title: Myeloid dendritic cells can kill T cells during chronic hepatitis C virus infection.
abstract: Myeloid dendritic cells (mDCs) are the most potent professional antigen-presenting cells that regulate specific T-cell responses. Here we studied the ability of mDCs to kill T cells during HCV infection. We found that mDCs from chronic hepatitis C (CHC) patients expressed upregulated levels of two inhibitory ligands, Fas ligand and the ligand 2 of PD-1 (PD-L2), compared to healthy mDCs. However, their expression of the ligand 1 of PD-1 (PD-L1), tumor necrosis factor-related apoptosis inducing ligand (TRAIL), and B lymphocyte stimulator (BLyS) on the cell surface was comparable to healthy mDCs. CHC patient mDCs had cytotoxic effects on autologous patient T cells and allogeneic healthy T cells. CHC patient T cells had increased expression of PD-1 compared to healthy T cells. These results indicate that the cytotoxic activity of mDCs is upregulated to kill T cells during chronic HCV infection, which represents a novel mechanism of HCV immune evasion.
authors: Li KaShing Institute of Virology, Department of Medical Microbiology and Immunology, University of Alberta , Edmonton, Alberta, Canada. lz1@ualberta.ca
authors: Li
authors: L
authors: Zhao
authors: David Lorne
authors: DL
authors: Tyrrell
mesh_terms: D000328:Adult; D003602:Cytotoxicity, Immunologic; D003713:Dendritic Cells / Q000276:immunology*; D053222:Fas Ligand Protein / Q000096:biosynthesis; D019698:Hepatitis C, Chronic / Q000276:immunology*; D006801:Humans; D057131:Immune Evasion; D008297:Male; D008875:Middle Aged; D061027:Programmed Cell Death 1 Ligand 2 Protein / Q000096:biosynthesis; D013601:T-Lymphocytes / Q000276:immunology*; D015854:Up-Regulation
chemical_list: D053222:Fas Ligand Protein; C556977:PDCD1LG2 protein, human; D061027:Programmed Cell Death 1 Ligand 2 Protein