Orsay virus infection increases Caenorhabditis elegans resistance to heat-shock

The heat shock response plays a role in the immune defense against viruses
across various organisms. Studies on model organisms show that inducing
this response prior to viral exposure enhances host resistance to
infections, while deficient responses make individuals more vulnerable.
Moreover, viruses rely on components of the heat shock response for their
own stability and viral infections improve thermal tolerance in plants,
giving infected individuals an advantage in extreme conditions, which aids
the virus in replication and transmission. Here, we examine the
interaction between the nematode Caenorhabditis elegans and its natural
pathogen the Orsay virus (OrV) under heat stress. We found that OrV
infection leads to differential expression of heat-stress related genes,
and infected populations showed increased resistance to heat shock. This
resistance correlated with increased expression of argonautes alg-1 and
alg-2, which are crucial for survival after heat shock and for OrV
replication. Overall, our study suggests an environmental-dependent
mutualistic relationship between the nematode and OrV, potentially
expanding the animal’s ecological niche and providing the virus with extra
opportunities for replication and adaptation to extreme conditions.