title: Preferential utilization of the perforin/granzyme pathway for lysis of Epstein-Barr virus-transformed lymphoblastoid cells by virus-specific CD4+ T cells.
abstract: In this report, we show that Epstein-Barr virus (EBV)-infected lymphoblastoid cell lines (LCL) express Fas and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 2 and that LCL are lysed following engagement of these receptors by agonist Fas and TRAIL receptor-specific monoclonal antibodies (MAb). We also show that EBV-specific CD4+ T cells mediate bystander lysis of susceptible targets through both the Fas/Fas ligand (FasL) and the TRAIL pathways, but find that the dominant mechanism of lysis following cognate, HLA class II-restricted recognition of LCL is the perforin/granzyme pathway. Killing of LCL by EBV-specific CD4+ T cells was strongly inhibited by concanamycin A, an agent that elevates granule pH, resulting in accelerated destabilization and degradation of perforin. In contrast, blocking anti-FasL MAb showed only limited inhibition of LCL killing. Blocking anti-TRAIL MAb had no effect on lysis of LCL by EBV-specific CD4+ T cells. We further show that culture of EBV-specific CD4+ T cells in the presence of interleukin 4 markedly abrogates effector cytotoxic function against LCL through direct depletion of intracellular perforin, with no evidence of a Th1 to Th2 shift in patterns of cytokine expression.
authors.affiliation: Department of Microbiology and Immunology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205, USA.
authors.forename: A
authors.initials: A
authors.lastname: Khanolkar
authors.forename: H
authors.initials: H
authors.lastname: Yagita
authors.forename: M J
authors.initials: MJ
authors.lastname: Cannon
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000911:Antibodies, Monoclonal; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism / Q000821:virology*; D002469:Cell Separation; D003602:Cytotoxicity, Immunologic; D053222:Fas Ligand Protein; D005434:Flow Cytometry; D004854:Herpesvirus 4, Human; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism; D015847:Interleukin-4 / Q000378:metabolism; D018942:Macrolides; D008562:Membrane Glycoproteins / Q000378:metabolism*; D054353:Perforin; D052899:Pore Forming Cytotoxic Proteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor / Q000096:biosynthesis* / Q000276:immunology; D018417:Th1 Cells / Q000378:metabolism; D018418:Th2 Cells / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D000911:Antibodies, Monoclonal; C505661:FASLG protein, human; D053222:Fas Ligand Protein; D018942:Macrolides; D008562:Membrane Glycoproteins; D052899:Pore Forming Cytotoxic Proteins; D053220:Receptors, TNF-Related Apoptosis-Inducing Ligand; D018124:Receptors, Tumor Necrosis Factor; C505639:TNFRSF10B protein, human; D054353:Perforin; D015847:Interleukin-4; C036978:concanamycin A; D007371:Interferon-gamma