Immunogenicity, Vaccine/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Adult , Antibodies, Neutralizing/immunology , COVID-19/prevention & control , Female , Humans , Immunity, Cellular/immunology , Immunity, Humoral/immunology , Immunization Schedule , Immunoglobulin G/blood , Lymphocyte Count , Male , Prospective Studies , Vaccination
14.
Front Immunol ; 12: 715023, 2021.
Article in English | MEDLINE | ID: covidwho-1477819

ABSTRACT

Emerging evidence has unveiled the secondary infection as one of the mortal causes of post-SARS-CoV-2 infection, but the factors related to secondary bacterial or fungi infection remains largely unexplored. We here systematically investigated the factors that might contribute to secondary infection. By clinical examination index analysis of patients, combined with the integrative analysis with RNA-seq analysis in the peripheral blood mononuclear cell isolated shortly from initial infection, this study showed that the antibiotic catabolic process and myeloid cell homeostasis were activated while the T-cell response were relatively repressed in those with the risk of secondary infection. Further monitoring analysis of immune cell and liver injury analysis showed that the risk of secondary infection was accompanied by severe lymphocytopenia at the intermediate and late stages and liver injury at the early stages of SARS-CoV-2. Moreover, the metagenomics analysis of bronchoalveolar lavage fluid and the microbial culture analysis, to some extent, showed that the severe pneumonia-related bacteria have already existed in the initial infection.


Subject(s)
Bacterial Infections/epidemiology , COVID-19/pathology , Coinfection/epidemiology , Coinfection/mortality , Mycoses/epidemiology , Adult , Aged , Aged, 80 and over , Bacterial Infections/mortality , Bronchoalveolar Lavage Fluid/microbiology , CD4 Lymphocyte Count , Female , Humans , Leukocytes, Mononuclear/immunology , Liver/injuries , Liver/virology , Lymphopenia/immunology , Male , Middle Aged , Mycoses/mortality , Retrospective Studies , Risk Factors , SARS-CoV-2/immunology , T-Lymphocytes/immunology
15.
BMC Immunol ; 22(1): 70, 2021 10 19.
Article in English | MEDLINE | ID: covidwho-1477260

ABSTRACT

BACKGROUND: Hemodialysis (HD) patients have an increased risk of acquiring infections due to many health care contacts and may, in addition, have a suboptimal response to vaccination and a high mortality from Covid-19 infection. METHODS: In 50 HD patients (mean age 69.4 years, 62% men) administration of SARS-CoV-2BNT162b2 mRNA vaccine began in Dec 2020 and the immune response was evaluated 7-15 weeks after the last dose. Levels of Covid-19 (SARS-CoV-2) IgG antibody against the nucleocapsid antigen (anti-N) and the Spike antigen (anti-S) and T-cell reactivity testing against the Spike protein using ELISPOT technology were evaluated. RESULTS: Out of 50 patients, anti-S IgG antibodies indicating a vaccine effect or previous Covid-19 infection, were detected in 37 (74%), 5 (10%) had a borderline response and 8 (16%) were negative after two doses of vaccine. T-cell responses were detected in 29 (58%). Of the 37 patients with anti-S antibodies, 25 (68%) had a measurable T-cell response. 2 (40%) out of 5 patients with borderline anti-S and 2 (25%) without anti-S had a concomitant T-cell response. Twenty-seven (54%) had both an antibody and T-cell response. IgG antibodies to anti-N indicating a previous Covid-19 disease were detected in 7 (14%) patients. CONCLUSIONS: Most HD patients develop a B- and/or T-cell response after vaccination against Covid-19 but approx. 20% had a limited immunological response. T-cell reactivity against Covid-19 was only present in a few of the anti-S antibody negative patients.


Subject(s)
Antibodies, Viral/blood , COVID-19 Vaccines/immunology , Coronavirus Nucleocapsid Proteins/immunology , Renal Dialysis , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Adult , Aged , Aged, 80 and over , Antibodies, Viral/immunology , COVID-19/prevention & control , Female , Humans , Immunoglobulin G/blood , Male , Middle Aged , Phosphoproteins/immunology , SARS-CoV-2/immunology , Uremia/immunology , Uremia/pathology , Vaccination
16.
Viral Immunol ; 34(6): 416-420, 2021.
Article in English | MEDLINE | ID: covidwho-1475758

ABSTRACT

Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which has infected millions of individuals in the world. However, the long-term effect of SARS-CoV-2 on the organs of recovered patients remains unclear. This study is to evaluate the impact of SARS-CoV-2 on the spleen and T lymphocytes. Seventy-six patients recovered from COVID-19, including 66 cases of moderate pneumonia and 10 cases of severe pneumonia were enrolled in the observation group. The control group consisted of 55 age-matched healthy subjects. The thickness and length of spleen were measured by using B-ultrasound and the levels of T lymphocytes were detected by flow cytometry. Results showed that the mean length of spleen in the observation group was 89.57 ± 11.49 mm, which was significantly reduced compared with that in the control group (103.82 ± 11.29 mm, p < 0.001). The mean thicknesses of spleen between observation group and control group were 29.97 ± 4.04 mm and 32.45 ± 4.49 mm, respectively, and the difference was significant (p < 0.001). However, no significant difference was observed in the size of spleen between common pneumonia and severe pneumonia (p > 0.05). In addition, the decreased count of T lymphocyte was observed in part of recovered patients. The counts of T suppressor lymphocytes in patients with severe pneumonia were significantly decreased compared with those with moderate pneumonia (p = 0.005). Therefore, these data indicate that SARS-CoV-2 infection affects the size of spleen and T lymphocytes.


Subject(s)
COVID-19/immunology , SARS-CoV-2 , Spleen/pathology , T-Lymphocytes/immunology , Adult , Aged , Female , Humans , Lymphocyte Count , Male , Middle Aged , Young Adult
17.
Front Immunol ; 12: 742914, 2021.
Article in English | MEDLINE | ID: covidwho-1472387

ABSTRACT

Constant efforts to prevent infections by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are actively carried out around the world. Several vaccines are currently approved for emergency use in the population, while ongoing studies continue to provide information on their safety and effectiveness. CoronaVac is an inactivated SARS-CoV-2 vaccine with a good safety and immunogenicity profile as seen in phase 1, 2, and 3 clinical trials around the world, with an effectiveness of 65.9% for symptomatic cases. Although vaccination reduces the risk of disease, infections can still occur during or after completion of the vaccination schedule (breakthrough cases). This report describes the clinical and immunological profile of vaccine breakthrough cases reported in a clinical trial in progress in Chile that is evaluating the safety, immunogenicity, and efficacy of two vaccination schedules of CoronaVac (clinicaltrials.gov NCT04651790). Out of the 2,263 fully vaccinated subjects, at end of June 2021, 45 have reported symptomatic SARS-CoV-2 infection 14 or more days after the second dose (1.99% of fully vaccinated subjects). Of the 45 breakthrough cases, 96% developed mild disease; one case developed a moderate disease; and one developed a severe disease and required mechanical ventilation. Both cases that developed moderate and severe disease were adults over 60 years old and presented comorbidities. The immune response before and after SARS-CoV-2 infection was analyzed in nine vaccine breakthrough cases, revealing that six of them exhibited circulating anti-S1-RBD IgG antibodies with neutralizing capacities after immunization, which showed a significant increase 2 and 4 weeks after symptoms onset. Two cases exhibited low circulating anti-S1-RBD IgG and almost non-existing neutralizing capacity after either vaccination or infection, although they developed a mild disease. An increase in the number of interferon-γ-secreting T cells specific for SARS-CoV-2 was detected 2 weeks after the second dose in seven cases and after symptoms onset. In conclusion, breakthrough cases were mostly mild and did not necessarily correlate with a lack of vaccine-induced immunity, suggesting that other factors, to be defined in future studies, could lead to symptomatic infection after vaccination with CoronaVac.


Subject(s)
Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19 Vaccines/immunology , COVID-19/immunology , SARS-CoV-2/immunology , T-Lymphocytes/immunology , Vaccines, Inactivated/immunology , Adult , Aged , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/pathology , Chile , Comorbidity , Female , Humans , Immunization Schedule , Immunogenicity, Vaccine/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Interferon-gamma/immunology , Lymphocyte Count , Male , Middle Aged , Severity of Illness Index , Vaccination , Young Adult
18.
Cell Rep ; 37(5): 109942, 2021 11 02.
Article in English | MEDLINE | ID: covidwho-1471904

ABSTRACT

Anti-viral monoclonal antibody (mAb) treatments may provide immediate but short-term immunity from coronavirus disease 2019 (COVID-19) in high-risk populations, such as people with diabetes and the elderly; however, data on their efficacy in these populations are limited. We demonstrate that prophylactic mAb treatment blocks viral replication in both the upper and lower respiratory tracts in aged, type 2 diabetic rhesus macaques. mAb infusion dramatically curtails severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-mediated stimulation of interferon-induced chemokines and T cell activation, significantly reducing development of interstitial pneumonia. Furthermore, mAb infusion significantly dampens the greater than 3-fold increase in SARS-CoV-2-induced effector CD4 T cell influx into the cerebrospinal fluid. Our data show that neutralizing mAbs administered preventatively to high-risk populations may mitigate the adverse inflammatory consequences of SARS-CoV-2 exposure.


Subject(s)
Antibodies, Monoclonal/therapeutic use , COVID-19/prevention & control , SARS-CoV-2/immunology , Aging/immunology , Animals , COVID-19/cerebrospinal fluid , COVID-19/complications , COVID-19/immunology , Diabetes Complications/immunology , Diabetes Complications/virology , Diabetes Mellitus, Experimental/complications , Diabetes Mellitus, Experimental/immunology , Female , Humans , Lymphocyte Activation , Macaca mulatta , Male , Neuritis/immunology , Neuritis/prevention & control , Pre-Exposure Prophylaxis , T-Lymphocytes/immunology , Virus Replication/immunology
19.
J Immunol ; 207(10): 2405-2410, 2021 11 15.
Article in English | MEDLINE | ID: covidwho-1471046

ABSTRACT

Severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) causes severe acute respiratory syndrome. mRNA vaccines directed at the SARS-CoV-2 spike protein resulted in development of Abs and protective immunity. To determine the mechanism, we analyzed the kinetics of induction of circulating exosomes with SARS-CoV-2 spike protein and Ab following vaccination of healthy individuals. Results demonstrated induction of circulating exosomes expressing spike protein on day 14 after vaccination followed by Abs 14 d after the second dose. Exosomes with spike protein, Abs to SARS-CoV-2 spike, and T cells secreting IFN-γ and TNF-α increased following the booster dose. Transmission electron microscopy of exosomes also demonstrated spike protein Ags on their surface. Exosomes with spike protein and Abs decreased in parallel after four months. These results demonstrate an important role of circulating exosomes with spike protein for effective immunization following mRNA-based vaccination. This is further documented by induction of humoral and cellular immune responses in mice immunized with exosomes carrying spike protein.


Subject(s)
Antibodies, Viral/metabolism , COVID-19 Vaccines/immunology , COVID-19/immunology , Exosomes/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism , T-Lymphocytes/metabolism , Animals , Blood Circulation , Cells, Cultured , Exosomes/immunology , Healthy Volunteers , Humans , Immunization , Interferon-gamma/metabolism , Mice , Mice, Inbred C57BL , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/immunology , Tumor Necrosis Factor-alpha/metabolism , Vaccination
20.
Int J Mol Sci ; 22(20)2021 Oct 18.
Article in English | MEDLINE | ID: covidwho-1470893

ABSTRACT

SputnikV is a vaccine against SARS-CoV-2 developed by the Gamaleya National Research Centre for Epidemiology and Microbiology. The vaccine has been shown to induce both humoral and cellular immune responses, yet the mechanisms remain largely unknown. Forty SputnikV vaccinated individuals were included in this study which aimed to demonstrate the location of immunogenic domains of the SARS-CoV-2 S protein using an overlapping peptide library. Additionally, cytokines in the serum of vaccinated and convalescent COVID-19 patients were analyzed. We have found antibodies from both vaccinated and convalescent sera bind to immunogenic regions located in multiple domains of SARS-CoV-2 S protein, including Receptor Binding Domain (RBD), N-terminal Domain (NTD), Fusion Protein (FP) and Heptad Repeats (HRs). Interestingly, many peptides were recognized by immunized and convalescent serum antibodies and correspond to conserved regions in circulating variants of SARS-CoV-2. This breadth of reactivity was still evident 90 days after the first dose of the vaccine, showing that the vaccine has induced a prolonged response. As evidenced by the activation of T cells, cellular immunity strongly suggests the high potency of the SputnikV vaccine against SARS-CoV-2 infection.


Subject(s)
COVID-19 Vaccines/administration & dosage , COVID-19/prevention & control , Immunity, Cellular , Immunity, Humoral , Adult , Amino Acid Sequence , COVID-19/immunology , COVID-19/virology , COVID-19 Vaccines/immunology , Cytokines/metabolism , Female , Humans , Male , Peptides/chemistry , Peptides/immunology , Principal Component Analysis , Recombinant Fusion Proteins/biosynthesis , Recombinant Fusion Proteins/genetics , Recombinant Fusion Proteins/immunology , SARS-CoV-2/isolation & purification , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry , Spike Glycoprotein, Coronavirus/immunology , T-Lymphocytes/cytology , T-Lymphocytes/immunology , T-Lymphocytes/metabolism , Vaccination
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