RESUMO
Dendritic cells (DCs) are professional antigen-presenting cells that play a crucial role in the priming and differentiation of CD4+ T cells into several distinct subsets including effector T helper (Th) 1, Th17 and Th2 cells, as well as regulatory T cells (Tregs). It is becoming increasingly clear that cellular metabolism shapes the functional properties of DCs. Specifically, the ability of DCs to drive polarization of different Th cell subsets may be orchestrated by the engagement of distinct metabolic pathways. In this review, we will discuss the recent advances in the DC metabolism field, by focusing on how cellular metabolism of DCs shapes their priming and polarization of distinct Th cell responses.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/imunologia , Células Dendríticas/imunologia , Ativação Linfocitária/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Animais , Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/metabolismo , Células Dendríticas/metabolismo , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Reguladores/metabolismoRESUMO
Dendritic cells (DC) are professional antigen presenting cells, uniquely able to induce naïve T cell activation and effector differentiation. They are, likewise, involved in the induction and maintenance of immune tolerance in homeostatic conditions. Their phenotypic and functional heterogeneity points to their great plasticity and ability to modulate, according to their microenvironment, the acquired immune response and, at the same time, makes their precise classification complex and frequently subject to reviews and improvement. This review will present general aspects of the DC physiology and classification and will address their potential and actual uses in the management of human disease, more specifically cancer, as therapeutic and monitoring tools. New combination treatments with the participation of DC will be also discussed.
Assuntos
Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Neoplasias/imunologia , Neoplasias/terapia , Animais , Biomarcadores , Vacinas Anticâncer , Diferenciação Celular , Terapia Combinada , Células Dendríticas/citologia , Humanos , Sistema Imunitário/imunologia , Sistema Imunitário/metabolismo , Fenômenos do Sistema Imunitário , Imunoterapia , Neoplasias/patologia , Fenótipo , Resultado do Tratamento , Microambiente Tumoral/imunologiaRESUMO
BACKGROUND: A functional variant in the promoter region of the gene encoding tumor necrosis factor (TNF; rs1800629, -308G>A) showed to confer susceptibility to T1D. However, TNF rs1800629 was found, in several populations, to be in linkage disequilibrium with HLA susceptibility haplotypes to T1D. We evaluated the association of TNF rs1800629 with T1D in a cohort of Brazilian subjects, and assessed the impact of HLA susceptibility haplotypes in this association. METHODS: 659 subjects with T1D and 539 control subjects were genotyped for TNF-308G>A variant. HLA-DRB1 and HLA-DQB1 genes were genotyped in a subset of 313 subjects with T1D and 139 control subjects. RESULTS: Associations with T1D were observed for the A-allele of rs1800629 (OR 1.69, 95% CI 1.33-2.15, p<0.0001, in a codominant model) and for 3 HLA haplotypes: DRB1*03:01-DQB1*02:01 (OR 5.37, 95% CI 3.23-8.59, p<0.0001), DRB1*04:01-DQB1*03:02 (OR 2.95, 95% CI 1.21-7.21, p=0.01) and DRB1*04:02-DQB1*03:02 (OR 2.14, 95% CI 1.02-4.50, p=0.04). Linkage disequilibrium was observed between TNF rs1800629 and HLA-DRB1 and HLA-DQB1 alleles. In a stepwise regression analysis HLA haplotypes, but not TNF rs1800629, remained independently associated with T1D. CONCLUSION: Our results do not support an independent effect of allelic variations of TNF in the genetic susceptibility to T1D.
Assuntos
Diabetes Mellitus Tipo 1/genética , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Fator de Necrose Tumoral alfa/genética , Adulto , Brasil , Estudos de Casos e Controles , Feminino , Genes Dominantes , Estudos de Associação Genética , Predisposição Genética para Doença , Haplótipos , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Adulto JovemRESUMO
Oxidative stress plays a pivotal role in the pathophysiology of diabetic nephropathy, and the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system is an important source of reactive oxygen species in hyperglycemic conditions in the kidney. Plasma concentration of advanced oxidation protein products (AOPP), a marker of oxidative stress, is increased in patients with diabetic nephropathy. We investigated associations of variants in the CYBA gene, encoding the regulatory subunit p22(phox) of NADPH oxidase, with diabetic nephropathy and plasma AOPP and myeloperoxidase (MPO) concentrations in type 1 diabetic patients. Seven SNPs in the CYBA region were analyzed in 1357 Caucasian subjects with type 1 diabetes from the SURGENE (n=340), GENEDIAB (n=444), and GENESIS (n=573) cohorts. Duration of follow-up was 10, 9, and 6 years, respectively. Cox proportional hazards and logistic regression analyses were used to estimate hazard ratios (HR) or odds ratios (OR) for incidence and prevalence of diabetic nephropathy. The major G-allele of rs9932581 was associated with the incidence of renal events defined as new cases of microalbuminuria or the progression to a more severe stage of nephropathy during follow-up (HR 1.59, 95% CI 1.17-2.18, P=0.003) in SURGENE. The same allele was associated with established/advanced nephropathy (OR 1.52, 95% CI 1.22-1.92, P=0.0001) and with the incidence of end-stage renal disease (ESRD) (HR 2.01, 95% CI 1.30-3.24, P=0.001) in GENEDIAB/GENESIS pooled studies. The risk allele was also associated with higher plasma AOPP concentration in subsets of SURGENE and GENEDIAB, with higher plasma MPO concentration in a subset of GENEDIAB, and with lower estimated glomerular filtration rate (eGFR) in the three cohorts. In conclusion, a functional variant in the promoter of the CYBA gene was associated with lower eGFR and with prevalence and incidence of diabetic nephropathy and ESRD in type 1 diabetic patients. These results are consistent with a role for NADPH oxidase in the pathophysiology of kidney complications of diabetes.
Assuntos
Diabetes Mellitus Tipo 1/genética , Nefropatias Diabéticas/genética , Falência Renal Crônica/genética , NADPH Oxidases/genética , Adulto , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/epidemiologia , Nefropatias Diabéticas/epidemiologia , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Incidência , Falência Renal Crônica/epidemiologia , Pessoa de Meia-Idade , Estresse Oxidativo , Polimorfismo de Nucleotídeo Único , Regiões Promotoras Genéticas , Estudos Prospectivos , Risco , Adulto JovemRESUMO
AIMS/HYPOTHESIS: Oxidative stress is involved in the pathogenesis of diabetic nephropathy. The antioxidant enzyme catalase plays a key role in redox regulation in the kidney. We investigated associations of catalase gene (CAT) polymorphisms and plasma catalase activity with diabetic nephropathy in type 1 diabetic patients. METHODS: We genotyped nine single nucleotide polymorphisms (SNPs) in the CAT region in participants from the Survival Genetic Nephropathy (SURGENE) (340 French participants, 10 year follow-up) and the Génétique de la Néphropathie Diabétique (GENEDIAB) (444 Belgian and French participants, 8 year follow-up) study cohorts. Replication was performed in a Brazilian cross-sectional cohort (n = 451). Baseline plasma catalase activity was measured in SURGENE (n = 120) and GENEDIAB (n = 391) participants. RESULTS: The A allele of rs7947841 was associated with the prevalence of incipient (OR 2.79, 95% CI 1.21, 6.24, p = 0.01) and established or advanced nephropathy (OR 5.72, 95% CI 1.62, 22.03, p = 0.007), and with the incidence of renal events, which were defined as new cases of microalbuminuria or progression to a more severe stage of nephropathy during follow-up (HR 1.82, 95% CI 1.13, 2.81, p = 0.01) in SURGENE participants. The same risk allele was associated with incipient nephropathy (OR 3.13, 95% CI 1.42, 7.24, p = 0.004) and with the incidence of end-stage renal disease (ESRD) (HR 2.11, 95% CI 1.23, 3.60, p = 0.008) in GENEDIAB participants. In both cohorts, the risk allele was associated with lower catalase activity. Associations with incipient and established or advanced nephropathy were confirmed in the replication cohort. CONCLUSIONS/INTERPRETATION: CAT variants were associated with the prevalence and incidence of diabetic nephropathy and ESRD in type 1 diabetic patients. Our results confirm the protective role of catalase against oxidative stress in the kidney.