Search results for "Natural killer"

Biological properties of extracellular vesicles and their physiological functions

2015

The authors wish to thank Dr R Simpson and Dr D Taylor for critical reading of the manuscript and acknowledge the Horizon 2020 European Cooperation in Science and Technology programme and its support of our European Network on Microvesicles and Exosomes in Health & Disease (ME-HaD; BM1202 www.cost.eu/COST_Actions/bmbs/Actions/BM1202). In the past decade, extracellular vesicles (EVs) have been recognized as potent vehicles of intercellular communication, both in prokaryotes and eukaryotes. This is due to their capacity to transfer proteins, lipids and nucleic acids, thereby influencing various physiological and pathological functions of both recipient and parent cells. While intensive invest…

Tumor cells convert immature myeloid dendritic cells into TGF-β–secreting cells inducing CD4+CD25+ regulatory T cell proliferation

2005

The mechanisms through which regulatory T cells accumulate in lymphoid organs of tumor-bearing hosts remain elusive. Our experiments indicate that the accumulation of CD4+CD25+ regulatory T cells (T reg cells) expressing FoxP3 and exhibiting immunosuppressive function originates from the proliferation of naturally occurring CD25+ T cells and requires signaling through transforming growth factor (TGF)–β receptor II. During tumor progression, a subset of dendritic cells (DCs) exhibiting a myeloid immature phenotype is recruited to draining lymph nodes. This DC subset selectively promotes the proliferation of T reg cells in a TGF-β–dependent manner in mice and rats. Tumor cells are necessary a…

Enterobacteria-infected T cells as antigen-presenting cells for cytotoxic CD8 T cells: a contribution to the self-limitation of cellular immune react…

1997

In enterobacteria-induced reactive arthritis (ReA), different T cell subsets play a role in the induction and maintenance of the synovitic process. Synovial fluid-derived alphabeta CD4, alphabeta CD8, and gammadelta T lymphocyte clones (TLC) that recognize Yersinia or Salmonella antigens on professional antigen-presenting cells (APC) have been characterized, and T cells themselves can function as nonprofessional APC. T cells were infected with the facultatively intracellular, arthritogenic enterobacterium Yersinia enterocolitica O:3. A CD8 TLC isolated from a patient with Yersinia-induced ReA recognized and efficiently lysed autologous and allogeneic Yersinia-infected T cells. Infected cyto…

Cancer Stem Cells: to be or not to be, is that the problem?

2014

Colon cancer stem cells: to be or not to be, is that the problem?

2014

Studio dell'infiltrato linfocitario peritumorale e dei linfociti circolanti in pazienti affetti da melanoma cutaneo

2014

I linfociti T γδ sono un gruppo di effettori “natural killer” del sistema immunitario innato che hanno rappresentato un interessante oggetto di studio nel corso degli ultimi anni. Il Dipartimento di Discipline Chirurgiche, Oncologiche ed Odontostomatologiche del Policlinico Universitario di Palermo, da anni attivo nei confronti della ricerca scientifica, ha recentemente condotto uno studio mirato alla conoscenza del potenziale effetto immunoterapeutico di questa popolazione linfocitaria verso i melanomi in stadio avanzato. Sulla base della classificazione della American Joint Committee on Cancer (AJCC) i pazienti affetti da melanoma maligno in stadio IV con neoplasia metastatica hanno una p…

Invariant natural killer T cells treated with rapamycin or transforming growth factor-β acquire a regulatory function and suppress T effector lymphoc…

2015

Invariant natural killer T cells treated with rapamycin or transforming growth factor-β acquire a regulatory function and suppress T effector lymphocytes

Transforming growth factor   induced FoxP3+ regulatory T cells suppress Th1 mediated experimental colitis

2006

Background and aims: The imbalance between effector and regulatory T cells plays a central role in the pathogenesis of inflammatory bowel diseases. In addition to the thymus, CD4+CD25+ regulatory T cells can be induced in the periphery from a population of CD25− T cells by treatment with transforming growth factor β (TGF-β). Here, we analysed the in vivo function of TGF-β induced regulatory T (Ti-Treg) cells in experimental colitis. Methods: Ti-Treg cells were generated in cell culture in the presence or absence of TGF-β and tested for their regulatory potential in experimental colitis using the CD4+CD62L+ T cell transfer model. Results: Ti-Treg cells significantly suppressed Th1 mediated c…

T cell avidity determines the level of CTL activation

2004

To investigate the influence of avidity on T cell activation in vitro and in vivo, we analyzed T cells from St40 and St42 mice, which express the same transgenic TCR specific for an E1a-derived epitope of adenovirus type 5 with different expression levels and therefore different avidities. Splenocytes from both strains showed comparable cytolytic activities and required identical peptide concentrations for efficient target cell lysis and up-regulation of activation markers. However, the kinetics of CD25 up-regulation were strikingly different: whereas the majority of the high-avidity St42 T cells up-regulated the IL-2Ralpha chain within a few hours, low-avidity St40 T cells expressed only 5…

Human intestinal Vdelta1+ lymphocytes recognize tumor cells of epithelial origin.

1996

gammadelta T cells can be grouped into discrete subsets based upon their expression of T cell receptor (TCR) variable (V) region families, their tissue distribution, and their specificity. Vdelta2+ T cells constitute the majority of gammadelta T cells in peripheral blood whereas Vdelta1+T cells reside preferentially in skin epithelium and in the intestine. gammadelta T cells are envisioned as first line host defense mechanisms capable of providing a source of immune effector T cells and immunomodulating cytokines such as interleukin (IL) 4 or interferon (IFN) gamma. We describe here the fine specificity of three distinct gammadelta+ tumor-infiltrating lymphocytes (TIL) obtained from patient…