From Immune Sanctuary to Neurological Battlefield: The Role of Neuroimmune Cells

The brain, traditionally regarded as immune-privileged due to the blood-brain barrier, harbors a sophisticated immune system crucial for maintaining neural health and resilience against various challenges. Microglia, the resident immune cells of the central nervous system, actively monitor their environment, participating in immune surveillance, synaptic pruning, and neuroprotection. Astrocytes also play vital roles by regulating neurotransmitter levels, supporting metabolism, and maintaining the blood-brain barrier integrity. Recent research underscores the involvement of T cells and monocytes in modulating neuroinflammation and immune responses within the brain. Neurological disorders such as Alzheimer’s and Parkinson’s disease highlight the brain’s vulnerability to immune dysregulation. This review aimed to elucidate the role of neuroimmune cells in brain health and the progression of neurological diseases. It aimed to identify critical mechanisms to enhance therapeutic strategies and improve outcomes. Understanding these interactions is essential for developing targeted therapies to mitigate neuroinflammation and preserve cognitive functions. This review critically examines neuroinflammation related to aging and disease, with a focus on neuroimmune cells and their underlying mechanisms. It highlights how chronic inflammation, driven by activated microglia and astrocytes, exacerbates neuronal damage, synaptic dysfunction, and cognitive decline. The disruption of immune privilege in these conditions involves complex pathways that trigger inflammatory responses, impairing essential neural functions. Despite its immune-privileged status, the brain’s immune system, primarily involving microglia and astrocytes, is crucial for maintaining homeostasis and managing illness. Our review strongly suggests that neurological diseases, influenced by genetic, environmental, and aging factors, often involve heightened neuroinflammation. Targeted therapies are needed to address infections, chronic inflammation, and environmental impacts. Additionally, research into mental health disorders and advancements in imaging techniques are critical for understanding immune dysfunction and enhancing treatment strategies.