Related Experiment Videos
IL-1-alpha and TNF-alpha differentially regulate CD4 and Mac-1 expression in mouse microglia
N Yu1, X Zhang, P J Magistretti
1Department of Neuropharmacology, The Scripps Research Institute, La Jolla, Calif 92037, USA.
Neuroimmunomodulation
|August 11, 1998
Summary
Proinflammatory cytokines interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) upregulate Mac-1 expression in mouse microglia. IL-1alpha also increases CD4 expression, suggesting a role in microglial immune responses.
Area of Science:
- Neuroimmunology
- Cellular and Molecular Neuroscience
- Cytokine Signaling
Background:
- Microglia are the primary immune cells of the central nervous system.
- Proinflammatory cytokines play crucial roles in neuroinflammation.
- The expression of cell surface markers like CD4 and Mac-1 on microglia is dynamic and can be modulated by inflammatory signals.
Purpose of the Study:
- To investigate the regulatory effects of interleukin-1alpha (IL-1alpha) and tumor necrosis factor-alpha (TNF-alpha) on CD4 and Mac-1 expression in mouse microglial cultures.
- To determine if these cytokines influence microglial immune marker expression in a dose- and time-dependent manner.
- To explore the molecular mechanisms underlying these regulatory effects, including mRNA level changes.
Main Methods:
- Primary mouse microglial cultures were established and characterized.
- Microglia were cultured with or without astrocytes, and cell surface marker expression (CD4, Mac-1) was assessed.
- The effects of IL-1alpha and TNF-alpha on CD4 and Mac-1 expression were analyzed using dose-response and time-course studies, with mRNA levels measured by RT-PCR and proliferation assessed by 3H-thymidine incorporation.
Main Results:
- Astrocyte-supported microglia exhibited high co-expression of CD4 and Mac-1.
- Replating microglia onto culture dishes (plate-supported) significantly reduced CD4 and Mac-1 expression.
- Both IL-1alpha and TNF-alpha upregulated Mac-1 expression in a time- and dose-dependent manner in plate-supported microglia.
- IL-1alpha, but not TNF-alpha, increased CD4 expression and CD4 mRNA levels in plate-supported microglia.
- Cell proliferation was ruled out as the cause of observed marker changes.
Conclusions:
- Cultured mouse microglia express CD4 molecules that can be upregulated by IL-1alpha.
- Mac-1 expression on microglia can be upregulated by both IL-1alpha and TNF-alpha.
- These findings highlight the regulatory role of specific proinflammatory cytokines on microglial immune marker expression, contributing to our understanding of neuroinflammatory processes.