Immune modulation by the human cytomegalovirus-encoded molecule UL18, a mystery yet to be solved.
Human cytomegalovirus infects human populations at a high frequency worldwide. During the long coevolution of virus and host, a fine balance has developed between viral immune evasion strategies and defense mechanisms of the immune system. Human cytomegalovirus encodes multiple proteins involved in the evasion of immune recognition, among them UL18, a MHC class I homologue. Despite almost 20 years of research and the discovery of a broadly expressed inhibitory receptor for this protein, its function in immune modulation is not clear yet. Recent data suggest that besides inhibitory effects on various immune cells, UL18 may also act as an activating component during CMV infection. In this review, we provide an overview of the biology of UL18 and discuss several attempts to shed light on its function.
Wagner
Claudia S
CS
Center for Infectious Medicine, Department of Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden. claudia.wagner@yale.edu
Ljunggren
Hans-Gustaf
HG
Achour
Adnane
A
D036022:Capsid Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003586:Cytomegalovirus Infections / Q000276:immunology* / Q000821:virology*; D003713:Dendritic Cells / Q000276:immunology / Q000821:virology; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology / Q000821:virology; D011487:Protein Conformation; D013601:T-Lymphocytes / Q000276:immunology / Q000821:virology
D036022:Capsid Proteins; D015395:Histocompatibility Antigens Class I; C079750:VP23 protein, Human herpesvirus 1