Search results for "interleukin 2"
showing 10 items of 320 documents
Immunologic Effects of Interferon
1990
Interferons can be defined as a family of induced proteins sharing the capacity to exert pleiotropic effects on cell functions and to render cells resistant to virus infection. They are activating genes coding for a number of enzymes, most of which have not yet been characterized, and also by enhancing the synthesis of cell surface components. This enables interferons to modulate the immune response at different levels. This article will focus on the effects of interferon on antigen presentation, regulation of the immune response, activation of macrophage functions, and on its role in the pathogenesis of some diseases.
Drug-induced expansion and differentiation of Vγ9Vδ2 T cells in vivo: The role of exogenous IL-2
2005
Human Vgamma9Vdelta2 T cells recognize nonpeptidic Ags generated by the 1-deoxy-d-xylulose 5-phosphate (many eubacteria, algae, plants, and Apicomplexa) and mevalonate (eukaryotes, archaebacteria, and certain eubacteria) pathways of isoprenoid synthesis. The potent Vgamma9Vdelta2 T cell reactivity 1) against certain cancer cells or 2) induced by infectious agents indicates that therapeutic augmentations of Vgamma9Vdelta2 T cell activities may be clinically beneficial. The functional characteristics of Vgamma9Vdelta2 T cells from Macaca fascicularis (cynomolgus monkey) are very similar to those from Homo sapiens. We have found that the i.v. administration of nitrogen-containing bisphosphonat…
Human GITR Ligand Is Expressed on Tumor Cells and Reduces Cytokine Production and Cellular Cytotoxicity of NK Cells Identified to Express GITR.
2005
Abstract Members of the tumor necrosis factor (TNF) superfamily mediate multiple cellular functions including cellular proliferation, differentiation, and cell death. Human Glucocorticoid-induced TNF Receptor (GITR) has been shown to be expressed on T cells, is upregulated following activation and mediates costimulatory signals. The human GITR ligand (GITRL) has been reported to be expressed on antigen presenting cells and various healthy nonlymphoid tissues including small intestine, ovary, testis, kidney and endothelial cells. We analyzed multiple tumor cell lines of hematopoietic and epithelial origin as well as of germ cell lineage and various gliomas by RT-PCR and FACS analysis. Both G…
Human CD25+ regulatory T cells: two subsets defined by the integrins alpha 4 beta 7 or alpha 4 beta 1 confer distinct suppressive properties upon CD4…
2004
Down-regulation of autoreactive T cell responses in vivo includes cell-contact-dependent as well as contact-independent mechanisms. Infectious tolerance is a contact-dependent mechanism used by naturally occurring CD25(+) T regulatory cells (Tregs) to confer suppressive activity upon conventional CD4(+) T cells thereby generating secondary T helper suppressor cells(Th(sup)), which inhibit T cell activation via soluble mediators. Here, we describe two distinct subsets of human Tregs, characterized by expression of either the alpha(4)beta(7) integrin or the alpha(4)beta(1) integrin. Upon activation, both subsets show an enhanced expression of FoxP3, recently described as a key transcription f…
Multifunctional CD4(+) T cells correlate with active Mycobacterium tuberculosis infection.
2010
Th1 CD4(+) T cells and their derived cytokines are crucial for protection against Mycobacterium tuberculosis. Using multiparametic flow cytometry, we have evaluated the distribution of seven distinct functional states (IFN-gamma/IL-2/TNF-alpha triple expressors, IFN-gamma/IL-2, IFN-gamma/TNF-alpha or TNF-alpha/IL-2 double expressors or IFN-gamma, IL-2 or TNF-alpha single expressors) of CD4(+) T cells in individuals with latent M. tuberculosis infection (LTBI) and active tuberculosis (TB). We found that triple expressors, while detectable in 85-90%TB patients, were only present in 10-15% of LTBI subjects. On the contrary, LTBI subjects had significantly higher (12- to 15-fold) proportions of…
Induction of accessory cell function of human alveolar macrophages by inhalation of human natural interleukin-2.
1996
Accessory function allows antigen-presenting cells to produce sufficient secondary signals for optimum T cell proliferation and interleukin-2 (IL-2) production. Alveolar macrophages are inferior accessory cells compared to monocytes (PBM). We report here that the accessory index (AI) of alveolar macrophages and PBM of patients with lung metastases of solid tumors treated with inhalations of human natural IL-2 (hnIL-2) increased following its administration (P0.005). The accessory index was significantly elevated from baseline values after 2 weeks of inhalation of 300,000 IU hnIL-2/day (8.2 +/- 10.2 compared to 1.1 +/- 1; P0.001). The inhalation of 150,000 IU also induced increases in the in…
Estimation of the frequency of self-reactive T cells in health and inflammatory diseases by limiting dilution analysis and single cell cloning.
1996
Autoreactive T cells have recently been detected not only in autoimmune diseases but also in healthy individuals, but their frequency is thought to be low. The aim of our study was to estimate the frequency of self-reactive T cells by using limiting dilution analyses of peripheral blood lymphocytes. Assessment of self-reactivity in this study was defined as T-cell proliferation to autologous non-T cells in the absence of foreign antigens. When culture conditions were optimized by adding interleukin 2, healthy individuals showed a frequency of self-reactive T cells ranging from 1/60 to 1/600. These results were confirmed by using unseparated peripheral blood leukocytes or Epstein-Barr virus …
A phase-II study of low-dose cyclophosphamide and recombinant human interleukin-2 in metastatic renal cell carcinoma and malignant melanoma.
1989
Recent preclinical and clinical studies that have demonstrated antitumor activity of high-dose recombinant interleukin-2 (rIL-2), and animal models that demonstrated a synergistic effect of low-dose cyclophosphamide, led us to study rIL-2 (Cetus Corp., Emeryville, Calif) in a phase II clinical trial in combination with low-dose cyclophosphamide in 32 patients, 18 with malignant melanoma and 14 with renal cell carcinoma. rIL-2 was given once daily at 3 x 10(6) U/m2, as a 30-min infusion for 14 days in cycle I and for 2 x 5 days in cycles II and III respectively; if tolerated, the dose was increased to a maximum of 6 x 10(6) U m-2 day-1; the cycles, separated by 1 week treatment-free interval…
Apoptosis and ageing.
1998
Stimulation of T cells from aged individuals leads to different kinds and/or size of responses if compared with the responses of T cells obtained from young individuals. In fact elderly is associated with a progressive decline of immune response besides an increasing incidence of autoimmune phenomena. These differences might be the result of modified cellular mechanisms controlling the immune system in the course of ageing. The apoptotic deletion of activated T cells has been proposed as the key mechanism to maintain T cell homeostasis, and in this respect CD95 (Fas antigen) seems to play a major role in this course of events. In this study we show that just collected lymphocytes from old s…
Abnormalities in serum concentrations of interleukin-2, interferon-alpha and interferon-gamma in schizophrenia not detected.
1992
The hypothesis of an immunological defect in schizophrenia has been supported by reports on abnormal production of interleukin-2 (IL-2) and interferons (IFNs) in schizophrenic patients. In the present study we determined the serum concentrations of IL-2, IFN-alpha and IFN-gamma in 10 first onset, neuroleptic-naive schizophrenics, in 6 pretreated patients who were drug free (1 week to 2 years) at the time of the investigation and in 15 matched healthy controls. No IFN-alpha was detected in schizophrenics' and in control sera. No differences were found in IL-2 and IFN-gamma levels between schizophrenics and controls. Thus the present study failed to support the hypothesis of an immunological …