A 3D cell culture approach for studying neuroinflammation.

Background: Neurodegenerative diseases are highly complex making them challenging to model in cell culture. All cell types of the brain have been implicated as exerting an effect on pathogenesis, and disease progression is likely influenced by the cross-talk between the different cell types. Sophisticated investigation of the cellular level consequences of cross-talk between different cells types requires three-dimensional (3D) co-culture systems.

New Method: Murine neural stem cells were differentiated into mixed-neuronal lineage populations in 3D culture. By seeding these differentiated cultures with microglia from adult brain, we have generated a 3D ex-vivo model of murine brain tissue populated with microglia.

Results: Monitoring the infiltration of GFP-expressing microglia into the 3D neuronal lineage cultures showed population throughout the tissue and assumption of ramified homeostatic morphology by the microglia. The co-cultures showed good longevity and were functionally responsive to external stimuli.

Comparison With Existing Methods: We have previously used 2-dimensional adhered cultures to model cell-cell interactions between microglia and neuronal lineage cells. While the microglia integrate well into these cultures and demonstrate inter-cellular cross-talk, it is known that adhered culture can change their activation state and therefore a 3D system better represents communication throughout a network of neuronal and support cells.

Conclusions: Our system offers a straight-forward and time effective way to model 3D mouse brain tissue that is responsive to external neuroinflammatory stimulus. It not only allows inter-cellular interactions to be studied in live tissue but additionally permits study of changes within any available mouse genotype.