Microglia, the predominate immune cells in the central nervous system (CNS), are the cellular mediators of neuroinflammation. They exist in a quiescent state in healthy CNS tissue and become activated following an insult or infection. Reactive microglia can acquire different phenotypes depending on the activating stimulus encountered. M1 microglia are the “classically” activated microglia that initiate a proinflammatory response. Microglia polarize to the M1 phenotype upon exposure to proinflammatory cytokines, such as IL-1 beta, IL-6, IFN-gamma, and TNF-alpha, and cellular and bacterial debris. These cells, in turn, produce additional pro-inflammatory cytokines and chemokines, redox molecules, and antigen-presenting molecules in order to eliminate the foreign pathogen and facilitate an adaptive immune response.
IL-1 beta in Rat M1 Microglia.
Isolated rat microglia were polarized to the M1 phenotype using Recombinant Rat IFN-gamma (R&D Systems, Catalog # 585-IF
) and Recombinant Rat TNF-alpha (R&D Systems, Catalog # 510-RT
). IL-1 beta, also called IL-1F2, was then detected in the immersion-fixed rat M1 microglia using a Goat Anti-Rat IL-1 beta/IL-1F2 Antigen Affinity-Purified Polyclonal Antibody (R&D Systems, Catalog # AF-501
). The cells were stained using the NorthernLights™
557-Conjugated Donkey Anti-Goat IgG Secondary Antibody (R&D Systems, Catalog # NL001
; red). Nuclei were counterstained with DAPI (blue). The cells were co-stained using a Rabbit Anti-Human/Mouse/Rat AIF-1/Iba1 Antigen Affinity-Purified Polyclonal Antibody (Novus Biologicals, Catalog # NBP2-16908
) and the NorthernLights™
493-Conjugated Donkey Anti-Rabbit IgG Secondary Antibody (R&D Systems, Catalog # NL006