Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by impairments in communication skills and social behaviors. Several studies have suggested that neuroimmune dysfunction plays a significant role in the pathogenesis of ASD; however, its exact etiology is unknown. Interleukin-16 (IL-16), a chemoattractant, is associated with various inflammatory processes. However, its role in children with ASD is unclear. This study aimed to investigate whether IL-16 expression is associated with immune dysfunction in children with ASD. We examined IL-16 expression in CD4(+), CD8(+), CD14(+), CCR3(+), and CXCR7(+) cells in typically developing (TD) controls and children with ASD using flow cytometry in peripheral blood mononuclear cells (PBMCs). We also investigated the expression of IL-1(+)IL-16(+), IL-6(+)IL-16(+), and TNF-+IL-16(+) in TD controls and children with ASD. We further explored IL-16 mRNA and protein expression using RT-PCR and western blotting. CD4(+)IL-16(+), CD8(+)IL-16(+), CD14(+)IL-16(+), CCR3(+)IL-16(+), and CXCR7(+)IL-16(+) cells increased significantly in children with ASD compared with TD controls. We also showed that expression of IL-1(+)IL-16(+), IL-6(+)IL-16(+), and TNF-+IL-16(+) was elevated in children with ASD compared with TD controls. Moreover, IL-16 mRNA and protein expression was significantly induced in children with ASD compared with TD controls. These results suggest that IL-16 expression could play an essential role in immune alteration in children with ASD.