Long-term adaptation of the influenza A virus by escaping cytotoxic T-cell recognition

Influenza is known to be subject of “antigenic drift”: a process in which through random mutation the HA and NA proteins gradually change with time, leading to loss of immunity in the population, and recurring epidemics. Many T cell epitopes are less prone to mutation due to structural constrains (one might argue that NA and HA have evolved to be evolvable). T-cell responses against influenza can prevent symptoms and reduce infectiousness, and might therefore be a target for immune escape as well. One complicating factor is HLA polymorphism, meaning that many individuals target different T-cell epitopes. To test if we can find a similar T-cell antigenic drift, we compiled a set of influenza sequences and T-cell responses from GISAID and IEDB. We found that the number of experimentally confirmed epitopes decreases with time, while confirmed non-epitopes are constant.

Recommended citation: Woolthuis, RG et al (2016). "Long-term adaptation of the influenza A virus by escaping cytotoxic T-cell recognition." Scientific Reports. 6: 33334.
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