Peripheral T cell tolerance, mediated by antigen-presenting steady state dendritic cells, is thought to significantly contribute to the prevention of autoimmunity. We set out to analyze the involvement of FoxP3+ regulatory T-cells, which are known to be important for maintenance of self-tolerance, in dendritic cell-induced peripheral tolerance of T-cells. Most autoreactive T cells are deleted in the thymus. Peripheral autoreactive T cells are controlled by peripheral tolerance, which acts through unresponsiveness/anergy, regulation/suppression and deletion. CD4+...

I have been registered as a PhD student at the Karolinska Institute on the 31th of May, 2007 and expect to finish my PhD in June 2011. Project 1 - Preparation and immunomontioring of a clinical trial in patients with advanced melanoma ? collaboration with Carl Figdor Patients will receive a DC vaccination regimen (3 vaccinations at weekly intervals) followed by 3 adoptive transfers of autologous in vitro expanded T cells. This novel approach combines in vivo priming by the DC vaccine with passive immunotherapy by lymphocyte infusion. Patients will undergo surg...

Predicted finish date for my PhD: February 2010 Our projects focuses on computational methods for the reconstruction of signalling pathways and the integration of gene expression data with existing biological information. In particular we target the response of dendritic cells to pathogenic and non pathogenic yeasts on a whole genome scale. At the same time our role in DC-THERA is to collaborate with bioinformaticians and with experimentalists for the solution of genomics problems that require highly interdisciplinary skills. We are also involved in the develop...

I will finish my PhD probably in 2010. Abstract: Toll-like receptors (TLRs) are important receptors of the innate immune system able to respond to molecular patterns borne by microbial and viral pathogens. TLR3, TLR7 and TLR9 form a subset of TLRs that are localized intracellularly and can recognize nucleic acids to initiate antiviral immune responses. Among these TLRs, TLR7 is triggered by viral or bacterial single stranded RNA (ssRNA) and mediates responses to RNA viruses. However, self-RNA can in some instances also activate TLR7, leading to the development o...

The objective of our work was to identify genes involved in the function of mature DCs by comparing genes expressed by DC before and after maturation. Immature and mature dendritic cells were purified from spleens at ULB. The transcriptomes of both populations were analyzed and compared at the University of Milano and the data were sent back to us. Interestingly, the gene STAT4 was the most upregulated during maturation (by 30-fold). We therefore compared the antigen-presenting-cell function of DC from WT versus STAT-4 KO mice but the results did not reveal anay...

I started my Ph.D in the lab of Federica Sallusto, Ph.D at the Institute for Research in Biomedicine, Bellinzona in November 2005. During the first part of my Ph.D I was mainly focused on the development of a novel assay to examine the repertoire of human naïve CD4+ and CD8+ T cells. The second part was then devoted to the validation and application of this method. After 3 ½ years of working on that project, I plan to defend my Ph.D next spring (April 2009). During vaccinations or in the course of natural infections a small number of antigen-specific T cells e...

My PhD project relates to the Tripartite motif (TRIM) proteins, which have been shown to be involved in many cellular functions including cell differentiation, apoptosis, cytokine signalling and some have antiviral activity. I have performed a comprehensive analysis of expression of TRIM molecules in cells of the innate and adaptive immune system. The cells used for my study include macrophages, myeloid and plasmacytoid dendritic cells (DC), and a panel of CD4+T cells (naïve T cells, Th1, Th2, and CD25+T regulatory cells and IL-10 T regulatory cells). My work u...

A number of soluble factors and the interaction between dendritic cells, T cells and other cell types of the immune system determine the magnitude and quality of the individual’s response to vaccination. Knowledge about this complex interplay is especially important for experimental therapies using dendritic cells, e.g in cancer patients with a disturbed immune system due to previous therapeutic administration of anti-proliferative drugs. We have analysed different aspects of the initiation of immune responses by dendritic cells: 1.In cooperation with R. Geig...

Dep. Dermatology, University Hospital Erlangen Expected completion: January 2010 To improve the routine monitoring of tumour-specific T-cell subsets by multicolour flow cytometry, we established a protocol for the combination of multimer staining and intracellular cytokine staining. After antigenic stimulation, human cytolytic T lymphocyte (CTL) exhibit a decrease in their binding to human leukocyte antigen (HLA)-peptide tetramers, since CTLs lose the colocalization of the T cell receptor (TCR) with CD8. It has been suggested by the group of Pierre van der Brug...

Plasmacytoid dendritic cells (pDCs) recognize pathogen-associated molecules, particularly viral, and represent an important mechanism in innate defense. They may however, also have roles in steady-state tolerogenic responses at mucosal sites. pDCs can be isolated from blood, mucosa, and lymph nodes (LNs). Although pDCs can express peripherally derived Ags in LNs and at mucosal sites, it is not clear whether pDCs actually migrate from the periphery in lymph or whether LN pDCs acquire Ags by other mechanisms. To determine whether pDCs migrate in lymph, intestine or ...

Tumor-derived peptides are used frequently as antigen (Ag) source in dendritic cell (DC) therapy in cancer patients. An alternative is to load DC with tumor-associated Ag (TAA)-encoding RNA. RNA-loading obviates prior knowledge of CTL and Th epitopes in the Ag. Multiple epitopes for many HLA alleles (both MHC class I and class II) are encoded by the RNA and loading is independent of the patient's HLA make-up. Herein, we determined the optimal conditions for mRNA-electroporation of monocyte-derived DC for clinical application in relation to different maturation co...

Prion diseases are fatal neurodegenerative diseases that are characterized by the conformational conversion of the normal, mainly alpha-helical cellular prion protein (PrP) into the abnormal beta-sheet-rich infectious isoform (PrP(Sc)). The immune system neither shows reaction against cellular PrP nor PrP(Sc), most likely due to profound self-tolerance. In previous studies, we were able to partly overcome self-tolerance using recombinantly expressed dimeric PrP (tandem PrP (tPrP)), in association with different adjuvants. Proof of principle for antiprion efficacy ...

We identified an antigen recognized on a human non-small-cell lung carcinoma by a cytotoxic T lymphocyte clone derived from autologous tumor-infiltrating lymphocytes. The antigenic peptide is presented by HLA-A2 and is encoded by the CALCA gene, which codes for calcitonin and for the alpha-calcitonin gene-related peptide. The peptide is derived from the carboxy-terminal region of the preprocalcitonin signal peptide and is processed independently of proteasomes and the transporter associated with antigen processing. Processing occurs within the endoplasmic reticul...

Dendritic cells (DCs) are crucial in immune induction. Not only do they collect antigens in peripheral tissues, and transport and process them for presentation to lymphocytes in draining lymph nodes, but they also regulate the immune response by modulating T-cell differentiation. Intestinal and hepatic DCs migrating in lymph can be collected from rats under near-physiological conditions. Initially, the mesenteric or celiac lymph nodes are removed from young rats (30 min). The afferent and efferent lymph vessels subsequently heal, permitting DCs to enter the thorac...

PURPOSE: New prognostic markers are needed for malignant melanoma. Inducible nitric oxide synthase (iNOS) and cyclooxygenase type 2 (COX-2) have been described to correlate with progression of melanoma. Moreover, activating mutations in BRAF/NRAS oncogenes are often detected in melanoma. The BRAF/NRAS mutation status and expression of COX-2 and iNOS were examined to compare their prognostic value for overall survival (OS) in stage III malignant cutaneous melanoma. EXPERIMENTAL DESIGN: The expression of iNOS and COX-2 in metastatic lymph nodes from 21 rapidly prog...

Interferon-producing killer dendritic cells (IKDCs) have been described as possessing the lytic potential of NK cells and the antigen-presenting capacity of dendritic cells (DCs). In this study, we examine the lytic function and antigen-presenting capacity of mouse spleen IKDCs, including those found in DC preparations. IKDCs efficiently killed NK cell targets, without requiring additional activation stimuli. However, in our hands, when exposed to protein antigen or to MHC class II peptide, IKDCs induced little or no T cell proliferation relative to conventional ...

To prevent excessive degradation of internalized antigens, which could destroy the peptides recognized by T lymphocytes, dendritic cells have developed several strategies that limit proteolytic activity in phagosomes. The recruitment of the NADPH oxidase NOX2 prevents acidification of phagosomes, limiting antigen degradation. Here, we show that dendritic cells derived from Rab27a-deficient ashen mice show increased phagosome acidification and antigen degradation, causing a defect in antigen cross-presentation. Enhanced acidification results from a delay in the rec...

BACKGROUND: The recent availability of high-throughput data in molecular biology has increased the need for a formal representation of this knowledge domain. New ontologies are being developed to formalize knowledge, e.g. about the functions of proteins. As the Semantic Web is being introduced into the Life Sciences, the basis for a distributed knowledge-base that can foster biological data analysis is laid. However, there still is a dichotomy, in tools and methodologies, between the use of ontologies in biological investigation, that is, in relation to experimen...

Some chemotherapeutic agents can elicit apoptotic cancer cell death, thereby activating an anticancer immune response that influences therapeutic outcome. We previously reported that anthracyclins are particularly efficient in inducing immunogenic cell death, correlating with the pre-apoptotic exposure of calreticulin (CRT) on the plasma membrane surface of anthracyclin-treated tumor cells. Here, we investigated the role of cellular Ca(2+) homeostasis on CRT exposure. A neuroblastoma cell line (SH-SY5Y) failed to expose CRT in response to anthracyclin treatment. ...