The Contribution of Human Herpes Viruses to gamma delta T Cell Mobilisation in Co-Infections

gamma delta T cells are activated in viral, bacterial and parasitic infections. Among viruses that promote gamma delta T cell mobilisation in humans, herpes viruses (HHVs) occupy a particular place since they infect the majority of the human population and persist indefinitely in the organism in a latent state. Thus, other infections should, in most instances, be considered co-infections, and the reactivation of HHV is a serious confounding factor in attributing gamma delta T cell alterations to a particular pathogen in human diseases. We review here the literature data on gamma delta T cell mobilisation in HHV infections and co-infections, and discuss the possible contribution of HHVs to gamma delta alterations observed in various infectious settings. As multiple infections seemingly mobilise overlapping gamma delta subsets, we also address the concept of possible cross-protection.