In silico predicted epitopes from the COOH-terminal extension of cysteine proteinase B inducing distinct immune responses during Leishmania (Leishmania) amazonensis experimental murine infection

<p>Abstract</p> <p>Background</p> <p><it>Leishmania </it>parasites have been reported to interfere and even subvert their host immune responses to enhance their chances of survival and proliferation. Experimental <it>Leishmania </it>infection in mice has been widely used in the identification of specific parasite virulence factors involved in the interaction with the host immune system. Cysteine-proteinase B (CPB) is an important virulence factor in parasites from the <it>Leishmania (Leishmania) mexicana </it>complex: it inhibits lymphocytes Th1 and/or promotes Th2 responses either through proteolytic activity or through epitopes derived from its COOH-terminal extension. In the present study we analyzed the effects of <it>Leishmania (Leishmania) amazonensis </it>CPB COOH-terminal extension-derived peptides on cell cultures from murine strains with distinct levels of susceptibility to infection: BALB/c, highly susceptible, and CBA, mildly resistant.</p> <p>Results</p> <p>Predicted epitopes, obtained by <it>in silico </it>mapping, displayed the ability to induce cell proliferation and expression of cytokines related to Th1 and Th2 responses. Furthermore, we applied <it>in silico </it>simulations to investigate how the MHC/epitopes interactions could be related to the immunomodulatory effects on cytokines, finding evidence that specific interaction patterns can be related to <it>in vitro </it>activities.</p> <p>Conclusions</p> <p>Based on our results, we consider that some peptides from the CPB COOH-terminal extension may influence host immune responses in the murine infection, thus helping <it>Leishmania </it>survival.</p

Single and concomitant experimental infectionsby Endotrypanum spp. and Leishmania (Viannia) guyanensis (Kinetoplastida: Trypanosomatidae) in the Neotropical sand fly Lutzomyia longipalpis (Diptera: Psychodidae)

Lutzomyia longipalpis females received single and mixed infections with Endotrypanum and Leishmania. Two biological parameters were analyzed: the percentage of infected females and the distribution of flagellates in the gut of the females. The principal comparisons were performed between (1) two strains of Endotrypanum, (2) cloned versus primary sample of one strain of Endotrypanum, (3) Endotrypanum versus Leishmania guyanensis, and (4) the pattern of flagellates behaviour by optical microscopy in females with single or mixed infection versus the identification of parasites isolated from digestive tracts by isoenzyme electrophoresis. Flagellates of Endotrypanum showed distinct patterns of infection suggesting that there is variation between and within strains. The distribution of Endotrypanum and L. guyanensis differed significantly in relation to the colonization of the stomodeal valve. In co-infection with L. guyanensis, a large number of flagellates were seen to be plentifully infecting the stomodeal valve in significantly more specimens than in females infected by Endotrypanum only. However, the electrophoretic profiles of isoenzymes of parasites recovered from all co-infected specimens corresponded to Endotrypanum. This suggests that the mere correlation sand fly infection-biochemical analysis of isolates may induce parasitological incorrect consideration

Aspects of gene regulation in the diploid and tetraploid Odontophrynus americanus (Amphibia, Anura, Leptodactylidae)

Erythropoietic and hemoglobin DNA transcriptional activities were analyzed in the diploid and the tetraploid Odontophrynus americanus. Flow cytometric analyses of DNA, RNA and mitochondrial contents showed increased genic activity in both diploid and tetraploid animals during erythropoiesis in vivo elicited by pretreatment phenylhydrazine. Generally, higher values were seen in immature tetraploid erythroid cells. On the 10th day of recovery from anemia, large amounts of messenger RNA were found in both specimens. Based on the mitochondrial content, the tetraploid cells had more intense energy metabolism than the diploid cells. Diploid O. americanus had about three times more erythroid cells than tetraploid specimens, indicating that there were differences in the regulatory mechanisms of erythroid cells. Hematological parameters showed that tetraploid cells had 30% more hemoglobin than the diploid, suggesting a regulatory mechanism of hemoglobin synthesis at the transcriptional level. Cytoplasmic inclusions resembling Heinz bodies were found in both types of cells. In the tetraploid cells they were previously found associated with RNA or RNP, suggesting that other regulatory system which controls the accumulation of nontranslated RNA transcribed in excess must be present. These differences at the physiological and molecular levels during erythropoiesis reinforce the hypothesis that speciation is occurring between diploid and tetraploid O. americanus

Aspects of gene regulation in the diploid and tetraploid Odontophrynus americanus (Amphibia, Anura, Leptodactylidae)

A eritropoese e a atividade de transcrição de DNA de hemoglobina foram analisadas em Odontophrynus americanus diplóides e tetraplóides. Dados de conteúdo celular relativo de DNA, RNA e mitocôndrias obtidos por citometria de fluxo mostraram uma atividade gênica aumentada em ambos os animais durante a eritropoese in vivo estimulada por tratamento com fenilhidrazina, com valores maiores em eritrócitos tetraplóides imaturos. No décimo dia de recuperação da anemia foram encontradas grandes quantidades de RNA mensageiro em ambos espécimens. Com base no conteúdo mitocondrial, as células tetraplóides apresentaram um metabolismo energético mais intenso. O. americanus diplóides apresentaram três vezes mais células eritróides que os animais tetraplóides, caracterizando um mecanismo regulador da produção de células eritróides. Determinações hematológicas mostraram que as células tetraplóides contêm 30% mais hemoglobina que as células diplóides. Uma vez que 25-30% mais ribossomos estão presentes nas células tetraplóides, parece que um mecanismo regulador da síntese de hemoglobina esteja relacionado ao nível transcricional. Como as inclusões citoplasmáticas semelhantes a corpos de Heinz, porém associadas com RNA ou RNP, são encontradas em ambos os espécimens, é possível que outro mecanismo regulador esteja presente, similar ao das hidden breaks descritas em peixes poliplóides, acumulando rRNA transcrito em excesso e não traduzido. Estas diferenças em níveis fisiológicos e moleculares, detectadas durante a eritropoese, reforçam que divergências em nível de especiação estão em curso entre os O. americanus diplóides e tetraplóides.Erythropoietic and hemoglobin DNA transcriptional activities were analyzed in the diploid and the tetraploid Odontophrynus americanus. Flow cytometric analyses of DNA, RNA and mitochondrial contents showed increased genic activity in both diploid and tetraploid animals during erythropoiesis in vivo elicited by pretreatment phenylhydrazine. Generally, higher values were seen in immature tetraploid erythroid cells. on the 10th day of recovery from anemia, large amounts of messenger RNA were found in both specimens. Based on the mitochondrial content, the tetraploid cells had more intense energy metabolism than the diploid cells. Diploid O. americanus had about three times more erythroid cells than tetraploid specimens, indicating that there were differences in the regulatory mechanisms of erythroid cells. Hematological parameters showed that tetraploid cells had 30% more hemoglobin than the diploid, suggesting a regulatory mechanism of hemoglobin synthesis at the transcriptional level. Cytoplasmic inclusions resembling Heinz bodies were found in both types of cells. In the tetraploid cells they were previously found associated with RNA or RNP, suggesting that other regulatory system which controls the accumulation of nontranslated RNA transcribed in excess must be present. These differences at the physiological and molecular levels during erythropoiesis reinforce the hypothesis that speciation is occurring between diploid and tetraploid O. americanus.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Immunophenotyping in Saliva as an Alternative Approach for Evaluation of Immunopathogenesis in Chronic Periodontitis

Made available in DSpace on 2015-05-27T13:39:47Z (GMT). No. of bitstreams: 2 license.txt: 1914 bytes, checksum: 7d48279ffeed55da8dfe2f8e81f3b81f (MD5) raquel_ferrazetal_IOC_2014.pdf: 1083647 bytes, checksum: 0cfdc88dfdfe0baee8dc35638525e5b8 (MD5) Previous issue date: 2014Universidade do Estado do Amazonas (UEA). Escola de Ciências da Saúde. Faculdade de Odontologia. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Plataforma de Citometria de Fluxo – Purificação Celular. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Centro de Pesquisas Leônidas e Maria Deane. Departamento de Biodiversidade em Saúde. Manaus, Am, Brasil.Universidade Federal do Amazonas (UFA). Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia. Manaus, AM, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Plataforma de Citometria de Fluxo – Purificação Celular. Laboratório de Imunoparasitologia. Rio de Janeiro, RJ, Brasil.Universidade Federal do Amazonas (UFA). Instituto de Ciências Biológicas. Departamento de Parasitologia. Laboratório de Imunologia. Manaus, AM, Brasil.Background: To date, flow cytometric immunophenotyping has not been used to investigate immune patterns in saliva samples from individuals with inflammatory processes in the oral cavity, such as chronic periodontitis (CP). Saliva analysis could be a non-invasive method for evaluating oral health. The objective of this study is to determine the phenotype of leukocytes and total immunoglobulin A (IgA), IgG, and IgM titers in the saliva of individuals with CP. Methods: Saliva samples were obtained from patients with CP (n = 12) and from a control group (n = 27) without oral diseases. Flow cytometry was performed to determine the frequency of T cells (CD4+ and CD8+), B cells, and natural killer (NK) cells as well as the total leukocyte population. Immunoglobulin titers were determined by dot enzyme-linked immunosorbent assay. Results: Cell immunophenotyping revealed that patients with CP had a higher frequency of total leukocytes (47.94% ± 5.1%; P < 0.001), B cells (43.93% ± 6.2%; P = 0.006), NK cells (0.16% ± 0.04%; P = 0.03), and CD4+ T cells (38.99% ± 4.4%; P = 0.002) than individuals without oral pathologies (24.75% ± 2.2%, 20.60% ± 2.7%, 0.09% ± 0.03%, and 16.82% ± 3.5%, respectively). No significant differences in salivary total IgA, IgG, and IgM titers were found between the two cohorts studied. Nevertheless, higher total IgG levels were observed in patients with CP, which could indicate a possible correlation between clinical attachment level and salivary IgG (P = 0.07; r2 = 0.08). Conclusion: These results show that cell phenotyping by flow cytometry could be an effective tool for determining leukocyte profiles in saliva samples from patients with CP and healthy individuals

Correlation analysis of clinical and/or immunological parameters from healed cutaneous leishmaniasis subjects.

<p>Correlation between the percentage of recently activated CD4⁺ (A, n=13) or CD8⁺ (B, n=14) T lymphocytes from PBMC after <i>in </i><i>vitro</i> Lb-Ag stimulation and the duration of clinical cure; Correlation between the percentage of activated CD4⁺ (C, n=8) or CD8⁺ (D, n=9) T lymphocytes and the concentration of IL-10 from cell culture supernatant; Each point represents one subject. The graphs show the best fitted lines with 95% confidence intervals. r= correlation coefficient; p= significance level, (Spearman test). </p