Conclusions
Studies have shown that OIT-induced remission of food allergy is associated with anergy of memory T cells and modest T regulatory cell activity that may be linked to the anergic T cell state. Type I interferons have recently emerged as candidate regulators of remission following OIT and may play a key role in suppression of the Th2 antigen response through regulatory action on GATA3 and the high affinity IgE receptor. In contrast, desensitisation without remission/SU is associated with transient regulatory activity that may be insufficient to support longer-lasting redirection of the allergic response, suggesting that a more stable induction of regulatory activity is required to achieve durable redirection of immune responses towards a tolerant state. Most studies have examined changes in CD4+ T cells and understanding of potential upstream factors or other cell types with pivotal roles in supporting stable remission remains limited. Systems biology approaches are well suited to provide a broader and much deeper understanding of OIT mechanisms and may facilitate development of more targeted and effective treatment approaches. For example, single cell profiling paired with cutting-edge computational tools holds great potential to unlock the immunological mechanisms underlying tolerance within the CD4 T cell compartment and beyond. There is also a need for larger studies including well-defined clinical outcomes and longitudinal sampling to enable high quality evidence of the key mechanisms driving redirection of the immune response in OIT. Such studies can unveil novel biomarkers of treatment response and associated therapeutic targets that can be leveraged to develop more effective treatments.