Conclusions

In this review, we sought to examine the emerging evidence that trained immunity may affect and be affected by T cell responses. Recent studies have indicated that T cells play a role in modulating trained immunity and there is a clear rationale to support the hypothesis that innate immune training will affect adaptive responses via the modulation of innate proinflammatory cytokine production and APC function (Table 1). Knowledge gaps remain in understanding the impact of trained immunity on the adaptive immune response, both in settings of acute and chronic inflammation. More specifically, there is still limited information on how specific drivers of trained immunity may differentially affect subpopulations of T cells and disrupt the delicate Treg/Th17 or Th1/Th2 balance, for example. Conversely, understanding how certain populations of T cells regulate the induction of trained immunity may help to identify cell targets for therapeutic interventions. A direct cause and effect relationship between trained immunity and T cell responses remains to be determined, however, there is evidence from current literature, discussed in this review, to suggest that this relationship may exist, at least in the contexts of certain inflammatory conditions.