Open AccessHuman cytomegalovirus inhibits antigen presentation by a sequential multistep process.
Author(s) -
Kwangseog Ahn,
Ana Angulo,
Peter Ghazal,
Per A. Peterson,
Young Mok Yang,
Klaus Früh
Publication year - 1996
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.93.20.10990
Subject(s) - mhc class i , endoplasmic reticulum , major histocompatibility complex , antigen presentation , transporter associated with antigen processing , biology , antigen processing , mhc restriction , human cytomegalovirus , antigen , microbiology and biotechnology , virology , genetics , immune system , virus , t cell
The human cytomegalovirus (HCMV) genomic unique short (US) region encodes a family of homologous genes essential for the inhibition of major histocompatibility complex (MHC) class I-mediated antigen presentation during viral infection. Here we show that US3, the only immediate early (IE) gene within the US region, encodes an endoplasmic reticulum-resident glycoprotein that prevents intracellular transport of MHC class I molecules. In contrast to the rapid degradation of newly synthesized MHC class I heavy chains mediated by the early gene product US11, we found that US3 retains stable MHC class I heterodimers in the endoplasmic reticulum that are loaded with peptides while retained in the ER. Consistent with the expression pattern of US3 and US11, MHC class I molecules are retained but not degraded during the IE period of infection. Our data identify the first nonregulatory role of an IE protein of HCMV and suggest that HCMV uses different T-cell escape strategies at different times during the infectious cycle.