An in vitro model for investigating human autologous neuronal-astrocyte and immune cell interactions underlying neurodegenerative and immunosuppressive processes in neuropathy.

Primary mixed neuronal-astrocytic cultures were established from human brain tissues from elective surgical procedures and maintained in vitro for over 21 days. The majority of cells (a) expressed morphological and cytoskeletal markers of differentiated neurons (MAP2a&b; Tau) or astrocytes (GFAP) in anticipated proportion (1:2), and (b) regenerated synaptic connections and neural-astrocytic associations. Co-cultures with autologous blood leukocytes established that alterations in the viability (by Annexin V/PI) of brain and immune cells over 3 days were indicative of neurodegenerative or immunosuppressive processes. During co-culture, B-cells (CD19+) remained largely unaffected while T-lymphocytes (CD3+) and monocytes (CD14+) declined, consistent with immunosuppressive process. Indications of immunosuppression were not observed when immune cells were maintained in free of neural cells medium collected from neuro-cultures. Decline in brain cell viability in neuro-immune co-cultures may be associated with density of activated monocytes (HLA-DR+/CD14+), consistent with neurodegenerative process. Our findings, though preliminary and associated with significant variability between individuals, establish an approach to investigate neuroimmune pathology in humans.