Public Relations & Press Office
Press Release
Athens, 14 September 2011
How HCMV evades the immune response

Human cytomegalovirus (HCMV) is a common strain of herpesviruses that infects between 50 and 80% of all adults. Although these infections are minor for healthy individuals, they can be life-threatening when the individual is immunocompromized as in the case of organ transplant recipients, newborn infants and HIV-infected persons. HCMV manages to infect so many individuals because it has evolved mechanisms that allow it to “hide” from the immune system. In a recent study, published in the journal Nature Immunology, the research groups from the Seoul National University in collaboration with the Protein Chemistry group in NCSR “Demokritos” describe a novel mechanism that HCMV uses to evade the immune response. HCMV uses molecules called microRNA to “trick” the cell it infects to reduce production of an enzyme called ERAP1.

ERAP1 is central to a process called antigen presentation, a process that the cell uses to recognize infectious agents. With ERAP1 gone, the immune system cells become unaware of the viral infection. This mechanism is probably key to the ability of the virus to establish long-term infections and opens new avenues for the development of vaccines and pharmacological treatments. It should be noted that common genetic variations in the same enzyme (ERAP1) have been recently linked with susceptibility to many serious human diseases (including autoimmunity, cancer and HIV infection) and are currently under investigation as useful diagnostic and prognostic tools by the NCSR Demokritos team (


More Information:

Human cytomegalovirus microRNA miR-US4-1 inhibits CD8(+) T cell responses by targeting the aminopeptidase ERAP1.
Kim S, Lee S, Shin J, Kim Y, Evnouchidou I, Kim D, Kim YK, Kim YE, Ahn JH, Riddell SR, Stratikos E, Kim VN, Ahn K.
Nature Immunology. 2011 Sep 4. doi: 10.1038/ni.2097.
Pubmed link:
Journal link:

For the NCSR Demokritos

The National Center for Scientific Research (NCSR) "Demokritos" is the largest multidisciplinary research center in the country with substantial scientific research, technological and educational activities in the areas of: Health, Biology and Biotechnology, New Materials Micro & Nanotechnology, Environment - Energy and Sustainable Development, Information Technology & Telecommunications, Nuclear Physics & Elementary Particle Physics, Nuclear Technology & Radiation Protection, Cultural Heritage. All the activities are coordinated by the eight Institutes of the Center: 1) Biology, 2) Materials Science, 3) Microelectronics,4) Computer and Telecommunications, 5) Nuclear Engineering and Radiological, 6) Nuclear Physics, 7) Chemistry, 8) Radioisotopes and Radiopharmaceuticals

For more information pls contact:

Floratou Zoe
Public Relations & Press Office
Τel. +30 210- 650 3002, email: