Immune Suppression of Glia Maturation Factor Reverses Behavioral Impairment, Attenuates Amyloid Plaque Pathology and Neuroinflammation in an Alzheimer's Disease Mouse Model

Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disorder recognized by accumulation of amyloid-plaques (APs) and neurofibrillary tangles (NFTs) and eventually loss of memory. Glia maturation factor (GMF), a neuroinflammatory protein first time isolated and cloned in our laboratory plays an important role in the pathogenesis of AD. However, no studies have been reported on whether anti-GMF antibody administration could downregulate neuroinflammation and attenuate amyloid pathology in AD brain. We investigated the potential effect of single dose of (2 mg/kg b.wt/mouse) intravenously (iv) injected with anti-GMF antibodyon cognitive function, neuroprotection, neuroinflammation and Aβ load in the brain of 9-month-old 5XFAD mice. Following 4 weeks of anti-GMF antibody delivery in mice, we found reduced expression of GMF, astrocytic glial fibrillary acidic protein (GFAP) and microglial ionizing calcium binding adaptor molecule 1 (Iba1) as well as improvement inneuroinflammatory response via inhibition of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6) production and amyloid pathology in the cerebral cortex and hippocampal CA1 region of 5XFAD mice. Correspondingly, blockade of GMF function with anti-GMF antibody improved spatial learning, memory, and long-term recognition memory in 5XFAD mice. The present study demonstrates that the immune checkpoint blockade of GMF function with anti-GMF antibody coordinates anti-inflammatory effects to attenuate neurodegeneration in the cortex and hippocampal CA1 region of 5XFAD mouse brain. Further, our data suggest, that pharmacological immune neutralization of GMF is a promising neuroprotective strategy totherapeutically target neuroinflammation and neurodegeneration in AD. Graphical Abstract 5XFAD mice Polyclonal anti-GMF antibody.