Human leptomeninges; inflammatory roles in motor neuron disease, and their potential in gene therapy

The leptomeninges, comprising the inner two layers of the meninges, were traditionally recognised solely for their protective role in the central nervous system (CNS), yet are now understood to be involved in numerous physiological functions including modulation of neurological disorders. Leptomeninges are relatively under-researched, so uncovering their anatomy and functional roles are key to furthering the understanding of CNS, in the contexts of health and disease. This thesis presents post-mortem human leptomeningeal explants as an ex vivo model to explore human leptomeninges. The suitability of the model was established by assessing cell composition and tissue health. Cell markers identified four specific cell populations in the intact explants expressing IBA1 and/or P2RY12, or PDGFRβ and/or lectin. Specific culture paradigms were used to explore culture-driven effects on the tissue model. Tissue health and cell populations within were unchanged after 5 weeks in culture. Based on the evidence of meningeal inflammation often preceding that of the CNS, the meninges are believed to drive processes of classic neuroinflammation, yet the extent of leptomeningeal contribution has not been investigated in human tissue. Following interleukin- 1 beta (IL1β), interferon gamma (IFNγ) or tumor necrosis factor alpha (TNFα) stimulation for 24 hours, sICAM-1, sVCAM-1, IL-6, IL-8 and MCP-1 were significantly upregulated, highlighting key inflammatory players in leptomeninges. Cytokine responses were influenced by the region and disease state from which they were derived. Lastly, adeno-associated viral (AAV) transduction of human leptomeningeal explants was evaluated. Suitable serotypes were identified using green fluorescent protein (GFP) and the viral titre was selected based on tissue health. Subsequently, AAV-BDNF-HA was used to transduce leptomeningeal explants derived from various CNS regions. This resulted in sustained transgenic expression over months, in cortical and spinal cord explants. This highlighted the potential use of leptomeninges as a recipient for viral therapy. The findings in this thesis demonstrate the involvement of leptomeninges in CNS related functions, both in physiological states and in neurological disease processes, and emphasized human leptomeninges as a suitable target for therapeutic interventions.

Name thesis:degree_name

PhD

Level thesis:degree_level

Doctoral

Discipline thesis:degree_discipline

Pharmacology

Grantor dc:publisher

ResearchSpace@Auckland

Year dc:date.issued

2022

Author dc:creator

• Naidoo, Serey

Advisors dc:contributor.advisor

• Scotter, Emma
• Dragunow, Michael

Statement dc:rights

• Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

Licence dc:rights.uri

• https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm

Handle dc:identifier.uri

https://hdl.handle.net/2292/63448

OAI identifier oai:identifier

oai:researchspace.auckland.ac.nz:2292/63448