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1.
Front Immunol ; 13: 891220, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35967383

RESUMO

Ym1 is a rodent-specific chitinase-like protein (CLP) lacking catalytic activity, whose cellular origins are mainly macrophages, neutrophils and other cells. Although the detailed function of Ym1 remains poorly understood, Ym1 has been generally recognized as a fundamental feature of alternative activation of macrophages in mice and hence one of the prevalent detecting targets in macrophage phenotype distinguishment. Studies have pointed out that Ym1 may have regulatory effects, which are multifaceted and even contradictory, far more than just a mere marker. Allergic lung inflammation, parasite infection, autoimmune diseases, and central nervous system diseases have been found associations with Ym1 to varying degrees. Thus, insights into Ym1's role in diseases would help us understand the pathogenesis of different diseases and clarify the genuine roles of CLPs in mammals. This review summarizes the information on Ym1 from the gene to its expression and regulation and focuses on the association between Ym1 and diseases.


Assuntos
Doença , Lectinas , Macrófagos , beta-N-Acetil-Hexosaminidases , Animais , Quitinases/genética , Quitinases/imunologia , Doença/genética , Imunidade/genética , Imunidade/imunologia , Lectinas/genética , Lectinas/imunologia , Macrófagos/imunologia , Mamíferos/genética , Mamíferos/imunologia , Camundongos , Neutrófilos/imunologia , beta-N-Acetil-Hexosaminidases/genética , beta-N-Acetil-Hexosaminidases/imunologia
2.
Front Immunol ; 13: 835156, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35237273

RESUMO

Complement plays an important role in the direct defense to pathogens, but can also activate immune cells and the release of pro-inflammatory cytokines. However, in critically ill patients with COVID-19 the immune system is inadequately activated leading to severe acute respiratory syndrome (SARS) and acute kidney injury, which is associated with higher mortality. Therefore, we characterized local complement deposition as a sign of activation in both lungs and kidneys from patients with severe COVID-19. Using immunohistochemistry we investigated deposition of complement factors C1q, MASP-2, factor D (CFD), C3c, C3d and C5b-9 as well as myeloperoxidase (MPO) positive neutrophils and SARS-CoV-2 virus particles in lungs and kidneys from 38 patients who died from COVID-19. In addition, tissue damage was analyzed using semi-quantitative scores followed by correlation with complement deposition. Autopsy material from non-COVID patients who died from cardiovascular causes, cerebral hemorrhage and pulmonary embolism served as control (n=8). Lung injury in samples from COVID-19 patients was significantly more pronounced compared to controls with formation of hyaline membranes, thrombi and edema. In addition, in the kidney tubular injury was higher in these patients and correlated with lung injury (r=0.361*). In autopsy samples SARS-CoV-2 spike protein was detected in 22% of the lungs of COVID-19 patients but was lacking in kidneys. Complement activation was significantly stronger in lung samples from patients with COVID-19 via the lectin and alternative pathway as indicated by deposition of MASP-2, CFD, C3d and C5b9. Deposits in the lung were predominantly detected along the alveolar septa, the hyaline membranes and in the alveolar lumina. In the kidney, complement was significantly more deposited in patients with COVID-19 in peritubular capillaries and tubular basement membranes. Renal COVID-19-induced complement activation occurred via the lectin pathway, while activation of the alternative pathway was similar in both groups. Furthermore, MPO-positive neutrophils were found in significantly higher numbers in lungs and kidneys of COVID-19 patients and correlated with local MASP-2 deposition. In conclusion, in patients who died from SARS-CoV-2 infection complement was activated in both lungs and kidneys indicating that complement might be involved in systemic worsening of the inflammatory response. Complement inhibition might thus be a promising treatment option to prevent deregulated activation and subsequent collateral tissue injury in COVID-19.


Assuntos
COVID-19/imunologia , Via Alternativa do Complemento/imunologia , Lectinas/imunologia , Idoso , Idoso de 80 Anos ou mais , Autopsia , COVID-19/patologia , COVID-19/virologia , Proteínas do Sistema Complemento/imunologia , Feminino , Humanos , Rim/imunologia , Rim/patologia , Rim/virologia , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/imunologia , Peroxidase/imunologia , SARS-CoV-2/imunologia
3.
Molecules ; 27(4)2022 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-35209158

RESUMO

Dietary food components have the ability to affect immune function; following absorption, specifically orally ingested dietary food containing lectins can systemically modulate the immune cells and affect the response to self- and co-administered food antigens. The mannose-binding lectins from garlic (Allium sativum agglutinins; ASAs) were identified as immunodulatory proteins in vitro. The objective of the present study was to assess the immunogenicity and adjuvanticity of garlic agglutinins and to evaluate whether they have adjuvant properties in vivo for a weak antigen ovalbumin (OVA). Garlic lectins (ASA I and ASA II) were administered by intranasal (50 days duration) and intradermal (14 days duration) routes, and the anti-lectin and anti-OVA immune (IgG) responses in the control and test groups of the BALB/c mice were assessed for humoral immunogenicity. Lectins, co-administered with OVA, were examined for lectin-induced anti-OVA IgG response to assess their adjuvant properties. The splenic and thymic indices were evaluated as a measure of immunomodulatory functions. Intradermal administration of ASA I and ASA II had showed a four-fold and two-fold increase in anti-lectin IgG response, respectively, vs. the control on day 14. In the intranasal route, the increases were 3-fold and 2.4-fold for ASA I and ASA II, respectively, on day 50. No decrease in the body weights of animals was noticed; the increases in the spleen and thymus weights, as well as their indices, were significant in the lectin groups. In the adjuvanticity study by intranasal administration, ASA I co-administered with ovalbumin (OVA) induced a remarkable increase in anti-OVA IgG response (~six-fold; p < 0.001) compared to the control, and ASA II induced a four-fold increase vs. the control on day 50. The results indicated that ASA was a potent immunogen which induced mucosal immunogenicity to the antigens that were administered intranasally in BALB/c mice. The observations made of the in vivo study indicate that ASA I has the potential use as an oral and mucosal adjuvant to deliver candidate weak antigens. Further clinical studies in humans are required to confirm its applicability.


Assuntos
Adjuvantes Imunológicos , Alho/química , Imunidade Humoral , Lectinas/imunologia , Administração Intranasal , Administração através da Mucosa , Animais , Biomarcadores , Ensaio de Imunoadsorção Enzimática , Imunização/métodos , Imunoglobulina G/imunologia , Imunomodulação , Lectinas/administração & dosagem , Lectinas/isolamento & purificação , Camundongos , Camundongos Endogâmicos BALB C , Especificidade de Órgãos/imunologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia
4.
Sci Rep ; 12(1): 53, 2022 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-34997041

RESUMO

Zika virus (ZIKV) is an arbovirus from the Flaviviridae family and Flavivirus genus. Neurological events have been associated with ZIKV-infected individuals, such as Guillain-Barré syndrome, an autoimmune acute neuropathy that causes nerve demyelination and can induce paralysis. With the increase of ZIKV infection incidence in 2015, malformation and microcephaly cases in newborns have grown considerably, which suggested congenital transmission. Therefore, the development of an effective vaccine against ZIKV became an urgent need. Live attenuated vaccines present some theoretical risks for administration in pregnant women. Thus, we developed an in silico multiepitope vaccine against ZIKV. All structural and non-structural proteins were investigated using immunoinformatics tools designed for the prediction of CD4 + and CD8 + T cell epitopes. We selected 13 CD8 + and 12 CD4 + T cell epitopes considering parameters such as binding affinity to HLA class I and II molecules, promiscuity based on the number of different HLA alleles that bind to the epitopes, and immunogenicity. ZIKV Envelope protein domain III (EDIII) was added to the vaccine construct, creating a hybrid protein domain-multiepitope vaccine. Three high scoring continuous and two discontinuous B cell epitopes were found in EDIII. Aiming to increase the candidate vaccine antigenicity even further, we tested secondary and tertiary structures and physicochemical parameters of the vaccine conjugated to four different protein adjuvants: flagellin, 50S ribosomal protein L7/L12, heparin-binding hemagglutinin, or RS09 synthetic peptide. The addition of the flagellin adjuvant increased the vaccine's predicted antigenicity. In silico predictions revealed that the protein is a probable antigen, non-allergenic and predicted to be stable. The vaccine's average population coverage is estimated to be 87.86%, which indicates it can be administered worldwide. Peripheral Blood Mononuclear Cells (PBMC) of individuals with previous ZIKV infection were tested for cytokine production in response to the pool of CD4 and CD8 ZIKV peptide selected. CD4 + and CD8 + T cells showed significant production of IFN-γ upon stimulation and IL-2 production was also detected by CD8 + T cells, which indicated the potential of our peptides to be recognized by specific T cells and induce immune response. In conclusion, we developed an in silico universal vaccine predicted to induce broad and high-coverage cellular and humoral immune responses against ZIKV, which can be a good candidate for posterior in vivo validation.


Assuntos
Biologia Computacional/métodos , Epitopos de Linfócito B/imunologia , Epitopos de Linfócito T/imunologia , Proteínas Virais/imunologia , Vacinas Virais/química , Vacinas Virais/imunologia , Zika virus/imunologia , Adjuvantes Imunológicos , Autoimunidade , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Citocinas/metabolismo , Epitopos de Linfócito B/química , Epitopos de Linfócito T/química , Flagelina/imunologia , Humanos , Imunidade Humoral , Imunogenicidade da Vacina , Lectinas/imunologia , Leucócitos Mononucleares/imunologia , Peptídeos/imunologia , Filogenia , Proteínas Ribossômicas/imunologia , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/imunologia , Proteínas Virais/química , Zika virus/química , Infecção por Zika virus/imunologia , Infecção por Zika virus/virologia
5.
Arthritis Rheumatol ; 74(2): 329-341, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34042322

RESUMO

OBJECTIVE: In this study, we sought a comprehensive understanding of myeloid cell types driving fibrosis in diffuse cutaneous systemic sclerosis (dcSSc) skin. METHODS: We analyzed the transcriptomes of 2,465 myeloid cells from skin biopsy specimens from 12 dcSSc patients and 10 healthy control subjects using single-cell RNA sequencing. Monocyte-derived dendritic cells (mo-DCs) were assessed using immunohistochemical staining and immunofluorescence analyses targeting ficolin-1 (FCN-1). RESULTS: A t-distributed stochastic neighbor embedding analysis of single-cell transcriptome data revealed 12 myeloid cell clusters, 9 of which paralleled previously described healthy control macrophage/DC clusters, and 3 of which were dcSSc-specific myeloid cell clusters. One SSc-associated macrophage cluster, highly expressing Fcγ receptor IIIA, was suggested on pseudotime analysis to be derived from normal CCR1+ and MARCO+ macrophages. A second SSc-associated myeloid population highly expressed monocyte markers FCN-1, epiregulin, S100A8, and S100A9, but was closely related to type 2 conventional DCs on pseudotime analysis and identified as mo-DCs. Mo-DCs were associated with more severe skin disease. Proliferating macrophages and plasmacytoid DCs were detected almost exclusively in dcSSc skin, the latter clustering with B cells and apparently derived from lymphoid progenitors. CONCLUSION: Transcriptional signatures in these and other myeloid populations indicate innate immune system activation, possibly through Toll-like receptors and highly up-regulated chemokines. However, the appearance and activation of myeloid cells varies between patients, indicating potential differences in the underlying pathogenesis and/or temporal disease activity in dcSSc.


Assuntos
Células Dendríticas/imunologia , Lectinas/imunologia , Macrófagos/imunologia , Monócitos/imunologia , Receptores de IgG/imunologia , Esclerodermia Difusa/imunologia , Humanos , Lectinas/biossíntese , Macrófagos/metabolismo , Monócitos/metabolismo , Receptores de IgG/biossíntese , Índice de Gravidade de Doença
6.
Nephrology (Carlton) ; 27(2): 208-214, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34676615

RESUMO

AIMS: Rapidly progressive crescentic glomerulonephritis occurs in number systemic and primary glomerular diseases, including anti-glomerular basement membrane disease, anti-neutrophil cytoplasmic antibody vasculitis and lupus nephritis. Our understanding of pathogenic mechanisms comes from animal models of disease such as the nephrotoxic nephritis model. The lectin pathway of complement activation has been shown to play a key role in several models of inflammation including renal ischaemia reperfusion. However, the lectin pathway is not required for crescentic glomerulonephritis in the anti-myeloperoxidase model of anti-neutrophil cytoplasmic antibody vasculitis. The aim of the current study was to explore the role of the lectin pathway in the nephrotoxic nephritis model, which is another model of crescentic glomerulonephritis. METHODS: Nephrotoxic nephritis was induced in wild type and mannan-binding lectin-associated serine protease-2 deficient mice. Diseases were assessed by quantifying glomerular crescents and macrophages, in addition to albuminuria and serum creatinine. RESULTS: There was no difference between wild type and MASP-2 deficient mice in any of the histological or biochemical parameters of disease assessed. In addition, there was no difference in the humoral immune response to sheep IgG. CONCLUSION: These data show that the lectin pathway of complement activation is not required for the development of crescentic glomerulonephritis in the nephrotoxic nephritis model, reinforcing previous findings in the anti-myeloperoxidase model.


Assuntos
Glomerulonefrite/imunologia , Lectinas/imunologia , Animais , Ativação do Complemento , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL
7.
Int Immunopharmacol ; 102: 108403, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34857478

RESUMO

BACKGROUND: Systemic lupus erythematosus (SLE) is a chronic autoimmune disease characterized by B cell dysregulation and the breakdown of self-tolerance, leading to pathogenic autoantibody production. Human Siglec-10 is a member of the sialic acid-binding immunoglobulin-type lectin (Siglec) family and a B cell surface coreceptor that inhibits B cell receptor-induced signalling. However, to date, no report has investigated CD19+Siglec-10+ B cells in SLE patients. Thus, this study aimed to measure the population of CD19+Siglec-10+ B cells in patients with SLE and its correlation with disease activity. METHODS: Flow cytometry was employed to measure the population of CD19+Siglec-10+ B cells in peripheral blood mononuclear cells (PBMCs) of both SLE patients and healthy controls (HCs). The correlation of the proportion of CD19+Siglec-10+ B cells with the values of SLE disease activity was analysed. PBMCs from HCs were challenged with serum from active SLE, inactive SLE, or HCs, and the proportion of CD19+Siglec-10+ B cells was then assessed. The effect of dexamethasone (DEX) or hydroxychloroquine (HCQ) treatment on the proportion of CD19+Siglec-10+ B cells in PBMCs from SLE patients was also determined. RESULTS: The proportion of CD19+Siglec-10+ B cells in SLE patients was significantly elevated (P < 0.05), correlated positively with the SLEDAI score (r = 0.304; P = 0.018) and negatively with complement component 3 (C3) (r = -0.283; P = 0.04). In vitro assays indicated that sera from active SLE patients could significantly enhance the proportion of CD19+Siglec-10+ B cells (P < 0.05), while HCQ treatment significantly attenuated their proportions (P < 0.01). CONCLUSIONS: The elevation of CD19+Siglec-10+ B cells and their correlation with disease activity may suggest a role for Siglec-10 in the pathogenesis and progression of SLE and provide a serum biomarker for SLE activity.


Assuntos
Antígenos CD19/imunologia , Linfócitos B/imunologia , Lectinas/imunologia , Lúpus Eritematoso Sistêmico/imunologia , Receptores de Superfície Celular/imunologia , Adulto , Linfócitos B/patologia , Biomarcadores/sangue , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Humanos , Lúpus Eritematoso Sistêmico/patologia , Contagem de Linfócitos , Masculino , Gravidade do Paciente
8.
J Allergy Clin Immunol ; 149(2): 550-556.e2, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34800432

RESUMO

BACKGROUND: Severe coronavirus disease 2019 (COVID-19) is characterized by impaired type I interferon activity and a state of hyperinflammation leading to acute respiratory distress syndrome. The complement system has recently emerged as a key player in triggering and maintaining the inflammatory state, but the role of this molecular cascade in severe COVID-19 is still poorly characterized. OBJECTIVE: We aimed at assessing the contribution of complement pathways at both the protein and transcriptomic levels. METHODS: To this end, we systematically assessed the RNA levels of 28 complement genes in the circulating whole blood of patients with COVID-19 and healthy controls, including genes of the alternative pathway, for which data remain scarce. RESULTS: We found differential expression of genes involved in the complement system, yet with various expression patterns: whereas patients displaying moderate disease had elevated expression of classical pathway genes, severe disease was associated with increased lectin and alternative pathway activation, which correlated with inflammation and coagulopathy markers. Additionally, properdin, a pivotal positive regulator of the alternative pathway, showed high RNA expression but was found at low protein concentrations in patients with a severe and critical disease, suggesting its deposition at the sites of complement activation. Notably, low properdin levels were significantly associated with the use of mechanical ventilation (area under the curve = 0.82; P = .002). CONCLUSION: This study sheds light on the role of the alternative pathway in severe COVID-19 and provides additional rationale for the testing of drugs inhibiting the alternative pathway of the complement system.


Assuntos
COVID-19/imunologia , Ativação do Complemento/genética , Via Alternativa do Complemento/genética , Proteínas do Sistema Complemento/genética , Coagulação Intravascular Disseminada/imunologia , SARS-CoV-2/patogenicidade , COVID-19/genética , COVID-19/terapia , COVID-19/virologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/imunologia , Doenças Cardiovasculares/terapia , Doenças Cardiovasculares/virologia , Estudos de Casos e Controles , Comorbidade , Proteínas do Sistema Complemento/imunologia , Diabetes Mellitus/genética , Diabetes Mellitus/imunologia , Diabetes Mellitus/terapia , Diabetes Mellitus/virologia , Coagulação Intravascular Disseminada/genética , Coagulação Intravascular Disseminada/terapia , Coagulação Intravascular Disseminada/virologia , Feminino , Regulação da Expressão Gênica , Humanos , Hipertensão/genética , Hipertensão/imunologia , Hipertensão/terapia , Hipertensão/virologia , Lectinas/genética , Lectinas/imunologia , Masculino , Pessoa de Meia-Idade , Neoplasias/genética , Neoplasias/imunologia , Neoplasias/terapia , Neoplasias/virologia , Properdina/genética , Properdina/imunologia , Respiração Artificial , SARS-CoV-2/genética , SARS-CoV-2/imunologia , Índice de Gravidade de Doença
9.
Fish Shellfish Immunol ; 121: 183-196, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34971736

RESUMO

Analyzing the health benefits of any two immunostimulants (synbiotics) in combined form and information on their interactions gain more visibility in the usage of synbiotics in aquafarms. With this intention, the current work explores the immunostimulant effect and structural interaction of synbiotic (ß-1, 3 glucan binding protein from marine crab, Portunus pelagicus (Ppß-GBP) and Bacillus licheniformis) on Oreochromis mossambicus. The experimental diet was prepared with Ppß-GBP and B. licheniformis, and nourished to the fingerlings of O. mossambicus for 30 days. After the experimental trial, a higher growth rate and immune reactions (lysozyme, protease, myeloperoxidase and alkaline phosphatase activity) were noticed in the fish nourished with synbiotic (B. licheniformis and Ppß-GBP) enriched diet. Moreover, the synbiotic enriched diet elevated the antioxidant responses like glutathione peroxidase (GSH-Px) and catalase (CAT) activity in the experimental diet-nurtured fish. At the end of the feed trial, synbiotic diet nourished fish shows an increased survival rate during Aeromonas hydrophila infection, reflecting the disease resistance potential of experimental fish. Also, the interaction between Ppß-GBP and Bacillus licheniformis was analyzed through computational approaches. The results evidenced that, Ppß-GBP interacts with the B. licheniformis through sugar-based ligand, ß-glucan through a hydrogen bond with a good docking score. Thus, the synbiotic diet would be an effective immunostimulant to strengthen the fish immune system for better productivity.


Assuntos
Adjuvantes Imunológicos , Bacillus licheniformis , Proteínas de Transporte/imunologia , Doenças dos Peixes , Lectinas/imunologia , Tilápia , Aeromonas hydrophila , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Bacillus licheniformis/imunologia , Dieta/veterinária , Resistência à Doença , Simbióticos
10.
Front Immunol ; 12: 772091, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34950141

RESUMO

Hemocyanin is an important non-specific innate immune defense molecule with phenoloxidase, antiviral, antibacterial, hemolytic, and antitumor activities. To better understand the mechanism of functional diversity, proteomics approach was applied to characterize hemocyanin (HMC) expression profiles from Litopenaeus vannamei. At first, hemocyanin was purified by Sephadex G-100 and DEAE-cellulose (DE-52) columns from shrimp serum, and 34 protein spots were identified as HMC on the 2-DE gels. Furthermore, we found that 9 HMC spots about 75 or 77 kDa were regulated by Streptococcus agalactiae and Vibrio parahaemolyticus infection at 6, 12, and 24 h. In addition, 6 different pathogen-binding HMC fractions, viz., HMC-Mix, HMC-Vp, HMC-Va, HMC-Vf, HMC-Ec, and HMC-Sa, showed different agglutinative and antibacterial activities. Moreover, lectin-blotting analysis showed significant differences in glycosylation level among HMC isomers and bacteria-binding HMC fractions. Particularly, the agglutinative activities of the HMC fractions were almost completely abolished when HMC was deglycosylated by O-glycosidase, which suggest that O-linked sugar chains of HMC played important roles in the innate immune recognition. Our findings demonstrated for the first time that L. vannamei HMC had molecular diversity in protein level, which is closely associated with its ability to recognize diverse pathogens, whereas glycan modification probably contributed to HMC's diversity and multiple immune activities.


Assuntos
Infecções Bacterianas/imunologia , Hemocianinas/imunologia , Penaeidae/imunologia , Penaeidae/microbiologia , Aglutinação , Animais , Infecções Bacterianas/veterinária , Glicosilação , Lectinas/imunologia
11.
Front Immunol ; 12: 765330, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34777382

RESUMO

AIMS: Although the exact factors promoting disease progression in COVID-19 are not fully elucidated, unregulated activation of the complement system (CS) seems to play a crucial role in the pathogenesis of acute lung injury (ALI) induced by SARS-CoV-2. In particular, the lectin pathway (LP) has been implicated in previous autopsy studies. The primary purpose of our study is to investigate the role of the CS in hospitalized COVID-19 patients with varying degrees of disease severity. METHODS: In a single-center prospective observational study, 154 hospitalized patients with PCR-confirmed SARS-CoV-2 infection were included. Serum samples on admission to the COVID-19 ward were collected for analysis of CS pathway activities and concentrations of LP proteins [mannose-binding lectin (MBL) and ficolin-3 (FCN-3)] & C1 esterase inhibitor (C1IHN). The primary outcome was mechanical ventilation or in-hospital death. RESULTS: The patients were predominately male and had multiple comorbidities. ICU admission was required in 16% of the patients and death (3%) or mechanical ventilation occurred in 23 patients (15%). There was no significant difference in LP activity, MBL and FCN-3 concentrations according to different peak disease severities. The median alternative pathway (AP) activity was significantly lower (65%, IQR 50-94) in patients with death/invasive ventilation compared to patients without (87%, IQR 68-102, p=0.026). An optimal threshold of <65.5% for AP activity was derived from a ROC curve resulting in increased odds for death or mechanical ventilation (OR 4,93; 95% CI 1.70-14.33, p=0.003) even after adjustment for confounding factors. Classical pathway (CP) activity was slightly lower in patients with more severe disease (median 101% for death/mechanical ventilation vs 109%, p=0.014). C1INH concentration correlated positively with length of stay, inflammatory markers and disease severity on admission but not during follow-up. CONCLUSION: Our results point to an overactivated AP in critically ill COVID-19 patients in vivo leading to complement consumption and consequently to a significantly reduced AP activity in vitro. The LP does not seem to play a role in the progression to severe COVID-19. Apart from its acute phase reaction the significance of C1INH in COVID-19 requires further studies.


Assuntos
COVID-19/imunologia , Proteínas do Sistema Complemento/imunologia , SARS-CoV-2 , Adulto , Idoso , COVID-19/sangue , COVID-19/mortalidade , COVID-19/terapia , Proteína Inibidora do Complemento C1/imunologia , Estado Terminal , Feminino , Mortalidade Hospitalar , Hospitalização , Humanos , Lectinas/imunologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Respiração Artificial , Índice de Gravidade de Doença
12.
Cell Mol Life Sci ; 78(24): 8165-8186, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34731252

RESUMO

B cell superantigens crosslink conserved domains of B cell receptors (BCRs) and cause dysregulated, polyclonal B cell activation irrespective of normal BCR-antigen complementarity. The cells typically succumb to activation-induced cell death, which can impede the adaptive immune response and favor infection. In the present study, we demonstrate that the fucose-binding lectin of Burkholderia ambifaria, BambL, bears functional resemblance to B cell superantigens. By engaging surface glycans, the bacterial lectin activated human peripheral blood B cells, which manifested in the surface expression of CD69, CD54 and CD86 but became increasingly cytotoxic at higher concentrations. The effects were sensitive to BCR pathway inhibitors and excess fucose, which corroborates a glycan-driven mode of action. Interactome analyses in a model cell line suggest BambL binds directly to glycans of the BCR and regulatory coreceptors. In vitro, BambL triggered BCR signaling and induced CD19 internalization and degradation. Owing to the lectin's six binding sites, we propose a BCR activation model in which BambL functions as a clustering hub for receptor glycans, modulates normal BCR regulation, and induces cell death through exhaustive activation.


Assuntos
Linfócitos B/metabolismo , Proteínas de Bactérias/metabolismo , Burkholderia/metabolismo , Lectinas/metabolismo , Polissacarídeos/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Superantígenos/metabolismo , Linfócitos B/imunologia , Proteínas de Bactérias/imunologia , Sítios de Ligação , Humanos , Lectinas/imunologia , Polissacarídeos/imunologia , Ligação Proteica , Receptores de Antígenos de Linfócitos B/imunologia , Transdução de Sinais , Superantígenos/imunologia
13.
Front Immunol ; 12: 744184, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34659241

RESUMO

Fusobacterium nucleatum is involved in the development of colorectal cancer (CRC) through innate immune cell modulation. However, the receptors of the interaction between F. nucleatum ssp. and immune cells remain largely undetermined. Here, we showed that F. nucleatum ssp. animalis interacts with Siglecs (sialic acid-binding immunoglobulin-like lectins) expressed on innate immune cells with highest binding to Siglec-7. Binding to Siglec-7 was also observed using F. nucleatum-derived outer membrane vesicles (OMVs) and lipopolysaccharide (LPS). F. nucleatum and its derived OMVs or LPS induced a pro-inflammatory profile in human monocyte-derived dendritic cells (moDCs) and a tumour associated profile in human monocyte-derived macrophages (moMϕs). Siglec-7 silencing in moDCs or CRISPR-cas9 Siglec-7-depletion of U-937 macrophage cells altered F. nucleatum induced cytokine but not marker expression. The molecular interaction between Siglec-7 and the LPS O-antigen purified from F. nucleatum ssp. animalis was further characterised by saturation transfer difference (STD) NMR spectroscopy, revealing novel ligands for Siglec-7. Together, these data support a new role for Siglec-7 in mediating immune modulation by F. nucleatum strains and their OMVs through recognition of LPS on the bacterial cell surface. This opens a new dimension in our understanding of how F. nucleatum promotes CRC progression through the generation of a pro-inflammatory environment and provides a molecular lead for the development of novel cancer therapeutic approaches targeting F. nucleatum-Siglec-7 interaction.


Assuntos
Antígenos de Diferenciação Mielomonocítica/imunologia , Neoplasias Colorretais/imunologia , Células Dendríticas/imunologia , Fusobacterium/imunologia , Lectinas/imunologia , Macrófagos/imunologia , Antígenos de Diferenciação Mielomonocítica/metabolismo , Carcinogênese/imunologia , Carcinogênese/metabolismo , Linhagem Celular , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/microbiologia , Células Dendríticas/metabolismo , Fusobacterium/metabolismo , Humanos , Imunomodulação/imunologia , Lectinas/metabolismo , Macrófagos/metabolismo
14.
Biomed Res Int ; 2021: 3192960, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34651045

RESUMO

Dogs are the main reservoir of Leishmania infantum in endemic regions. Canine leishmaniasis, caused by L. infantum, can progress to a chronic disease resulting in death. Vaccines have been developed with a certain degree of success. The pathogenesis of this disease is not completely understood, especially in previously vaccinated dogs. We herein described clinical data, parasite load, serum levels of cytokines, and the reservoir potential in vdogs vaccinated with the fucose-mannose ligand (FML)/QuilA saponin vaccine (Leishmune™) naturally infected (Vi) and compared to vaccinated not infected dogs (Vn). Thirty-four dogs from private owners were divided into two groups: vaccinated/infected and vaccinated/uninfected. Clinical evaluation, hematological and biochemical parameters, and serum levels of cytokines were measured by conventional methods. The parasite burden in the bone marrow was measured by quantitative real-time PCR, and the transmissibility of parasites to sand flies was assessed by xenodiagnosis. Clinical, biochemical, and hematological parameters of vaccinated infected dogs were mostly normal. Vi dogs developed mild disease with low clinical scores. Serum levels of IL-10 were higher in Vi dogs, and a strong correlation was observed in IL-4 levels and the A/G ratio in Vi dogs. These results suggest a role of TH2 response in Vi dogs, although more data is needed to better understand the disease in vaccinated dogs.


Assuntos
Citocinas/sangue , Lectinas/imunologia , Leishmania infantum/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/veterinária , Vacinação , Animais , Cães , Feminino , Interleucina-4/sangue , Leishmaniose Visceral/sangue , Leishmaniose Visceral/patologia , Masculino
15.
Blood ; 138(19): 1830-1842, 2021 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-34289026

RESUMO

Acute myeloid leukemia (AML) is an attractive entity for the development of chimeric antigen receptor (CAR) T-cell immunotherapy because AML blasts are susceptible to T-cell-mediated elimination. Here, we introduce sialic acid-binding immunoglobulin-like lectin 6 (Siglec-6) as a novel target for CAR T cells in AML. We designed a Siglec-6-specific CAR with a targeting domain derived from the human monoclonal antibody JML-1. We found that Siglec-6 is commonly expressed on AML cell lines and primary AML blasts, including the subpopulation of AML stem cells. Treatment with Siglec-6 CAR T cells confers specific antileukemia reactivity that correlates with Siglec-6 expression in preclinical models, including induction of complete remission in a xenograft AML model in immunodeficient mice (NSG/U937). In addition, we confirmed Siglec-6 expression on transformed B cells in chronic lymphocytic leukemia (CLL), and specific anti-CLL reactivity of Siglec-6 CAR T cells in vitro. Of particular interest, we found that Siglec-6 is not detectable on normal hematopoietic stem and progenitor cells (HSPCs) and that treatment with Siglec-6 CAR T cells does not affect their viability and lineage differentiation in colony-formation assays. These data suggest that Siglec-6 CAR T-cell therapy may be used to effectively treat AML without the need for subsequent allogeneic hematopoietic stem cell transplantation. In mature normal hematopoietic cells, we detected Siglec-6 in a proportion of memory (and naïve) B cells and basophilic granulocytes, suggesting the potential for limited on-target/off-tumor reactivity. The lack of expression of Siglec-6 on normal HSPCs is a key to differentiating it from other Siglec family members (eg, Siglec-3 [CD33]) and other CAR target antigens (eg, CD123) that are under investigation in AML, and it warrants the clinical investigation of Siglec-6 CAR T-cell therapy.


Assuntos
Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/imunologia , Imunoterapia Adotiva , Lectinas/imunologia , Leucemia Mieloide Aguda/terapia , Animais , Linhagem Celular Tumoral , Citotoxicidade Imunológica , Feminino , Humanos , Imunoterapia Adotiva/métodos , Leucemia Mieloide Aguda/imunologia , Linfócitos T/imunologia , Células U937
16.
Life Sci ; 282: 119793, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34242658

RESUMO

Visceral leishmaniasis (VL) is a neglected and highly lethal disease. VL is endemic in South American countries, with Brazil being responsible for 96% of the cases. In this continent, VL is caused by the protozoan Leishmania (Leishmania) infantum (L. infantum), transmitted by the bite of infected female phlebotomine sandflies. Immediately after the inoculation of L.infantum promastigotes into the vertebrate host, the complement, as part of the first line of innate response, becomes activated. L. infantum promastigotes glycocalyx is rich in carbohydrates that can activate the lectin pathway of complement system. In this study, we evaluated whether the lectin pathway collectins [manose binding lectin (MBL) and collectin-11 (CL-11)] and ficolins (-1, -2 and -3) interact with L.infantum promastigotes, using confocal microscopy and flow cytometry. The binding of MBL, CL-11 and ficolins -1 and -3, but not ficolin-2, was observed on the surface of live metacyclic promastigotes after incubation with normal human serum (NHS) or recombinant proteins. C3 and C4 deposition as well as complement mediated lyses was also demonstrated after interaction with NHS. These results highlight a role for collectins and ficolins in the initial immune response to L.infantum.


Assuntos
Proteínas do Sistema Complemento/imunologia , Lectinas/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Ativação do Complemento , Interações Hospedeiro-Parasita , Humanos , Leishmania infantum/fisiologia
18.
Chem Commun (Camb) ; 57(50): 6209-6212, 2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34059855

RESUMO

Toll-like receptor 4 (TLR4) recognizes various protein ligands; however, the protein-TLR4 binding model is unclear. Here we demonstrate a Crenomytilus grayanus lectin (CGL)-TLR4/MD2 model to show that CGL interacts with a TLR4/myeloid differentiation factor 2 (MD2) complex independently of sugar-binding properties. CGL could suppress lipopolysaccharide-induced immune responses significantly, suggesting that TLR4 itself has potential as a therapeutic target.


Assuntos
Carboidratos/química , Lectinas/química , Antígeno 96 de Linfócito/química , Receptor 4 Toll-Like/química , Animais , Sítios de Ligação , Bivalves , Carboidratos/imunologia , Humanos , Lectinas/imunologia , Antígeno 96 de Linfócito/imunologia , Receptor 4 Toll-Like/imunologia
19.
JCI Insight ; 6(13)2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34143756

RESUMO

We explored the potential link between chronic inflammatory arthritis and COVID-19 pathogenic and resolving macrophage pathways and their role in COVID-19 pathogenesis. We found that bronchoalveolar lavage fluid (BALF) macrophage clusters FCN1+ and FCN1+SPP1+ predominant in severe COVID-19 were transcriptionally related to synovial tissue macrophage (STM) clusters CD48hiS100A12+ and CD48+SPP1+ that drive rheumatoid arthritis (RA) synovitis. BALF macrophage cluster FABP4+ predominant in healthy lung was transcriptionally related to STM cluster TREM2+ that governs resolution of synovitis in RA remission. Plasma concentrations of SPP1 and S100A12 (key products of macrophage clusters shared with active RA) were high in severe COVID-19 and predicted the need for Intensive Care Unit transfer, and they remained high in the post-COVID-19 stage. High plasma levels of SPP1 were unique to severe COVID-19 when compared with other causes of severe pneumonia, and IHC localized SPP1+ macrophages in the alveoli of COVID-19 lung. Investigation into SPP1 mechanisms of action revealed that it drives proinflammatory activation of CD14+ monocytes and development of PD-L1+ neutrophils, both hallmarks of severe COVID-19. In summary, COVID-19 pneumonitis appears driven by similar pathogenic myeloid cell pathways as those in RA, and their mediators such as SPP1 might be an upstream activator of the aberrant innate response in severe COVID-19 and predictive of disease trajectory including post-COVID-19 pathology.


Assuntos
Artrite Reumatoide/imunologia , COVID-19/imunologia , Monócitos/imunologia , Neutrófilos/imunologia , Osteopontina/imunologia , Artrite Reumatoide/metabolismo , Antígeno B7-H1/imunologia , Líquido da Lavagem Broncoalveolar/imunologia , Antígeno CD48/imunologia , COVID-19/induzido quimicamente , COVID-19/metabolismo , Proteínas de Ligação a Ácido Graxo/imunologia , Humanos , Lectinas/imunologia , Receptores de Lipopolissacarídeos/imunologia , Receptores de Lipopolissacarídeos/metabolismo , Pulmão/diagnóstico por imagem , Pulmão/imunologia , Pulmão/metabolismo , Pulmão/patologia , Macrófagos/imunologia , Macrófagos/metabolismo , Glicoproteínas de Membrana/imunologia , Monócitos/metabolismo , Neutrófilos/metabolismo , Osteopontina/sangue , Receptores Proteína Tirosina Quinases/metabolismo , Receptores Imunológicos/imunologia , Proteína S100A12/imunologia , Proteína S100A12/metabolismo , Membrana Sinovial/imunologia , Tomografia Computadorizada por Raios X
20.
Glycoconj J ; 38(4): 509-516, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34146213

RESUMO

Physiological role of a core fucose specific lectin from Cephalosporium curvulum isolated from mycotic keratitis patient in mediating pathogenesis was reported earlier. CSL has opposite effects on HCECs, at the initiation of infection when lectin concentration is low, CSL induces proinflammatory response and at higher concentration it inhibits growth as the infection progresses. Here we delineate detailed mechanism of opposing effects of CSL by confirming the binding of CSL and anti TLR 2 and 4 antibodies to TLRs 2 and 4 purified from HCECs using Galectin-3 Sepharose 4B column. Further, the expression of signaling proteins were monitored by Western blotting and apoptosis assay. At concentration of 0.3 µg/ml, CSL induced the activation of TLR-2,-4 and adapter protein MyD88. CSL also induced the expression of transcription factors NFkB, C-Jun and proinflammatory cytokines like interleukins -6 and -8 essential in maintaining cell proliferation. In contrast at higher concentrations i.e. 5 µg/ml CSL induces apoptotic effect as evidenced by increase in early and late apoptotic population as demonstrated by Annexin V-PI assay. Western blotting revealed that CSL treated HCECs at higher concentration lead to MyD88 dependent expression of apoptotic proteins like FADD, Caspase -8 and -3. All these results are in line with and substantiate our earlier results that indeed CSL is involved in mediating host pathogen interactions by interacting with cell surface TLRs, activating downstream signaling pathways leading to pathogenesis. Findings are of clinical significance in developing carbohydrate based therapeutic strategy to control infection and the disease.


Assuntos
Acremonium/metabolismo , Células Epiteliais/efeitos dos fármacos , Epitélio Corneano/citologia , Ceratite/microbiologia , Lectinas/toxicidade , Apoptose , Linhagem Celular , Proliferação de Células , Humanos , Ceratite/patologia , Lectinas/imunologia , Fator 88 de Diferenciação Mieloide
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