T cell receptor (TCR) down-modulation after antigen presentation is a fundamental process that regulates TCR signal transduction. Current understanding of this process is that intrinsic TCR/CD28 signal transduction leads to TCR down-modulation. Here, we show that the interaction between programmed cell death 1 ligand 1 (PD-L1) on dendritic cells (DCs) and programmed death 1 (PD-1) on CD8 T cells contributes to ligand-induced TCR down-modulation. We provide evidence that this occurs via Casitas B-lymphoma (Cbl)-b E3 ubiquitin ligase up-regulation in CD8 T cells. Interference with PD-L1/PD-1 signalling markedly inhibits TCR down-modulation leading to hyper-activated, proliferative CD8 T cells as assessed in vitro and in vivo in an arthritis model. PD-L1 silencing accelerates anti-tumour immune responses and strongly potentiates DC anti-tumour capacities, when combined with mitogen-activated kinase (MAPK) modulators that promote DC activation.
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http://dx.doi.org/10.1002/emmm.201100165 | DOI Listing |
Oncoimmunology
December 2018
Institute of Immunity and Transplantation, UCL Division of Infection and Immunity, University College London, Royal Free Hospital, London, UK.
We explored whether engineering of T cell specificity and effector function improves immunotherapy of solid tumors. Although IL-12 can enhance cancer immunity, a strategy of safe IL-12 delivery without toxicity is currently lacking. We engineered T cells to express IL-12 controlled by the NFAT promoter responsive to TCR stimulation, or by the Tet-On promoter responsive to doxycycline.
View Article and Find Full Text PDFWe have previously demonstrated co-receptor level-associated functional heterogeneity in apparently homogeneous naive peripheral CD4 T cells, dependent on MHC-mediated tonic signals. Maturation pathways can differ between naive CD4 and naive CD8 cells, so we tested whether the latter showed similar co-receptor level-associated functional heterogeneity. We report that, when either polyclonal and T-cell receptor (TCR)-transgenic monoclonal peripheral naive CD8 T cells from young mice were separated into CD8 and CD8 subsets, CD8 cells responded poorly, but CD8 and CD8 subsets of CD8 single-positive (SP) thymocytes responded similarly.
View Article and Find Full Text PDFJ Invest Dermatol
March 2019
Faculty of Veterinary Medicine, Fundamental and Applied Research for Animals and Health, University of Liège, Liège, Belgium; Veterinary Mycology, Fundamental and Applied Research for Animals and Health, University of Liège, Liège, Belgium. Electronic address:
Dermatophytoses are among the most common fungal infections worldwide, but little is known about the immune response in them. By comparing Trichophyton benhamiae acute superficial dermatophytosis in wild-type and Rag2 mice, we showed that TCR-mediated immunity is critical for fungal clearance and clinical recovery. In WT mice, CD4 T cells isolated from the skin-draining lymph nodes exhibit both T helper type (Th) 1 and Th17 differentiation during infection, with regard to produced cytokines or mRNA levels of transcription factors.
View Article and Find Full Text PDFPLoS Pathog
August 2018
Institute of Molecular Virology, Ulm University Medical Center, Ulm, Germany.
SERINC5 is a host restriction factor that impairs infectivity of HIV-1 and other primate lentiviruses and is counteracted by the viral accessory protein Nef. However, the importance of SERINC5 antagonism for viral replication and cytopathicity remained unclear. Here, we show that the Nef protein of the highly divergent SIVcol lineage infecting mantled guerezas (Colobus guereza) is a potent antagonist of SERINC5, although it lacks the CD4, CD3 and CD28 down-modulation activities exerted by other primate lentiviral Nefs.
View Article and Find Full Text PDFImmunity
December 2017
The Walter and Eliza Hall Institute of Medical Research, 1G Royal Parade, Parkville, VIC 3052, Australia; Department of Microbiology and Immunology, The University of Melbourne, Parkville, VIC 3010, Australia; The Peter Doherty Institute for Infection and Immunity, University of Melbourne, Melbourne, VIC 3000, Australia. Electronic address:
During chronic stimulation, CD8 T cells acquire an exhausted phenotype characterized by expression of inhibitory receptors, down-modulation of effector function, and metabolic impairments. T cell exhaustion protects from excessive immunopathology but limits clearance of virus-infected or tumor cells. We transcriptionally profiled antigen-specific T cells from mice infected with lymphocytic choriomeningitis virus strains that cause acute or chronic disease.
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