RESUMEN
Macrophages play a pivotal role in tissue homeostasis, pathogen defense, and inflammation resolution. M1 and M2 macrophage phenotypes represent two faces in a spectrum of responses to microenvironmental changes, crucial in both physiological and pathological conditions. Neuraminidase 1 (Neu1), a lysosomal and cell surface sialidase responsible for removing terminal sialic acid residues from glycoconjugates, modulates several macrophage functions, including phagocytosis and Toll-like receptor (TLR) signaling. Current evidence suggests that Neu1 expression influences M1/M2 macrophage phenotype alterations in the context of cardiovascular diseases, indicating a potential role for Neu1 in macrophage polarization. For this reason, we investigated the impact of Neu1 deficiency on macrophage polarization in vitro and in vivo. Using bone marrow-derived macrophages (BMDMs) and peritoneal macrophages from Neu1 knockout (Neu1-/- ) mice and wild-type (WT) littermate controls, we demonstrated that Neu1-deficient macrophages exhibit an aberrant M2-like phenotype, characterized by elevated macrophage mannose receptor 1 (MMR/CD206) expression and reduced responsiveness to M1 stimuli. This M2-like phenotype was also observed in vivo in peritoneal and splenic macrophages. However, lymph node (LN) macrophages from Neu1-/- mice exhibited phenotypic alterations with reduced CD206 expression. Further analysis revealed that peripheral LNs from Neu1-/- mice were highly fibrotic, with overexpression of transforming growth factor-beta 1 (TGF-ß1) and hyperactivated TGF-ß signaling in LN macrophages. Consistently, TGF-ß1 was found to alter M1/M2 macrophage polarization in vitro. Our findings showed that Neu1 deficiency prompts macrophages towards an M2 phenotype and that microenvironmental changes, particularly increased TGF-ß1 in fibrotic tissues such as peripheral LNs in Neu1-/- mice, further influence M1/M2 macrophage polarization, highlighting its sensitivity to the local microenvironment. Therapeutic interventions targeting Neu1 or TGF-ß signaling pathways may offer the potential to regulate macrophage behavior across different diseases.
Asunto(s)
Microambiente Celular , Fibrosis , Ganglios Linfáticos , Macrófagos , Ratones Noqueados , Neuraminidasa , Animales , Ratones , Macrófagos/inmunología , Macrófagos/metabolismo , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Neuraminidasa/deficiencia , Neuraminidasa/genética , Neuraminidasa/metabolismo , Ratones Endogámicos C57BL , Activación de Macrófagos , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/deficiencia , Macrófagos Peritoneales/inmunología , Macrófagos Peritoneales/metabolismo , Células Cultivadas , Transducción de Señal , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores de Superficie Celular/deficiencia , Receptor de Manosa , Fenotipo , Factor de Crecimiento Transformador beta1/metabolismoRESUMEN
The immunopathogenesis of recurrent vulvovaginal candidiasis (RVVC) is poorly understood. Recently, it was reported that patients with RVVC present a decrease in both the fungicidal capacity of neutrophils and the proliferative capability of peripheral blood mononuclear cells in response to Candida albicans infection, suggesting an alteration in the innate and adaptive immune response. The aim of this study was to determine the in-situ expression, in the vaginal mucosa, of genes associated with the immune response, as well as the serum concentrations of dectin-1, mannose-binding lectin (MBL), and vitamin D in patients with RVVC. A study was carried out on 40 patients with a diagnosis of RVVC and 26 healthy women. Vaginal scrapings were obtained, and the expression of genes that encode cytokines and transcription factors specific for Th1, Th2, Th17, Treg, pro-inflammatory profiles, and enzymes related to oxidative/microbicidal mechanisms was evaluated by quantitiative polymerase chain reaction (qPCR). Additionally, serum levels of vitamin D and the soluble receptors dectin-1 and MBL were determined by enzyme-linked immunosorbent assay (ELISA). In patients with RVVC, a decreased expression of T-bet, RORγ-T, IL-1ß, and IL-17, and an increase in the expression of FOXP3, IL-4, IL-8, IL-10, and IL-18 were observed when compared to healthy women: moreover, decreased levels of MBL were also observed in these patients. These results confirm that patients with RVVC present in-situ alterations in both the specific and adaptive immune response against Candida spp., a fact that could be associated with the exaggerated vaginal inflammatory response.
The study concerns the immune response of women with recurrent vulvovaginal candidiasis; we observed an alteration in the expression of genes that participate in the control of infection, a fact that could be associated with the exaggerated vaginal inflammatory response observed in those patients.
Asunto(s)
Candidiasis Vulvovaginal , Citocinas , Lectinas Tipo C , Vagina , Vitamina D , Humanos , Candidiasis Vulvovaginal/inmunología , Candidiasis Vulvovaginal/microbiología , Femenino , Lectinas Tipo C/genética , Adulto , Citocinas/sangre , Vagina/microbiología , Vagina/inmunología , Vitamina D/sangre , Adulto Joven , Recurrencia , Lectina de Unión a Manosa/sangre , Lectina de Unión a Manosa/genética , Membrana Mucosa/inmunología , Membrana Mucosa/microbiología , Candida albicans/inmunologíaRESUMEN
BACKGROUND: Dectin-1 is a transmembrane receptor that plays a pivotal role in recognising fungi and Mycobacterium tuberculosis (Mtb). A specific variant, DECTIN-1 rs16910526, results in a truncated receptor that disrupts membrane expression and ligand binding and is clinically associated with recurrent cutaneous mycoses. Previous research has clarified the role of Dectin-1 in boosting immune defenses against mycobacteria by enhancing reactive oxygen species (ROS) production in neutrophils (PMNs). Here, we investigated the association between the rs16910526 variant and Dectin-1 expression in PMNs, as well as intracellular ROS production in response to Mtb. Furthermore, we explored the potential link between the rs16910526 gene variant and TB outcomes in Argentina. METHODS: DNA was extracted from blood samples obtained from a cohort of 178 TB patients and healthy subjects (HS) in Argentina. PCR amplification and sequencing were performed to identify the rs16910526 variant. Flow cytometry was utilised to assess Dectin-1 expression on the PMN plasma membrane and to measure intracellular ROS levels, as indicated by the oxidation of DHR123 in response to the Mtb antigen. RESULTS: PMNs carrying the rs16910526 variant exhibited diminished Dectin-1 expression and ROS production in response to Mtb (p < 0.0001). In a caseâcontrol study, the rs16910526 variant had an allelic frequency of 0.112 in TB patients and 0.051 in HS. Notably, 10 out of 88 HS and 18 out of 62 TB patients harboured the variant (odds ratio [OR]: 2.55 [95% CI 1.1-5.9, p = 0.03]), indicating a potential association with TB disease. Furthermore, TB patients with the rs16910526 variant exhibited a delayed sputum smear conversion time (p < 0.004) and 100% positivity for acid-fast bacilli smears (p < 0.00001). CONCLUSION: Our study identified a significant association between the SNP variant rs16910526 in the DECTIN-1 gene and Dectin-1 expression in the PMN, leading to altered ROS production. The higher frequency of this variant in TB patients compared to HS suggests a possible link with susceptibility to TB disease in Argentina.
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Predisposición Genética a la Enfermedad , Lectinas Tipo C , Especies Reactivas de Oxígeno , Tuberculosis , Humanos , Especies Reactivas de Oxígeno/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Masculino , Femenino , Adulto , Tuberculosis/genética , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Neutrófilos/metabolismo , Mycobacterium tuberculosisRESUMEN
Background: Paracoccidioidomycosis (PCM) is a systemic endemic fungal disease prevalent in Latin America. Previous studies revealed that host immunity against PCM is tightly regulated by several suppressive mechanisms mediated by tolerogenic plasmacytoid dendritic cells, the enzyme 2,3 indoleamine dioxygenase (IDO-1), regulatory T-cells (Tregs), and through the recruitment and activation of myeloid-derived suppressor cells (MDSCs). We have recently shown that Dectin-1, TLR2, and TLR4 signaling influence the IDO-1-mediated suppression caused by MDSCs. However, the contribution of these receptors in the production of important immunosuppressive molecules used by MDSCs has not yet been explored in pulmonary PCM. Methods: We evaluated the expression of PD-L1, IL-10, as well as nitrotyrosine by MDSCs after anti-Dectin-1, anti-TLR2, and anti-TLR4 antibody treatment followed by P. brasiliensis yeasts challenge in vitro. We also investigated the influence of PD-L1, IL-10, and nitrotyrosine in the suppressive activity of lung-infiltrating MDSCs of C57BL/6-WT, Dectin-1KO, TLR2KO, and TLR4KO mice after in vivo fungal infection. The suppressive activity of MDSCs was evaluated in cocultures of isolated MDSCs with activated T-cells. Results: A reduced expression of IL-10 and nitrotyrosine was observed after in vitro anti-Dectin-1 treatment of MDSCs challenged with fungal cells. This finding was further confirmed in vitro and in vivo by using Dectin-1KO mice. Furthermore, MDSCs derived from Dectin-1KO mice showed a significantly reduced immunosuppressive activity on the proliferation of CD4+ and CD8+ T lymphocytes. Blocking of TLR2 and TLR4 by mAbs and using MDSCs from TLR2KO and TLR4KO mice also reduced the production of suppressive molecules induced by fungal challenge. In vitro, MDSCs from TLR4KO mice presented a reduced suppressive capacity over the proliferation of CD4+ T-cells. Conclusion: We showed that the pathogen recognition receptors (PRRs) Dectin-1, TLR2, and TLR4 contribute to the suppressive activity of MDSCs by inducing the expression of several immunosuppressive molecules such as PD-L1, IL-10, and nitrotyrosine. This is the first demonstration of a complex network of PRRs signaling in the induction of several suppressive molecules by MDSCs and its contribution to the immunosuppressive mechanisms that control immunity and severity of pulmonary PCM.
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Antígeno B7-H1 , Modelos Animales de Enfermedad , Interleucina-10 , Lectinas Tipo C , Ratones Endogámicos C57BL , Células Supresoras de Origen Mieloide , Paracoccidioidomicosis , Receptor Toll-Like 2 , Receptor Toll-Like 4 , Animales , Ratones , Interleucina-10/metabolismo , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 2/genética , Receptor Toll-Like 2/inmunología , Células Supresoras de Origen Mieloide/inmunología , Células Supresoras de Origen Mieloide/metabolismo , Receptor Toll-Like 4/metabolismo , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/inmunología , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Antígeno B7-H1/metabolismo , Antígeno B7-H1/genética , Paracoccidioidomicosis/inmunología , Paracoccidioides/inmunología , Tirosina/análogos & derivados , Tirosina/metabolismo , Linfocitos T Reguladores/inmunología , Pulmón/inmunología , Pulmón/microbiología , Transducción de Señal , Masculino , Indolamina-Pirrol 2,3,-Dioxigenasa/metabolismo , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Ratones NoqueadosRESUMEN
Although non-front fanged snakes account for almost two-thirds of snake diversity, most studies on venom composition and evolution focus exclusively on front-fanged species, which comprise most of the clinically relevant accidents. Comprehensive reports on venom composition of non-front fanged snakes are still scarce for several groups. In this study, we address such shortage of knowledge by providing new insights about the venom composition among species of Phalotris, a poorly studied Neotropical dipsadid genus. Phalotris are known for their specialized venom delivery system and toxic venoms, which can cause life-threatening accidents in humans. We evaluate the venom-gland transcriptome of Phalotris, comparing the following three South American species: P. reticulatus for the Araucaria Pine forests, P. lemniscatus for the Pampa grasslands, and P. mertensi for the Brazilian Cerrado. Our results indicate similar venom profiles, in which they share a high expression level of Kunitz-type inhibitors (KUNZ). On the other hand, comparative analyses revealed substantial differences in the expression levels of C-type lectins (CTL) and snake venom metalloproteinases (SVMP). The diverse set of SVMP and CTL isoforms shows signals of positive selection, and we also identified truncated forms of type III SVMPs, which resemble type II and type I SVMPs of viperids. Additionally, we identified a CNP precursor hosting a proline-rich region containing a BPP motif resembling those commonly detected in viperid venoms with hypotensive activity. Altogether, our results suggest an evolutionary history favoring high expression levels of few KUNZ isoforms in Phalotris venoms, contrasting with a highly diverse set of SVMP and CTL isoforms. Such diversity can be comparable with the venom variability observed in some viperids. Our findings highlight the extreme phenotypic diversity of non-front fanged snakes and the importance to allocate greater effort to study neglected groups of Colubroidea.
Asunto(s)
Transcriptoma , Animales , Venenos de Serpiente/genética , Lectinas Tipo C/genética , Brasil , Metaloproteasas/genéticaRESUMEN
The Red Queen Hypothesis (RQH), derived from Lewis Carroll's "Through the Looking-Glass", postulates that organisms must continually adapt in response to each other to maintain relative fitness. Within the context of host-pathogen interactions, the RQH implies an evolutionary arms race, wherein viruses evolve to exploit hosts and hosts evolve to resist viral invasion. This study delves into the dynamics of the RQH in the context of virus-cell interactions, specifically focusing on virus receptors and cell receptors. We observed multiple virus-host systems and noted patterns of co-evolution. As viruses evolved receptor-binding proteins to effectively engage with cell receptors, cells countered by altering their receptor genes. This ongoing mutual adaptation cycle has influenced the molecular intricacies of receptor-ligand interactions. Our data supports the RQH as a driving force behind the diversification and specialization of both viral and host cell receptors. Understanding this co-evolutionary dance offers insights into the unpredictability of emerging viral diseases and potential therapeutic interventions. Future research is crucial to dissect the nuanced molecular changes and the broader ecological consequences of this ever-evolving battle. Here, we combine phylogenetic inferences, structural modeling, and molecular dynamics analyses to describe the epidemiological characteristics of major Brazilian DENV strains that circulated from 1990 to 2022 from a combined perspective, thus providing us with a more detailed picture on the dynamics of such interactions over time.
Asunto(s)
Moléculas de Adhesión Celular , Virus del Dengue , Evolución Molecular , Interacciones Huésped-Patógeno , Receptores de Superficie Celular , Proteínas del Envoltorio Viral , Envoltura Viral , Humanos , Brasil , Moléculas de Adhesión Celular/metabolismo , Moléculas de Adhesión Celular/genética , Moléculas de Adhesión Celular/química , Dengue/virología , Virus del Dengue/genética , Virus del Dengue/metabolismo , Interacciones Huésped-Patógeno/genética , Lectinas Tipo C/metabolismo , Lectinas Tipo C/genética , Lectinas Tipo C/química , Simulación de Dinámica Molecular , Filogenia , Unión Proteica , Receptores de Superficie Celular/metabolismo , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/química , Receptores Virales/metabolismo , Receptores Virales/química , Receptores Virales/genética , Envoltura Viral/metabolismo , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/metabolismo , Proteínas del Envoltorio Viral/químicaRESUMEN
The immune response is crucial for coronavirus disease 19 (COVID-19) progression, with the participation of proinflammatory cells and cytokines, inducing lung injury and loss of respiratory function. CLEC5A expression on monocytes can be triggered by viral and bacterial infections, leading to poor outcomes. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is able to induce neutrophil activation by CLEC5A and Toll-like receptor 2, leading to an aggressive inflammatory cascade, but little is known about the molecular interactions between CLEC5A and SARS-CoV-2 proteins. Here, we aimed to explore how CLEC5A expression could be affected by SARS-CoV-2 infection using immunological tools with in vitro, in vivo, and in silico assays. The findings revealed that high levels of CLEC5A expression were found in monocytes from severe COVID-19 patients in comparison with mild COVID-19 and unexposed subjects, but not in vaccinated subjects who developed mild COVID-19. In hamsters, we detected CLEC5A gene expression during 3-15 days of Omicron strain viral challenge. Our results also showed that CLEC5A can interact with SARS-CoV-2, promoting inflammatory cytokine production, probably through an interaction with the receptor-binding domain in the N-acetylglucosamine binding site (NAG-601). The high expression of CLEC5A and high levels of proinflammatory cytokine production were reduced in vitro by a human CLEC5A monoclonal antibody. Finally, CLEC5A was triggered by spike glycoprotein, suggesting its involvement in COVID-19 progression; therapy with a monoclonal antibody could be a good strategy for COVID-19 treatment, but vaccines are still the best option to avoid hospitalization/deaths.
Asunto(s)
COVID-19 , Humanos , SARS-CoV-2 , Tratamiento Farmacológico de COVID-19 , Glicoproteína de la Espiga del Coronavirus , Citocinas , Anticuerpos Monoclonales , Glicoproteínas , Receptores de Superficie Celular/genética , Lectinas Tipo C/genéticaRESUMEN
Fasciola hepatica, one of the agents that causes fasciolosis, modulates the host immune system to allow parasite survival in the host. F. hepatica expresses carbohydrate-containing glycoconjugates that are decoded by C-type lectin receptors, such as Dectin-1, mannose receptor, DC-SIGN and MGL, that are mainly present on myeloid antigen presenting cells (APCs) and can mediate immunoregulatory properties on T cells. In particular, Macrophage Gal/GalNAc lectin 2 (MGL2) expands modified Th2 immune responses, while suppressing Th1 polarization, upon recognition of GalNAc-glycosylated parasite components. In this study, by using MGL2-DTR transgenic mice that encode human diphtheria toxin receptor in MGL2+ cells, we demonstrate the role of peritoneal APCs during F. hepatica infection in favoring parasite survival. This process might be mediated by the induction of splenic Tregs in vivo, since the depletion of MGL2+ cells conferred mice with partial resistance to the infection and abrogated the increase of CD4+/CD25+ FoxP3+ Tregs induced by the parasite. Therefore, MGL2+ cells are critical determinants of F. hepatica infection and could constitute immune checkpoints to control parasite infection.
Asunto(s)
Fasciola hepatica , Fascioliasis , Humanos , Ratones , Animales , Factor de Crecimiento Similar a EGF de Unión a Heparina , Linfocitos T Reguladores , Fascioliasis/parasitología , Lectinas Tipo C/genética , Células Presentadoras de Antígenos , Glicoconjugados , Macrófagos , Factores de Transcripción ForkheadRESUMEN
OBJECTIVE: The current work aimed to investigate the expression and potential clinical significance of C-type Lectin domain family 14 (CLEC14A) in hepatocellular carcinoma. METHODS: The relative expressions of CLEC14A in the Hepatocellular Carcinoma (HCC) tissue and adjacent normal tissue of 105 HCC patients were examined using RT-qPCR methods. Furthermore, Receiver Operating Characteristic (ROC) curve was drawn for exploring the diagnostic value of CLEC14A. Next, the expressions of CLEC14A in HCC cell lines and normal liver epithelial cells were compared, and the effects of knockdown of CLEC14A on the growth and apoptosis of HCC cells were examined. RESULTS: The authors found that the expression of CLEC14A was markedly increased in hepatocellular carcinoma tumors in comparison with the adjacent tissue, and the expression level of CLEC14A was positively correlated with the size and differentiation of the tumor. Moreover, results of ROC analysis showed CLEC14A might function as a sensitive diagnostic biomarker for HCC. Furthermore, CLEC14A was up-regulated in HCC cell lines, and transient over-expression of CLEC14A decreased the proliferation and increased the apoptosis of HCC cells in vitro. CONCLUSIONS: Our results suggested that CLEC14A was up-regulated in HCC and might function as a potential diagnostic marker.
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Carcinoma Hepatocelular , Neoplasias Hepáticas , Apoptosis , Biomarcadores , Biomarcadores de Tumor , Carcinoma Hepatocelular/diagnóstico , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Moléculas de Adhesión Celular/metabolismo , Regulación Neoplásica de la Expresión Génica , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Neoplasias Hepáticas/diagnóstico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Curva ROCRESUMEN
This is a case series study to evaluate immunological markers associated with schistosomiasis advanced fibrosis, including 69 patients from an endemic area from the State of Sergipe and from the Hepatology Service of the University Hospital in Sergipe, Brazil. Hepatic fibrosis was classified based on Niamey protocol for ultrasonography (US). Immune response to Schistosoma mansoni antigens was evaluated by stimulating peripheral blood mononuclear cells (PBMCs) from these patients with either adult worm (SWAP-10 µg/ml) or egg (SEA-10 µg/ml) antigens or purified protein derivative of turberculin (PPD-10 µg/ml) or phytohemagglutinin (PHA-1 µg/ml) for 72 h. The levels of IFN-γ, TNF-α, IL-5, IL-10, and IL-17 were measured in these supernatants by ELISA and IL-9 by Luminex. Single nucleotide polymorphisms in IL-17, IL10, and CD209 genes were genotyped using TaqMan probe by qPCR. Higher levels of IL-9, IL-10, and IL-17 were found in PBMC supernatants of patients with advanced hepatic fibrosis. Direct correlations were detected between IL-9 and IL-17 levels with US spleen sizes, portal vein diameters, and periportal thickening. The CD209 rs2287886 AG polymorphism patients produce higher IL-17 levels. Together, these data suggest a role of these cytokines in the immunopathogenesis of advanced fibrosis in human schistosomiasis.
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Antígenos Helmínticos/inmunología , Interleucina-10/metabolismo , Interleucina-17/metabolismo , Interleucina-9/metabolismo , Leucocitos Mononucleares/metabolismo , Cirrosis Hepática/sangre , Schistosoma mansoni/inmunología , Esquistosomiasis mansoni/sangre , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Animales , Biomarcadores/metabolismo , Estudios de Casos y Controles , Moléculas de Adhesión Celular/genética , Células Cultivadas , Niño , Femenino , Interacciones Huésped-Parásitos , Humanos , Interleucina-10/genética , Interleucina-17/genética , Lectinas Tipo C/genética , Leucocitos Mononucleares/inmunología , Leucocitos Mononucleares/parasitología , Cirrosis Hepática/inmunología , Cirrosis Hepática/parasitología , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Receptores de Superficie Celular/genética , Schistosoma mansoni/patogenicidad , Esquistosomiasis mansoni/genética , Esquistosomiasis mansoni/inmunología , Esquistosomiasis mansoni/parasitología , Adulto JovenRESUMEN
Microsporidia are recognized as opportunistic pathogens in individuals with immunodeficiencies, especially related to T cells. Although the activity of CD8+ T lymphocytes is essential to eliminate these pathogens, earlier studies have shown significant participation of macrophages at the beginning of the infection. Macrophages and other innate immunity cells play a critical role in activating the acquired immunity. After programmed cell death, the cell fragments or apoptotic bodies are cleared by phagocytic cells, a phenomenon known as efferocytosis. This process has been recognized as a way of evading immunity by intracellular pathogens. The present study evaluated the impact of efferocytosis of apoptotic cells either infected or not on macrophages and subsequently challenged with Encephalitozoon cuniculi microsporidia. Macrophages were obtained from the bone marrow monocytes from C57BL mice, pre-incubated with apoptotic Jurkat cells (ACs), and were further challenged with E. cuniculi spores. The same procedures were performed using the previously infected Jurkat cells (IACs) and challenged with E. cuniculi spores before macrophage pre-incubation. The average number of spores internalized by macrophages in phagocytosis was counted. Macrophage expression of CD40, CD206, CD80, CD86, and MHCII, as well as the cytokines released in the culture supernatants, was measured by flow cytometry. The ultrastructural study was performed to analyze the multiplication types of pathogens. Macrophages pre-incubated with ACs and challenged with E. cuniculi showed a higher percentage of phagocytosis and an average number of internalized spores. Moreover, the presence of stages of multiplication of the pathogen inside the macrophages, particularly after efferocytosis of infected apoptotic bodies, was observed. In addition, pre-incubation with ACs or IACs and/or challenge with the pathogen decreased the viability of macrophages, reflected as high percentages of apoptosis. The marked expression of CD206 and the release of large amounts of IL-10 and IL-6 indicated the polarization of macrophages to an M2 profile, compatible with efferocytosis and favorable for pathogen development. We concluded that the pathogen favored efferocytosis and polarized the macrophages to an M2 profile, allowing the survival and multiplication of E. cuniculi inside the macrophages and explaining the possibility of macrophages acting as Trojan horses in microsporidiosis.
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Apoptosis/genética , Encephalitozoon cuniculi/inmunología , Evasión Inmune , Macrófagos/microbiología , Esporas Fúngicas/inmunología , Animales , Médula Ósea/inmunología , Médula Ósea/microbiología , Diferenciación Celular , Técnicas de Cocultivo , Encephalitozoon cuniculi/genética , Encephalitozoon cuniculi/crecimiento & desarrollo , Femenino , Expresión Génica , Humanos , Interleucina-10/genética , Interleucina-10/inmunología , Interleucina-6/genética , Interleucina-6/inmunología , Células Jurkat , Lectinas Tipo C/genética , Lectinas Tipo C/inmunología , Macrófagos/inmunología , Receptor de Manosa , Lectinas de Unión a Manosa/genética , Lectinas de Unión a Manosa/inmunología , Ratones , Ratones Endogámicos C57BL , Fagocitosis , Cultivo Primario de Células , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/inmunología , Esporas Fúngicas/genética , Esporas Fúngicas/crecimiento & desarrolloRESUMEN
BACKGROUND: Chikungunya infections range from subclinical infection to debilitating arthralgia and to chronic inflammatory rheumatism. Tumor necrosis factor (TNF) α, DC-SIGN (dendritic cell-specific intercellular adhesion molecule 3-grabbing nonintegrin), Toll-like receptor (TLR) 3, and blood groups have been directly or indirectly implicated in the susceptibility and pathogenesis of chikungunya. METHODS: To test the hypothesis that polymorphisms in genes coding for these molecules determine clinical outcomes of chikungunya infection, a retrospective case-control study was performed in León, Nicaragua. The study included 132 case patients and 132 controls, matched for age, sex and neighborhood. Case patients had clinical symptoms of chikungunya, which was diagnosed by means of polymerase chain reaction. Controls were individuals not reporting abrupt presentation of clinical chikungunya-like symptoms. Polymorphisms were identified by TaqMan single-nucleotide polymorphism genotyping assays. RESULTS: After adjustment for sociodemographic risk factors, chikungunya disease was associated with polymorphism in DC-SIGN and TLR3 genes (odds ratios, 5.2 and 3.3, respectively), and TNF-α with reduced persistent joint pain (0.24). Persistent joint pain was also associated with age, female sex and other comorbid conditions. Most interestingly, the Lewis-negative phenotype was strongly associated with both symptomatic chikungunya and immunoglobulin G seropositivity (odds ratios, 2.7, and 3.3, respectively). CONCLUSION: This study identified polymorphisms in DC-SIGN, TLR3, and TNF-α genes as well as Lewis-negative phenotype as risk factors for chikungunya infection and disease progression.
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Moléculas de Adhesión Celular/genética , Fiebre Chikungunya/epidemiología , Fiebre Chikungunya/etiología , Predisposición Genética a la Enfermedad , Lectinas Tipo C/genética , Polimorfismo de Nucleótido Simple , Receptores de Superficie Celular/genética , Receptor Toll-Like 3/genética , Factor de Necrosis Tumoral alfa/genética , Estudios de Casos y Controles , Fiebre Chikungunya/diagnóstico , Estudios de Asociación Genética , Genotipo , Humanos , Nicaragua/epidemiología , Fenotipo , Medición de Riesgo , Factores de RiesgoRESUMEN
The yellow fever vaccine (YF17DD) is highly effective with a single injection conferring protection for at least 10 years. The YF17DD induces polyvalent responses, with a TH1/TH2 CD4+ profile, robust T CD8+ responses, and synthesis of interferon-gamma (IFN-γ), culminating in high titers of neutralizing antibodies. Furthermore, C-type lectin domain containing 5A (CLEC5A) has been implicated in innate outcomes in other flaviviral infections. Here, we conducted a follow-up study in volunteers immunized with YF17DD, investigating the humoral response, cellular phenotypes, gene expression, and single nucleotide polymorphisms (SNPs) of IFNG and CLEC5A, to clarify the role of these factors in early response after vaccination. Activation of CLEC5A+ monocytes occurred five days after vaccination (DAV). Following, seven DAV data showed activation of CD4+ and CD8+T cells together with early positive correlations between type II IFN and genes of innate antiviral response (STAT1, STAT2, IRF7, IRF9, OAS1, and RNASEL) as well as antibody levels. Furthermore, individuals with genotypes rs2430561 AT/AA, rs2069718 AG/AA (IFNG), and rs13237944 AC/AA (CLEC5A), exhibited higher expression of IFNG and CLEC5A, respectively. Together, we demonstrated that early IFN-γ and CLEC5A responses, associated with rs2430561, rs2069718, and rs13237944 genotypes, may be key mechanisms in the long-lasting immunity elicited by YF17DD.
Asunto(s)
Interacciones Huésped-Patógeno/genética , Interacciones Huésped-Patógeno/inmunología , Inmunidad , Interferón gamma/metabolismo , Lectinas Tipo C/genética , Receptores de Superficie Celular/genética , Vacunación , Vacuna contra la Fiebre Amarilla/inmunología , Fiebre Amarilla/etiología , Fiebre Amarilla/prevención & control , Adulto , Animales , Femenino , Humanos , Inmunogenicidad Vacunal , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Linfocitos T/inmunología , Linfocitos T/metabolismo , Adulto JovenRESUMEN
Numerous researchers have described the potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) for the treatment of various infectious and inflammatory diseases. However, contrary to what has been reported, the transplantation of BM-MSCs in a mouse model of Paracoccidioides brasiliensis-induced pulmonary fibrosis exacerbated the inflammatory process and fibrosis, worsening the course of the infection. The aim of this work was to determine whether P. brasiliensis exerts an immunomodulatory effect on BM-MSCs. The results indicate that P. brasiliensis can activate BM-MSCs through a mechanism dependent on TLR2, TLR4 and Dectin-1. In addition, it was found that these fungal cells can adhere and internalize within BM-MSCs. Nonetheless, this process did not affect the survival of the fungus and on the contrary, triggered the expression of inflammatory mediators such as IL-6, IL-17, TNF-α, and TGF-ß. The present findings correlate with the loss of a fungicidal effect and poor control of the fungus, evidenced by the count of the colony-forming units. Previously reported in vivo results are thus confirmed, showing that P. brasiliensis induces an inflammatory profile in BM-MSCs when producing pro-inflammatory molecules that amplify such response. Numerous researchers have described the potential of bone marrow-derived mesenchymal stem cells (BM-MSCs) for the treatment of various infectious and inflammatory diseases. However, contrary to what has been reported, the transplantation of BM-MSCs in a mouse model of Paracoccidioides brasiliensis-induced pulmonary fibrosis exacerbated the inflammatory process and fibrosis, worsening the course of the infection. The aim of this work was to determine whether P. brasiliensis exerts an immunomodulatory effect on BM-MSCs. The results indicate that P. brasiliensis can activate BM-MSCs through a mechanism dependent on TLR2, TLR4 and Dectin-1. In addition, it was found that these fungal cells can adhere and internalize within BM-MSCs. Nonetheless, this process did not affect the survival of the fungus and on the contrary, triggered the expression of inflammatory mediators such as IL-6, IL-17, TNF-α, and TGF-ß. The present findings correlate with the loss of a fungicidal effect and poor control of the fungus, evidenced by the count of the colony-forming units. Previously reported in vivo results are thus confirmed, showing that P. brasiliensis induces an inflammatory profile in BM-MSCs when producing pro-inflammatory molecules that amplify such response.
Asunto(s)
Lectinas Tipo C/genética , Células Madre Mesenquimatosas/microbiología , Paracoccidioides/inmunología , Paracoccidioidomicosis/inmunología , Receptor Toll-Like 2/genética , Receptor Toll-Like 4/genética , Animales , Modelos Animales de Enfermedad , Femenino , Lectinas Tipo C/inmunología , Ratones , Ratones Endogámicos BALB C , Receptor Toll-Like 2/inmunología , Receptor Toll-Like 4/inmunologíaRESUMEN
Palmitoleic acid (POA, 16:1n-7) is a lipokine that has potential nutraceutical use to treat non-alcoholic fatty liver disease. We tested the effects of POA supplementation (daily oral gavage, 300 mg/Kg, 15 days) on murine liver inflammation induced by a high fat diet (HFD, 59% fat, 12 weeks). In HFD-fed mice, POA supplementation reduced serum insulin and improved insulin tolerance compared with oleic acid (OA, 300 mg/Kg). The livers of POA-treated mice exhibited less steatosis and inflammation than those of OA-treated mice with lower inflammatory cytokine levels and reduced toll-like receptor 4 protein content. The anti-inflammatory effects of POA in the liver were accompanied by a reduction in liver macrophages (LM, CD11c+; F4/80+; CD86+), an effect that could be triggered by peroxisome proliferator activated receptor (PPAR)-γ, a lipogenic transcription factor upregulated in livers of POA-treated mice. We also used HFD-fed mice with selective deletion of PPAR-γ in myeloid cells (PPAR-γ KOLyzCre+) to test whether the beneficial anti-inflammatory effects of POA are dependent on macrophages PPAR-γ. POA-mediated improvement of insulin tolerance was tightly dependent on myeloid PPAR-γ, while POA anti-inflammatory actions including the reduction in liver inflammatory cytokines were preserved in mice bearing myeloid cells deficient in PPAR-γ. This overlapped with increased CD206+ (M2a) cells and downregulation of CD86+ and CD11c+ liver macrophages. Moreover, POA supplementation increased hepatic AMPK activity and decreased expression of the fatty acid binding scavenger receptor, CD36. We conclude that POA controls liver inflammation triggered by fat accumulation through induction of M2a macrophages independently of myeloid cell PPAR-γ.
Asunto(s)
Ácidos Grasos Monoinsaturados/farmacología , Inflamación/tratamiento farmacológico , Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , PPAR gamma/genética , Quinasas de la Proteína-Quinasa Activada por el AMP , Animales , Antígeno B7-2/genética , Antígeno CD11c/genética , Dieta Alta en Grasa/efectos adversos , Ácidos Grasos Monoinsaturados/metabolismo , Humanos , Inflamación/genética , Inflamación/metabolismo , Inflamación/patología , Resistencia a la Insulina/genética , Lectinas Tipo C/genética , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Receptor de Manosa , Lectinas de Unión a Manosa/genética , Ratones , Células Mieloides/efectos de los fármacos , Células Mieloides/metabolismo , Enfermedad del Hígado Graso no Alcohólico/genética , Enfermedad del Hígado Graso no Alcohólico/metabolismo , Ácido Oléico/metabolismo , Ácido Oléico/farmacología , Proteínas Quinasas/genética , Receptores de Superficie Celular/genéticaRESUMEN
C-Type Lectin Receptors (CTLR) are involved in the activation of innate and adaptative immune responses. Among these receptors, the Dendritic Cell-Specific ICAM-3-Grabbing nonintegrin (DC-SIGN/CD209) has become a hot topic due to its ability to bind and facilitate the infections processes of several pathogens. Although well characterized in mammals, little documentation exists about the receptor in salmonid fishes. Here, we report the sequence and expression analysis of eight DC-SIGN-like genes in Salmo salar. Each receptor displays structural similarities to DC-SIGN molecules described in mammals, including internalization motifs, a neck region with heptad repeats, and a Ca+2-dependent carbohydrate recognition domain. The receptors are expressed in multiple tissues of fish, and fish cell lines, with differential expression upon infection with viral and bacterial pathogens. The identification of DC-SIGN-like receptors in Salmo salar provides new information regarding the structure of the immune system of salmon, potential markers for cell subsets, as well as insights into DC-SIGN conservation across species.
Asunto(s)
Moléculas de Adhesión Celular/genética , Proteínas de Peces/genética , Isavirus/fisiología , Lectinas Tipo C/genética , Infecciones por Orthomyxoviridae/inmunología , Piscirickettsia/fisiología , Infecciones por Piscirickettsiaceae/inmunología , Receptores de Superficie Celular/genética , Salmo salar/inmunología , Animales , Biomarcadores/metabolismo , Moléculas de Adhesión Celular/metabolismo , Línea Celular , Clonación Molecular , Proteínas de Peces/metabolismo , Regulación de la Expresión Génica , Inmunidad , Lectinas Tipo C/metabolismo , Receptores de Superficie Celular/metabolismo , TranscriptomaRESUMEN
S-layer (glyco)-proteins (SLPs) form a nanostructured envelope that covers the surface of different prokaryotes and show immunomodulatory activity. Previously, we have demonstrated that the S-layer glycoprotein from probiotic Lactobacillus kefiri CIDCA 8348 (SLP-8348) is recognized by Mincle (macrophage inducible C-type lectin receptor), and its adjuvanticity depends on the integrity of its glycans. However, the glycan's structure has not been described so far. Herein, we analyze the glycosylation pattern of three SLPs, SLP-8348, SLP-8321, and SLP-5818, and explore how these patterns impact their recognition by C-type lectin receptors and the immunomodulatory effect of the L. kefiri SLPs on antigen-presenting cells. High-performance anion-exchange chromatography-pulse amperometric detector performed after ß-elimination showed glucose as the major component in the O-glycans of the three SLPs; however, some differences in the length of hexose chains were observed. No N-glycosylation signals were detected in SLP-8348 and SLP-8321, but SLP-5818 was observed to have two sites carrying complex N-glycans based on a site-specific analysis and a glycomic workflow of the permethylated glycans. SLP-8348 was previously shown to enhance LPS-induced activation on both RAW264.7 macrophages and murine bone marrow-derived dendritic cells; we now show that SLP-8321 and SLP-5818 have a similar effect regardless of the differences in their glycosylation patterns. Studies performed with bone marrow-derived dendritic cells from C-type lectin receptor-deficient mice revealed that the immunostimulatory activity of SLP-8321 depends on its recognition by Mincle, whereas SLP-5818's effects are dependent on SignR3 (murine ortholog of human DC-SIGN). These findings encourage further investigation of both the potential application of these SLPs as new adjuvants and the protein glycosylation mechanisms in these bacteria.
Asunto(s)
Antígenos CD/metabolismo , Lactobacillus/metabolismo , Lectinas Tipo C/metabolismo , Glicoproteínas de Membrana/metabolismo , Secuencia de Aminoácidos , Animales , Antígenos CD/genética , Cromatografía Líquida de Alta Presión , Células Dendríticas/citología , Células Dendríticas/efectos de los fármacos , Células Dendríticas/metabolismo , Glicopéptidos/análisis , Glicopéptidos/química , Glicosilación , Inmunización , Interferón gamma/metabolismo , Lectinas Tipo C/deficiencia , Lectinas Tipo C/genética , Lipopolisacáridos/farmacología , Glicoproteínas de Membrana/química , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Polisacáridos/análisis , Polisacáridos/química , Células RAW 264.7 , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Chromoblastomycosis (CBM) is a chronic worldwide subcutaneous mycosis, caused by several dimorphic, pigmented dematiaceous fungi. It is difficult to treat patients with the disease, mainly because of its recalcitrant nature. The correct activation of host immune response is critical to avoid fungal persistence in the tissue and disease chronification. CD4+ T cells are crucial for the development of protective immunity to F. pedrosoi infection. Here, we investigated T helper cell response dynamics during experimental CBM. Following footpad injection with F. pedrosoi hyphae and conidia, T cells were skewed towards a Th17 and Th1 phenotype. The Th17 population was the main Th cell subset found in the infected area during the early stages of experimental murine CBM, followed by Th1 predominance in the later stages, coinciding with the remission phase of the disease in this experimental model. Depletion of CD25+ cells, which leads to a reduction of Treg cells in the draining lymph node, resulted in decline in fungal burden after 14 days of infection. However, fungal cells were not cleared in the later stages of the disease, prolonging CBM clinical features in those animals. IL-17A and IFN-γ neutralization hindered fungal cell elimination in the course of the disease. Similarly, in dectin-2 KO animals, Th17 contraction in the course of experimental CBM was accompanied by fungal burden decrease in the first 14 days of infection, although it did not affect disease resolution. In this study, we gained insight into T helper subsets' dynamics following footpad injections of F. pedrosoi propagules and uncovered their contribution to disease resolution. The Th17 population proved to be important in eliminating fungal cells in the early stages of infection. The Th1 population, in turn, closely assisted by Treg cells, proved to be relevant not only in the elimination of fungal cells at the beginning of infection but also essential for their complete elimination in later stages of the disease in a mouse experimental model of CBM.
Asunto(s)
Ascomicetos/inmunología , Cromoblastomicosis/inmunología , Lectinas Tipo C/metabolismo , Linfocitos T Reguladores/inmunología , Células TH1/inmunología , Células Th17/inmunología , Animales , Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Cromoblastomicosis/microbiología , Cromoblastomicosis/patología , Modelos Animales de Enfermedad , Humanos , Hifa , Interferón gamma/metabolismo , Interleucina-17/metabolismo , Lectinas Tipo C/genética , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Esporas FúngicasRESUMEN
Interleukin-32 is a novel inflammatory mediator that has been described to be important in the immunopathogenesis and control of infections caused by Leishmania parasites. By performing experiments with primary human cells in vitro, we demonstrate that the expression of IL-32 isoforms is dependent on the time exposed to L. amazonensis and L. braziliensis antigens. Moreover, for the first time we show the functional consequences of three different genetic variations in the IL32 (rs4786370, rs4349147, rs1555001) modulating IL-32γ expression, influencing innate and adaptive cytokine production after Leishmania exposure. Using a Brazilian cohort of 107 American Tegumentary Leishmaniasis patients and a control cohort of 245 healthy individuals, the IL32 rs4786370 genetic variant was associated with protection against ATL, whereas the IL32 rs4349147 was associated with susceptibility to the development of localized cutaneous and mucosal leishmaniasis. These novel insights may help improve therapeutic strategies and lead to benefits for patients suffering from Leishmania infections.
Asunto(s)
Predisposición Genética a la Enfermedad , Variación Genética , Interleucinas/genética , Leishmania/clasificación , Leishmaniasis Cutánea/genética , Adulto , Anciano , Brasil/epidemiología , Citocinas/genética , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica/inmunología , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/metabolismo , Masculino , Persona de Mediana Edad , Proteína Adaptadora de Señalización NOD2/genética , Proteína Adaptadora de Señalización NOD2/metabolismo , Isoformas de Proteínas , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismoRESUMEN
Cytotoxic activity mediated by CD8+ T cells is the main signature of the immunopathogenesis of cutaneous leishmaniasis (CL). Here, we performed a broad evaluation of natural killer (NK) cell phenotypic and functional features during cutaneous leishmaniasis. We demonstrate for the first time that CL patients present the accumulation of circulating NK cells with multiple features of replicative senescence including low proliferative capacity and shorter telomeres, elevated expression of CD57, KLRG1 but diminished CD27 stimulatory receptor expression. Moreover, they exhibited higher cytotoxic and inflammatory potential than age-matched controls. The accumulation of circulating senescent NK cells (CD56dim CD57bright ) correlated positively with skin lesion size in the same patients, suggesting that they, like circulating senescent CD8+ T cells, may contribute to the immunopathology of CL. However, this senescent population had lower cutaneous lymphocyte antigen expression and so had diminished skin-homing potential compared with total or senescent CD8+ T cells. This was confirmed in CL skin lesions where we found a predominance of CD8+ T cells (both senescent and non-senescent) that correlated with the severity of the disease. Although there was also a correlation between the proportions of senescent NK cells (CD56+ CD57+ ) in the skin and lesion size, this was less evident. Collectively our results demonstrate first-hand that senescent cytotoxic cells may mediate skin pathology during human cutaneous leishmaniasis. However, as senescent cytotoxic CD8+ T cells predominate in the skin lesions, they may have a greater role than NK cells in mediating the non-specific skin damage in CL.