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Updated: Sep 27, 2026
Characterization and Isolation of Mouse Primary Microglia by Density Gradient Centrifugation
Published on: February 16, 2018
Prolactin-cytokine network in the defence against Acanthamoeba castellanii in murine microglia [corrected]
Nunzia Benedetto1, Claude Auriault
1Institute of Microbiology, Faculty of Medicine and Surgery, Second University of the Studies of Naples, Italy. nunzia.benedetto@unina2.it
Abstract:
In the central nervous system, cytokine-primed microglia play a pivotal role in host defence against parasite infections. In this study, the effect of recombinant (r) prolactin (rPRL) and rIFN-gamma on A. castellanii infection in murine microglia was examined. Priming of microglia with rPRL and rIFN-gamma synergistically triggered, in a dose-dependent manner, amebastatic activity and the release of endogenous IL-1alpha, IL-1beta, IL-6 and TNF-alpha. More than 53, 57, 49, 89 or 96 % of amebastatic activity was abrogated by anti-PRLR, IFN-gammaR, IL-1beta (but not IL-1alpha), IL-6 or TNF-alpha antibodies, suggesting that these two receptors and proinflammatory cytokines participate in the anti-microbial function. Inasmuch as DPI and AET, both inhibitors of NO synthase, blocked amebastatic activity only during the priming process, the NO-dependent pathway itself appears not to be directly involved in the anti-parasitic capacity. These data suggest that the PRL/PRLR and IFN-gamma/IFN-gamma/R complexes, by the induction of the IFN-gammaR on microglia, up-regulate the release of endogenous TNF-alpha, IL-6 and IL-1beta by these cells, which could trigger anti-microbial activity against A. castellanii infection in the brain [corrected].
Insights
Recombinant prolactin and interferon-gamma prime microglia, enhancing defense against Acanthamoeba castellanii infections. This priming boosts anti-parasitic activity by releasing key inflammatory cytokines.
Area of Science:
- Neuroimmunology
- Parasitology
- Cellular Microbiology
Background:
- Microglia are crucial for central nervous system defense against parasitic infections.
- Cytokine priming enhances microglial activity in host defense mechanisms.
Purpose of the Study:
- To investigate the effects of recombinant prolactin (rPRL) and recombinant interferon-gamma (rIFN-gamma) on Acanthamoeba castellanii infection in murine microglia.
- To elucidate the mechanisms underlying microglial anti-parasitic activity induced by rPRL and rIFN-gamma.
Main Methods:
- Murine microglia were primed with varying doses of rPRL and rIFN-gamma.
- Amebostatic activity was assessed, along with the release of endogenous cytokines (IL-1alpha, IL-1beta, IL-6, TNF-alpha).
- The role of specific receptors (PRLR, IFN-gammaR) and cytokines was evaluated using neutralizing antibodies; nitric oxide synthase inhibition was also tested.
Main Results:
- rPRL and rIFN-gamma synergistically induced dose-dependent amebastatic activity and cytokine release.
- Neutralizing antibodies against prolactin receptor (PRLR), interferon-gamma receptor (IFN-gammaR), IL-1beta, IL-6, and TNF-alpha significantly abrogated this activity.
- Nitric oxide synthase inhibitors only blocked amebastatic activity during the priming phase, indicating a non-direct role in the anti-parasitic capacity.
Conclusions:
- The prolactin/PRLR and IFN-gamma/IFN-gammaR pathways synergistically enhance microglial anti-parasitic function against A. castellanii.
- This enhancement is mediated by the induction of IFN-gammaR on microglia and subsequent release of endogenous TNF-alpha, IL-6, and IL-1beta.
- These cytokines contribute to the anti-microbial activity crucial for combating brain infections by A. castellanii.
