Search results for " T-cell"
showing 10 items of 320 documents
Drp1 Controls Effective T Cell Immune-Surveillance by Regulating T Cell Migration, Proliferation, and cMyc-Dependent Metabolic Reprogramming
2018
Summary Mitochondria are key players in the regulation of T cell biology by dynamically responding to cell needs, but how these dynamics integrate in T cells is still poorly understood. We show here that the mitochondrial pro-fission protein Drp1 fosters migration and expansion of developing thymocytes both in vitro and in vivo. In addition, we find that Drp1 sustains in vitro clonal expansion and cMyc-dependent metabolic reprogramming upon activation, also regulating effector T cell numbers in vivo. Migration and extravasation defects are also exhibited in Drp1-deficient mature T cells, unveiling its crucial role in controlling both T cell recirculation in secondary lymphoid organs and acc…
Facilitating matched pairing and expression of TCR chains introduced into human T cells.
2006
AbstractAdoptive transfer of T lymphocytes is a promising treatment for a variety of malignancies but often not feasible due to difficulties generating T cells that are reactive with the targeted antigen from patients. To facilitate rapid generation of cells for therapy, T cells can be programmed with genes encoding the α and β chains of an antigen-specific T-cell receptor (TCR). However, such exogenous α and β chains can potentially assemble as pairs not only with each other but also with endogenous TCR α and β chains, thereby generating αβTCR pairs of unknown specificity as well as reducing the number of exogenous matched αβTCR pairs at the cell surface. We demonstrate that introducing cy…
HCV-induced immune responses influence the development of operational tolerance after liver transplantation in humans.
2014
Pathogen-induced immune responses prevent the establishment of transplantation tolerance in experimental animal models. Whether this occurs in humans as well remains unclear. The development of operational tolerance in liver transplant recipients with chronic hepatitis C virus (HCV) infection allows us to address this question. We conducted a clinical trial of immunosuppression withdrawal in HCV-infected adult liver recipients to elucidate (i) the mechanisms through which allograft tolerance can be established in the presence of an ongoing inflammatory response and (ii) whether anti-HCV heterologous immune responses influence this phenomenon. Of 34 enrolled liver recipients, drug withdrawal…
Rasburicase-induced Methemoglobinemia: A Case Report and Literature Review.
2020
Rasburicase is a recombinant urate oxidase enzyme indicated for tumor lysis syndrome, a potential life-threatening oncologic emergency that occurs most commonly during initial chemotherapy for hematological malignancies. As a result of the defects in the physiological antioxidant pathway, erythrocytes of patients with glucose-6-phosphate dehydrogenase deficiency are not protected against the oxidizing stress exerted by hydrogen peroxide generated with the administration of rasburicase. The authors report a 14-year-old patient, diagnosed with T-cell acute lymphoblastic leukemia, who developed methemoglobinemia and hemolytic anemia with low oxygen saturation after starting steroids, hyperhydr…
Gamma-delta T-cell lymphomas.
2009
Peripheral T-cell lymphomas (TCLs) are uncommon neoplasms, accounting for about 12% of all lymphoid tumors worldwide. TCLs in which gammadelta T-cell receptors are expressed (gammadelta TCLs) are extremely aggressive and rare (<1% of lymphoid neoplasms). gammadelta TCLs originate from gammadelta T cells, a small subset of peripheral T cells with direct antigen recognition capability acting at the interface between innate and adaptive immunity. Two distinct gammadelta TCL entities are recognized: hepatosplenic T-cell lymphoma (HSTL) and primary cutaneous gammadelta T-cell lymphoma (PCGD-TCL). HSTL is a well-characterized extranodal lymphoma that has a disguised onset, secondary to intrasinus…
γδT cells elicited by CMV reactivation after allo-SCT cross-recognize CMV and leukemia.
2013
Human cytomegalovirus (CMV) infections and relapse of disease remain major problems after allogeneic stem cell transplantation (allo-SCT), in particular in combination with CMV-negative donors or cordblood transplantations. Recent data suggest a paradoxical association between CMV reactivation after allo-SCT and reduced leukemic relapse. Given the potential of Vδ2-negative γδT cells to recognize CMV-infected cells and tumor cells, the molecular biology of distinct γδT-cell subsets expanding during CMV reactivation after allo-SCT was investigated. Vδ2(neg) γδT-cell expansions after CMV reactivation were observed not only with conventional but also cordblood donors. Expanded γδT cells were ca…
Are human Vδ2(pos) T cells really resistant to aging and Human Cytomegalovirus infection?()
2019
In their recent paper, Weili Xu et al. [1] described the different behaviors of Vδ1pos and Vδ2pos T cell subsets in response to lifelong stress and claimed that Vδ2pos T cells are not affected by aging and Human Cytomegalovirus (HCMV) infection. While we agree that these two γδ T cell subsets diverge both in phenotype/function and in tissue distribution, we are somewhat surprised that authors did not take into account the several previously published and contradictory experimental evidence in regards to senescence of Vδ2pos T cells [2,3]. These latter studies reported that HCMV infection not only induces a clonal expansion of a distinct Vγ9neg/Vδ2pos T cell subset, but also determines a con…
The immunogenicity of human and murine cytomegaloviruses.
2000
Cytomegaloviruses are strictly host-species-specific. During an aeon of co-evolution, virus and host have found an arrangement: the productive and cytopathogenic cycle of viral gene expression is held in check by the host's immune response. As a consequence, cytomegalovirus disease is restricted to the immunocompromised host. The virus has evolved strategies to avoid its elimination and eventually hides itself in a silent state, referred to as 'viral latency'. Redundant molecular mechanisms have been identified by which cytomegaloviruses interfere with antigen presentation pathways to 'evade' immune control. In the annual period covered by this review, the IE1 protein was revisited as an im…
Identification of transcripts of the T cell antigen receptor beta chain gene and major histocompatibility complex class II genes in antigen-presentin…
1988
The cloned murine cell line BK-BI-2.6.C6 has previously been shown to exhibit T cell characteristics, to synthesize and express MHC class II molecules, and to present protein antigens to antigen-dependent T cell clones. As a more definitive proof of the T-cell nature of these cells, transcripts of the rearranged T cell antigen receptor (TcR) beta gene were assessed by Northern blot analysis. BK-BI-2.6.C6 cells constitutively transcribe mRNA for the light chain of TcR and express the disulphide-linked alpha, beta TcR heterodimer at the cell surface. In addition mRNA for the polymorphic MHC class II subunits A alpha and A beta as well as for the invariant gamma chain were detected. BK-BI-2.6.…
T-Cell Subsets (TCM, TEM, TEMRA) and Poly-Functional Immune Response in Patients with Human Immunodeficiency Virus (HIV) Infection and Different T-CD…
2019
OBJECTIVE: Dynamic changes of cytotoxic T cell responses against Human Immunodeficiency Virus 1 (HIV-1) infection have been the subject of an innovative investigation using antiretroviral therapy (ART). Currently, human CD8 naïve central memory (TCM), effector memory (TEM), and effector memory cells re-expressing CD45RA (TEMRA) T-cells have been thoroughly studied with ART. CD45RA is a marker usually found on naïve T-cells. MATERIALS AND METHODS: We performed a longitudinal study of mono-/polyfunctional T-cells in the peripheral blood while targeting three functionally distinct cell populations of CD4+ and CD8+ T-cells (single IL2 and IFN-γ, dual IL2/IFN-γ) in 50 HIV-1 patients. These patie…