The pathogenesis of cutaneous leishmaniasis (CL) caused by Leishmania (Viannia) braziliensis is dictated mainly by the immune-mediated-tissue inflammation developed. The understanding of the immunological mechanisms that generate tissue damage or resolution of lesions is the key to the development of effective vaccine protocols and proper therapeutic schemes. It is clear that the specific immune response mediated by T cells is responsible for the beneficial outcome of the disease, however, the roles of CD4+ T, CD8+ T, NK and NKT cell subpopulations in immunopathogenesis of CL need to be elucidated.
View Article and Find Full Text PDFPlasmodium falciparum-specific antibodies tend to be short-lived, but their cognate memory B cells (MBCs) circulate in the peripheral blood of exposed subjects for several months or years after the last infection. However, the time course of antigen-specific antibodies and B-cell responses to the relatively neglected parasite Plasmodium vivax remains largely unexplored. Here, we showed that uncomplicated vivax malaria elicits short-lived antibodies but long-lived MBC responses to a major blood-stage P vivax antigen, apical membrane protein 1 (PvAMA-1), in subjects exposed to declining malaria transmission in the Amazon Basin of Brazil.
View Article and Find Full Text PDFBackground: Cutaneous leishmaniasis (CL) is caused by Leishmania (Viannia) braziliensis, which infects dermal macrophages and dendritic cells, causing an intense immune-mediated-tissue inflammation and a skin ulcer with elevated borders that can heal spontaneously or after antimonial therapy. The resolution of lesions depends on an adaptive immune response, and cytotoxic cells seem to have a fundamental role in this process. The aim of this study is to better understand the role of cytotoxicity mediated mechanisms that occur during the immune response in the CL lesion milieu, considering distinct cytotoxic-related CD107a cells, such as CD8, CD4, CD4 CD8 (double-negative, DN) and CD4CD8 (double-positive, DP) T lymphocytes, as well as NK and NKT cells.
View Article and Find Full Text PDFPurpose: To evaluate the role of miR-124a in the regulation of genes involved in insulin exocytosis and its effects on the kinetics of insulin secretion in pancreatic islets from pregnant rats submitted to a low-protein diet.
Methods: Adult control non-pregnant (CNP) and control pregnant (CP) rats were fed a normal protein diet (17%), whereas low-protein non-pregnant (LPNP) and low-protein pregnant (LPP) rats were fed a low-protein diet (6%) from days 1 to 15 of pregnancy. Kinetics of the glucose-induced insulin release and measurement of [Ca] in pancreatic islets were assessed by standard protocols.
In human cutaneous leishmaniasis (CL), the immune response is mainly mediated by T-cells. The role of CD8+ T-lymphocytes, which are related to healing or deleterious functions, in affecting clinical outcome is controversial. The aim of this study was to evaluate T-cell receptor diversity in late-differentiated effector (LDE) and memory CD8+ T-cell subsets in order to create a profile of specific clones engaged in deleterious or protective CL immune responses.
View Article and Find Full Text PDFBackground: Leishmaniasis is an important parasitic disease affecting millions worldwide. Human cutaneous leishmaniasis (CL) is endemic in Rio de Janeiro, Brazil, where is caused by Leishmania braziliensis. The adaptive immune response is accountable for the healing of CL and despite of key role of CD8+ T cells in this immune response little is known about the CD8+ T lymphocytes frequencies, apoptosis and antigen-responsive CD8+ T lymphocytes of CL patients during antimonial therapy.
View Article and Find Full Text PDFBackground: 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.
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