Innate Immune Cell Death in Neuroinflammation and Alzheimer's Disease

Cells. 2022 Jun 10;11(12):1885. doi: 10.3390/cells11121885.

Abstract

Alzheimer's disease (AD) is a neurodegenerative disorder molecularly characterized by the formation of amyloid β (Aβ) plaques and type 2 microtubule-associated protein (Tau) abnormalities. Multiple studies have shown that many of the brain's immunological cells, specifically microglia and astrocytes, are involved in AD pathogenesis. Cells of the innate immune system play an essential role in eliminating pathogens but also regulate brain homeostasis and AD. When activated, innate immune cells can cause programmed cell death through multiple pathways, including pyroptosis, apoptosis, necroptosis, and PANoptosis. The cell death often results in the release of proinflammatory cytokines that propagate the innate immune response and can eliminate Aβ plaques and aggregated Tau proteins. However, chronic neuroinflammation, which can result from cell death, has been linked to neurodegenerative diseases and can worsen AD. Therefore, the innate immune response must be tightly balanced to appropriately clear these AD-related structural abnormalities without inducing chronic neuroinflammation. In this review, we discuss neuroinflammation, innate immune responses, inflammatory cell death pathways, and cytokine secretion as they relate to AD. Therapeutic strategies targeting these innate immune cell death mechanisms will be critical to consider for future preventive or palliative treatments for AD.

Keywords: AIM2; Alzheimer’s disease; Amyloid β; MLKL; NLRP3; PANoptosis; PANoptosome; RIPK1; RIPK3; Tau; Toll-like receptor; ZBP1; apoptosis; caspase-1; caspase-3; caspase-6; caspase-7; caspase-8; caspase-9; cell death; inflammasome; innate immunity; microglia; necroptosis; neuroinflammation; pyroptosis.

Publication types

  • Review
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • Alzheimer Disease* / metabolism
  • Amyloid beta-Peptides
  • Cell Death
  • Humans
  • Immunity, Innate
  • Inflammasomes / metabolism
  • Neuroinflammatory Diseases
  • Pyroptosis

Substances

  • Amyloid beta-Peptides
  • Inflammasomes

Grants and funding

Work from the Kanneganti laboratory is supported by the National Institutes of Health (AI101935, AI124346, AI160179, AR056296, and CA253095 to T.-D.K.) and the American Lebanese Syrian Associated Charities (to T.-D.K.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.