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Danielian S.,Servicio de Inmunologia y Reumatologia | Basile N.,Servicio de Inmunologia y Reumatologia | Rocco C.,Laboratorio Of Biologia Celular Y Retrovirus | Prieto E.,Servicio de Inmunologia y Reumatologia | And 7 more authors.
Journal of Clinical Immunology

Introduction: Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disease with major diagnostic and therapeutic difficulties, basically comprising two different conditions: primary and secondary forms. Recent advances regarding molecular diagnosis may be useful to distinguish from one another, especially in sporadic cases starting in early infancy. Materials and Methods In this report, we evaluated three Argentinean patients with clinical suspicion of HLH, but without family history. We excluded mutations in the perforin gene but identified in the three patients a novel homozygous deletion (c. 581-584delTGCC; p.Leu194- ProfsX2) in the gene-encoding syntaxin 11 (STX11), causing a premature termination codon. Results and Conclusion Each parent from the three unrelated families resulted heterozygous for this deletion confirming the diagnosis of familial hemophagocytic lymphohistiocytosis type 4. Patients shared the same single-nucleotide polymorphism profile in STX11 gene, and genotyping at ten microsatellites surrounding this gene support the presence of a single-haplotype block carrying the novel mutation. © Springer Science+Business Media, LLC 2010. Source

Fiorito C.,CONICET | Fiorito C.,University of Buenos Aires | Palacios C.,University of Buenos Aires | Palacios C.,CONICET | And 6 more authors.
Diseases of Aquatic Organisms

Poxvirus skin disease has been reported in several species of cetaceans, principally in odontocetes, and a single report in mysticetes. Southern right whales Eubalaena australis in Peninsula Valdes, Argentina, show a variety of skin lesions of unknown etiology, and the number of these lesions has increased in recent years. Samples from dead whales were taken in order to establish the etiology of these lesions. One calf and one adult presented ring-type lesions, characterized by a circumscribed and slightly raised area of skin. Lesions were histologically characterized by the presence of microvesicles and vacuolated cells in the stratum spinosum, along with hyperplasia of the stratum corneum and eosinophilic inclusion bodies in the cytoplasm of the epithelial cells. Transmission electron microscopy showed aggregations of virions with typical poxvirus morphology. PCR of cetacean poxvirus (CPV) DNA polymerase, DNA topoisomerase I and parapoxvirus DNA polymerase gene fragments was done, and confirmed the presence of poxvirus in one sample. Phylogenetic analysis showed that the detected poxvirus belongs to the CPV-2 group. This is the first confirmed report of poxvirus in southern right whales in Argentina. © Inter-Research 2015. Source

Simesen De Bielke M.G.,Servicio de Inmunologia y Reumatologia | Yancoski J.,Servicio de Inmunologia y Reumatologia | Rocco C.,Laboratorio Of Biologia Celular Y Retrovirus | Perez L.E.,Servicio de Inmunologia y Reumatologia | And 5 more authors.
Journal of Clinical Immunology

Mutations in the Fas gene (TNFRSF6) are the most common causes of Autoimmune Lymphoproliferative Syndrome (ALPS-FAS). Purpose: In Argentina almost a third of patients with ALPS-FAS present a missense mutation affecting the extracellular cysteine rich domain 2 of Fas, p.Cys107Tyr (C107Y). This change was found in homozygous state in 2 patients from a consanguineous family, and heterozygously, in 3 other patients from 3 unrelated families. In these families, 12 relatives were identified as healthy carriers of the mutation. We sought to test the hypothesis that this mutation actually represents a single haplotype of TNFRSF6. Methods: DNAs from ALPS-C107Y patients and their families, as well as from 150 Argentinean control subjects were sequenced for the known higher frequency single nucleotide polymorphisms (SNPs) of TNFRSF6. The C107Y-carriers were also genotyped at 5 microsatellites proximal to the Fas gene locus. Results: All C107Y alleles presented a unique intragenic haplotype that could be restricted to this group. Extent of haplotype sharing and variability of microsatellite alleles in C107Y chromosomes support the presence of a single haplotype block including the mutation and encompassing 2.395 Mb. Conclusions: A founder effect for C107Y has been evidenced in this work and the most common recent ancestor to the patients probably lived 350 years ago. This constitutes the first report of a founder event in ALPS. © 2012 Springer Science+Business Media, LLC. Source

Corro G.,Laboratorio Of Biologia Celular Y Retrovirus | Corro G.,CONICET | Rocco C.A.,Laboratorio Of Biologia Celular Y Retrovirus | De Candia C.,University of Buenos Aires | And 9 more authors.
AIDS Research and Human Retroviruses

Among persons infected by HIV-1, the rate of progression to AIDS is multifactorial being affected by host and viral factors, including the HIV-encoded negative factor (Nef). Our aim was to define whether variations in the nef gene as well as its functions may be associated with slower HIV disease course in infected children. The proviral HIV-1 nef gene was cloned, sequenced, and compared in children with contrasting disease course: 10 long-term nonprogressors (LTNP) and six rapid progressor (RP). The CD4 and MHC-I down-modulation ability of nef alleles derived from LTNP and RP children was analyzed. We observed that only one of our 10 LTNP had a protective genetic background, and out of them, 40% had defective nef genes, carrying substitutions at the (AWLEAQ56-61) and the (Rxx22-24) domains, and that those alleles were unable of down-regulate CD4 and MHC-I. The emergence or presence of Nef L58V substitution was associated with viral attenuation, indicated by a reduction in HIV viral loads, a persistent preservation of CD4+ T cell counts, and lack of AIDS-related symptoms. Our results demonstrate that HIV-1 perinatally infected children carrying functionally defective nef HIV-1 strains have prolonged asymptomatic phases without therapy, suggesting a relevant role of CD4 and MHC-I down-modulation Nef domains on in vivo HIV-1 pathogenesis and pediatric immunodeficiency outcome. © Copyright 2012, Mary Ann Liebert, Inc. Source

Catano G.,University of Texas Health Science Center at San Antonio | Chykarenko Z.A.,Dnepropetrovsk State Medical Academy | Mangano A.,Laboratorio Of Biologia Celular Y Retrovirus | Anaya J.-M.,El Rosario University | And 8 more authors.
Journal of Infectious Diseases

We used cutaneous delayed-type hypersensitivity responses, a powerful in vivo measure of cell-mediated immunity, to evaluate the relationships among cell-mediated immunity, AIDS, and polymorphisms in CCR5, the HIV-1 coreceptor. There was high concordance between CCR5 polymorphisms and haplotype pairs that influenced delayed-type hypersensitivity responses in healthy persons and HIV disease progression. In the cohorts examined, CCR5 genotypes containing -2459G/G (HHA/HHA, HHA/HHC, HHC/HHC) or -2459A/A (HHE/HHE) associated with salutary or detrimental delayed-type hypersensitivity and AIDS phenotypes, respectively. Accordingly, the CCR5-D32 allele, when paired with non-Δ32-bearing haplotypes that correlate with low (HHA, HHC) versus high (HHE) CCR5 transcriptional activity, associates with disease retardation or acceleration, respectively. Thus, the associations of CCR5-Δ32 heterozygosity partly reflect the effect of the non-Δ32 haplotype in a background of CCR5 haploinsufficiency. The correlations of increased delayed-type hypersensitivity with -2459G/G-containing CCR5 genotypes, reduced CCR5 expression, decreased viral replication, and disease retardation suggest that CCR5 may influence HIV infection and AIDS, at least in part, through effects on cell-mediated immunity. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. Source

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