Immune Evasion by Viruses
Published Online: 13 JUN 2013
Copyright © 2001 John Wiley & Sons, Ltd. All rights reserved.
How to Cite
Simmons, R. A., Willberg, C. B. and Paul, K. 2013. Immune Evasion by Viruses. eLS. .
- Published Online: 13 JUN 2013
When a virus infects a host, a complex immune response develops to eliminate the invading pathogen. Viruses, in turn, have evolved a profusion of strategies to escape from the immune system. Mechanisms of viral evasion can be separated into those that occur at the cellular level and those that are important at the systemic level. Viruses can avoid detection by both innate and adaptive immune responses. Pattern recognition receptors in infected cells, interferons, dendritic cells, T cell receptors and antibodies are all targets of viral evasion proteins. Viruses can express proteins that directly interfere with host processes or mimic host proteins and compete to bind specific receptors. Pathogens are also able to directly deplete immune cells, and prevent their recruitment to the site of infection. In a state of latency, viruses remain dormant and undetectable in host cells. The diversity of these mechanisms has allowed us to dissect the immune system further and understand how viruses persist despite such a strong counterattack by the immune system.
Viruses have evolved a plethora of mechanisms to inhibit every step of the innate and adaptive immune responses.
Viruses avoid detection by pattern recognition receptors, T cell receptors and antibodies by modifying the ligands for these receptors.
Different viruses target every stage of antigen processing and presentation by MHC molecules, thus inhibiting recognition by T cells.
Interferons, cytokines and chemokines are mimicked or blocked by viral proteins to prevent the efficient development of an immune response.
Through repression of their replication, viruses are able to enter latency and remain dormant inside the cell, remaining undetectable.
- immune evasion;
- antigen presentation;
- cellular response MHC;
- immune response;