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D Mauri

Publications and source records attributed to D Mauri.

33 records · Page 2Linked to original sources
PubMed1994

Peptide-induced T cell clones: specificity, MHC restriction, proliferation and cytokine pattern as a function of different stimulations.

CD4+ T cell clones were generated to tetanus toxin or to two tetanus toxin-derived peptides p2 (AA 830-834) and p30 (AA 947-976). 11 of the 24 p30-specific clones reacted to shorter p30 subunits (p301 or p302), and only 14 of the p2 or p30-specific clones reacted with TT presented by EBV-transformed B cell lines (B-LCL). The p30-specific clones were HLA-DP4 restricted. In contrast to autologous B cell lines, the majority of allogeneic, but HLA-DP4-positive cell lines failed to present p30 to the specific clones. We concluded that T cell clones are highly specific and that both, small alterations of the peptide length as well as discrete differences of the HLA-molecule may abrogate recognition of the peptide HLA complex by T cells. Moreover, use of peptides as stimulators of T cells may recruit and activate T cells which fail the "original" peptide, derived from normal antigen processing. Clones could usually be maintained in culture for 4-6 months, but with the help of freezing and thawing some clones are now available for over 2 years and still specific. Comparison of different autologous antigen-presenting cells, namely B-LCL and activated MHC class II-positive T cells revealed that not all clones were able to mount a proliferative response to peptide presentation by T cells, while all clones proliferated to B cells as APC. If stimulated with peptide and B-LCL, the clone proliferating to T cells as APC (so-called T responder clones) secreted a broad spectrum of cytokines (Th0-like) and were easier to maintain in culture. In contrast, clones which were unable to proliferate to peptide presentation, so-called T-nonresponder clones, showed a more restricted cytokine pattern and elevated or very low IL4/IFN gamma ratio upon antigen specific stimulation. However, all clones secreted at least small amounts of IL2, IL4, IFN gamma and TNF alpha, if stimulated by PMA and ionomycin. Thus, both chemical and antigen-specific stimulations should be considered if T cell clones are classified as Th1 or Th2, whereby those clones, which secrete a limited cytokine pattern after antigen stimulation only, might be named Th1 or Th2 like clones, while clones which even after PMA/ionomycin do not secrete all cytokines, might represent "real" Th1 or Th2 clones.

Clone Cells↗
PubMed1993

Carrier-mediated uptake and presentation of a major histocompatibility complex class I-restricted peptide.

Antigenic peptides derived from endogenous or viral proteins can associate with class I or class II major histocompatibility complex (MHC) molecules, while exogenous antigens are endocytosed, processed intracellularly and presented on MHC class II molecules. Here we describe a method that allows the presentation of an MHC class I-restricted antigenic peptide on MHC class I molecules, although it was taken up from the outside. The HLA-A2-restricted influenza virus matrix protein-derived peptide (flu, 57-68) was used either in soluble form or coupled via an S-S bridge to transferrin (Tf-flu). Target cells were incubated with flu or Tf-flu and the effective antigen presentation was detected in a cytotoxicity assay using flu peptide-specific, HLA-A2-restricted CD8+ cytotoxic T lymphocytes. Sensitization of target cells with Tf-flu required 5 to 10 times higher molar concentrations of peptide compared to sensitization with soluble free peptide. The Tf-flu construct was taken up by the cells via the Tf receptor (CD71) as the binding of Tf-flu was blocked by an excess of Tf. In contrast to the flu peptide, cytotoxicity elicited by Tf-flu was blocked by brefeldin A but not by chloroquine nor inhibitors of intracellular reducing steps, like 1-buthionine-(s,r)-sulfoximine or n-ethylmaleimide. Presentation of the flu peptide derived from Tf-flu construct is not hindered in the mutant T2 cell line, which lacks genes coding for transporter proteins for antigenic peptides (TAP1/TAP2) and proteasomes subunits, suggesting that the processing pathway described in this report may involve TAP-independent steps.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

Antigen-presenting human T cells and antigen-presenting B cells induce a similar cytokine profile in specific T cell clones.

One of the factors that may influence the cytokine secretion profile of a T cell is the antigen-presenting cell (APC). Since activated human T cells have been described to express major histocompatibility complex (MHC) class II molecules as well as costimulatory molecules for T cell activation, like e.g. ICAM-1, LFA-3 and B7, they might play a role as APC and be involved in the regulation of T-Tcell interactions. To define further the role of T cells as APC we tested their capacity to induce proliferation and cytokine production in peptide- or allospecific T cell clones and compared it with conventional APC, like B lymphoblasts (B-LCL) or HTLV-1-transformed T cells, or with non-classical APC, like activated keratinocytes or eosinophils. CD4+, DP-restricted T cell clones specific for a tetanus toxin peptide (amino acids 947-967) and CD4+, DR-restricted allospecific T cell clones produced interleukin (IL)-2, IL-4, tumor necrosis factor-alpha and interferon-gamma (IFN-gamma) after phorbol 12-myristate 13-acetate and ionomycin stimulation and a more restricted cytokine pattern after antigen stimulation. Dose-response curves revealed that the antigen-presenting capacity of activated, MHC class II+, B7+ T cells was comparable to the one of B-LCL. Both APC induced the same cytokine profile in the T cell clones despite a weaker proliferative response with T cells as APC. Suboptimal stimulations resulted in a lower IFN-gamma/IL-4 ratio. Cytokine-treated, MHC class II+ keratinocytes and eosinophils differed in the expression of adhesion molecules and their capacity to restimulate T cell clones. The strongly ICAM-1-positive keratinocytes induced rather high cytokine levels. In contrast, eosinophils, which express only low densities of MHC class II and no or only low levels of adhesion molecules (B7, ICAM-1 and LFA3), provided a reduced signal resulting in a diminished IFN-gamma/IL-4 ratio. We conclude that non-classical APC differ in their capacity to restimulate T cell clones, whereby the intensity of MHC class II and adhesion molecules (B7, ICAM-1) expressed seems to determine the efficacy of this presentation.

Antigen-Presenting Cells↗
PubMed1986

Deinstitutionalization, another way: the Italian mental health reform.

The article describes the Italian experience of deinstitutionalization in psychiatry, a reform which has attracted international recognition as being the only instance of an industrial society eliminating detention in a mental hospital from its range of mental health agencies and services. The first part of the article highlights the differences between the Italian experience and psychiatric reforms in Europe and the US, where deinstitutionalization has been reduced to dehospitalization. The problems and failings of these reforms are examined. The second part describes the operation, very different in content and method from the above quoted experiences, of the Italian form of deinstitutionalization. Starting from a critique of the rationalistic problem-solution "paradign" in psychiatry, it has developed as a complex social process which: a) involves all its subjects as active participants, b) transforms the power relationship existing between the patient (and citizen) and the institution, c) creates mental health services which completely replace detention in mental hospitals by deconstructing them and reconverting the material and human resources found in them. An example of this reconversion is given in the way in which mental health services have been organized in Trieste. The fourth part examines the reform law arising from the deinstitutionalization process and the characteristics of its implementation, in order to show how this process continues through implementation. In the light of these considerations, deinstitutionalization is no longer perceived as an aspect of the "welfare crisis", but rather as a significant pointer to new-post-welfare social policies.

Deinstitutionalization↗
PubMedDate not supplied

Hyperpyrexia secondary to acute hypocalcemic status. Is there a role for calcitonin therapy in bone metabolism derangements due to anticonvulsant drugs?

Hypocalcemia, hyperparathyroidism, hypovitaminosis D, hypocalcitoninemia and decreased bone mass are side effects of several anticonvulsant drugs. Since calcitonin inhibits the mineral mobilization of bone and augments minerals bone content, combined therapy with calcitonin, calcium, vitamin-C and vitamin-D was administrated to a patient with severe anticonvulsant disturbances of bone metabolism. Calcitonin hypersensitivity was evident. The symptomatology, characterized by the rare hypocalcemic hyperpyrexia, regressed after calcium infusion.

Adolescent↗
PubMedDate not supplied

Non-small cell lung cancer in the young: a retrospective analysis of diagnosis, management and outcome data.

BACKGROUND: Non-small cell lung cancer (NSCLC) in young patients is uncommon and is thought to constitute a distinct oncological entity with characteristic clinicopathological patterns. Since the reported data are scant and discordant, the presentation, management and outcome data of NSCLC patients aged under 45 years of age were analyzed and compared with those of patients over 45 years old. Prognostic factors for risk classification were also evaluated. MATERIALS AND METHODS: The data were abstracted from the Hellenic Cooperative Oncology Group (HeCOG) cancer registry database. The presentation, management and outcome data of patients with histologically confirmed NSCLC, managed from 1989 until 2004 in HeCOG participating centers, were retrospectively analyzed. The clinicopathological characteristics of patients aged < and > than 45 years old were compared and evaluated for prognostic significance regarding outcome. RESULTS: The data for NSCLC patients (1906), of whom 115 were aged <45, were retrieved. In comparative analysis, the young patients were more frequently asymptomatic at diagnosis, while older patients presented significantly higher rates of thoracic pain, cough and fatigue (p<0.01). The young patients were more commonly diagnosed with adenocarcinoma and less frequently with squamous cancer than patients aged over 45. Although the stage distribution was distinct, with older patients presenting higher rates of stage IV disease (21.9% vs. 12.2%), the rates of early lung cancer (stages I-IIIa) were similar. The overall survival (OS) was not significantly different (median OS 12 vs. 11.5 months, p=0.277). Among patients who underwent first-line palliative chemotherapy, young individuals had a significantly shorter time to progression: 4.3 vs. 5.8 months (p=0.0049). Univariate and multivariate regression analyses established the prognostic usefulness of the performance status, disease stage and disease-free interval for the risk of death, both in the total number of patients (1906) and in young patients (115). CONCLUSION: This large retrospective series failed to present strong evidence that NSCLC among young individuals constitutes a distinct clinicopathological entity with differing biological behavior, since the same clinicopathological prognostic factors were valid in both age groups. Molecular phenotypic studies are needed to shed light on this controversial subject.

Adult↗