Related Experiment Videos
Human cytomegalovirus US2 destabilizes major histocompatibility complex class I heavy chains
1Department of Molecular Biology, Wyeth-Ayerst Research, Pearl River, New York 10965, USA. jonest@war.wyeth.com
Journal of Virology
|April 1, 1997
Summary
Human cytomegalovirus (HCMV) infection down-regulates major histocompatibility complex class I. Researchers identified US2 as a key viral gene responsible for this immune evasion, working alongside US11 and US3.
Area of Science:
- Virology
- Immunology
- Molecular Biology
Background:
- Human cytomegalovirus (HCMV) infection is known to down-regulate major histocompatibility complex (MHC) class I heavy chains.
- Previous studies identified two HCMV loci responsible for this phenotype, with US11 being one of them.
Purpose of the Study:
- To identify the second HCMV locus involved in the down-regulation of MHC class I heavy chains.
- To elucidate the mechanism by which US2 affects MHC class I stability and transport.
Main Methods:
- Construction and analysis of defined viral mutants.
- Analysis of stably transfected cell lines expressing viral genes.
- Biochemical characterization of viral protein products and their targets.
Main Results:
- US2 was identified as the second HCMV locus responsible for MHC class I down-regulation.
- US2 encodes a 24-kDa glycoprotein that targets free class I heavy chains for degradation shortly after synthesis.
- US2, US11, and US3 function together to down-regulate MHC class I, affecting both stability and transport from the endoplasmic reticulum.
Conclusions:
- Three HCMV genes (US2, US11, and US3) have been identified that modulate MHC class I heavy chain stability or transport.
- The early abundance of these viral proteins suggests a role in immune modulation during latent or persistent HCMV infection and reactivation.