There are numerous sporadic developmental brain malformations (DBM) associated with intractable epilepsy, intellectual disability, and autism. Several DBM subtypes such as focal cortical dysplasia (FCD), hemimegalencephaly (HME), and ganglioglioma (GG) are associated with enhanced mTOR pathway signaling during brain development. Although aberrant mTOR activation can be caused by gene mutations in upstream mTOR effectors, the etiology of mTOR activation in most DBM has not been fully explained. To date, only a few genetic etiologies have been identified for small case numbers of HME and GG. The majority of malformations especially FCDs result from unknown causes. Recently, the high-risk human papillomavirus (type 16) E6 oncoprotein was identified as a potent activator of mTOR signaling. Recent data from our lab has demonstrated E6 protein in FCD type IIB. In the first Aim, we will define the expression of HPV16 E6 oncoprotein in DBM brain specimens resected for the treatment of intractable epilepsy. We will show that E6 labeled cells co-express markers of mTOR cascade activation. We will then demonstrate that HPV16 E6 DNA and mRNA are detected in DBM specimens by PCR, reverse transcriptase PCR, in situ hybridization, and single cell mRNA amplification assays.
In Aim 2, we will generate HPV pseudovirions containing E6 to assay the mechanism of viral attachment and internalization in mouse neural progenitor cells as well as effects on cell size and mTOR signaling.
In Aim 3, we will use in utero electroporation to introduce E6 into fetal mouse cortex as a strategy to show that E6 can cause altered cortical development. These experiments will provide a new and highly relevant etiology for DBM associated with epilepsy. These experiments would demonstrate for the first time HPV infection in the human brain and would thus open doors to many new avenues for investigation.
Developmental brain malformations (DBM) are common causes of epilepsy, autism, and intellectual disability. We will demonstrate that human papilloma virus (HPV) can be detected in DBM and that animal models of brain HPV infection can be generated.
|Aronica, Eleonora; Crino, Peter B (2014) Epilepsy related to developmental tumors and malformations of cortical development. Neurotherapeutics 11:251-68|