Autism Spectrum Disorders: Role of Pre- and Post-Natal GammaDelta (γδ) T Cells and Immune Regulation

Background: It is widely accepted that alterations in immune functioning are an important aspect of the pathoetiology and pathophysiology of autism spectrum disorders (ASD). A relatively under-explored aspect of these alterations is the role of gammaDelta (γδ) T cells, prenatally and in the postnatal gut, which seem important hubs in driving the course of ASD. Methods: The present article describes the role of γδ T cells in ASD, including their interactions with other immune cells shown to be altered in this spectrum of conditions, including natural killer cells and mast cells. Results: Other risk factors in ASD, such as decreased vitamins A & D, as well as toxin-associated activation of the aryl hydrocarbon receptor, may also be intimately linked to γδ T cells, and alterations in the regulation of these cells. A growing body of data has highlighted an important role for alterations in mitochondria functioning in the regulation of immune cells, including natural killer cells and mast cells. This is an area that requires investigation in γδ T cells and their putative subtypes. Conclusions: It is also proposed that maternal stress may be acting via alterations in the maternal microbiome, leading to changes in how the balance of short chain fatty acids, such as butyrate, may act to regulate the placenta and developing foetus. Following an overview of previous research on immune, especially γδ T cells, effects in ASD, the future research implications are then detailed.