21 research outputs found
Regulation and subversion of HPV16-specific immunity in cancer patients
Cervical cancer is induced by HPV in virtually all cases, but it is still unknown how these virus-positive tumors arise in the face of immunity. In this thesis we examined the role of different arms of the adaptive immune response on cervical cancer. In previous studies, it was shown that cancer patients do have a detectable immune response against the HPV16 E6 and E7 antigens. However, in general this response was not associated with cytokine production. In the present study, the mechanism underlying this dysfunctional immune response was investigated by studying the presence, specificity and function of the local T-cell response in patients with HPV-induced cervical malignancies at different stages of disease. Low CD8/Treg ratio is a significant independent unfavorable prognostic factor in cervical cancer patients. Frequently, the tumor is also infiltrated with HPV-specific CD4+ and CD8+ T-cells which can potentially attack the tumor. The infiltrating T-cells also include HPV-specific regulatory T-cells which are able to suppress the reactivity of neighboring T-cells. Their presence may explain the failure of the immune system to control HPV-induced tumors.funded by NWO ZonMw (917.56.311) supported by J.E. Jurriaanse Stichting, Bontius Stichting, BD Bioscience, Greiner Bio-One and Corning BV and ISA pharmaceuticals.UBL - phd migration 201
Patients with anaphylaxis to pea can have peanut allergy caused by cross-reactive IgE to vicilin (Ara h 1)
Background: Serologic cross-reactivity among legumes has been described; however, it is rarely clinically significant. In this study 3 patients with a history of anaphylaxis to pea are described who subsequently had symptoms after ingestion of peanut. Objective: We investigated whether the peanut-related symptoms were due to cross-reactivity between pea and peanut proteins. Methods: Peanut-related symptoms were documented according to case history or double-blind, placebo-controlled food challenge results. Skin prick tests were performed, and specific IgE levels were determined for pea and peanut with the CAP system FEIA. IgE-binding proteins in pea and peanut were identified by using immunoblot analysis. Cross-reactivity was studied by means of immunoblot and ELISA inhibition studies with whole extracts and purified allergens. Results: Peanut-related symptoms consisted of oral symptoms in all patients, with additional urticaria and dyspnea or angioedema in 2 patients. All patients had a positive skin prick test response and an increased IgE level to pea and peanut. Immunoblotting revealed strong IgE binding to mainly vicilin in pea extract and exclusively to Ara h 1 in crude peanut extract. Immunoblot and ELISA inhibition studies with crude extracts, as well as purified proteins, showed that IgE binding to peanut could be inhibited by pea but not or only partially the other way around. Conclusion: Clinically relevant cross-reactivity between pea and peanut does occur. Vicilin homologues in pea and peanut (Ara h 1) are the molecular basis for this cross-reactivit
An in vitro immune response model to determine tetanus toxoid antigen (vaccine) specific immunogenicity: Selection of sensitive assay criteria
Peanut allergen Ara h 3: Isolation from peanuts and biochemical characterization.
Background: Peanut allergen Ara h 3 has been the subject of investigation for the last few years. The reported data strongly depend on recombinant Ara h 3, since a purification protocol for Ara h 3 from peanuts was not available. Methods: Peanut allergen Ara h 3 (glycinin), was purified and its posttranslational processing was investigated. Its allergenic properties were determined by studying IgE binding characteristics of the purified protein. Results: Ara h 3 consists of a series of polypeptides ranging from approximately 14 to 45 kDa that can be classified as acidic and basic subunits, similar to the subunit organization of soy glycinin. N-terminal sequences of the individual polypeptides were determined, and using the cDNA deduced amino-acid sequence, the organization into subunits was explained by revealing posttranslational processing of the different polypeptides. IgE-binding properties of Ara h 3 were investigated using direct elisa and Western blotting with sera from peanut-allergic individuals. The basic subunits, and to a lesser extent the acidic subunits, bind IgE and may act as allergenic peptides. Conclusions: We conclude that peanut-derived Ara h 3, in contrast to earlier reported recombinant Ara h 3, resembles, to a large extent, the molecular organization typical for proteins from the glycinin family. Furthermore, posttranslational processing of Ara h 3 affects the IgE-binding properties and is therefore an essential subject of study for research on the allergenicity of Ara h 3
Identification of a novel SCA14 mutation in a Dutch autosomal dominant cerebellar ataxia family.
Item does not contain fulltextOBJECTIVE: To report a Dutch family with autosomal dominant cerebellar ataxia (ADCA) based on a novel mutation in the PRKCG gene. METHODS: The authors studied 13 affected members of the six-generation family. After excluding the known spinocerebellar ataxia (SCA) genes, a combination of the shared haplotype approach, linkage analysis, and genealogic investigations was used. Exons 4 and 5 of the candidate gene, PRKCG, were sequenced. RESULTS: Affected subjects displayed a relatively uncomplicated, slowly progressive cerebellar syndrome, with a mean age at onset of 40.8 years. A focal dystonia in two subjects with an onset of disease in their early 20s suggests extrapyramidal features in early onset disease. Significant linkage to a locus on chromosome 19q was found, overlapping the SCA-14 region. Based on the recent description of three missense mutations in the PRKCG gene, located within the boundaries of the SCA-14 locus, we sequenced exons 4 and 5 of this gene and detected a novel missense mutation in exon 4, which involves a G-->A transition in nucleotide 353 and results in a glycine-to-aspartic acid substitution at residue 118. CONCLUSION: A SCA-14-linked Dutch ADCA family with a novel missense mutation in the PRKCG gene was identified
Influenza matrix 1-specific human CD4(+) FOXP3(+) and FOXP3(-) regulatory T cells can be detected long after viral clearance
Control and termination of infection with Influenza A virus is associated with increased IL-10 production in mouse models. Notably, IL-10 can be produced by Treg. Therefore, we investigated whether the population of IL-10-producing influenza-specific CD4(+) T cells comprised Treg as they are potent suppressors of the adaptive immune response. Influenza-specific IL-10-producing T cells were detected in all human donors displaying influenza-specific immunity. Isolation of Matrix 1 protein-specific IL-10-producing T-cell clones revealed that a substantial proportion of these T-cell clones displayed the capacity to suppress effector cells, functionally identifying them as Treg. Both FOXP3(+) and FOXP3(-) CD4(+) Treg were isolated and all were able to exert their suppressive capacity when stimulated with cognate antigen, including influenza virus-infected cells. In vitro suppression was not mediated by IL-10 but involved interference with the IL-2 axis. The isolated Treg suppressed amongst others the IL-2 production of influenza-specific T-helper cells as well as partially prevented the upregulation of the high-affinity IL-2 receptor on CD8 effector cells. So far the induction of virus-specific Treg has only been studied in the context of chronic viral infections. This study demonstrates that virus-specific Treg can also be induced by viruses that are rapidly cleared in humans.Experimental cancer immunology and therap
NKG2A Blockade Potentiates CD8 T Cell Immunity Induced by Cancer Vaccines
Experimental cancer immunology and therap