Search results for "t-lymphocytes"
showing 10 items of 1380 documents
Oral immunization with HCV-NS3-transformed Salmonella: induction of HCV-specific CTL in a transgenic mouse model.
2001
Abstract Background & Aims: The ability to induce cytotoxic T cells is considered an important feature of a candidate hepatitis C virus (HCV) vaccine. We used an oral immunization strategy with attenuated HCV-NS3–transformed Salmonella typhimurium to deliver DNA directly to the gut-associated lymphoid tissue. Methods: HLA-A2.1 transgenic mice were immunized once with transformed attenuated Salmonella . HCV-specific CD8 + T cells were analyzed in vitro as well as in vivo by challenge of mice with recombinant HCV-NS3 vaccinia virus. Results: Salmonella (10 8 colony-forming units; 20 μg plasmid DNA) induced cytotoxic and IFN-γ–producing CD8 + T cells specific for the immunodominant epitope NS3…
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…
Inhibition of the pro-inflammatory mediators' production and anti-inflammatory effect of the iridoid scrovalentinoside.
2007
We have studied scrovalentinoside, an iridoid with anti-inflammatory properties isolated from Scrophularia auriculata ssp. pseudoauriculata, as an anti-inflammatory agent in different experimental models of delayed-type hypersensitivity. We found that scrovalentinoside reduced the edema induced by oxazolone at 0.5 mg/ear and sheep red blood cells at 10 mg/kg. The observed effect occurred during the last phase or inflammatory response; during the earlier phase or induction of the delayed-type hypersensitivity reaction, no significant activity was noted. Thus, scrovalentinoside reduced both the edema and cell infiltration in vivo and reduced lymphocyte proliferation in vitro, affecting the cy…
Phenotypic and Immunometabolic Aspects on Stem Cell Memory and Resident Memory CD8+ T Cells
2022
The immune system, smartly and surprisingly, saves the exposure of a particular pathogen in its memory and reacts to the pathogen very rapidly, preventing serious diseases.Immunologists have long been fascinated by understanding the ability to recall and respond faster and more vigorously to a pathogen, known as “memory”.T-cell populations can be better described by using more sophisticated techniques to define phenotype, transcriptional and epigenetic signatures and metabolic pathways (single-cell resolution), which uncovered the heterogeneity of the memory T-compartment. Phenotype, effector functions, maintenance, and metabolic pathways help identify these different subsets. Here, we exam…
Phylodynamic Analysis and Implication of HCV Genotype 4 Variability on Antiviral Drug Response and T-Cell Recognition.
2020
Therapies for HCV care could change the prevalence and the geographic distribution of genotypes due to differences in Sustained Virologic Response (SVR). In this scenario, uncommon genotypes/subtypes, such as genotype 4, could spread from high-risk groups, replacing genotypes eradicated by antiviral drugs. Genotype eradication is also strongly influenced by the CD8+ T cell response. In this study, the genetic variability in HCV genotype 4 strains obtained from a cohort of 67 patients naï
Transporter (TAP)- and proteasome-independent presentation of a melanoma-associated tyrosinase epitope.
2000
The melanosomal protein tyrosinase is considered as a target of specific immunotherapy against melanoma. Two tyrosinase-derived peptides are presented in association with HLA-A2.1 [Wolfel et al., Eur. J. Immunol., 24, 759-764 (1994)]. Peptide 1-9 (MLLAVLYCL) is generated from the putative signal sequence. The internal peptide 369-377 is posttranslationally converted at residue 371, and its presentation is dependent on functional TAP transporters and proteasomes [Mosse et al., J. exp. Med.187, 37-48 (1998)]. Herein, we report on the processing and transport requirements for the signal sequence-derived peptide 1-9 that were studied in parallel to those for peptide 369-377. After infection of …
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
Nanosecond pulsed electric field inhibits malignant melanoma growth by inducing the change of systemic immunity
2019
Background Nanosecond pulsed electric fields (nsPEFs) showed an inhibitory effect on proliferation of malignant melanoma. In this study, the growth of melanoma were inhibited by changing the systemic immunity. Material and Methods C57BL/6 mice with B16 malignant were exposed to 200 pulses of 100 ns duration, 30kV/cm. The mice were executed four days later. T lymphocyte has been extracted from spleen. Cell viability was evaluated by CCK-8 assay. CD3+CD4+ T cells, CD3+CD8+ T cells, regulatory T cells (Treg) and myeloid-derived suppressor cells (MDSC) were analyzed by flow cytometry. TNF-α, IL-2, IL-10, TGF-β, IFN– γ levels in supernatants were assessed by ELISA. Results C57 malignant melanoma…
Dacarbazine-mediated upregulation of NKG2D ligands on tumor cells activates NK and CD8 T cells and restrains melanoma growth.
2013
International audience; Dacarbazine (DTIC) is a cytotoxic drug widely used for melanoma treatment. However, the putative contribution of anticancer immune responses in the efficacy of DTIC has not been evaluated. By testing how DTIC affects host immune responses to cancer in a mouse model of melanoma, we unexpectedly found that both natural killer (NK) and CD8(+) T cells were indispensable for DTIC therapeutic effect. Although DTIC did not directly affect immune cells, it triggered the upregulation of NKG2D ligands on tumor cells, leading to NK cell activation and IFNγ secretion in mice and humans. NK cell-derived IFNγ subsequently favored upregulation of major histocompatibility complex cl…
Parvovirus H-1-Induced Tumor Cell Death Enhances Human Immune Response In Vitro via Increased Phagocytosis, Maturation, and Cross-Presentation by Den…
2005
Oncotropic and oncolytic viruses have attracted high attention as antitumor agents because they preferentially kill cancer cells in vitro and reduce the incidence of spontaneous, induced, or implanted animal tumors. Some autonomous parvoviruses (H-1, minute virus of mice) and derived recombinant vectors are currently under preclinical evaluation. Still not fully understood, their antitumor properties involve more than just tumor cell killing. Because wild-type parvovirus-mediated tumor cell lysates (TCLs) may trigger antigen-presenting cells (APCs) to augment the host immune repertoire, we analyzed phagocytosis, maturation, and crosspresentation of H-1-induced TCLs by human dendritic cells …