RESUMO
BACKGROUND: Syphilis is a chronic infectious disease caused by Treponema pallidum (Tp) infection, which causes local inflammation in the host. TpF1 is an oligomeric protein expressed by the Tp-infected host that can induce the host immune response. There are few studies regarding the role of TpF1 in macrophage activation and the subsequent release of cytokines. OBJECTIVE: The objective of this study is to elucidate the effects of TpF1 on the pathological process of Syphilis. In addition, we explored how purinergic 2X7 (P2X7R) induced NOD-like receptor family protein 3 (NLRP3) -dependent release of interleukin-1ß (IL-1ß) and the underlying mechanisms. METHODS: We explored the influence of TpF1 on cytokine release by macrophages using qRT-PCR and ELISA. The specific phenotype of activated macrophages was determined by flow cytometry. RESULTS: TpF1 was able to activate macrophages and induce the M1 macrophage phenotype. Moreover, TpF1 activated the NLRP3 inflammasome in macrophages, which was mediated by P2X7R. CONCLUSION: The Tp-induced protein TpF1 is able to induce macrophage activation and P2X7R-induced NLRP3-dependent release of IL-1ß. Our findings provide a theoretical basis for clarifying the clinical symptoms and pathogenesis of syphilis.
Assuntos
Antígenos de Bactérias , Ativação de Macrófagos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Sífilis , Antígenos de Bactérias/imunologia , Citocinas/metabolismo , Humanos , Interleucina-1beta/metabolismo , Macrófagos/imunologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Receptores Purinérgicos P2X7/genética , Receptores Purinérgicos P2X7/metabolismo , Sífilis/imunologia , Treponema pallidumRESUMO
Proteins entering the secretory pathway of eukaryotic cells are folded into their native structures in the endoplasmic reticulum (ER). Disruption of protein folding causes ER stress and activates signaling cascades, designated the unfolded protein response (UPR), that restore folding capacity. In mammals and yeast, the protein disulfide isomerases (PDIs) are key protein folding catalysts activated during UPR. However, little is known about the response of PDI genes to UPR in plants. In Arabidopsis thaliana, we identified 12 PDI genes that differed in polypeptide length, presence of signal peptide and ER retention signal, and the number and positions of thioredoxin and transmembrane domains. AtPDI gene expression was investigated in different tissues, in response to chemically induced UPR, and in null mutants of UPR signaling mediators (AtIRE1-2 and AtbZIP60). The expression of six AtPDI genes was significantly up-regulated by UPR and sharply attenuated by the transcription inhibitor, actinomycin D, indicating UPR induced AtPDI gene transcription. AtPDI and BIP2 (Binding protein) gene expression was not affected in the Atire1-2 mutant exposed to UPR, however, the expression of four AtPDI genes was decreased in the Atbzip60 mutant. We proposed that additional UPR signaling factors complement AtbZIP60 in the activation of AtPDI gene expression during ER stress in plants.
Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/enzimologia , Arabidopsis/genética , Fatores de Transcrição de Zíper de Leucina Básica/genética , Retículo Endoplasmático/patologia , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Isomerases de Dissulfetos de Proteínas/genética , Arabidopsis/efeitos dos fármacos , Proteínas de Arabidopsis/metabolismo , Fatores de Transcrição de Zíper de Leucina Básica/metabolismo , Dactinomicina/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Retículo Endoplasmático/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Mutação/genética , Filogenia , Proteínas Quinases/metabolismo , Sinais Direcionadores de Proteínas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/genética , Análise de Sequência de DNA , Transcrição Gênica/efeitos dos fármacos , Tunicamicina/farmacologiaRESUMO
Disruption of the protein-folding capacity in the ER induces the accumulation of unfolded proteins and ER stress, which activate the unfolded protein response (UPR). Although UPR has been extensively studied in yeast and mammals, much less is known about UPR and its relationship with light in plants. Here, we examined the effects of chemically induced UPR and light on a molecular marker of UPR (binding protein, BiP2, gene expression) and a secretory green fluorescent protein marker (GFP-2SC) that is trafficked from the ER to vacuole in Arabidopsis thaliana (L). UPR, which was induced by DTT and tunicamycin (TM), increased Bip2 mRNA levels and decreased the levels of microsomal and vacuolar forms of GFP-2SC. Treatment with protease inhibitors lessened the effects of DTT and TM on GFP-2SC, indicating the decrease in GFP levels partially involved protein degradation. Light treatments synergistically enhanced the decrease in GFP levels in both the ER and vacuole and induced the expression of UPR marker genes for BiP2 and protein disulfide isomerase (PDI, EC 5.3.4.1). DTT and TM treatments required light for maximal induction of the UPR. Light-induced UPR occurred during the daily dark to light cycle and when dark-adapted plants were exposed to light. We propose that light activates the UPR to increase the protein folding capacity in the ER to accommodate an increase in translation during dark to light transitions.