RESUMO
Innate immunity receptors (Toll-like receptors/TLRs and RIG-like receptors/RLRs) are important for the initial recognition of Zika virus (ZIKV), modulation of protective immune response, and IFN-α and IFN-ß production. Immunological mechanisms involved in protection or pathology during ZIKV infection have not yet been determined. In this study, we evaluated the mRNA expression of innate immune receptors (TLR3, TLR7, TLR8, TLR9, melanoma differentiation-associated protein 5/MDA-5, and retinoic acid inducible gene/RIG-1), its adapter molecules (Myeloid Differentiation Primary Response Gene 88/Myd88, Toll/IL-1 Receptor Domain-Containing Adaptor-Inducing IFN-ß/TRIF), and cytokines (IL-6, IL-12, TNF-α, IFN-α, IFN-ß, and IFN-γ) in the acute phase of patients infected by ZIKV using real-time PCR in peripheral blood. Patients with acute ZIKV infection had high expression of TLR3, IFN-α, IFN-ß, and IFN-γ when compared to healthy controls. In addition, there was a positive correlation between TLR3 expression compared to IFN-α and IFN-ß. Moreover, viral load is positively correlated with TLR8, RIG-1, MDA-5, IFN-α, and IFN-ß. On the other hand, patients infected by ZIKV showed reduced expression of RIG-1, TLR8, Myd88, and TNF-α molecules, which are also involved in antiviral immunity. Similar expressions of TLR7, TLR9, MDA-5, TRIF, IL-6, and IL-12 were observed between the group of patients infected with ZIKV and control subjects. Our results indicate that acute infection (up to 5 days after the onset of symptoms) by ZIKV in patients induces the high mRNA expression of TLR3 correlated to high expression of IFN-γ, IFN-α, and IFN-ß, even though the high viral load is correlated to high expression of TLR8, RIG-1, MDA-5, IFN-α, and IFN-ß in ZIKV patients.
Assuntos
Imunidade Inata , Fatores Imunológicos/biossíntese , Receptores Imunológicos/biossíntese , Infecção por Zika virus/imunologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Carga Viral , Zika virus/isolamento & purificaçãoRESUMO
BACKGROUND: The leishmaniases are important neglected diseases caused by Leishmania spp. which are transmitted by sand flies, Lutzomyia longipalpis being the main vector of visceral leishmaniasis in the Americas. The methodologies for leishmaniasis control are not efficient, causing 1.5 million reported cases annually worldwide, therefore showing the need for development of novel strategies and interventions to control transmission of the disease. The bacterium Wolbachia pipientis is being used to control viruses transmitted by mosquitoes, such as dengue and Zika, and its introduction in disease vectors has been effective against parasites such as Plasmodium. Here we show the first successful establishment of Wolbachia into two different embryonic cell lines from L. longipalpis, LL-5 and Lulo, and analysed its effects on the sand fly innate immune system, followed by in vitro Leishmania infantum interaction. RESULTS: Our results show that LL-5 cells respond to wMel and wMelPop-CLA strains within the first 72 h post-infection, through the expression of antimicrobial peptides and inducible nitric oxide synthase resulting in a decrease of Wolbachia detection in the early stages of infection. In subsequent passages, the wMel strain was not able to infect any of the sand fly cell lines while the wMelPop-CLA strain was able to stably infect Lulo cells and LL-5 at lower levels. In Wolbachia stably infected cells, the expression of immune-related genes involved with downregulation of the IMD, Toll and Jak-Stat innate immune pathways was significantly decreased, in comparison with the uninfected control, suggesting immune activation upon Wolbachia transinfection. Furthermore, Wolbachia transinfection did not promote a negative effect on parasite load in those cells. CONCLUSIONS: Initial strong immune responses of LL5 cells might explain the inefficiency of stable infections in these cells while we found that Lulo cells are more permissive to infection with Wolbachia causing an effect on the cell immune system, but not against in vitro L. infantum interaction. This establishes Lulo cells as a good system for the adaptation of Wolbachia in L. longipalpis.
Assuntos
Expressão Gênica , Imunidade Inata , Fatores Imunológicos/biossíntese , Leishmania infantum/crescimento & desenvolvimento , Interações Microbianas , Psychodidae/imunologia , Wolbachia/imunologia , Animais , Linhagem Celular , Carga Parasitária , Psychodidae/microbiologia , Wolbachia/crescimento & desenvolvimentoRESUMO
Oral mucositis is an important dose-limiting and costly side effect of cancer chemotherapy. Soluble proteins obtained of the latex of Calotropis procera have been extensively characterized as anti-inflammatory in different experimentally induced inflammatory conditions, including arthritis and sepsis. In this study, the phytomodulatory laticifer proteins (LP) were challenged to regress the inflammatory events associated with 5-fluorouracil-induced oral mucositis. We also evaluated the expression of pro-inflammatory cytokines and inducible enzymes, such as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS). Oral mucositis was induced in hamsters by two injections of 5-fluorouracil (5-FU; 60 and 40 mg/kg, i.p., on experimental days 1 and 2, respectively). LP (5 mg/kg, i.p.) was injected 24 h before and 24 h after mechanical trauma of the cheek pouches. A normal control group received only saline. On day 10, the animals were sacrificed, and the cheek pouches were excised for macroscopic and histopathological analysis, myeloperoxidase activity measurement, and immunohistochemical assessment of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), iNOS, and COX-2. LP significantly inhibited macroscopic histopathological scores and myeloperoxidase activity compared with the 5-FU control group. 5-Fluorouracil also induced marked immunostaining of TNF-α, IL-1ß, iNOS, and COX-2 on inflamed conjunctive and epithelial tissue compared with the normal control group. Such damage was significantly inhibited (p < 0.05) by LP treatment compared with the 5-FU group. These findings demonstrate an anti-inflammatory effect of LP on 5-FU-induced oral mucositis. The protective mechanism appears to involve inhibition of the expression of iNOS, COX-2, TNF-α, and IL-1ß.
Assuntos
Antimetabólitos Antineoplásicos/efeitos adversos , Calotropis/química , Fluoruracila/efeitos adversos , Fatores Imunológicos/imunologia , Látex/química , Proteínas de Plantas/uso terapêutico , Estomatite/prevenção & controle , Animais , Cricetinae , Ciclo-Oxigenase 2/biossíntese , Ciclo-Oxigenase 2/imunologia , Citocinas/biossíntese , Citocinas/imunologia , Modelos Animais de Doenças , Regulação para Baixo , Imuno-Histoquímica , Fatores Imunológicos/biossíntese , Masculino , Mesocricetus , Óxido Nítrico Sintase Tipo II/biossíntese , Óxido Nítrico Sintase Tipo II/imunologia , Peroxidase/metabolismo , Proteínas de Plantas/administração & dosagem , Proteínas de Plantas/isolamento & purificação , Estomatite/induzido quimicamente , Estomatite/imunologia , Estomatite/patologiaRESUMO
Helminths secrete several molecules that can modulate the immune responses, favoring their evasion and perpetuate their survival in the host. These molecules interfere with antigen presentation, cell proliferation and activation, antibody production, cause cell death, and stimulate regulatory responses. Here, we focus on some helminth products and address their immunomodulatory effects in the host immune system and, also, we describe some anti-inflammatory properties of an Ascaris suum-derived immunomodulatory molecule, named PAS-1. This protein is a 200-kDa molecule isolated by affinity chromatography using MAIP-1 (monoclonal antibody which recognizes PAS-1), coupled to Sepharose 4B. It suppresses the inflammatory responses in murine models of delayed-type hypersensitivity, lung allergic inflammation and LPS-induced inflammation into air pouches. PAS-1 also stimulates the secretion of regulatory cytokines such as IL-10 and TGF-beta and primes IFN-gamma-secreting CD8+ and IL-10/ TGF-beta-secreting CD4+CD25+ cell clones that avoid the lung inflammation. Thus, this protein is a potent immunomodulatory component that may be used for therapeutic interventions in inflammatory diseases.