Related Experiment Video
Updated: Aug 30, 2026
Multi-electrode Array Recordings of Human Epileptic Postoperative Cortical Tissue
Published on: October 26, 2014
Detection of human herpesvirus-6 in mesial temporal lobe epilepsy surgical brain resections
D Donati1, N Akhyani, A Fogdell-Hahn
1Neuroimmunology Branch, National Institute of Neurological Disorders and Stroke, NIH, Bethesda, MD 20892, USA.
Background:
Human herpesvirus-6 (HHV-6), a ubiquitous beta-herpesvirus, is the causative agent of roseola infantum and has been associated with a number of neurologic disorders including seizures, encephalitis/meningitis, and multiple sclerosis. Although the role of HHV-6 in human CNS disease remains to be fully defined, a number of studies have suggested that the CNS can be a site for persistent HHV-6 infection.
Objective:
To characterize the extent and distribution of HHV-6 in human glial cells from surgical brain resections of patients with mesial temporal lobe epilepsy (MTLE).
Method:
Brain samples from eight patients with MTLE and seven patients with neocortical epilepsy (NE) undergoing surgical resection were quantitatively analyzed for the presence of HHV-6 DNA using a virus-specific real-time PCR assay. HHV-6 expression was also characterized by western blot analysis and in situ immunohistochemistry (IHC). In addition, HHV-6-reactive cells were analyzed for expression of glial fibrillary acidic protein (GFAP) by double immunofluorescence.
Results:
DNA obtained from four of eight patients with MTLE had significantly elevated levels of HHV-6 as quantified by real-time PCR. HHV-6 was not amplified in any of the seven patients with NE undergoing surgery. The highest levels of HHV-6 were demonstrated in hippocampal sections (up to 23,079 copies/10(6) cells) and subtyped as HHV-6B. Expression of HHV-6 was confirmed by western blot analysis and IHC. HHV-6 was co-localized to GFAP-positive cells that morphologically appeared to be astrocytes.
Conclusions:
HHV-6B is present in brain specimens from a subset of patients with MTLE and localized to astrocytes in the absence of inflammation. The amplification of HHV-6 from hippocampal and temporal lobe astrocytes of MTLE warrants further investigation into the possible role of HHV-6 in the development of MTLE.
Insights
Human herpesvirus-6 (HHV-6) DNA was found in brain samples from epilepsy patients, specifically in astrocytes of those with mesial temporal lobe epilepsy (MTLE). Further research is needed to explore HHV-6's role in MTLE development.
Area of Science:
- Neurovirology
- Epileptology
- Molecular Biology
Background:
- Human herpesvirus-6 (HHV-6) is a beta-herpesvirus linked to neurological disorders.
- Persistent HHV-6 infection in the central nervous system (CNS) is suggested by previous studies.
Purpose of the Study:
- To determine the presence and location of HHV-6 in glial cells from epilepsy patients.
- To analyze brain tissue from patients with mesial temporal lobe epilepsy (MTLE) and neocortical epilepsy (NE).
Main Methods:
- Quantitative real-time PCR to detect HHV-6 DNA.
- Western blot and immunohistochemistry (IHC) to assess HHV-6 expression.
- Double immunofluorescence to co-localize HHV-6 with glial fibrillary acidic protein (GFAP).
Main Results:
- HHV-6 DNA was detected in 4 of 8 MTLE patients, but not in NE patients.
- Elevated HHV-6 levels, identified as HHV-6B, were highest in hippocampal sections.
- HHV-6 expression was confirmed and co-localized with GFAP-positive astrocytes.
Conclusions:
- HHV-6B is present in brain tissue from a subset of MTLE patients.
- The virus is localized within astrocytes without signs of inflammation.
- The presence of HHV-6 in MTLE astrocytes warrants further investigation into its potential role in epilepsy development.
