Improved technique that allows the performance of large-scale SNP genotyping on DNA immobilized by FTA (R) technology

International audienceno abstrac

Cytokine Regulation of Periportal Fibrosis in Humans Infected with Schistosoma mansoni: IFN-γ is Associated with Protection Against Fibrosis and TNF-α with Aggravation of Disease

International audienceHepatic periportal fibrosis, which affects 5–10% of subjects infected by Schistosoma mansoni, is caused by the T cell-dependent granuloma that develop around schistosome eggs. Experimental models of infection have shown that granuloma and fibrosis are tightly regulated by cytokines. However, it is unknown why advanced periportal fibrosis occurs only in certain subjects. The goal of the present study was to evaluate the cytokine response of S. mansoni-infected subjects with advanced liver disease in an attempt to relate susceptibility to periportal fibrosis with an abnormal production of cytokines that regulate granuloma and fibrosis. Fibrosis was evaluated by ultrasound on 795 inhabitants of a Sudanese village in which S. mansoni is endemic: advanced periportal fibrosis was observed in 12% of the population; 35% of the affected subjects exhibited signs of portal hypertension. Age (odds ratio (OR), 11.5), gender (OR, 4.2), and infection levels (OR, 2.2) were significantly (p < 0.01) associated with hepatic fibrosis. Cytokines produced by egg-stimulated blood mononuclear cells from 99 subjects were measured (75 with no or mild fibrosis; 24 subjects with advanced fibrosis). Multivariate analysis of cytokine levels showed that high IFN-γ levels were associated with a marked reduction of the risk of fibrosis (p = ‫OR, 0.1); in contrast, high TNF-α levels were associated with an increased risk (p = 0.05; OR, 4.6) of periportal fibrosis. Moreover, infection levels were negatively associated with IFN-γ production. These results with observations in experimental models strongly suggest that IFN-γ plays a key role in the protection of S. mansoni-infected patients against periportal fibrosis, whereas TNF-α may aggravate the disease

Immunological and genetic evidence for a crucial role of IL-10 in cutaneous lesions in humans infected with Leishmania braziliensis

International audienceIn populations exposed to Leishmania braziliensis, certain subjects develop skin ulcers, whereas others are naturally protected against cutaneous leishmaniasis. We have evaluated which cytokines are most crucial in the development of skin lesions. We found that active lesions occur in subjects with polarized Th2 or mixed Th1/Th2 responses, both associated with elevated IL-10 production. IL-10 was strongly associated (p = 0.004, odd ratio (OR) = 6.8, confidence interval = 1.9-25) with lesions, excluding IFN-gamma, IL-12, TNF, IL-13, and IL-4 from the regression model. IL-10 was produced by blood monocytes and CD4(+)CD25(+) T lymphocytes (mostly Foxp3(+)). However, we did not observe any difference between the number of these cells present in the blood of subjects with active lesions and those present in resistant subjects. Genetic analysis of the IL10-819C/T polymorphism, located in the IL10 promoter, showed that the C allele increased the risk of lesions (OR = 2.5 (1.12-5.7), p = 0.003). Functional analysis of these variants showed allele-specific binding of nuclear factors. The IL10-819C/C genotype was associated with higher levels of IL-10 than C/T and T/T genotypes. These observations demonstrate an important role for IL-10 in skin lesions in humans infected with L. braziliensis, and identify circulating monocytes and Tregs as principal sources of IL-10 in these patients

Liver ultrasound elastography for the evaluation of periportal fibrosis in schistosomiasis mansoni: A cross-sectional study.

BackgroundARFI elastrography has been used as a noninvasive method to assess the severity of liver fibrosis in viral hepatitis, although with few studies in schistosomiasis mansoni. We aimed to evaluate the performance of point shear wave elastography (pSWE) for predicting significant periportal fibrosis (PPF) in schistosomotic patients and to determine its best cutoff point.Methodology/principal findingsThis cross-sectional study included 358 adult schistosomotic patients subjected to US and pSWE on the right lobe. Two hundred two patients (62.0%) were women, with a median age of 54 (ranging 18-92) years. The pSWE measurements were compared to the US patterns of PPF, as gold standard, according to the Niamey classification. The performance of pSWE was calculated as the area under the ROC curve (AUC). Patients were further classified into two groups: 86 patients with mild PPF and 272 patients with significant PPF. The median pSWE of the significant fibrosis group was higher (1.40 m/s) than that of mild fibrosis group (1.14 m/s, p1.39 m/s, with specificity of 86.1% and positive predictive value of 92.0%.Conclusions/significancepSWE was able to differentiate significant from mild PPF, with better performance to predict significant PPF

Correction: FOXP3+ Regulatory T Cells in Hepatic Fibrosis and Splenomegaly Caused by Schistosoma japonicum: The Spleen May Be a Major Source of Tregs in Subjects with Splenomegaly

International audienc

FOXP3+ Regulatory T Cells in Hepatic Fibrosis and Splenomegaly Caused by Schistosoma japonicum: The Spleen May Be a Major Source of Tregs in Subjects with Splenomegaly

International audienceSchistosoma eggs cause chronic liver inflammation and a complex disease characterized by hepatic fibrosis (HF) and splenomegaly (SplM). FOXP3+ Tregs could regulate inflammation, but it is unclear where these cells are produced and what roles they play in human schistosomiasis. We investigated blood and spleen FOXP3+ Tregs in Chinese fishermen with lifelong exposure to Schistosoma japonicum and various degrees of liver and spleen disease. FOXP3+ Tregs accounted for 4.3% of CD4+ T cells and 41.2% of FOXP3+CD4+ T cells; they could be divided into CD45RA-FOXP3hi effector (eTregs) and CD45RA+FOXP3low naive Tregs. Blood Treg levels were high in severe HF (+1.3; p = 0.004) and in SplM (+1.03, p = 0.03). Multivariate regression showed that severe HF (+0.85, p = 0.01) and SplM (+0.97; p = 0.05) were independently associated with the higher proportion of Tregs in the blood. This effect was mostly due to an increase in the proportion of eTregs in the blood of HF+++ (+0.9%; p = 0.04) and SplM (+0.9%; p = 0.04) patients. The proportion of eTregs expressing CXCR3 in the blood was lower in the HF+++ patients (37.4 +/- 5.9%) than in those with milder fibrosis (51.7 ± 2%; p = 0.009), whereas proportion were similar for cells expressing CD25hi, CCR7, and CTLA-4. Splenectomy improves symptoms and was associated with decreases in blood FOXP3+ Treg (-2.5; p<0.001) and eTreg (-1.3; p = 0.03) levels. SplM spleens contained a high proportion of eTregs with CXCR3, CCR5 and CTLA4 upregulation and CCR7 downregulation. This, and the strong expression of ligands of CXCR3 and CCR5 in the liver (n = 8) but not in the spleen suggested that spleen eTregs migrated to Th1-infiltrated liver tissues. Such migration may be attenuated in hepatosplenic patients due to lower levels of CXCR3 expression on Tregs (p = 0.009). Thus, higher blood Treg levels are associated with severe liver disease and splenomegaly. Our data are consistent with the hypothesis that the spleen is a major source of Tregs in subjects with splenomegaly. In most cases, Tregs migrate to the Th1-infiltrated liver and the lower levels of CXCR3+ Tregs in the blood of patients with severe schistosomiasis suggest that decreases in Treg migration sites of inflammation may aggravate the disease

IL2RA genetic variants reduce IL-2-dependent responses and aggravate human cutaneous leishmaniasis.

Submitted by Ana Maria Fiscina Sampaio ([email protected]) on 2015-07-15T13:48:42Z No. of bitstreams: 1 Oliveira PRS Il2RA genetic....pdf: 1114932 bytes, checksum: 3425fff6699fbc584d4c59220849bf32 (MD5)Approved for entry into archive by Ana Maria Fiscina Sampaio ([email protected]) on 2015-07-15T14:18:03Z (GMT) No. of bitstreams: 1 Oliveira PRS Il2RA genetic....pdf: 1114932 bytes, checksum: 3425fff6699fbc584d4c59220849bf32 (MD5)Made available in DSpace on 2015-07-15T14:18:03Z (GMT). No. of bitstreams: 1 Oliveira PRS Il2RA genetic....pdf: 1114932 bytes, checksum: 3425fff6699fbc584d4c59220849bf32 (MD5) Previous issue date: 2015Aix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, France / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Laboratório de Patologia e Biointervenção. Salvador, BA, BrasilAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Laboratorio de Imunogenética. Departamento de Imunologia. Recife, PE, BrasilAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceFundação Oswaldo Cruz. Centro de Pesquisas Aggeu Magalhães. Laboratorio de Imunogenética. Departamento de Imunologia. Recife, PE, BrasilFundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Laboratório de Patologia e Biointervenção. Salvador, BA, BrasilFederal University of the Triangulo Mineiro. Laboratory of Immunology. Department of Biological Sciences. Uberaba, MG, BrasilPasteur Institute of Tehran. Laboratory of Immunology. Tehran, IranAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceAix Marseille Universite. Génétique et Immunologie des Maladies Parasitaires Unité Mixte de Recherche. Marseille, France / INSERM. Marseille, FranceThe outcome of Leishmania infections varies substantially, depending on the host and the parasite strain; infection may be asymptomatic or cause mild or severe skin ulcers (cutaneous leishmaniasis [CL]), limited or disseminated lesions, or lethal visceral disease. We previously reported an association between IL-2R mutations and susceptibility to visceral leishmaniasis in children infected with Leishmania donovani. In the present study, we evaluated the possible role of IL-2 signaling in human CL. We first showed that the transcripts of several genes of the IL-2 pathway were abundant in skin lesions caused by Leishmania braziliensis. We then carried out a genetic analysis, focusing on major genes of the IL-2 pathway. We used a family-based approach and found that polymorphisms of several genes appeared to be associated with CL in a Brazilian population. Moreover, two polymorphisms of the IL2RA gene were significantly and independently associated with CL. We confirmed this result in a second Brazilian sample (also exposed to L. braziliensis) and in Iranians infected with Leishmania tropica: IL2RA rs10905669 T (Pcombined = 6 3 1027) and IL2RA rs706778 T (Pcombined = 2 3 1029) were associated with greater susceptibility to lesion development. These alleles were also correlated with a poor IFN-g response and poor FOXP3+ regulatory T cell activation. Thus, IL-2 plays a crucial role in protection against the cutaneous ulcers caused by Leishmania, and the IL-2 pathway is a potential target for strategies aiming to control Leishmania-related diseases