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1.
Gene ; 706: 181-187, 2019 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-31082500

RESUMO

Systemic lupus erythematous (SEL) is a heterogeneous, systemic autoimmune disorder which is defined by its autoantibody pattern. Transcriptomic data analysis has shown pathways and immune system responses associated with SLE. Eight up-regulated genes (SOCE, MMP9, CXCL8, JUN, IL1B, NFKBIA, TNF and FOS) have been examined with four interactions among different pathways. These genes are associated with SNPs which have been identified through two datasets from SLE genome-wide association studies (GWAS). In this investigation, the GWAS results were integrated with pathway analysis of transcriptomes and several genes were detected with known SLE-related variations (TYK2, C5, SH2B, IRF5, IL2RA, STAT4, FCGR2A, IL7R, LYN, HLA-DRB and TNFAIP3). Pathway-based analysis on the Wikipathway Human Collection allowed the identification of prioritized variants in the relevant pathways, such as thymic stromal lymphopoietin (TSLP) signaling pathway linked to LYN, IL7R, STAT4 and rs7574865. Analysis of existing transcriptomes and GWAS data identified eight up-regulated candidate genes with more than four relationships among the different pathways associated with SNPs to pinpoint the relevant loci linked to SLE. The results of this investigation have expanded the number of candidate genes related to SLE and have highlighted possible pathways and GWAS-based methods for gene detection. Identification of the fundamental genes would assist in revealing the mechanisms responsible for SLE.


Assuntos
Perfilação da Expressão Gênica/métodos , Lúpus Eritematoso Sistêmico/genética , Estudos de Casos e Controles , Bases de Dados Genéticas , Ontologia Genética , Redes Reguladoras de Genes/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Genótipo , Humanos , Fatores Reguladores de Interferon/genética , Lúpus Eritematoso Sistêmico/fisiopatologia , Polimorfismo de Nucleotídeo Único/genética , Receptores de IgG/genética , Fator de Transcrição STAT4/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética
2.
Nat Commun ; 10(1): 1970, 2019 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-31036800

RESUMO

Several tolerance checkpoints exist throughout B cell development to control autoreactive B cells and prevent the generation of pathogenic autoantibodies. FcγRIIb is an Fc receptor that inhibits B cell activation and, if defective, is associated with autoimmune disease, yet its impact on specific B cell tolerance checkpoints is unknown. Here we show that reduced expression of FcγRIIb enhances the deletion and anergy of autoreactive immature B cells, but in contrast promotes autoreactive B cell expansion in the germinal center and serum autoantibody production, even in response to exogenous, non-self antigens. Our data thus show that FcγRIIb has opposing effects on pre-immune and post-immune tolerance checkpoints, and suggest that B cell tolerance requires the control of bystander germinal center B cells with low or no affinity for the immunizing antigen.


Assuntos
Linfócitos B/imunologia , Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Tolerância Imunológica/imunologia , Receptores de IgG/metabolismo , Algoritmos , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Centro Germinativo , Humanos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Camundongos , Receptores de IgG/genética , Software
3.
Nat Commun ; 10(1): 2141, 2019 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-31105267

RESUMO

Costimulation of T cell responses with monoclonal antibody agonists (mAb-AG) targeting 4-1BB showed robust anti-tumor activity in preclinical models, but their clinical development was hampered by low efficacy (Utomilumab) or severe liver toxicity (Urelumab). Here we show that isotype and intrinsic agonistic strength co-determine the efficacy and toxicity of anti-4-1BB mAb-AG. While intrinsically strong agonistic anti-4-1BB can activate 4-1BB in the absence of FcγRs, weak agonistic antibodies rely on FcγRs to activate 4-1BB. All FcγRs can crosslink anti-41BB antibodies to strengthen co-stimulation, but activating FcγR-induced antibody-dependent cell-mediated cytotoxicity compromises anti-tumor immunity by deleting 4-1BB+ cells. This suggests balancing agonistic activity with the strength of FcγR interaction as a strategy to engineer 4-1BB mAb-AG with optimal therapeutic performance. As a proof of this concept, we have developed LVGN6051, a humanized 4-1BB mAb-AG that shows high anti-tumor efficacy in the absence of liver toxicity in a mouse model of cancer immunotherapy.


Assuntos
Anticorpos Monoclonais Humanizados/farmacologia , Imunoterapia/métodos , Melanoma Experimental/terapia , Receptores de IgG/metabolismo , Neoplasias Cutâneas/terapia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/antagonistas & inibidores , Células 3T3 , Animais , Anticorpos Monoclonais Humanizados/imunologia , Anticorpos Monoclonais Humanizados/uso terapêutico , Linhagem Celular Tumoral/transplante , Ensaios de Seleção de Medicamentos Antitumorais , Técnicas de Introdução de Genes , Humanos , Fígado/efeitos dos fármacos , Melanoma Experimental/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de IgG/genética , Neoplasias Cutâneas/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia
4.
Toxicol Lett ; 312: 34-44, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31059760

RESUMO

Inflammation is one of the factors that may increase the sensitivity of hepatic cells to acetaminophen (APAP) induced toxicity. To investigate the mechanisms, we exposed 3-dimensional (3D) Human Liver Microtissues, a co-culture of primary human hepatocytes (PHH) and Kupffer cells (KCs), to 0, 0.5 (low), 5 (median) and 10 mM (high dose) APAP for 24 h, with/without lipopolysaccharide (LPS). Microarray-technology was used to evaluate the transcriptome changes. In the presence of LPS, the median-dose of APAP is sufficient to inhibit the expression of respiratory chain- and antioxidant-related genes, suggesting the involvement of reactive oxygen species (ROS) and oxidative stress. Furthermore, the median- and high-dose of APAP inhibited the expression of Fc fragment receptor (FcγR)-coding genes, regardless of the presence of LPS. The toll-like receptor 4 (TLR4) expression, however, was continuously elevated after the LPS/APAP co-exposures, which may result in reduced KC-phagocytosis and unbalanced cytokine patterns. Compared to the treatment with LPS only, LPS/APAP co-exposures induced the production of interleukin (IL)-8, a pro-inflammatory cytokine, but suppressed the secretion of IL-6, a cytokine regulating hepatic regeneration, along with the increase in APAP dosages. In addition to the disrupted mitochondrial functions, the presence of LPS exacerbated APAP toxicity. These findings suggest that 3D Microtissues are a suitable model for the mechanistic exploration of inflammation-associated drug toxicity.


Assuntos
Citocinas/metabolismo , Inflamação/metabolismo , Lipopolissacarídeos/toxicidade , Técnicas de Cultura de Tecidos/métodos , Acetaminofen/toxicidade , Analgésicos não Entorpecentes/toxicidade , Técnicas de Cocultura , Regulação da Expressão Gênica/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Humanos , Macrófagos do Fígado/efeitos dos fármacos , Receptores de IgG/genética , Receptores de IgG/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/metabolismo , Transcriptoma/efeitos dos fármacos
5.
Cell Physiol Biochem ; 52(3): 397-407, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30845379

RESUMO

BACKGROUND/AIMS: TNF-α-mediated pro-inflammatory phenotypic change in monocytes is known to be implicated in the pathogenesis of metabolic inflammation and insulin resistance. However, the mechanism by which TNF-α-induces inflammatory phenotypic shift in monocytes is poorly understood. Since long-chain acyl-CoA synthetase 1 (ACSL1) is associated with inflammatory monocytes/macrophages, we investigated the role of ACSL1 in the TNF-α-driven inflammatory phenotypic shift in the monocytes. METHODS: Monocytes (Human monocytic THP-1 cells) were stimulated with TNF-α. Inflammatory phenotypic markers (CD16, CD11b, CD11c and HLA-DR) expression was determined with real time RTPCR and flow cytometry. IL-1ß and MCP-1 were determined by ELISA. Signaling pathways were identified by using ACSL1 inhibitor, ACSL1 siRNA and NF-κB reporter monocytic cells. Phosphorylation of NF-κB was analyzed by western blotting and flow cytometry. RESULTS: Our data show that TNF-α induced significant increase in the expression of CD16, CD11b, CD11c and HLA-DR. Inhibition of ACSL1 activity in the cells with triacsin C significantly suppressed the expression of these inflammatory markers. Using ACSL-1 siRNA, we further demonstrate that TNF-α-induced inflammatory markers expression in monocytic cells requires ACSL1. In addition, IL-1b and MCP-1 production by TNF-α activated monocytic cells was significantly blocked by the inhibition of ACSL-1 activity. Interestingly, elevated NF-κB activity resulting from TNF-α stimulation was attenuated in ACSL1 deficient cells. CONCLUSION: Our findings provide an evidence that TNF-α-associated inflammatory polarization in monocytes is an ACSL1 dependent process, which indicates its central role in TNF-α-driven metabolic inflammation.


Assuntos
Coenzima A Ligases/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/patologia , Fator de Necrose Tumoral alfa/farmacologia , Linhagem Celular , Quimiocina CCL2/análise , Coenzima A Ligases/antagonistas & inibidores , Coenzima A Ligases/genética , Antígenos HLA-DR/genética , Antígenos HLA-DR/metabolismo , Humanos , Inflamação/metabolismo , Interleucina-1beta/análise , Monócitos/citologia , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , NF-kappa B/metabolismo , Fosforilação , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Triazenos/química , Triazenos/metabolismo
6.
Nat Commun ; 10(1): 1322, 2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30899022

RESUMO

Heparin-induced thrombocytopenia/thrombosis (HIT) is a serious immune reaction to heparins, characterized by thrombocytopenia and often severe thrombosis with high morbidity and mortality. HIT is mediated by IgG antibodies against heparin/platelet factor 4 antigenic complexes. These complexes are thought to activate platelets leading to thrombocytopenia and thrombosis. Here we show that HIT immune complexes induce NETosis via interaction with FcγRIIa on neutrophils and through neutrophil-platelet association. HIT immune complexes induce formation of thrombi containing neutrophils, extracellular DNA, citrullinated histone H3 and platelets in a microfluidics system and in vivo, while neutrophil depletion abolishes thrombus formation. Absence of PAD4 or PAD4 inhibition with GSK484 abrogates thrombus formation but not thrombocytopenia, suggesting they are induced by separate mechanisms. NETs markers and neutrophils undergoing NETosis are present in HIT patients. Our findings demonstrating the involvement of NETosis in thrombosis will modify the current concept of HIT pathogenesis and may lead to new therapeutic strategies.


Assuntos
Plaquetas/imunologia , Armadilhas Extracelulares/imunologia , Heparina/efeitos adversos , Neutrófilos/imunologia , Receptores de IgG/genética , Trombocitopenia/imunologia , Trombose/imunologia , Animais , Complexo Antígeno-Anticorpo/biossíntese , Plaquetas/efeitos dos fármacos , Citrulinação , Inibidores Enzimáticos/farmacologia , Armadilhas Extracelulares/química , Armadilhas Extracelulares/efeitos dos fármacos , Regulação da Expressão Gênica , Histonas/genética , Histonas/imunologia , Humanos , Imunoglobulina G/biossíntese , Camundongos , Camundongos Transgênicos , Técnicas Analíticas Microfluídicas , Ativação de Neutrófilo/efeitos dos fármacos , Ativação de Neutrófilo/imunologia , Neutrófilos/efeitos dos fármacos , Ativação Plaquetária/efeitos dos fármacos , Ativação Plaquetária/imunologia , Fator Plaquetário 4/genética , Fator Plaquetário 4/imunologia , Desiminases de Arginina em Proteínas/antagonistas & inibidores , Desiminases de Arginina em Proteínas/genética , Desiminases de Arginina em Proteínas/imunologia , Receptores de IgG/imunologia , Transdução de Sinais , Trombocitopenia/induzido quimicamente , Trombocitopenia/patologia , Trombose/induzido quimicamente , Trombose/patologia , Trombose/prevenção & controle
7.
Immunity ; 50(4): 1099-1114.e10, 2019 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-30876876

RESUMO

Inflammatory bowel disease is a chronic, relapsing condition with two subtypes, Crohn's disease (CD) and ulcerative colitis (UC). Genome-wide association studies (GWASs) in UC implicate a FCGR2A variant that alters the binding affinity of the antibody receptor it encodes, FcγRIIA, for immunoglobulin G (IgG). Here, we aimed to understand the mechanisms whereby changes in FcγRIIA affinity would affect inflammation in an IgA-dominated organ. We found a profound induction of anti-commensal IgG and a concomitant increase in activating FcγR signaling in the colonic mucosa of UC patients. Commensal-IgG immune complexes engaged gut-resident FcγR-expressing macrophages, inducing NLRP3- and reactive-oxygen-species-dependent production of interleukin-1ß (IL-1ß) and neutrophil-recruiting chemokines. These responses were modulated by the FCGR2A genotype. In vivo manipulation of macrophage FcγR signal strength in a mouse model of UC determined the magnitude of intestinal inflammation and IL-1ß-dependent type 17 immunity. The identification of an important contribution of IgG-FcγR-dependent inflammation to UC has therapeutic implications.


Assuntos
Anticorpos Antibacterianos/imunologia , Colite Ulcerativa/imunologia , Microbioma Gastrointestinal/imunologia , Imunoglobulina G/imunologia , Interleucina-1beta/imunologia , Células Th17/imunologia , Animais , Colite/induzido quimicamente , Colite/imunologia , Colite/microbiologia , Colite/patologia , Colite Ulcerativa/microbiologia , Colite Ulcerativa/patologia , Sulfato de Dextrana/toxicidade , Regulação da Expressão Gênica , Genótipo , Humanos , Inflamação , Interleucina-8/biossíntese , Interleucina-8/genética , Mucosa Intestinal/imunologia , Mucosa Intestinal/microbiologia , Macrófagos/imunologia , Camundongos , Fagócitos/imunologia , RNA Mensageiro/biossíntese , Espécies Reativas de Oxigênio , Receptores de IgG/biossíntese , Receptores de IgG/genética , Receptores de IgG/imunologia
8.
Viruses ; 11(3)2019 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-30857329

RESUMO

Expansion of natural killer (NK) cells expressing NKG2C occurs following human cytomegalovirus (HCMV) infection and is amplified by human immunodeficiency virus (HIV) co-infection. These NKG2C-expressing NK cells demonstrate enhanced CD16-dependent cytokine production and downregulate FcεRIγ and promyelocytic leukemia zinc finger protein (PLZF). Lacking NKG2C diminishes resistance to HIV infection, but whether this affects NK cell acquisition of superior antibody-dependent function is unclear. Therefore, our objective was to investigate whether HCMV-driven NK cell differentiation is impaired in NKG2Cnull HIV-infected individuals. Phenotypic (CD2, CD16, CD57, NKG2A, FcεRIγ, and PLZF expression) and functional (cytokine induction and cytotoxicity) properties were compared between HIV⁻infected NKG2Cnull and NKG2C-expressing groups. Cytokine production was compared following stimulation through natural cytotoxicity receptors or through CD16. Cytotoxicity was measured by anti-CD16-redirected lysis and by classical antibody-dependent cell-mediated cytotoxicity (ADCC) against anti-class I human leukocyte antigen (HLA) antibody-coated cells. Our data indicate highly similar HCMV-driven NK cell differentiation in HIV infection with or without NKG2C. While the fraction of mature (CD57pos) NK cells expressing CD2 (p = 0.009) or co-expressing CD2 and CD16 (p = 0.03) was significantly higher in NKG2Cnull HIV-infected individuals, there were no significant differences in NKG2A, FcεRIγ, or PLZF expression. The general phenotypic and functional equivalency observed suggests NKG2C-independent routes of HCMV-driven NK cell differentiation, which may involve increased CD2 expression.


Assuntos
Infecções por Citomegalovirus/imunologia , Citomegalovirus/patogenicidade , Infecções por HIV/imunologia , Células Matadoras Naturais/virologia , Subfamília C de Receptores Semelhantes a Lectina de Células NK/genética , Adulto , Citotoxicidade Celular Dependente de Anticorpos , Diferenciação Celular , Coinfecção/imunologia , Coinfecção/virologia , Citocinas/imunologia , Feminino , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/imunologia , Humanos , Células Matadoras Naturais/citologia , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Subfamília C de Receptores Semelhantes a Lectina de Células NK/imunologia , Proteína com Dedos de Zinco da Leucemia Promielocítica/genética , Proteína com Dedos de Zinco da Leucemia Promielocítica/imunologia , Receptores de IgE/genética , Receptores de IgE/imunologia , Receptores de IgG/genética , Receptores de IgG/imunologia
9.
Viruses ; 11(2)2019 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-30744065

RESUMO

Dendritic cells (DCs) express Fcγ receptors (FcγRs) for the binding immune complexes (ICs) consisting of IgG and antigens (Ags). IC⁻FcγR interactions have been demonstrated to enhance activation and antigen-presenting functions of DCs. Utilizing Friend virus (FV), an oncogenic mouse retrovirus, we investigated the effect of IgG-opsonization of retroviral particles on the infection of DCs and the subsequent presentation of viral antigens by DCs to virus-specific CD8 T cells. We found that opsonization by virus-specific non-neutralizing IgG abrogated DC infection and as a consequence significantly reduced the capacity of DCs to activate virus-specific CD8 T cells. Effects of IgG-opsonization were mediated by the high-affinity FcγR type I, CD64, expressed on DCs. Our results suggest that different opsonization patterns on the retroviral surface modulate infection and antigen-presenting functions of DCs, whereby, in contrast to complement, IgG reduces the capacity of DCs to activate cytotoxic T cell (CTL) responses.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Células Dendríticas/imunologia , Vírus da Leucemia Murina de Friend/imunologia , Ativação Linfocitária , Receptores de IgG/imunologia , Animais , Apresentação do Antígeno , Complexo Antígeno-Anticorpo/imunologia , Células Dendríticas/virologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de IgG/genética
10.
Molecules ; 24(3)2019 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-30699986

RESUMO

A promising strategy in cancer immunotherapy is the employment of a bispecific agent that can bind with both tumor markers and immunocytes for recruitment of lymphocytes to tumor sites and enhancement of anticancer immune reactions. Mucin1 (MUC1) is a tumor marker overexpressed in almost all adenocarcinomas, making it a potentially important therapeutic target. CD16 is expressed in several types of immunocytes, including NK cells, γδ-T cells, monocytes, and macrophages. In this study, we constructed the first bispecific aptamer (BBiApt) targeting both MUC1 and CD16. This aptamer consisted of two MUC1 aptamers and two CD16 aptamers linked together by three 60 nt DNA spacers. Compared with monovalent MUC1 or CD16 aptamers, BBiApt showed more potent avidity to both MUC1-positive tumor cells and CD16-positive immunocytes. Competition experiments indicated that BBiApt and monovalent aptamers bound to the same sites on the target cells. Moreover, BBiApt recruited more CD16-positive immunocytes around MUC1-positive tumor cells and enhanced the immune cytotoxicity against the tumor cells in vitro. The results suggest that, apart from bispecific antibodies, bispecific aptamers may also potentially serve as a novel strategy for targeted enhancement of antitumor immune reactions against MUC1-expressing malignancies.


Assuntos
Imunoterapia/métodos , Mucina-1/metabolismo , Receptores de IgG/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Mucina-1/genética , Receptores de IgG/genética
11.
Scand J Immunol ; 89(5): e12758, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30786049

RESUMO

Several studies already explored associations between Fc gamma receptor (FCGR) polymorphisms and immune thrombocytopenia (ITP), but the results of these studies were not consistent. Consequently, we conducted a meta-analysis of relevant studies to better analyse the effects of FCGR polymorphisms on individual susceptibility to ITP. PubMed, Web of Science, Embase and CNKI were searched for eligible studies. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated. Totally 17 studies were eligible for analyses (1200 cases and 1723 controls). Significant associations with ITP were observed for FCGR3A F158V polymorphism in dominant (P < 0.0001, OR = 0.47, 95% CI 0.39-0.57), recessive (P < 0.0001, OR = 2.03, 95% CI 1.58-2.61), overdominant (P < 0.0001, OR = 1.42, 95% CI 1.19-1.69) and allele (P < 0.0001, OR = 0.58, 95% CI 0.51-0.65) models in overall analyses. But we did not observe any significant associations with ITP for FCGR2A H131R and FCGR2B I232T polymorphisms in overall analyses. Subgroup analyses by ethnicity yielded similar positive results for FCGR3A F158V polymorphism in both Asians and Caucasians. Furthermore, subgroup analyses by type of disease revealed that FCGR2A H131R polymorphism was significantly associated with childhood-onset ITP, and FCGR3A F158V polymorphism was significantly associated with both childhood-onset and adult-onset ITP. In summary, our findings suggested that FCGR2A H131R polymorphism may serve as a potential genetic biomarker of childhood-onset ITP, while FCGR3A F158V polymorphism may serve as a potential genetic biomarker of both childhood-onset and adult-onset ITP.


Assuntos
Marcadores Genéticos/genética , Púrpura Trombocitopênica Idiopática/genética , Receptores de IgG/genética , Adulto , Idade de Início , Biomarcadores/metabolismo , Criança , China , Frequência do Gene , Estudos de Associação Genética , Humanos , Fenótipo , Polimorfismo Genético
12.
Dev Comp Immunol ; 90: 186-198, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30273630

RESUMO

Receptors for the Fc region of IgG (FcγRs) play a key role in protecting the immune system and host from infection. In this study, we described the cloning, sequencing and characterization of porcine FcγRI, and reported six different FcγRI isoforms, four of which have never been reported before. Further analysis revealed that FcγR isoforms are generated by alternative splicing mechanisms, including two membrane isoforms and four soluble isoforms. Importantly, we found FcγRI splice variants differentially influence PRRSV antibody-dependent enhancement (ADE) effects. Membrane pCD64-T1 promotes endocytosis of the PRRSV-antibody complex to enhance PRRSV replication, and soluble pCD64-T3 has no ADE effect on PRRSV proliferation, but shows an inflammation enhancement effect. The differential expression of selective splicing in primary PAM cells and 3D4/21 cell lines are altered and regulated by PRRSV infection and inflammatory environment. Our results indicated that porcine FcγRI plays dual regulatory roles in PRRSV multiplication and PRRSV inflammation process by the alternatively spliced mechanism, which will be a new target in PRRSV prevention and control.


Assuntos
Anticorpos Antivirais/metabolismo , Inflamação/imunologia , Macrófagos Alveolares/imunologia , Síndrome Respiratória e Reprodutiva Suína/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/fisiologia , Receptores de IgG/genética , Receptores de IgG/metabolismo , Suínos/imunologia , Processamento Alternativo , Animais , Anticorpos Facilitadores , Linhagem Celular , Clonagem Molecular , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Macrófagos Alveolares/virologia , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Processamento de RNA , Replicação Viral
13.
Immunogenetics ; 71(2): 123-136, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30564855

RESUMO

Safety and efficacy of therapeutic antibodies are often dependent on their interaction with Fc receptors for IgG (FcγRs). The Göttingen minipig represents a valuable species for biomedical research but its use in preclinical studies with therapeutic antibodies is hampered by the lack of knowledge about the porcine FcγRs. Genome analysis and sequencing now enabled the localization of the previously described FcγRIIIa in the orthologous location to human FCGR3A. In addition, we identified nearby the gene coding for the hitherto undescribed putative porcine FcγRIIa. The 1'241 bp long FCGR2A cDNA translates to a 274aa transmembrane protein containing an extracellular region with high similarity to human and cattle FcγRIIa. Like in cattle, the intracellular part does not contain an immunoreceptor tyrosine-based activation motif (ITAM) as in human FcγRIIa. Flow cytometry of the whole blood and single-cell RNA sequencing of peripheral blood mononuclear cells (PBMCs) of Göttingen minipigs revealed the expression profile of all porcine FcγRs which is compared to human and mouse. The new FcγRIIa is mainly expressed on platelets making the minipig a good model to study IgG-mediated platelet activation and aggregation. In contrast to humans, minipig blood monocytes were found to express inhibitory FcγRIIb that could lead to the underestimation of FcγR-mediated effects of monocytes observed in minipig studies with therapeutic antibodies.


Assuntos
Receptores de IgG/genética , Porco Miniatura/imunologia , Sequência de Aminoácidos , Animais , Bovinos , Humanos , Camundongos , Receptores de IgG/análise , Receptores de IgG/química , Suínos
14.
Immunology ; 156(1): 69-73, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30179254

RESUMO

Vaccines can serve as essential tools to prevent bacterial diseases via the induction of long-lasting IgG responses. The efficacy of such vaccines depends on the effector mechanisms triggered by IgG. The complement system and Fc-gamma receptors (FcγRs) can potentially play a crucial role in IgG-mediated immunity against bacterial diseases. However, their relative importance in vivo is unclear, and has been the object of controversy and debate. In this brief study, we have used gene-targeted mice lacking either FcγRI, II, II and IV or the C3 complement component as well as a novel mouse strain lacking both C3 and FcγRs to conclusively show the essential role of complement in antibody-mediated host resistance to Salmonella enterica systemic infection. By comparing the effect of IgG2a antibodies against Salmonella O-antigen in gene-targeted mice, we demonstrate that the complement system is essential for the IgG-mediated reduction of bacterial numbers in the tissues.


Assuntos
Complemento C3/metabolismo , Antígenos O/imunologia , Receptores de IgG/metabolismo , Infecções por Salmonella/imunologia , Vacinas contra Salmonella/imunologia , Salmonella enterica/fisiologia , Animais , Carga Bacteriana , Ativação do Complemento , Complemento C3/genética , Humanos , Imunidade Humoral , Imunoglobulina G/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de IgG/genética
15.
J Pharmacol Sci ; 137(4): 342-349, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30190171

RESUMO

Lupus nephritis, one of the most serious complications of systemic lupus erythematosus (SLE), has been confirmed in a large number of clinical surveys. Current studies have suggested that inflammatory situation is generally considered to facilitate the occurrence and development of lupus nephritis. Previous research found that Fcγ receptor I (FcγRI) was compulsory for several autoimmune and inflammatory diseases, and it might be involved in the treatment of lupus nephritis. Furthermore, the possible molecular mechanism of the role of FcγRI in lupus nephritis still needs a further study. In the present study, in order to evaluate the effect of FcγRI on kidney function in lupus-prone MLR/lpr mice, FcγRI knockdown was implemented utilizing FcγRI-RNAi lentivirus. We reported that the administration of FcγRI-RNAi lentivirus (1) mainly inhibited FcγRI expression on macrophage of the kidneys, lowered the levels of urinary protein and serum anti-dsDNA antibody and prevented the impairment of renal function; (2) reduced the renal inflammatory cytokines (IL-1ß and IL-18); (3) decreased NF-κB p65 nuclear migration, suppressed NOD-like receptor protein 3 (NLRP3) inflammasome activation, and finally inhibited renal inflammation. Together, these results showed the role of FcγRI on macrophages to involve in renal inflammatory response, potentially via regulating the NLRP3 inflammasome-associated signaling.


Assuntos
Técnicas de Silenciamento de Genes/métodos , Terapia Genética/métodos , Vetores Genéticos , Inflamassomos/genética , Lentivirus/genética , Nefrite Lúpica/genética , Nefrite Lúpica/terapia , NF-kappa B/genética , NF-kappa B/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Interferência de RNA , Receptores de IgG/genética , Transdução de Sinais/genética , Animais , Feminino , Inflamassomos/metabolismo , Macrófagos/metabolismo , Camundongos Transgênicos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo
16.
J Virol ; 92(19)2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30021906

RESUMO

Kaposi's sarcoma-associated herpesvirus (KSHV) induces B cell hyperplasia and neoplasia, such as multicentric Castleman's disease (MCD) and primary effusion lymphoma (PEL). To explore KSHV-induced B cell reprogramming in vivo, we expressed the KSHV latency locus, inclusive of all viral microRNAs (miRNAs), in B cells of transgenic mice in the absence of the inhibitory FcγRIIB receptor. The BALB/c strain was chosen as this is the preferred model to study B cell differentiation. The mice developed hyperglobulinemia, plasmacytosis, and B lymphoid hyperplasia. This phenotype was ameliorated by everolimus, which is a rapamycin derivative used for the treatment of mantle cell lymphoma. KSHV latency mice exhibited hyperresponsiveness to the T-dependent (TD) antigen mimic anti-CD40 and increased incidence of pristane-induced inflammation. Lastly, the adaptive immunity against a secondary infection with Zika virus (ZIKV) was markedly enhanced. These phenotypes are consistent with KSHV lowering the activation threshold of latently infected B cells, which may be beneficial in areas of endemicity, where KSHV is acquired in childhood and infections are common.IMPORTANCE Kaposi's sarcoma-associated herpesvirus (KSHV) establishes latency in B cells and is stringently linked to primary effusion lymphoma (PEL) and the premalignant B cell hyperplasia multicentric Castleman's disease (MCD). To investigate potential genetic background effects, we expressed the KSHV miRNAs in BALB/c transgenic mice. BALB/c mice are the preferred strain for B cell hybridoma development because of their propensity to develop predictable B cell responses to antigen. The BALB/c latency mice exhibited a higher incidence of B cell hyperplasia as well as sustained hyperglobulinemia. The development of neutralizing antibodies against ZIKV was augmented in BALB/c latency mice. Hyperglobulinemia was dampened by everolimus, a derivative of rapamycin, suggesting a role for mTOR inhibitors in managing immune activation, which is hallmark of KSHV infection as well as HIV infection.


Assuntos
Linfócitos B/virologia , Resistência à Doença/genética , Herpesvirus Humano 8/imunologia , Receptores de IgG/imunologia , Sarcoma de Kaposi/imunologia , Latência Viral , Infecção por Zika virus/imunologia , Animais , Antineoplásicos/farmacologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Diferenciação Celular/efeitos dos fármacos , Coinfecção , Everolimo/farmacologia , Herpesvirus Humano 8/efeitos dos fármacos , Herpesvirus Humano 8/genética , Humanos , Hipergamaglobulinemia/genética , Hipergamaglobulinemia/imunologia , Hipergamaglobulinemia/virologia , Imunossupressores/farmacologia , Camundongos Endogâmicos BALB C , Camundongos Knockout , Camundongos Nus , MicroRNAs/genética , MicroRNAs/imunologia , Plasmocitoma/genética , Plasmocitoma/imunologia , Plasmocitoma/virologia , RNA Viral/genética , RNA Viral/imunologia , Receptores de IgG/deficiência , Receptores de IgG/genética , Sarcoma de Kaposi/genética , Sarcoma de Kaposi/virologia , Terpenos/farmacologia , Zika virus/efeitos dos fármacos , Zika virus/genética , Zika virus/imunologia , Infecção por Zika virus/genética , Infecção por Zika virus/virologia
17.
Hum Immunol ; 79(8): 632-637, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29879453

RESUMO

Glycoprotein-A repetitions predominant (GARP) is a transmembrane protein that is highly expressed in breast cancer. Its overexpression correlates with worse survival, and antibodies to GARP appear to play a protective role in a mouse model. No large-scale studies of immunity to GARP in humans have yet been undertaken. In this investigation, using a large multiethnic cohort (1738 subjects), we aimed to determine whether the magnitude of anti-GARP antibody responsiveness was significantly different in patients with breast cancer from that in matched healthy controls. We also investigated whether the allelic variation at the immunoglobulin GM (γ marker), KM (κ marker), and Fcγ receptor (FcγR) loci contributed to the interindividual variability in anti-GARP IgG antibody levels. A combined analysis of all subjects showed that levels of anti-GARP antibodies were significantly higher in patients with breast cancer than in healthy controls (mean ±â€¯SD: 7.4 ±â€¯3.5 vs. 6.9 ±â€¯3.5 absorbance units per mL (AU/µL), p < 0.0001). In the two populations with the largest sample size, the probability of breast cancer generally increases as anti-GARP antibody levels increase. Several significant individual and epistatic effects of GM, KM, and FcγR genotypes on anti-GARP antibody responsiveness were noted in both patients and controls. These results, if confirmed by independent investigations, will aid in devising personalized GARP-based immunotherapeutic strategies against breast cancer and other GARP-overexpressing malignancies.


Assuntos
Neoplasias da Mama/genética , Genótipo , Alótipos da Imunoglobulina Gm/genética , Alótipos Km de Imunoglobulina/genética , Imunoterapia/métodos , Proteínas de Membrana/imunologia , Receptores de IgG/genética , Formação de Anticorpos , Brasil , Neoplasias da Mama/imunologia , Estudos de Casos e Controles , Estudos de Coortes , Epistasia Genética , Grupos Étnicos , Feminino , Humanos , Imunoglobulina G/sangue , Proteínas de Membrana/genética , Polimorfismo Genético , Medicina de Precisão
18.
Cancer Immunol Immunother ; 67(8): 1239-1250, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29855696

RESUMO

The monocyte network is important for therapeutic efficacy of antibody therapies against cancer. One mechanism which monocytes/macrophages use to kill cancer cells is phagocytosis. Using trastuzumab and human breast cancer cell lines as a model, we used flow cytometry to evaluate the importance of avidity, antigen density, Fcγ receptor (FcγR) expression, and FcγR polymorphisms in human monocyte phagocytosis. By increasing avidity for the tumor through the addition of pertuzumab to trastuzumab, there was a two-to-threefold increase in phagocytosis potency against the HCC1419 cell line compared to antibodies alone, while NK cell-mediated antibody-dependent cellular cytotoxicity (ADCC) failed to increase tumor cell death. Consistent with increasing the avidity through multiple antibodies, antigen density significantly enhanced phagocytosis with breast cancer cell lines that were HER2 gene-amplified compared to non-amplified tumor cells. Confirmation that high antigen density enhanced phagocytosis was obtained when HER2 was overexpressed in HER2 non-amplified cell lines. In contrast, NK cell ADCC failed to distinguish differences in tumor cell death when comparing gene-amplified and non-amplified breast cancer cell lines. The level of phagocytosis was influenced by FcγRIIa and FcγRIIIa expression. Most monocytes are FcγRIIIa-, and the induction of the receptor significantly enhances antibody-dependent phagocytosis. Although both receptors are involved, when blocked FcγRIIIa had a greater influence on phagocytosis. Furthermore, the polymorphism FcγRIIIa 158V significantly enhanced phagocytosis; whereas FcγRIIa 131H polymorphism appeared to improve phagocytosis but was not statistically significant. Targeting of monocytes for enhanced phagocytosis may improve the effectiveness of therapeutic antibodies to improve clinical outcomes.


Assuntos
Citotoxicidade Celular Dependente de Anticorpos/imunologia , Antineoplásicos Imunológicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Células Matadoras Naturais/imunologia , Monócitos/imunologia , Fagocitose , Anticorpos Monoclonais Humanizados/farmacologia , Citotoxicidade Celular Dependente de Anticorpos/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Feminino , Amplificação de Genes , Humanos , Células Matadoras Naturais/efeitos dos fármacos , Monócitos/efeitos dos fármacos , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Receptores de IgG/genética , Receptores de IgG/metabolismo , Trastuzumab/farmacologia , Células Tumorais Cultivadas
19.
Virus Res ; 253: 92-102, 2018 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-29857122

RESUMO

BACKGROUND: Hantaan virus infection causes lethal hemorrhagic fever with renal syndrome (HFRS) in humans. Little is known about how monocytes contribute to HFRS pathogenesis. In this study, we aimed to investigate changes in various monocyte subsets in HFRS patients. METHODS: A total of 41 HFRS patients and 17 age-, sex-, and ethnicity-matched healthy control subjects were included in this study. Numbers/percentages of various monocyte subsets were quantitatively determined using flow cytometry. Serum levels of interleukin (IL)-10, IL-12, and tumor necrosis factor alpha (TNF-α) were detected using a cytometric bead array (CBA). RESULTS: CD14++CD16+ intermediate monocytes were significantly higher in HFRS patients compared to healthy controls (P < 0.01), especially during the acute phase. The expression of both CD163 and CD206 on CD14++CD16+ intermediate monocytes were increased during the acute phase of HFRS (P < 0.01 and P < 0.05, respectively) when comparing the convalescent phase and healthy controls. Furthermore, the numbers of CD14++CD16+ monocytes during the acute phase, and the percentages of CD14++CD16+CD163+ monocytes in patients with severe/critical HFRS were much higher compared to patients with mild/moderate HFRS. This also positively correlated with increased levels of white blood cells (WBC), blood urea nitrogen (BUN), and creatinine (Cr). However, the percentages of CD14++CD16+CD206+monocytes were higher in mild/moderate HFRS than in severe/critical HFRS, and they negatively correlated with platelets (PLT) and Cr. CONCLUSIONS: Higher frequency of the CD14++CD16+ intermediate monocytes and increased expression of CD163+ and CD206+ markers on CD14++CD16+ monocytes were detected in patients with HFRS. The changes in the frequency of CD14++CD16+ monocytes and expression of CD163 and CD206 markers on CD14++CD16+ monocytes positively correlated with the severity of HFRS.


Assuntos
Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Febre Hemorrágica com Síndrome Renal/metabolismo , Nefropatias/metabolismo , Lectinas Tipo C/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Lectinas de Ligação a Manose/metabolismo , Monócitos/metabolismo , Receptores de Superfície Celular/metabolismo , Receptores de IgG/metabolismo , Adulto , Antígenos CD/genética , Antígenos de Diferenciação Mielomonocítica/genética , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Vírus Hantaan/fisiologia , Febre Hemorrágica com Síndrome Renal/genética , Febre Hemorrágica com Síndrome Renal/patologia , Febre Hemorrágica com Síndrome Renal/virologia , Humanos , Interleucina-10/sangue , Interleucina-12/sangue , Nefropatias/genética , Nefropatias/patologia , Nefropatias/virologia , Lectinas Tipo C/genética , Receptores de Lipopolissacarídeos/genética , Masculino , Lectinas de Ligação a Manose/genética , Pessoa de Meia-Idade , Receptores de Superfície Celular/genética , Receptores de IgG/genética , Índice de Gravidade de Doença , Fator de Necrose Tumoral alfa/sangue , Adulto Jovem
20.
Cell Mol Biol (Noisy-le-grand) ; 64(5): 97-101, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29729700

RESUMO

Lifetime blood transfusion experienced by major ß-thalassemia patients complicated with iron overload, therefore, may lead to their tissue injury. Ultimately, free toxic iron may alter immune response via dysregulation of immune cell activity producing prolonged effector reaction. Neutrophil as one of the vital innate immune cell despite serves as the first line of defense resulting acute inflammation has a pivotal role in chronic inflammation while releasing the toxic substance that interferes biological processes. This process is initiated by one of them by activation of Fcγ Receptor III (CD16), a neutrophil membrane-bound protein. A cross-sectional laboratory study involving lysed-erythrocyte heparinized whole blood of fifty pediatric major ß-thalassemia patients treated with monoclonal antibodies i.e. CD16, CD14, and HLA-DR, dissected into CD16+ and CD16++ population using flow cytometry. Expression of Fcγ Receptor III was measured as Median Fluorescent Intensity (MFI). Hematology and iron status were measured. A correlation analysis was done. MFI of CD16 neutrophil [509.5 (371 - 796.5)] and ferritin level [(3209 µg/L, 1862 - 4564)] was positively correlated (r = 0.4, P = 0.007). Respectively, ferritin and serum iron were found negatively correlated with segmented neutrophils (r = -0.3, P = 0.02; r = -0.3, P = 0.02). Change in CD16 expression may implicate preliminarily neutrophil activation as a response of iron-overloaded tissue and result in chronic inflammation in ß-thalassemia patients. However, the maturity of this cell may be altered.  Future study in the understanding of neutrophil-mediated inflammation, particularly related to immune complexes and functionality, is imperative to be explored.


Assuntos
Ferritinas/genética , Sobrecarga de Ferro/genética , Ferro/metabolismo , Neutrófilos/metabolismo , Receptores de IgG/genética , Talassemia beta/genética , Criança , Pré-Escolar , Estudos Transversais , Transfusão de Eritrócitos/efeitos adversos , Feminino , Ferritinas/sangue , Proteínas Ligadas por GPI/genética , Proteínas Ligadas por GPI/metabolismo , Regulação da Expressão Gênica , Humanos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/patologia , Masculino , Neutrófilos/patologia , Receptores de IgG/metabolismo , Talassemia beta/sangue , Talassemia beta/patologia
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