A human herpesvirus 7 glycoprotein, U21, diverts major histocompatibility complex class I molecules to lysosomes.
All members of the herpesvirus family persist in their host throughout life. In doing so, herpesviruses exploit a surprising number of different strategies to evade the immune system. Human herpesvirus 7 (HHV-7) is a relatively recently discovered member of the herpesvirus family, and little is known about how it escapes immune detection. Here we show that HHV-7 infection results in premature degradation of major histocompatibility complex class I molecules. We identify and characterize a protein from HHV-7, U21, that binds to and diverts properly folded class I molecules to a lysosomal compartment. Thus, U21 is likely to function in the normal course of HHV-7 infection to downregulate surface class I molecules and prevent recognition of infected cells by cytotoxic T lymphocytes.
Hudson
A W
AW
Department of Pathology, Harvard Medical School, Boston, Massachusetts 02115, USA. ahudson@hms.harvard.edu
Howley
P M
PM
Ploegh
H L
HL
D000595:Amino Acid Sequence; D002460:Cell Line; D003208:Concanavalin A / Q000494:pharmacology; D005805:Genes, MHC Class I; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D016199:Herpesvirus 7, Human / Q000502:physiology*; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008247:Lysosomes / Q000378:metabolism*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017510:Protein Folding; D014764:Viral Proteins / Q000502:physiology*
D006023:Glycoproteins; D015395:Histocompatibility Antigens Class I; D014764:Viral Proteins; D003208:Concanavalin A