DEWTON DE MORAES VASCONCELOS
Projetos de Pesquisa
Unidades Organizacionais
Instituto Central, Hospital das Clínicas, Faculdade de Medicina - Médico
LIM/56 - Laboratório de Investigação em Dermatologia e Imunodeficiências, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
LIM/56 - Laboratório de Investigação em Dermatologia e Imunodeficiências, Hospital das Clínicas, Faculdade de Medicina
LIM/31 - Laboratório de Genética e Hematologia Molecular, Hospital das Clínicas, Faculdade de Medicina
5 resultados
Resultados de Busca
Agora exibindo 1 - 5 de 5
- CD18 deficiency evolving to megakaryocytic (M7) acute myeloid leukemia: Case report(2014) VASCONCELOS, Dewton de Moraes; BEITLER, Beatriz; MARTINEZ, Gracia A.; PEREIRA, Juliana; AMIGO FILHO, Jose Ulysses; KLAUTAU, Giselle Burlamaqui; LIAN, Yu Cheng; NEGRA, Marinella Della; DUARTE, Alberto Jose da SilvaLeukocyte adhesion deficiency type 1 (LAD 1 - CD18 deficiency) is a rare disease characterized by disturbance of phagocyte function associated with less severe cellular and humoral dysfunction. The main features are bacterial and fungal infections predominantly in the skin and mucosal surfaces, impaired wound healing and delayed umbilical cord separation. The infections are indolent, necrotic and recurrent. In contrast to the striking difficulties in defense against bacterial and fungal microorganisms, LAD 1 patients do not exhibit susceptibility to viral infections and neoplasias. The severity of clinical manifestations is directly related to the degree of CD18 deficiency. Here, a 20 year-old female presenting a partial CD18 deficiency that developed a megakaryocytic (M7) acute myeloid leukemia is described for the first time. The clinical features of the patient included relapsing oral thrush due to Candida, cutaneous infections and upper and lower respiratory tract infections, followed by a locally severe necrotic genital herpetic lesion. The patient's clinical features improved for a period of approximately two years, followed by severe bacterial infections. At that time, the investigation showed a megakaryocytic acute myeloid leukemia, treated with MEC without clinical improvement. The highly aggressive evolution of the leukemia in this patient suggests that adhesion molecules could be involved in the protection against the spread of neoplastic cells. (C) 2014 Published by Elsevier Inc.
- Autoimmune regulator (AIRE) contributes to Dectin-1-induced TNF-alpha production and complexes with caspase recruitment domain-containing protein 9 (CARD9), spleen tyrosine kinase (Syk), and Dectin-1(2012) PEDROZA, Luis A.; KUMAR, Vipul; SANBORN, Keri B.; MACE, Emily M.; NIINIKOSKI, Harri; NADEAU, Kari; VASCONCELOS, Dewton de Moraes; PEREZ, Elena; JYONOUCHI, Soma; JYONOUCHI, Harumi; BANERJEE, Pinaki P.; RUUSKANEN, Olli; CONDINO-NETO, Antonio; ORANGE, Jordan S.Background: Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) syndrome is a complex immunologic disease caused by mutation of the autoimmune regulator (AIRE) gene. Autoimmunity in patients with APECED syndrome has been shown to result from deficiency of AIRE function in transcriptional regulation of thymic peripheral tissue antigens, which leads to defective T-cell negative selection. Candidal susceptibility in patients with APECED syndrome is thought to result from aberrant adaptive immunity. Objective: To determine whether AIRE could function in anticandidal innate immune signaling, we investigated an extrathymic role for AIRE in the immune recognition of beta-glucan through the Dectin-1 pathway, which is required for defense against Candida species. Methods: Innate immune signaling through the Dectin-1 pathway was assessed in both PBMCs from patients with APECED syndrome and a monocytic cell line. Subcellular localization of AIRE was assessed by using confocal microscopy. Results: PBMCs from patients with APECED syndrome had reduced TNF-alpha responses after Dectin-1 ligation but in part used a Raf-1-mediated pathway to preserve function. In the THP-1 human monocytic cell line, reducing AIRE expression resulted in significantly decreased TNF-a release after Dectin-1 ligation. AIRE formed a transient complex with the known Dectin-1 pathway components phosphorylated spleen tyrosine kinase and caspase recruitment domain-containing protein 9 after receptor ligation and localized with Dectin-1 at the cell membrane. Conclusion: AIRE can participate in the Dectin-1 signaling pathway, indicating a novel extrathymic role for AIRE and a defect that likely contributes to fungal susceptibility in patients with APECED syndrome. (J Allergy Clin Immunol 2012;129:464-72.)
- Lymphocyte transformation assay for C neoformans antigen is not reliable for detecting cellular impairment in patients with Neurocryptococcosis(2012) ROCHA, Katya C.; PINHAL, Cinthia; CAVALCANTI, Sonia; VIDAL, Monica S. M.; TOSCANO, Matheus; MORAES-VASCONCELOS, Dewton; DUARTE, Alberto J. S.; FONSECA, Fernando L. A.; ABREU, Luiz Carlos de; VALENTI, Vitor E.; GRUMACH, Anete S. G.Background: Cryptococcus neoformans causes meningitis and disseminated infection in healthy individuals, but more commonly in hosts with defective immune responses. Cell-mediated immunity is an important component of the immune response to a great variety of infections, including yeast infections. We aimed to evaluate a specific lymphocyte transformation assay to Cryptococcus neoformans in order to identify immunodeficiency associated to neurocryptococcosis (NCC) as primary cause of the mycosis. Methods: Healthy volunteers, poultry growers, and HIV-seronegative patients with neurocryptococcosis were tested for cellular immune response. Cryptococcal meningitis was diagnosed by India ink staining of cerebrospinal fluid and cryptococcal antigen test (Immunomycol-Inc, SP, Brazil). Isolated peripheral blood mononuclear cells were stimulated with C. neoformans antigen, C. albicans antigen, and pokeweed mitogen. The amount of H-3-thymidine incorporated was assessed, and the results were expressed as stimulation index (SI) and log SI, sensitivity, specificity, and cut-off value (receiver operating characteristics curve). We applied unpaired Student t tests to compare data and considered significant differences for p<0.05. Results: The lymphotoxin alpha showed a low capacity with all the stimuli for classifying patients as responders and non-responders. Lymphotoxin alpha stimulated by heated-killed antigen from patients with neurocryptococcosis was not affected by TCD4+ cell count, and the intensity of response did not correlate with the clinical evolution of neurocryptococcosis. Conclusion: Response to lymphocyte transformation assay should be analyzed based on a normal range and using more than one stimulator. The use of a cut-off value to classify patients with neurocryptococcosis is inadequate. Statistical analysis should be based on the log transformation of SI. A more purified antigen for evaluating specific response to C. neoformans is needed.
- Contribution of Complement System pathways to the killing of Leptospira spp.(2020) SILVA, Priscilla Yuri Okochi Alves da; MIDON, Leonardo Moura; HEINEMANN, Marcos Bryan; VASCONCELOS, Dewton de Moraes; BARBOSA, Angela Silva; ISAAC, LourdesThe Complement System (CS) plays an important role in the immune response against leptospirosis and can be activated by the Alternative and Lectin Pathways (Innate Immunity) and by the Classical Pathway (Acquired Immunity). Here we analyzed a broad range of nonpathogenic and pathogenic Leptospira strains considering their interaction with each CS pathway. We determined bacterial survival rate and CS protein deposition in the presence of purified proteins, specific component depleted sera and NHS treated with the chelating agents EDTA (inhibits all three activation pathways) or EGTA (inhibits the Classical and Lectin Pathways). We suggest that the Lectin and the Alternative Pathways have an important role to eliminate saprophytic leptospires since i) approximately 50% survival of both saprophytic strains was observed in the presence of MBL-deficient serum; ii) approximately 50% survival of Leptospira biflexa Patoc I was observed in the presence of NHS - EGTA and iii) C1q-depleted serum caused significant bacterial lysis. In all serovars investigated the deposition of C5-C9 proteins on saprophytic Leptospira strains was more pronounced when compared to pathogenic species confirming previous studies in the literature. No difference on C3 deposition was observed between nonpathogenic and pathogenic strains. In conclusion, Leptospira strains interact to different degrees with CS proteins, especially those necessary to form MAC, indicating that some strains and specific ligands could favor the binding of certain CS proteins. (C) 2020 Published by Elsevier Masson SAS on behalf of Institut Pasteur.
- Encephalopathy Caused by Human Parvovirus B19 Genotype 1 Associated with Haemophilus influenzae Meningitis in a Newborn(2023) FERREIRA, Noely Evangelista; COSTA, Antonio C. da; KALLAS, Esper G.; SILVEIRA, Cassia G. T.; OLIVEIRA, Ana Carolina S. de; HONORATO, Layla; PAIAO, Heuder G. O.; LIMA, Silvia H.; VASCONCELOS, Dewton de M.; CORTES, Marina F.; COSTA, Silvia F.; MENDOZA, Tania R. T.; GOMES, Helio R.; WITKIN, Steven S.; MENDES-CORREA, Maria C.Parvovirus B19 infection is associated with a wide range of clinical manifestations, from asymptomatic to severe neurological disorders. Its major clinical symptoms, fever and rash, are common to multiple viruses, and laboratory tests to detect B19 are frequently not available. Thus, the impact of B19 on public health remains unclear. We report the case of a 38-day old girl admitted to Sao Paulo Clinical Hospital, Brazil, with an initial diagnosis of bacterial meningitis, seizures, and acute hydrocephalus. Antibiotic therapy was maintained for one week after admission and discontinued after negative laboratory results were obtained. Nine days after symptoms onset, a cerebral spinal fluid (CSF) sample revealed persistent pleocytosis. The complete B19 complete genome was subsequently identified in her CSF by a metagenomic next-generation sequencing approach. This report highlights the possible involvement of B19 in the occurrence of acute neurological manifestations and emphasizes that its possible involvement might be better revealed by the use of metagenomic technology to detect viral agents in clinical situations of unknown or uncertain etiology.