Search results for "t-lymphocytes"
showing 10 items of 1380 documents
Dendritic cells lentivirally engineered to overexpress interleukin-10 inhibit contact hypersensitivity responses, despite their partial activation in…
2010
Background Dendritic cells (DCs) constitute an attractive target for immunotherapeutic approaches. Because DCs are largely refractory to transfection with plasmid DNA, several viral transduction protocols were established. The potential side-effects of lentiviral transduction on the phenotype and activation state of DCs left unstimulated after transduction have not been assessed. There is a need to analyse these parameters as a result of the requirement of using DCs with a low activation state for therapeutic strategies intended to induce tolerance. Methods Lentivirally-transduced bone marrow (BM)-derived DCs (LV-DCs) in comparison with mock-transduced (Mock-DCs) and untreated DCs were anal…
Cancer-Initiating Cells from Colorectal Cancer Patients Escape from T Cell-Mediated Immunosurveillance In Vitro through Membrane-Bound IL-4
2014
Abstract Cancer-initiating cells (CICs) that are responsible for tumor initiation, propagation, and resistance to standard therapies have been isolated from human solid tumors, including colorectal cancer (CRC). The aim of this study was to obtain an immunological profile of CRC-derived CICs and to identify CIC-associated target molecules for T cell immunotherapy. We have isolated cells with CIC properties along with their putative non-CIC autologous counterparts from human primary CRC tissues. These CICs have been shown to display “tumor-initiating/stemness” properties, including the expression of CIC-associated markers (e.g., CD44, CD24, ALDH-1, EpCAM, Lgr5), multipotency, and tumorigenic…
T cell–mediated response to SARS‐CoV‐2 in liver transplant recipients with prior COVID‐19
2021
Abstract Whether immunosuppression impairs severe acute respiratory syndrome coronavirus 2‐specific T‐cell‐mediated immunity (SARS‐CoV‐2‐CMI) after liver transplantation (LT) remains unknown. We included 31 LT recipients in whom SARS‐CoV‐2‐CMI was assessed by intracellular cytokine staining (ICS) and interferon (IFN)‐γ FluoroSpot assay after a median of 103 days from COVID‐19 diagnosis. Serum SARS‐CoV‐2 IgG antibodies were measured by ELISA. A control group of non‐transplant immunocompetent patients were matched (1:1 ratio) by age and time from diagnosis. Post‐transplant SARS‐CoV‐2‐CMI was detected by ICS in 90.3% (28/31) of recipients, with higher proportions for IFN‐γ‐producing CD4+ than …
An RNA vaccine drives expansion and efficacy of claudin-CAR-T cells against solid tumors.
2019
A one-two, CAR-T cell punch Chimeric antigen receptor (CAR)–T cells have been clinically effective in killing certain hematological malignancies, but achieving long-term patient responses for solid tumors remains a challenge. Reinhard et al. describe a two-part “CARVac” strategy to overcome poor CAR-T cell stimulation and responses in vivo. They introduce the tight junction protein claudin 6 (CLDN6) as a new CAR-T cell target and designed a nanoparticulate RNA vaccine encoding a chimeric receptor directed toward CLDN6. This lipoplex RNA vaccine promotes CLDN6 expression on the surface of dendritic cells, which in turn stimulates and enhances the efficacy of CLDN6-CAR-T cells for improved tu…
Harnessing dendritic cells in cancer.
2011
Dendritic cells (DCs) are central to the initiation of tumor-specific immune responses. However, the tumor microenvironment generates immunosuppressive cells and soluble mediators that compromise DC functions and limit the success of DC-based therapies. Progress in understanding DC metabolism in cancer is uncovering novel therapeutic targets that could restore DC capacity to prime T cells and trigger effective anticancer responses. Accumulating evidence also indicates that conventional chemo- and radiotherapy protocols can cause DC activation, enhance antigen cross-presentation, selectively eliminate immunosuppressive cells and revert the immunosuppression state caused by cancer, suggesting…
Mast cell growth-enhancing activity (MEA) is structurally related and functionally identical to the novel mouse T cell growth factor P40/TCGFIII (int…
1990
We have previously shown that certain bone marrow-derived mast cell (BMMC) lines proliferate in response to a mast cell growth-enhancing activity (MEA) that is distinct from interleukin (IL) 3 and IL 4. Here we provide evidence that MEA is identical with the recently cloned mouse T cell growth factor P40. The evidence is as follows: (a) recombinant P40 displayed all the biological activities ascribed to MEA: it supported the growth of MEA-sensitive BMMC lines, it induced IL 6 secretion by these cells, and it enhanced survival of primary mast cell cultures; (b) highly purified MEA stimulated the growth of P40-dependent cell lines; (c) a rabbit monospecific antiserum directed against P40 spec…
CD40 activity on mesenchymal cells negatively regulates OX40L to maintain bone marrow immune homeostasis under stress conditions
2021
BackgroundWithin the bone marrow (BM), mature T cells are maintained under homeostatic conditions to facilitate proper hematopoietic development. This homeostasis depends upon a peculiar elevated frequency of regulatory T cells (Tregs) and immune regulatory activities from BM-mesenchymal stem cells (BM-MSCs). In response to BM transplantation (BMT), the conditioning regimen exposes the BM to a dramatic induction of inflammatory cytokines and causes an unbalanced T-effector (Teff) and Treg ratio. This imbalance negatively impacts hematopoiesis, particularly in regard to B-cell lymphopoiesis that requires an intact cross-talk between BM-MSCs and Tregs. The mechanisms underlying the ability of…
HLA-B27-restricted T cells from patients with ankylosing spondylitis recognize peptides from B*2705 that are similar to bacteria-derived peptides
2003
SUMMARY Ankylosing spondylitis (AS) is an inflammatory systemic disease affecting the spine, sacroiliacal and peripheral joints. Although the aetiology of AS remains unknown, the strong association with the HLA-B27 allele might reflect directly a detrimental effect of the HLA-B27 molecule itself, resulting from its potential capability to present ‘arthritogenic’ peptides to CD8+ T cells. Because some forms of SpA are triggered by enterobacterial infection, such arthritogenic peptides might originate from autologous and/or bacterial proteins triggering cross-reactive CD8+ T cell clones. Intriguingly, two peptides from the second extracellular domain of HLA-B*2705 share sequence homologies wi…
HLA-B27-restricted CD8 T cells derived from synovial fluids of patients with reactive arthritis and ankylosing spondylitis.
1993
Ankylosing spondylitis and seronegative spondylarthropathies such as Reiter's syndrome and reactive arthritis are strongly associated with HLA-B27. However, the mechanisms by which HLA-B27 is involved in disease susceptibility and pathogenesis are unknown. If the disease association is a consequence of HLA-B27's physiological function in antigen presentation, the disease should be mediated by cytotoxic T lymphocytes (CTLs) that recognise bacterial or self peptides presented by HLA-B27. Proof of this arthritogenic peptide model requires isolation of B27-restricted CD8 T cells from arthritic joints of patients with spondylarthropathies. An important question is whether "arthritogenic" bacteri…
HLA-B27-restricted cytotoxic T lymphocyte responses to arthritogenic enterobacteria or self-antigens are dominated by closely related TCRBV gene segm…
1996
Identification of the T-cell receptors (TCR) used by synovial cytotoxic T lymphocytes (CTL) of patients with reactive arthritis (ReA) may be crucial to better understanding the pathogenetic mechanism underlying the HLA-B27 association of spondylarthropathies. The authors, therefore, sequenced 25 TCRB chains from HLA-B27-restricted CD8+ CTL clones and two clonal lines specific for self- or Yersinia enterocolitica antigen isolated from synovial fluids of 3 HLA-B27+ patients with ReA and PBL of one healthy HLA-B27+ individual. Fourteen non-HLA-B27-restricted CTL served as controls. Both autoreactive and Y. enterocolitica specific HLA-B27-restricted CTL used a highly limited set of VB genes wit…