Characterization of the Neuroimmune Response of the Human 15q13.3 Microdeletion Syndrome in Mouse Model Challenged with LPS and Poly (I:C)

Mental disorders pose a major challenge both financially and emotionally to patients, caregivers, and medical providers. Copy number variations (CNVs), which consist of deletions, duplications, or rearrangements of portions of the genome, have been identified as important risk factors for a variety of neuropsychiatric and neurodevelopmental disorders. The human 15q13.3 microdeletion syndrome has been associated with intellectual disability, schizophrenia, autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD), mood disorders, and an increased risk of idiopathic generalized epilepsy. The syndrome is caused by a rare (1 in 40,000 live births) and mostly inherited, heterozygous 1.5Mb genomic deletion on the long arm of human chromosome 15. The deletion encompasses six genes (FAN1 [MTMR15], MTMR10, TRPM1, KLF13, OTUD7A, and CHRNA7); all but one (TRPM1) are expressed in the brain. The 15q13.3 microdeletion (MD) has high phenotypic variability and incomplete penetrance, suggesting that additional factors such as inflammation could affect the phenotypic outcome. Interestingly, both CHRNA7 and KLF13 are known to be involved in the regulation of the immune response, therefore altered immune responses could potentially contribute to the development of neuropathological behaviors and deficits. In order determine potential immune response mechanisms that may underlie the deficits seen with the 15q13.3 deletion syndrome (15q13.3 DS), we used a transgenic mouse model developed by Fejgin et al. (2014) with a heterozygous deletion of the orthologous genomic region of 15q13.3 on mouse chromosome 7. In this study, we investigated the differential mRNA expression of a variety of pro-inflammatory cytokines and chemokines following a peripheral immune challenge with a bacteriomimetic agent (LPS) and a viral mimetic agent (Poly(I:C)). In addition, we tested whether or not the previously mentioned immune stimulants had an effect on burrowing behavior