Upregulation of interleukin (IL)-31, a cytokine producing CXCR1 peripheral immune cells, contributes to the immune abnormalities of autism spectrum disorder

Abstract Autism spectrum disorders (ASD) are a group of neurodevelopmental disorders characterized by communication deficits, impaired social interactions, and restricted stereotypical behaviors. Several immune cells are associated with immune dysfunction in ASD; however, IL-31 has not been explored in ASD. This study aims to investigate the role of inflammatory cytokines and transcription factors of the CXCR1 cells in children with ASD. In the current study, we investigated the cytokines and transcription factors produced by CXCR1+ cells (IL-31, IL-9, IL-21R, IL-21, NF-κB p65, RORγT, STAT1, and FoxP3) in peripheral blood mononuclear cells (PBMCs), from children with ASD and typically developing (TD) control children, using flow cytometric analysis. In addition, we measured mRNA and protein expression levels of IL-31 using quantitative real-time PCR and western blot analyses in PBMCs. In our study, children with ASD had increased CXCR1+IL-31+, CXCR1+IL-9+, CXCR1+IL-21R+, CXCR1+IL-21+, CXCR1+NF-κB+ p65, CXCR1+RORγT+, and CXCR1+STAT1+, and decreased CXCR1+FoxP3+ cells as compared with cells from the TD control samples. Similarly, children with ASD showed increased IL-31 mRNA and protein expression levels as compared to those of TD control samples. Our results suggest that upregulated production of inflammatory cytokines and transcription factors in CXCR1+ cells cause immunological imbalance in children with ASD. Therefore, attenuation of inflammatory cytokines/mediators and transcription factors could have a therapeutic potential in the treatment of ASD.