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This study tested the hypothesis that sickle red blood cell (SS-RBC) can induce inflammasome NLRP3 components gene expression in peripheral blood mononuclear cells (PBMCs) as well as interleukin-1β (IL-1β) and leukotriene B4 (LTB4) production. Additionally, we investigated the effect of hydroxyurea (HU) treatment in these inflammatory markers. PBMCs from healthy donors (AA-PBMC) were challenged with intact and lysed RBCs from SCA patients (SS-RBC) and from healthy volunteers (AA-RBC). NLRP3, IL-1β, IL-18 and Caspase-1 gene expression levels were assessed by quantitative PCR (qPCR). IL-1β protein levels and LTB4 were measured by ELISA. We observed that lysed SS-RBC induced the expression of inflammasome NLRP3 components, but this increase was more prominent for CASP1 and IL18 expression levels. Moreover, we observed that intact SS-RBC induced higher production of IL-1β and LTB4 than lysed SS-RBC. Although SCA patients treated with HU have a reduction in NLRP3 gene expression and LTB4 production, this treatment did not modulate the expression of other inflammasome components or IL-1β production. Thus, our data suggest that caspase-1, IL-1β and IL-18 may contribute to the inflammatory status observed in SCA and that HU treatment may not interfere in this inflammatory pathway.

The mechanisms involved in the development of resistance to infection/reinfection by Schistosoma mansoni still arouse great interest and controversy. Some authors demonstrate that resistance to infection is attributed to a mixed Th1 and Th2 response and resistance to reinfection after repeated treatments through mechanisms associated with the Th2 response. Through flow cytometry, the phenotypic characterization of B and T lymphocytes in individuals residing in endemic areas with low parasite loads over 10 years was evaluated for the first time in humans. In this study, individuals with low parasite loads for Schistosoma mansoni had a higher proportion of Th1 and Th2 cells. In addition, lymphocytes from these individuals showed a higher degree of expression of costimulatory molecules CD28 and CTLA-4 and regulatory molecules FoxP3 and IL-10, when compared to individuals with high parasite loads. Our data indicate that the control of the parasite load of S. mansoni must be associated with a Th1, Th2, and regulatory response, and that further studies are needed to elucidate the possibility of mechanisms associated with the hyporesponsiveness of lymphocytes from individuals with high parasite loads.

Fundação Oswaldo Cruz, Instituto Oswaldo Cruz. Laboratório de Educação em Ambiente e Saúde. Rio de Janeiro, RJ, Brasil. Fundação Oswaldo Cruz, Instituto Oswaldo Cruz. Laboratório de Educação em Ambiente e Saúde. Rio de Janeiro, RJ, Brasil. Universidade Federal do Ceará. Departamento de Análises Clínicas e Toxicológicas. Fortaleza, CE, Brasil. Universidade Federal do Espírito Santo. Centro de Ciências da Saúde.Unidade de Doenças Infecciosas. Vitória, ES, Brasil / Pontifícia Universidade Católica do Rio Grande do Sul. Laboratório de Parasitologia Biomédica. Porto Alegre, RS, Brasil. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil. Instituto Evandro Chagas. Laboratório de Parasitoses Intestinais, Esquistossomose e Malacologia. Secção de Parasitologia, Ananindeua, PA, Brasil. Fundação Oswaldo Cruz. Instituto René Rachou. Belo Horizonte, MG, Brasil. Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil. Fundação Oswaldo Cruz. Instituto Gonçalo Moniz. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Medicina. Salvador, BA, Brasil / Yale University, School of Public Health, Department of Epidemiology of Microbial Diseases. New Haven, CT, USA. Fundação Oswaldo Cruz, Instituto Oswaldo Cruz. Laboratório de Educação em Ambiente e Saúde. Rio de Janeiro, RJ, Brasil. Background: The World Health Organization recommends reliable point-of-care (POC) diagnostic testing to eliminate schistosomiasis. Lateral flow immunoassay that detects schistosome circulating cathodic antigen (CCA) in urine to establish prevalence thresholds for intervention in endemic areas is recommended. Stored urine may be useful if surveying at-risk populations is delayed or interrupted by unforeseen circumstances, such as the current COVID-19 pandemic. This study evaluated the manufacturer’s claim that Schistosoma mansoni infection can be reliably diagnosed in urine samples stored at -20°C for one year. Methods: Two-hundred-forty-two subjects from an endemic site in Brazil provided one urine sample each for testing with URINE CCA (SCHISTO) ECO TESTE® (POC-ECO) and one stool sample each for testing with Kato-Katz (KK) and Helmintex® (HTX) as a robust reference standard for infection status. At least 2 ml of urine from each participant was stored at -20°C; after one year, 76 samples were randomly selected for POC-ECO retesting. Results: The POC-ECO agreement between freshly collected and stored urine was inadequate considering trace results as positive (Cohen’s kappa coefficient κ = 0.08) and negative (κ = 0.36). POC-ECO accuracy was not significantly greater than that of routine KK (54%; 95% confidence interval: 42.1%-65.5%). Conclusions: The precision and accuracy of POC-ECO have to be optimized in both freshly collected and stored urine before it can be recommended for use in control programs in Brazil.

This work was funded by the Secretaria de Vigil?ncia em Sa?de / Fundo Nacional de Sa?de / Minist?rio da Sa?de (SVS/FNS/MS) - [TED/FNS: 118/2017; SIAFI: 691919/25000.479741/2017?05]. Universidade Federal do Esp?rito Santo.Center for Health Sciences. Infectious Diseases Unit. Vit?ria, ES, Brazil / Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Pont?ficia Universidade Cat?lica do Rio Grande do Sul. School of Sciences. Research Group on Biomedical Parasitology. Porto Alegre, RS, Brazil. Universidade Federal do Cear?. Department of Clinical and Toxicological Analyses. Fortaleza, CE, Brazil. Funda??o Oswaldo Cruz.Ren? Rachou Institute. Belo Horizonte, MG, Brazil. Minist?rio da Sa?de. Secretaria de Vigil?ncia em Sa?de. Instituto Evandro Chagas. Ananindeua, PA, Brasil. Funda??o Oswaldo Cruz. Oswaldo Cruz Institute. Rio de Janeiro, RJ, Brazil. Funda??o Oswaldo Cruz.Ren? Rachou Institute. Belo Horizonte, MG, Brazil. Funda??o Oswaldo Cruz. Gon?alo Muniz Institute. Salvador, BA, Brazil. Funda??o Oswaldo Cruz. Gon?alo Muniz Institute. Salvador, BA, Brazil / Federal University of Bahia. Faculty of Medicine of Bahia. Salvador, BA, Brazil / Yale University. School of Public Health. Department of Epidemiology of Microbial Diseases. New Haven, CT, United States of America. Funda??o Oswaldo Cruz. Oswaldo Cruz Institute. Rio de Janeiro, RJ, Brazil. A point-of-care test for detecting schistosome circulating cathodic antigen in urine (POC[sbnd]CCA) has been proposed for mapping infection and defining prevalence thresholds for mass drug administration (MDA). However, there is increasing evidence that POC[sbnd]CCA may yield false-positive results, which requires rigorous specificity evaluation in non-endemic areas. POC[sbnd]CCA was applied in an area known to be free from infection and devoid of any condition for schistosomiasis transmission as part of a multicentre study to evaluate the performance of POC[sbnd]CCA in Brazil's low or potentially endemic settings. Besides POC[sbnd]CCA detection in urine, a search for eggs in stool was performed by Kato-Katz (KK) and Helmintex (HTX) methods. One-hundred-and-seventy-four participants returned urine samples, 140 of which delivered stool samples. All these were HTX-negative for Schistosoma mansoni, and all 118 tested with KK were negative for both S. mansoni and soil-transmitted helminths. POC[sbnd]CCA results from freshly collected urine yielded a specificity of 62.1% (95% CI: 53.6% - 70.2%), taking trace outcomes as positive according to the manufacturer's instructions. Retesting urine from the 140 HTX-negatives after one-year storage at -20 ?C with two new POC[sbnd]CCA batches simultaneously yielded significantly different specificities (34.3%; 95%CI: 26.5% ? 42.8% and 75.0%; 95% CI: 67.0% - 81.9%). These two batches had a weak agreement (Cohen's kappa: 0.56; 95%CI: 0.44?0.68) among the 174 urine samples retested. At present, POC[sbnd]CCA cannot be recommended either as a cut-off point for MDA or a reliable diagnostic tool for treatment of the infection carriers (selective chemotherapy) in low endemic areas and at final stages of transmission interruption. Manufacturers should be required to optimize production standardization and to assure quality and reproducibility of the test. Extended rigorous performance evaluations by different users from different regions are needed before POC[sbnd]CCA is widely recommended

Author(s): Daya, Michelle; Rafaels, Nicholas; Brunetti, Tonya M; Chavan, Sameer; Levin, Albert M; Shetty, Aniket; Gignoux, Christopher R; Boorgula, Meher Preethi; Wojcik, Genevieve; Campbell, Monica; Vergara, Candelaria; Torgerson, Dara G; Ortega, Victor E; Doumatey, Ayo; Johnston, Henry Richard; Acevedo, Nathalie; Araujo, Maria Ilma; Avila, Pedro C; Belbin, Gillian; Bleecker, Eugene; Bustamante, Carlos; Caraballo, Luis; Cruz, Alvaro; Dunston, Georgia M; Eng, Celeste; Faruque, Mezbah U; Ferguson, Trevor S; Figueiredo, Camila; Ford, Jean G; Gan, Weiniu; Gourraud, Pierre-Antoine; Hansel, Nadia N; Hernandez, Ryan D; Herrera-Paz, Edwin Francisco; Jimenez, Silvia; Kenny, Eimear E; Knight-Madden, Jennifer; Kumar, Rajesh; Lange, Leslie A; Lange, Ethan M; Lizee, Antoine; Maul, Pissamai; Maul, Trevor; Mayorga, Alvaro; Meyers, Deborah; Nicolae, Dan L; O'Connor, Timothy D; Oliveira, Ricardo Riccio; Olopade, Christopher O; Olopade, Olufunmilayo; Qin, Zhaohui S; Rotimi, Charles; Vince, Nicolas; Watson, Harold; Wilks, Rainford J; Wilson, James G; Salzberg, Steven; Ober, Carole; Burchard, Esteban G; Williams, L Keoki; Beaty, Terri H; Taub, Margaret A; Ruczinski, Ingo; Mathias, Rasika A; Barnes, Kathleen C; CAAPA | Abstract: An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Schistosomiasis affects about 240 million people worldwide and is estimated that about 700 million people live in areas at risk of infection. In the context of immune response associated with infection by Schistosoma mansoni, the role of memory T cells is not well understood. Aim: To evaluate the frequency of memory CD4+ and CD8+ T cells from individuals resistant and susceptible to Schistosoma mansoni infection. Methods and Results: We selected individuals with low (resistant) and high (susceptible) parasite burden using databases generated during previous studies carried out in the same endemic area. The cell surface markers were performed using flow cytometry. In this study, the resistant individuals showed an increase in the CD4+ memory T‐cell pool associated with an increase in the central memory cell (TCM) and a decrease in the effector memory cell (TEM). Individuals susceptible to infection had higher frequencies of effector memory cells compared to resistant individuals. Conclusions: These data suggest that resistance to S mansoni infection may be associated with an increase in the number of CD4+ memory T cells and susceptibility to infection is associated with a decrease in the central memory cell as well as high proportions of effector memory cells.

We used a deeply sequenced dataset of 910 individuals, all of African descent, to construct a set of DNA sequences that is present in these individuals but missing from the reference human genome. We aligned 1.19 trillion reads from the 910 individuals to the reference genome (GRCh38), collected all reads that failed to align, and assembled these reads into contiguous sequences (contigs). We then compared all contigs to one another to identify a set of unique sequences representing regions of the African pan-genome missing from the reference genome. Our analysis revealed 296,485,284 bp in 125,715 distinct contigs present in the populations of African descent, demonstrating that the African pan-genome contains ~10% more DNA than the current human reference genome. Although the functional significance of nearly all of this sequence is unknown, 387 of the novel contigs fall within 315 distinct protein-coding genes, and the rest appear to be intergenic. Assembly of a pan-genome from 910 humans of African descent identifies 296.5 Mb of novel DNA mapping to 125,715 distinct contigs. This African pan-genome contains ~10% more DNA than the current human reference genome.

Background: Combined oral contraceptive (COC) use has been associated with an unfavorable impact on carbohydrate and lipid metabolism in diverse populations of normal-weight and obese women. The present study aimed to evaluate the cardiometabolic and inflammatory profiles of women in northeastern Brazil with respect to COC use and obesity. Methods: We performed a cross-sectional study to verify cardiovascular parameters, including blood pressure, fasting serum glucose, lipid and inflammatory profile, in a population of women aged 15-45 years, considering obesity and COC use. Our sample consisted of 591 women, 481 women who were COC users and 110 age-matched women who were COC non-users, classified as obese and non-obese according to BMI. Results: COC use and obesity were associated with increased systolic (p ≤0.001) and diastolic blood pressure (p =0.001), blood glucose (p ≤0.001), total cholesterol (p =0.008), low density lipoprotein cholesterol (p ≤0.001), very low density lipoprotein cholesterol (p ≤0.001), triglycerides (p ≤0.001), ferritin (p =0.006), C-reactive protein (CRP)(p ≤0.001) and nitric oxide metabolites (p ≤0.001), as well as decreased high density lipoprotein cholesterol (HDL-c) (p ≤0.001) in comparison to controls. CRP and HDL-c levels in obese COC users were determined to be outside reference range values. The odds of having lower levels of HDL-c and elevated CRP increased among obese COC users. COC use was independently associated with low levels of HDL-c, especially second-generation progestins (p

BACKGROUNDAsthma is a complex disease with striking disparities across racial and ethnic groups, which may be partly attributable to genetic factors. One of the main goals of the Consortium on Asthma among African-ancestry Populations in the Americas (CAAPA) is to discover genes conferring risk to asthma in populations of African descent.METHODSWe performed a genome-wide meta-analysis of asthma across 11 CAAPA datasets (4,827 asthma cases and 5,397 controls), genotyped on the African Diaspora Power Chip (ADPC) and including existing GWAS array data. The genotype data were imputed up to a whole genome sequence reference panel from n=880 African ancestry individuals for a total of 61,904,576 SNPs. Statistical models appropriate to each study design were used to test for association, and results were combined using the weighted Z-score method. We also used admixture mapping as a complementary approach to identify loci involved in asthma pathogenesis in subjects of African ancestry.RESULTSSNPs rs787160 and rs17834780 on chromosome 2q22.3 were significantly associated with asthma (p=6.57 × 10−9 and 2.97 × 10−8, respectively). These SNPs lie in the intergenic region between the Rho GTPase Activating Protein 15 (ARHGAP15) and Glycosyltransferase Like Domain Containing 1 (GTDC1) genes. Four low frequency variants on chromosome 1q21.3, which may be involved in the “atopic march” and which are not polymorphic in Europeans, also showed evidence for association with asthma (1.18 ×10−6 ≤ p ≤ 3.06 ×10−6). SNP rs11264909 on chromosome 1q23.1, close to a region previously identified by the EVE asthma meta-analysis as having a putative African ancestry specific effect, only showed differences in counts in subjects homozygous for alleles of African ancestry. Admixture mapping also identified a significantly associated region on chromosome 6q23.2, which includes the Transcription Factor 21 (TCF21) gene, previously shown to be differentially expressed in bronchial tissues of asthmatics and non-asthmatics.CONCLUSIONSWe have identified a number of novel asthma association signals warranting further investigation.

FundingCNPQ (Universal 479417/2008 3), NIH (R01AI079238A). Hospital Universitário Professor Edgard Santos. Serviço de Imunologia. Salvador, BA, Brasil Hospital Universitário Professor Edgard Santos. Serviço de Imunologia. Salvador, BA, Brasil / Universidade Federal da Bahia. Faculdade de Farmácia. Departamento de Análises Clínicas e Toxicológicas. Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais. INCT-DT. CNPq/MCT. Salvador, BA, Brasil Hospital Universitário Professor Edgard Santos. Serviço de Imunologia. Salvador, BA, Brasil Hospital Universitário Professor Edgard Santos. Serviço de Imunologia. Salvador, BA, Brasil / Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, BA, Brasil Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas. Departamento de Bioquímica e Imunologia. Belo Horizonte, MG, Brasil Australian Institute of Tropical Health and Medicine, James Cook University, Queensland, Australia Hospital Universitário Professor Edgard Santos. Serviço de Imunologia. Salvador, BA, Brasil / Escola Baiana de Medicina e Saúde Pública, Salvador, BA, Brasil / Instituto Nacional de Ciência e Tecnologia em Doenças Tropicais. INCT-DT. CNPq/MCT. Salvador, BA, Brasil HTLV-1 is the causal agent of Adult T cell Leukemia/lymphoma (ATLL) and HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). The immune response to HTLV-1-infection is polarized to the Th1-type, and the presence of CXCL9/CXCL10 chemokines may lead to an increase in the recruitment of pro-inflammatory molecules in spinal cord tissue, contributing to the damage observed in the development of HAM/TSP. It has been observed that in chronic helminth-infections, such as schistosomiasis, there is a deviation toward the Th2/regulatory immune response. Objective: To evaluate the ability of Schistosoma spp. proteins to decrease the in vitro CXCL9 and CXCL10 production by PBMC of HTLV-1-infected individuals. Methods: The Schistosoma proteins rSm29, rSh-TSP-2 and PIII were added to PBMC cultures of HTLV-1- infected individuals and the levels of chemokines in the supernatants were measured using a sandwich ELISA method. Results: The addition of rSm29 to the cultures resulted in decreased production of CXCL9 in all the analyzed individuals and HAM/TSP group (18167 ± 9727 pg/mL, p = 0.044; 20237 ± 6023 pg/mL, p = 0.028, respectively) compared to the levels in unstimulated cultures (19745 ± 9729 pg/mL; 25078 ± 2392 pg/mL, respectively). The addition of rSh-TSP-2 decreased the production of CXCL9 in all studied individuals and carriers group (16136 ± 9233 pg/mL, p = 0.031; 13977 ± 8857 pg/mL, p = 0.026) vs unstimulated cultures (19745 ± 9729 pg/mL; 18121 ± 10508 pg/mL, respectively). Addition of PIII did not alter the results. There was no significant change in the levels of CXCL10 by the addition of the studied proteins. Conclusion: The Schistosoma proteins used in this study were able to down modulate the production of CXCL9, a chemokine associated with the inflammatory process in HTLV-1-infection.

In the version of this article initially published, the statement "there are no pan-genomes for any other animal or plant species" was incorrect. The statement has been corrected to "there are no reported pan-genomes for any other animal species, to our knowledge." We thank David Edwards for bringing this error to our attention. The error has been corrected in the HTML and PDF versions of the article.

Characterization of genetic admixture of populations in the Americas and the Caribbean is of interest for anthropological, epidemiological, and historical reasons. Asthma has a higher prevalence and is more severe in populations with a high African component. Association of African ancestry with asthma has been demonstrated. We estimated admixture proportions of samples from six trihybrid populations of African descent and determined the relationship between African ancestry and asthma and total serum IgE levels (tIgE). We genotyped 237 ancestry informative markers in asthmatics and nonasthmatic controls from Barbados (190/277), Jamaica (177/529), Brazil (40/220), Colombia (508/625), African Americans from New York (207/171), and African Americans from Baltimore/Washington, D.C. (625/757). We estimated individual ancestries and evaluated genetic stratification using Structure and principal component analysis. Association of African ancestry and asthma and tIgE was evaluated by regression analysis. Mean ± SD African ancestry ranged from 0.76 ± 0.10 among Barbadians to 0.33 ± 0.13 in Colombians. The European component varied from 0.14 ± 0.05 among Jamaicans and Barbadians to 0.26 ± 0.08 among Colombians. African ancestry was associated with risk for asthma in Colombians (odds ratio (OR) = 4.5, P = 0.001) Brazilians (OR = 136.5, P = 0.003), and African Americans of New York (OR: 4.7; P = 0.040). African ancestry was also associated with higher tIgE levels among Colombians (β = 1.3, P = 0.04), Barbadians (β = 3.8, P = 0.03), and Brazilians (β = 1.6, P = 0.03). Our findings indicate that African ancestry can account for, at least in part, the association between asthma and its associated trait, tIgE levels.

Human T cell lymphotropic virus type 1 (HTLV-1) is the causal agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). While the immune response to HTLV-1 infection is polarized to the Th1-type, chronic helminth infections drive the Th2- and T regulatory-type, and are able to downregulate the inflammatory response in some autoimmune diseases. Objective: To evaluate whether Schistosoma spp. antigens alter the in vitro cytokine response in HTLV-1 infection. Methods: The recombinant Schistosoma antigens Sm29 and ShTSP2 (tetraspanin) and PIII, a fraction of the Schistosoma mansoni adult worm antigen were added to peripheral blood mononuclear cell (PBMC) cultures of HTLV-1-infected individuals and the levels of interferon (IFN)-γ and interleukin (IL)-10 in the supernatants were measured using the ELISA sandwich technique. Results: Compared to the levels of cytokine in nonstimulated cultures, the levels of IFN-γ were reduced in 50, 47 and 50% of patients by the presence of Sm29, ShTsp2 and PIII, respectively. The downregulation of IFN-γ production in the presence of Sm29 antigen was observed mainly in subjects who had lower basal levels of this cytokine. The levels of IL-10, however, increased by the addition of the three antigens in the cultures in 74, 62 and 44% of individuals, respectively. In addition, there was a decrease in the ratio of IFN-γ/IL-10 levels in cultures stimulated with Sm29 and ShTSP2 when compared to nonstimulated ones. Conclusions: The Schistosoma spp. antigens used in this study were able to downmodulate IFN-γ production in vitro in HTLV-1 infection. This may be associated with the increased levels of IL-10 induced by the antigens.

Field studies have suggested an immune-mediated mechanism associated with resistance to Schistosoma mansoni infection. Overall, levels of specific IgE have been correlated with resistance to infection, whereas levels of IgG4 have been associated with susceptibility. This study aimed to evaluate serum levels of soluble adult worm antigen preparation (SWAP)-specific IgE and IgG4 in relation to current infection in a large casuistic of individuals living in an endemic area of schistosomiasis in Bahia, Brazil. The prevalence of S. mansoni infection was 37·7% and the mean parasite burden was 55·4 (0-2100) epg/faeces. There was no significant difference in the levels of SWAP-specific IgE in individuals with different parasite burden, whereas high producers of parasite-specific IgG4 presented higher parasite burden when compared to low IgG4 producers. Additionally, S. mansoni parasite load was positively correlated with the levels of specific IgG4 or total IgE. No significant correlation was observed between parasite burden and SWAP-specific IgE. Nevertheless, SWAP-specific IgE/IgG4 ratio was higher in uninfected or lightly infected individuals (1-99 epg/faeces) than in heavily infected ones (≥400 epg/feces). These findings highlight the important role of IgE/IgG4 ratio in the resistance to infection, which could be useful for further studies in schistosomiasis vaccine candidates.

High levels of proinflammatory cytokines such as IFN-γand TNF are associated with tissue lesions in cutaneous leishmaniasis (CL). We previously demonstrated thatSchistosoma mansoniantigens downmodulate thein vitrocytokine response in CL. In the current study we evaluated whetherS. mansoniantigens alter monocyte and T-lymphocyte phenotypes in leishmaniasis. Peripheral blood mononuclear cells of CL patients were cultured withL. braziliensisantigen in the presence or absence of theS. mansoniantigens rSm29, rSmTSP-2- and PIII. Cells were stained with fluorochrome conjugated antibodies and analyzed by flow cytometry. The addition of rSm29 to the cultures decreased the expression of HLA-DR in nonclassical (CD14+CD16++) monocytes, while the addition of PIII diminished the expression of this molecule in classical (CD14++CD16-) and intermediate (CD14++CD16+) monocytes. The addition of PIII and rSmTSP-2 resulted in downmodulation of CD80 expression in nonclassical and CD86 expression in intermediate monocytes, respectively. These two antigens increased the expression of CTLA-4 in CD4+T cells and they also expanded the frequency of CD4+CD25highFoxp3+T cells. Taken together, we show thatS. mansoniantigens, mainly rSmTSP-2 and PIII, are able to decrease the activation status of monocytes and also to upregulate the expression of modulatory molecules in T lymphocytes.

This study tested the hypothesis that sickle red blood cell (SS-RBC) induce Toll-like receptors (TLR) and Nod-like receptor family, pyrin domain containing 3 (NLRP3)- inflammasome expression in peripheral blood mononuclear cells (PBMC). TLR and NLRP3 inflammasome could contribute to the maintenance of the inflammatory status in sickle cell anemia (SCA) patients, since SS-RBC act as danger signals activating these pathways. In this study, first, we evaluated TLR (2, 4, 5 and 9), NLRP3, Caspase-1, interleukin (IL)-1β and IL-18 expression in PBMC freshly isolated from SCA patients (SS-PBMC) in comparison with PBMC from healthy individuals (AA-PBMC). In the second moment, we investigated whether SS-RBC could interfere with the expression of these molecules in PBMC from healthy donor, in the absence or presence of hydroxyurea (HU) in vitro. TLRs and NLRP3 inflammasome expression were investigated by qPCR. IL-1β, Leukotriene-B4 (LTB4) and nitrite production were measured in PBMC (from healthy donor) culture supernatants. TLR2, TLR4, TLR5, NLRP3 and IL-1β were highly expressed in SS-PBMC when compared to AA-PBMC. Additionally, SS-RBC induced TLR9, NLRP3, Caspase-1, IL-1β and IL-18 expression and induced IL-1β, LTB4 and nitrite production in PBMC cultures. HU did not prevent TLR and NLRP3 inflammasome expression, but increased TLR2 and IL-18 expression and reduced nitrite production. In conclusion, our data suggest that TLR and inflammasome complexes may be key inducers of inflammation in SCA patients, probably through SS-RBC; also, HU does not prevent NLRP3 inflammasome- and TLR-dependent inflammation, indicating the need to develop new therapeutic strategies to SCA patients that act with different mechanisms of those observed for HU.

SummarySchistosoma mansoni infection has been associated with protection against allergies. The mechanisms underlying this association may involve regulatory cells and cytokines. We evaluated the immune response induced by the S. mansoni antigens Sm22·6, PIII and Sm29 in a murine model of ovalbumin (OVA)-induced airway inflammation. BALB/c mice were sensitized with subcutaneously injected OVA-alum and challenged with aerolized OVA. Mice were given three doses of the different S. mansoni antigens. Lung histopathology, cellularity of bronchoalveolar lavage (BAL) and eosinophil peroxidase activity in lung were evaluated. Immunoglobulin (Ig)E levels in serum and cytokines in BAL were also measured. Additionally, we evaluated the frequency of CD4+forkhead box P3 (FoxP3)+ T cells in cultures stimulated with OVA and the expression of interleukin (IL)-10 by these cells. The number of total cells and eosinophils in BAL and the levels of OVA-specific IgE were reduced in the immunized mice. Also, the levels of IL-4 and IL-5 in the BAL of mice immunized with PIII and Sm22·6 were decreased, while the levels of IL-10 were higher in mice immunized with Sm22·6 compared to the non-immunized mice. The frequency of CD4+FoxP3+ T cells was higher in the groups of mice who received Sm22·6, Sm29 and PIII, being the expression of IL-10 by these cells only higher in mice immunized with Sm22·6. We concluded that the S. mansoni antigens used in this study are able to down-modulate allergic inflammatory mediators in a murine model of airway inflammation and that the CD4+FoxP3+ T cells, even in the absence of IL-10 expression, might play an important role in this process.

Background Chronic schistosomiasis and its severe complication, periportal fibrosis, are characterized by a predominant T h 2 response. To date, specific single nucleotide polymorphisms in ST2 have been some of the most consistently associated genetic variants for asthma. Objective We investigated the role of ST2 (a receptor for the T h 2 cytokine IL-33) in chronic and late-stage schistosomiasis caused by Schistosoma japonicum and the potential effect of ST2 genetic variants on stage of disease and ST2 expression. Methods We recruited 947 adult participants (339 with end-stage schistosomiasis and liver cirrhosis, 307 with chronic infections without liver fibrosis, and 301 health controls) from a S japonicum –endemic area (Hubei, China). Six ST2 single nucleotide polymorphisms were genotyped. Serum soluble ST2 (sST2) was measured by ELISA, and ST2 expression in normal liver tissues, Hepatitis B virus–induced fibrotic liver tissues, and S japonicum –induced fibrotic liver tissues was measured by immunohistochemistry. Results We found sST2 levels were significantly higher in the end-stage group (36.04 [95% CI, 33.85-38.37]) compared with chronic cases and controls (22.7 [95% CI, 22.0-23.4], P S japonicum –induced fibrotic liver tissues showed increased ST2 staining compared with normal liver tissues ( P = .0001). Markers rs12712135, rs1420101, and rs6543119 were strongly associated with sST2 levels ( P = 2E-10, 5E-05, and 6E-05, respectively), and these results were replicated in an independent cohort from Brazil living in a S mansoni endemic region. Conclusions We demonstrate for the first time that end-stage schistosomiasis is associated with elevated sST2 levels and show that ST2 genetic variants are associated with sST2 levels in patients with schistosomiasis.

Rationale: Asthma prevalence and severity are high among underserved minorities, including those of African descent. The Duffy antigen/receptor for chemokines is the receptor for Plasmodium vivax on erythrocytes and functions as a chemokine-clearing receptor. Unlike European populations, decreased expression of the receptor on erythrocytes is common among populations of African descent, and results from a functional T-46C polymorphism (rs2814778) in the promoter. This variant provides an evolutionary advantage in malaria-endemic regions, because Duffy antigen/receptor for chemokines-negative erythrocytes are more resistant to infection by P. vivax. Objectives: To determine the role of the rs2814778 polymorphism in asthma and atopy as measured by total serum IgE levels among four populations of African descent (African Caribbean, African American,Brazilian,andColombian)andaEuropeanAmericanpopulation. Methods: Family-based association tests were performed in each of the five populations to test for association between the rs2814778 polymorphism and asthma or total IgE concentration. Measurements and Main Results: Asthma was significantly associated with the rs2814778 polymorphism in the African Caribbean, Colombian, and Brazilian families (P , 0.05). High total IgE levels were associated with this variant in African Caribbean and Colombian families (P , 0.05). The variant allele was not polymorphic among European Americans. Conclusions: Susceptibility to asthma and atopy among certain populations of African descent is influenced by a functional polymorphism in the gene encoding Duffy antigen/receptor for chemokines. This genetic variant, which confers resistance to malarial parasitic infection, may also partially explain ethnic differences in morbidity of asthma.

Background Evidence of genetic control for total serum IgE (tIgE) level has been reported in multiple populations, although populations with substantial exposure to helminths have yielded lower estimates of heritability, despite evidence suggesting that genes also control a significant portion of the variation in the number of Schistosoma mansoni eggs per gram of fecal matter. Methods By use of a whole-population ascertainment scheme, 822 individuals were enrolled from a schistosomiasis-endemic area in Conde, Bahia, in Brazil. Heritability was estimated by using an additive polygenic model, and segregation analysis was performed for 2 quantitative traits, tIgE level and egg count. Results After adjusting for nongenetic covariates, the heritability of log-transformed tIgE level and log-transformed egg count was estimated at 60% and 31%, respectively. No evidence for a single major gene controlling tIgE level or egg count was observed in segregation analysis for 781 individuals and 403 individuals, respectively, in 318 families, however, which suggests complex biological control. Conclusions The high heritability of tIgE level indicates that genetic factors are likely to control tIgE level even in the presence of helminthic infection. Substantial heritability for the burden of S. mansoni infection was confirmed in these Brazilian families. Further genetic studies will be needed to dissect the specific genetic factors that underlie these traits.

T lymphocytes recognize antigens as peptides bound to major histocompatibility complex (MHC) molecules. The fine specificity of the T cell is defined by the T-cell receptor (TCR). Most T lymphocytes express the TCR αβ and either CD4 or CD8 molecules (22). These molecules stabilize the TCR-peptide/MHC interaction, are essential for intrathymic selection, and contribute to transmembrane signaling, with important roles in the development and activation of helper and cytotoxic T cells (8, 10, 17). A small population of αβ T cells lacking these coreceptors, CD4− CD8− (double negative [DN]) T cells, have been identified in the peripheral immune system of mice and humans and have been associated with human and murine autoimmune and immunodeficiency diseases (4, 15). While little is known concerning DN T cells and their direct role in disease pathology or normal immunity in humans, recent studies indicate that the lack of coreceptors allows this population to tolerate chronic stimulation. In contrast, chronic stimulation of CD4 or CD8 T cells limits their expansion through an apoptosis-dependent mechanism (14). In the murine model, αβ DN T cells exhibit markers of activation/memory, a lowered threshold of activation, ex vivo cytolytic activity, and the ability to rapidly secrete gamma interferon (IFN-γ). Furthermore, they can also compete for interleukin-2 (IL-2) produced by helper T cells, thereby inhibiting the expansion of bystander CD8 T cells, suggesting their role in immunoregulation (25). In healthy humans, DN αβ T cells have been identified in peripheral blood, thymus, and skin (13, 21, 31). This population constitutes a rare population of cells in healthy subjects, expressing molecules associated with activation, memory, and cytotoxic function (6). Another interesting point was reported by Porcelli et al. (24), who showed that proliferative and cytotoxic responses of DN αβ T cells specific for Mycobacterium tuberculosis are restricted to the nonpolymorphic MHC-like CD1 molecules. Immunity against Leishmania spp. is cell mediated. Usually, this parasite escapes the humoral immune response residing in the phagolysosome of macrophages, which employs a number of defense strategies against the infecting parasite. Lymphocytes also play an essential role in the immune response against Leishmania infection, induced by Th1 clones during infection. IL-12-producing phagocytic cells, as well as IFN-γ produced by natural killer cells and previously activated T cells, induce the differentiation of IFN-γ- and tumor necrosis factor alpha (TNF-α)-producing T lymphocytes. TNF-α produced by the macrophages can also act in an autocrine manner, activating itself for nitric oxide production, which is toxic for the parasite (20, 26). Thus, IFN-γ is an important cytokine produced in response to Leishmania antigens, leading to an efficient cell-mediated immune response. Recently, data from our laboratory (5) demonstrated that in peripheral blood mononuclear cells (PBMC) from cutaneous leishmaniasis (CL) patients, DN lymphocytes are the second most abundant source of IFN-γ-producing cells following CD4+ T cells. Moreover, Amprey et al. recently demonstrated the involvement of CD1d-restricted DN T cells in the response to Leishmania in infected mice (1). Thus, to better understand the role DN T cells may have in the human immune response to Leishmania, a detailed study of the activation state and cytokine profiles of both αβ and γδ DN T cells in a group of well-defined CL patients was performed.

Background Helminth infections have been associated with reduced reactivity to aeroallergens, which could be related to interleukin 10 (IL-10) production, as reported in schistosomiasis. Objective To compare skin responses to aeroallergens with Der p specific IL-10 production in patients with asthma or rhinitis according to Ascaris infection status. Methods Cross-sectional study of 113 patients with asthma or rhinitis from a region endemic for geohelminths. Stool examinations and skin prick tests to aeroallergens were performed in all the patients. Der p specific IL-10 production was measured in the supernatant of peripheral blood mononuclear cell (PBMC) cultures of a subsample of 53 patients. Results Forty-seven patients had Ascaris in their stool samples. Skin test results were positive in 77% of Ascaris- infected patients and in 71% of uninfected individuals. Median levels of Der p specific IL-10 in PBMC cultures of infected and uninfected patients were similar (7.8 and 8.4 pg/mL, respectively). The lack of association remained when parasite load was taken into account and when patients with evidence of previous infection were removed from the uninfected group. Conclusions In patients with asthma or rhinitis living in an urban area endemic for geohelminths, we found no association between Ascaris infection and skin reactivity to aeroallergens. Furthermore, there was no difference in Der p specific IL-10 production by PBMCs. These negative findings indicate that different from what is observed in Schistosoma infection, Ascaris lumbricoides infection in individuals living in an urban area does not induce strong regulatory responses.

Helminthic infections have been shown to inhibit allergy skin-prick tests and to modify the course of asthma. We evaluated Dermatophagoides pteronyssinus-specific immune responses in patients with asthma by measuring levels of T helper 2 (Th2) cytokines in peripheral blood mononuclear cell (PBMC) cultures. PBMCs from Schistosoma mansoni-infected patients with asthma living in an area of polyhelminthic endemicity produced lower levels of interleukin (IL)-5 and IL-4 in response to D. pteronyssinus antigen (Ag) 1 than did PBMCs from helminth-free patients with asthma. In contrast, D. pteronyssinus Ag 1-specific production of IL-10 was higher in helminth-infected patients than in helminth-free patients. The addition of recombinant human IL-10 to D. pteronyssinus Ag 1-stimulated cultures of PBMCs from helminth-free patients led to down-modulation of production of IL-5. After helminth-infected patients with asthma received antihelminthic treatment, there was down-modulation of D. pteronyssinus Ag 1-specific production of IL-10 in vitro. S. mansoni-infected patients with asthma produce lower levels of Th2 cytokines than do helminth-free patients with asthma, and this modulation is likely done by IL-10.

The HTLV-1 is the causal agent of HTLV-1-associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). The immune response in HTLV-1 infection is polarized to the Th1-type, and previous data from our group had demonstrated that the use of Schistosoma antigens to cell cultures in HTLV-1 infection resulted in down-modulation of Th1/inflammatory response. The aim of this study was to evaluate whether the modulation of inflammatory response by S. mansoni antigens depends upon the presence of IL-10, TGF-β and CTLA-4. The antibodies anti-IL-10, anti-TGF-β and anti-CTLA-4 with or without the S. mansoni antigen Sm29 were added to the PBMC cultures of HTLV-1- infected individuals and the levels of cytokines in the supernatants were measure using ELISA sandwich method. Compared to the levels of cytokine in non stimulated cultures (1.073 pg/ml, median values), the levels of IFN-gproduction (552 pg/ml, 1.002 pg/ml and 548 pg/ml, respectively; p

Introduction: MPs are stable units that express on their surface specific proteins of the cells that were originated. In this sense, neutrophils MPs have a singular importance since they present in their surface myeloperoxidase (MPO), an enzyme that are involved with vascular inflammatory conditions. Studies have shown that the use of HU, currently the only pharmacological drug approved to treat SCA patients, leads to reduction in count neutrophils, monocytes and reticulocytes, and the slight increase in total hemoglobin concentration. However, some studies have shown that MPs levels are not affected by HU treatment. Recently, our group showed that nod-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome and interleukin (IL)-1β could contribute to the inflammatory condition in SCA patients. This study tested the hypothesis that neutrophils challenged with serum of sickle cell anemia (SCA) patients, treated with hydroxyurea (HU), decrease neutrophils microparticles (MPs) production. Therefore, the aim of this study was to evaluate the inflammatory state of neutrophils from healthy volunteers by NLRP3 and IL1B gene expression and of SCA patients treated or untreated with HU and to measure the production of MPs derived from neutrophils challenged with SCA patient's serum, treated or not with HU. Methods: We enrolled 10 SCA patients (all in steady state with age of 8.0 ± 1.9 years), from the Fundação de Hematologia e Hemoterapia do Estado da Bahia (HEMOBA). Neutrophils were isolated from one healthy donor as previously described (Pitanga et al, 2014). The protein concentration of neutrophils MPs was evaluated using the BCA method (Thermo Scientific,Waltham, MA, USA) according to the manufacturer's protocol and described by Pitanga et al (2014). NLRP3 and IL1Bgene expressions genes were performed by real time PCR with SYBR Green assays from neutrophils RNA in trizol reagent. Relative expression was estimated through the 2ddct method, with GAPDH and ACTB genes. Serum biochemical analysis was evaluated using commercially available biochemical kits. This study was conducted in accordance and approved by the Research Ethics Committee of the Fundação Oswaldo Cruz - FIOCRUZ, Brazil; and also with the Helsinki Declaration of 1975, and its revisions. The informed consents were signed by patients or official responsible. Results: Our findings showed that NLRP3 (6.95 ± 1.77)and IL1B (6.46 ± 3.31) genes are highly expressed in neutrophils of SCA patients comparing to healthy volunteers (2.43 ± 0.73, p=0.0286; 2.65 ± 1.30, p=0.0081 respectively). Additionally, neutrophils from SCA patients treated with HU decrease NLRP3 gene expression (4.06 ± 1.12; p= 0.0357), but it was not observed for IL1B gene expression (6.03 ± 3.13; p=0.3472). We demonstrated that serum from SCA patients increased neutrophils MPs production (181.90 ± 53.00) comparing to healthy volunteer's serum (37.63 ± 13.06; p=0.0011). However, HU treatment decreased this scenario (30.33 ± 13.70; p=0.0022). Conclusions: This study highlighted that HU acts decreasing NLRP3 gene expression and neutrophils MPs production suggesting that NLRP3 protein could participate of cellular activation and production of MPs, contributing to the maintenance of inflammation as well as vascular activation. Disclosures No relevant conflicts of interest to declare.

Introduction: Sickle cell anemia (SCA) presents a chronic inflammatory condition associated with vaso-occlusive painful episodes and intravascular hemolysis. For the innate response, a family of cellular receptors called Toll-like receptors (TLRs) has multiples functions, which may lead to several different pathways that can modulate the SCA pathogenesis. For example, TLR expression is not restricted to leukocytes, but has been reported in multiple cell types, including endothelial cells, implying that the role of the TLR pathway may not be limited to immune response. TLRs are thought to play important role in the maintenance of the inflammatory status observed in these patients. We aim to evaluate the role that lysed red blood cells (RBC) from SCA patients play in TLR2, TLR4, TLR5 and TLR9 gene expression in peripheral blood mononuclear cells (PBMC) in presence or absence of hydroxyurea (HU). Methods: Ten SCA patients in steady-state (age 10.3 ± 4.6 years) and 7 healthy volunteers (age 14.5 ± 5.2 years) were recruited at the Fundação de Hematologia e Hemoterapia da Bahia (HEMOBA). PBMC were isolated from one healthy donor for cell cultures challenged by lysed RBC of SCA patients (SS-RBC) and RBC of healthy volunteers (AA-RBC), in presence or absence of HU. TLRs gene expressions were performed by qPCR. Serum biochemical analysis was evaluated using commercially available biochemical kits. This study was approved by the Research Ethics Committee of the Oswaldo Cruz Foundation, and was developed in accordance with the Declaration of Helsinki of 1975 and its revisions. All subjects or their legal guardians agreed to collect the biological sample after read and sign the informed consent. Results: We observed that TLR4 (185.0 ± 37.51, p=0.0167) and TLR9 (1.80 ± 1.51, p=0.0394) were higher expressed in PBMC culture challenged by lysed SS-RBC than by lysed AA-RBC (148.5 ± 21.43, p=0.0238; 0.38 ± 0.29, p=0.3429 respectively), whereas PBMC challenged by lysed SS-RBC had TLR2 (1.56 ± 0.34, p=0.0167) and TLR5 (1.48 ± 0.50, p=0.0043) gene expression similar to lysed AA-RBC (1.61 ± 0.30, p=0.0238; 1.55 ± 0.23, p=0.0079 respectively). Surprisingly, HU treatment did not modulate TLR expression. It is known that hemolytic byproducts such as heme and hemoglobin are able to bind TLR4 and TLR9. Conclusion: Despite the global relevance of SCA, mechanisms that contribute to the disease severity and heterogeneity are poorly understood, even though that is the same underlying genetic mechanism. In an attempt to contribute to the field, our data reinforce the hypothesis that lysed RBCs, especially lysed SS-RBCs, act as danger signals, stimulating TLR expression and contributing to inflammation. This study highlighted that HU does not prevent TLR-dependent inflammation, pointing out the need to develop new drugs that act with different mechanisms of action of those observed for HU. Disclosures No relevant conflicts of interest to declare.

Despite the availability of many parasitological methods for detection of Cryptosporidium and Isospora (Cystoisospora) belli in fecal samples, there are uncertainties about the accuracy of these techniques in laboratory practice. In this study, 27 formalin-fixed positive stool samples for Cryptosporidium and 15 for I. belli were analyzed by 2 concentration methods, sedimentation by centrifugation (SC) and formalin-ethyl acetate (FE), and by 3 tintorial techniques, modified Ziehl-Neelsen (ZN), safranin (SF), and auramine (AR). No significant differences were observed on Cryptosporidium identification between concentration methods, while a significantly higher number of I. belli oocysts (P0.0001) was detected in fecal smears concentrated by the SC than by the FE method. Fecal samples processed by FE produced a median oocyst loss to the fatty ring of 34.8% for Cryptosporidium and 45.4% for I. belli. However, FE concentration provided 63% of Cryptosporidium and 100% of I. belli slides classified as superior for microscopic examination. Regarding the efficiency of staining methods, a more significant detection of Cryptosporidium oocysts was observed in fecal smears stained by ZN (P0.01) or AR (P0.05) than by the SF method. Regular to high-quality slides for microscopic examination were mostly observed in fecal smears stained with AR or ZN for Cryptosporidium and with SF or ZN for I. belli. This study suggests a great variability in oocyst power detection by routine parasitological methods, and that the most frequent intestinal coccidians in humans have specific requirements for concentration and staining.

p. 1-8 Submitted by Suelen Reis (suziy.ellen@gmail.com) on 2014-03-20T12:38:56Z No. of bitstreams: 1 10.1155-2013-710647.pdf: 2671872 bytes, checksum: 14dcea6b765e057c30ae25952f57ea63 (MD5) Approved for entry into archive by Rodrigo Meirelles (rodrigomei@ufba.br) on 2014-09-09T14:48:03Z (GMT) No. of bitstreams: 1 10.1155-2013-710647.pdf: 2671872 bytes, checksum: 14dcea6b765e057c30ae25952f57ea63 (MD5) Made available in DSpace on 2014-09-09T14:48:03Z (GMT). No. of bitstreams: 1 10.1155-2013-710647.pdf: 2671872 bytes, checksum: 14dcea6b765e057c30ae25952f57ea63 (MD5) Previous issue date: 2013 The Th2 immune response in chronic schistosomiasis is associated with the development of periportal fibrosis. However, little is known about the phenotype and activation status of T cells in the process. Objective. To evaluate the profile of T cells in schistosomiasis patients with periportal fibrosis. Methods. It was a cross-sectional study, conducted in the village of Agua Preta, Bahia, Brazil, which included 37 subjects with periportal fibrosis determined by ultrasound. Peripheral blood mononuclear cells were obtained by the Ficcol-hypaque gradient and the frequency of T cells expressing the surface markers CD28, CD69, CD25, and CTLA-4 was determined by flow cytometry. Results. The frequency of CD4+CD28+ T lymphocytes was higher in individuals with moderate to severe fibrosis compared to patients with incipient fibrosis. We did not observe any significant difference in the frequency of CD4+ T cells expressing CD69 among groups of individuals. There was also no significant difference in the frequency of CD8+ T cells expressing CD28 or CD69 among the studied groups. Individuals with moderate to severe fibrosis presented a lower frequency of CD8+ T cells, CD4+CD25high T cells, and CD4+CTLA-4+ T cells when compared to patients without fibrosis or incipient fibrosis. The frequency of CD4+CD25low cells did not differ between groups. Conclusion. The high frequency of activated T cells coinciding with a low frequency of putative Treg cells may account for the development of periportal fibrosis in human schistosomiasis.

Texto completo: acesso restrito. p. 393–401 Submitted by Edileide Reis (leyde-landy@hotmail.com) on 2014-11-19T11:41:52Z No. of bitstreams: 1 Candelaria Vergara.pdf: 683776 bytes, checksum: 3f244a5ee46560431d06949a67843bd9 (MD5) Approved for entry into archive by Delba Rosa (delba@ufba.br) on 2015-05-05T16:06:05Z (GMT) No. of bitstreams: 1 Candelaria Vergara.pdf: 683776 bytes, checksum: 3f244a5ee46560431d06949a67843bd9 (MD5) Made available in DSpace on 2015-05-05T16:06:05Z (GMT). No. of bitstreams: 1 Candelaria Vergara.pdf: 683776 bytes, checksum: 3f244a5ee46560431d06949a67843bd9 (MD5) Previous issue date: 2013 Characterization of genetic admixture of populations in the Americas and the Caribbean is of interest for anthropological, epidemiological, and historical reasons. Asthma has a higher prevalence and is more severe in populations with a high African component. Association of African ancestry with asthma has been demonstrated. We estimated admixture proportions of samples from six trihybrid populations of African descent and determined the relationship between African ancestry and asthma and total serum IgE levels (tIgE). We genotyped 237 ancestry informative markers in asthmatics and nonasthmatic controls from Barbados (190/277), Jamaica (177/529), Brazil (40/220), Colombia (508/625), African Americans from New York (207/171), and African Americans from Baltimore/Washington, D.C. (625/757). We estimated individual ancestries and evaluated genetic stratification using Structure and principal component analysis. Association of African ancestry and asthma and tIgE was evaluated by regression analysis. Mean ± SD African ancestry ranged from 0.76 ± 0.10 among Barbadians to 0.33 ± 0.13 in Colombians. The European component varied from 0.14 ± 0.05 among Jamaicans and Barbadians to 0.26 ± 0.08 among Colombians. African ancestry was associated with risk for asthma in Colombians (odds ratio (OR) = 4.5, P = 0.001) Brazilians (OR = 136.5, P = 0.003), and African Americans of New York (OR: 4.7; P = 0.040). African ancestry was also associated with higher tIgE levels among Colombians (β = 1.3, P = 0.04), Barbadians (β = 3.8, P = 0.03), and Brazilians (β = 1.6, P = 0.03). Our findings indicate that African ancestry can account for, at least in part, the association between asthma and its associated trait, tIgE levels.

Human T cell lymphotropic virus type 1 (HTLV-1) is the causal agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). While the immune response to HTLV-1 infection is polarized to the Th1-type, chronic helminth infections drive the Th2- and T regulatory-type, and are able to downregulate the inflammatory response in some autoimmune diseases.To evaluate whether Schistosoma spp. antigens alter the in vitro cytokine response in HTLV-1 infection.The recombinant Schistosoma antigens Sm29 and ShTSP2 (tetraspanin) and PIII, a fraction of the Schistosoma mansoni adult worm antigen were added to peripheral blood mononuclear cell (PBMC) cultures of HTLV-1-infected individuals and the levels of interferon (IFN)-γ and interleukin (IL)-10 in the supernatants were measured using the ELISA sandwich technique.Compared to the levels of cytokine in nonstimulated cultures, the levels of IFN-γ were reduced in 50, 47 and 50% of patients by the presence of Sm29, ShTsp2 and PIII, respectively. The downregulation of IFN-γ production in the presence of Sm29 antigen was observed mainly in subjects who had lower basal levels of this cytokine. The levels of IL-10, however, increased by the addition of the three antigens in the cultures in 74, 62 and 44% of individuals, respectively. In addition, there was a decrease in the ratio of IFN-γ/IL-10 levels in cultures stimulated with Sm29 and ShTSP2 when compared to nonstimulated ones.The Schistosoma spp. antigens used in this study were able to downmodulate IFN-γ production in vitro in HTLV-1 infection. This may be associated with the increased levels of IL-10 induced by the antigens.

A series of studies have demonstrated that activation of the sympathetic nervous system (SNS) causes osteopenia via β2-adrenoceptor (β2-AR) signaling. However, in a recent study, we found an unexpected and generalized phenotype of high bone mass in female mice with chronic sympathetic hyperactivity, due to double gene inactivation of adrenoceptors that negatively regulate norepinephrine release, α2A-and α2C-AR (α2A/2C-AR-/-). These findings suggest that β2-AR is not the single adrenoceptor involved in bone turnover regulation and show that α2-AR signaling may also mediate the SNS actions in the skeleton. In addition, we found that α2A/2C-AR-/- animals are resistant to the thyrotoxicosis-induced osteopenia, suggesting that thyroid hormone (TH), when in supraphysiological levels, interacts with the SNS to control bone mass and structure, and that this interaction may also involve α2-AR signaling. In the present study, to further investigate these hypotheses and to discriminate the roles of α2-AR subtypes, we have evaluated the bone phenotype of mice with the single gene inactivation of α2C-AR subtype, which mRNA expression was previously shown to be down regulated by triiodothyronine (T3). A cohort of 30 day-old female α2CAR-/- mice and their wild-type (WT) controls were treated with a supraphysiological dose of T3 for 30 or 90 days, which induced a thyrotoxic state in both mouse lineages. The micro-computed tomographic (μCT) analysis showed that α2C-AR-/- mice present lower trabecular bone volume (BV/TV) and number (Tb.N), and increased trabecular separation (Tb.Sp) in the femur compared with WT mice; which was accompanied by decreased bone strength (determined by the three-point bending test) in the femur and tibia. The opposite was observed in the vertebra, where α2C-AR-/- mice show increased BV/TV, Tb.N and trabecular thickness (Tb.Th), and decreased Tb.Sp, compared with WT animals. In spite of the contrasting bone phenotypes of the femur and L5, thyrotoxicosis negatively regulated most of the micro architectural features of the trabecular bone in both skeletal sites of WT, but not of α2C-AR-/- mice. T3 treatment also decreased biomechanical properties (maximum load and ultimate load) in the femur and tibia of WT, but not of knockout mice. The mRNA expression of osteocalcin, a marker of mature osteoblasts, and tartrate-resistant acid phosphatase, which is expressed by osteoclasts and is involved in collagen degradation, was increased by T3 treatment only in WT, and not in α2C-AR-/- mice. Altogether, these findings suggest that α2C-AR subtype mediates the effects of the SNS in the bone in a skeletal site-dependent manner, and that thyrotoxicosis depends on α2C-AR signaling to promote bone loss, which sustains the hypothesis of a TH-SNS interaction to modulate bone remodeling and structure.

Periportal fibrosis in schistosomiasis has been associated to the host immune response to parasite antigens. We evaluated the immune response inS. mansoniinfected individuals with different degrees of periportal fibrosis. Cytokine and chemokines were measured in serum and in supernatants of PBMC cultures stimulated with the soluble adult worm (SWAP) or egg (SEA) antigens, using a sandwich ELISA. The levels of IL-5 in response to SEA were higher in individuals with moderate to severe fibrosis (310.9 pg/mL) compared to individuals without fibrosis (36.8 pg/mL;P=0.0418). There was also a higher production of TNF-αin cultures stimulated with SWAP in patients with insipient fibrosis (1446 pg/mL) compared to those without fibrosis (756.1 pg/mL;P=0.0319). The serum levels of IL-13 and MIP-1αwere higher in subjects without fibrosis than in those with moderate to severe fibrosis. However a positive association between serum levels of IL-13, TNF-α, MIP-1α, and RANTES andS. mansoniparasite burden was found. From these data we conclude that IL-5 and TNF-αmay participate in liver pathology in schistosomiasis. The positive association between IL-13, TNF-α, MIP-1α, and RANTES with parasite burden, however, might predict the development of liver pathology.

Protective factors associated with atopy or asthma in rural areas include socioeconomic level, overcrowding, and helminth infection. However, little epidemiological information was originated from schistosomiasis areas. This study aimed to investigate factors associated with asthma in a schistosomiasis endemic area. A questionnaire was used to obtain information on demographics, socioeconomic, and environmental features. The ISAAC questionnaire was used to identify individuals with asthma. Parasitological exam was done in all participants and skin prick test to aeroallergens in all asthmatics. Prevalence ofSchistosoma mansoniinfection was 57.4% andAscaris lumbricoides,30.8%. Asthma was found in 13.1% of the population, and 35.1% of them had a positive SPT. Active and passive smoking was positively associated with asthma, whereasA. lumbricoideswas negatively associated. In a schistosomiasis hyperendemic region, current infection withA. lumbricoidesis protective against asthma. However, we cannot rule out the involvement ofS. mansoniinfection in this process.

Detailed knowledge of factors associated with resistance to Schistosoma mansoni infection in endemic areas might facilitate more effective schistosomiasis control. We conducted a cross-sectional study of persons resistant to schistosomiasis and found no association between socioeconomic status and resistance to infection. Mononuclear cells of resistant subjects produced higher levels of interleukin-5 (IL-5), IL-13 and interferon-γ upon stimulation with soluble egg antigen (SEA) compared with infected persons. When stimulated with Sm21.6 or Sm22.6, levels of IL-10 were higher in cell culture of resistant persons. Levels of IgE against soluble adult worm antigen (SWAP) and against interleukin-4-inducing principle from S. mansoni eggs (IPSE) and levels of IgG4 against SWAP, SEA, and Sm22.6 were lower in the resistant group compared with the susceptible group. Our data suggest that socioeconomic status could not fully explain resistance to S. mansoni infection observed in the studied area. However, a mixture of Th1 and Th2 immune responses and low levels of specific IgG4 against parasite antigens could be mediating resistance to infection.