title: Regulation of CD1d expression and function by a herpesvirus infection.
abstract: Little is known about the role of CD1d-restricted T cells in antiviral immune responses. Here we show that the lytic replication cycle of the Kaposi sarcoma-associated herpesvirus (KSHV) promotes downregulation of cell-surface CD1d. This is caused by expression of the 2 modulator of immune recognition (MIR) proteins of the virus, each of which promotes the loss of surface CD1d expression following transfection into uninfected cells. Inhibition of CD1d surface expression is due to ubiquitination of the CD1d alpha-chain on a unique lysine residue in its cytoplasmic tail, which triggers endocytosis. Unlike MIR-mediated MHC class I downregulation, however, CD1d downregulation does not appear to include accelerated lysosomal degradation. MIR2-induced downregulation of CD1d results in reduced activation of CD1d-restricted T cells in vitro. KSHV modulation of CD1d expression represents a strategy for viral evasion of innate host immune responses and implicates CD1d-restricted T cells as regulators of this viral infection.
authors.affiliation: George Williams Hooper Foundation, University of California, San Francisco, 94143, USA.
authors.forename: David Jesse
authors.initials: DJ
authors.lastname: Sanchez
authors.forename: Jenny E
authors.initials: JE
authors.lastname: Gumperz
authors.forename: Don
authors.initials: D
authors.lastname: Ganem
mesh_terms: D018949:Antigens, CD1 / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D055610:Antigens, CD1d; D015536:Down-Regulation / Q000502:physiology; D006566:Herpesviridae Infections / Q000276:immunology / Q000378:metabolism*; D019288:Herpesvirus 8, Human / Q000276:immunology / Q000378:metabolism*; D006801:Humans; D025801:Ubiquitin / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication / Q000502:physiology*; D017874:Immediate-Early Proteins
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; D025801:Ubiquitin; D014764:Viral Proteins; C526877:CD1D protein, human; C501887:MIR1 protein, human herpesvirus 8; C405867:K5 protein, Human herpesvirus 8; D017874:Immediate-Early Proteins