Elevated IL-16 expression is associated with development of immune dysfunction in children with autism

Area of Science:

• Neuroimmunology
• Developmental Neuroscience

Background:

• Autism spectrum disorder (ASD) is a neurodevelopmental condition impacting social interaction and communication.
• Neuroimmune dysfunction is implicated in ASD pathogenesis, but the precise mechanisms remain unclear.
• Interleukin-16 (IL-16), a known chemoattractant involved in inflammation, has an undefined role in pediatric ASD.

Purpose of the Study:

• To investigate the association between IL-16 expression and immune alterations in children diagnosed with ASD.
• To quantify IL-16 levels on specific immune cell populations in children with ASD compared to typically developing controls.

Main Methods:

• Flow cytometry was employed to analyze IL-16 expression on CD4+, CD8+, CD14+, CCR3+, and CXCR7+ cells in peripheral blood mononuclear cells (PBMCs) from children with ASD and typically developing (TD) controls.
• Co-expression of IL-16 with inflammatory cytokines (IL-1β, IL-6, TNF-α) was assessed.
• Quantitative RT-PCR and Western blotting were used to measure IL-16 mRNA and protein levels.

Main Results:

• Significantly higher percentages of CD4+IL-16+, CD8+IL-16+, CD14+IL-16+, CCR3+IL-16+, and CXCR7+IL-16+ cells were observed in children with ASD compared to TD controls.
• Elevated co-expression of IL-16 with IL-1β, IL-6, and TNF-α was found in children with ASD.
• IL-16 mRNA and protein expression levels were significantly increased in children with ASD.

Conclusions:

• The findings indicate a significant upregulation of IL-16 expression across multiple immune cell types in children with ASD.
• Elevated IL-16 and its co-expression with pro-inflammatory cytokines suggest a crucial role for IL-16 in the immune dysregulation observed in ASD.
• IL-16 warrants further investigation as a potential biomarker or therapeutic target in autism spectrum disorder.