Sex differences in regulatory cells in experimental stroke.

Area of Science:

• Neuroscience
• Immunology
• Stroke Research

Background:

• Stroke is a leading cause of disability in the US.
• Sex differences in stroke severity and immune response are observed.
• Immune-modulating interventions may have differential efficacy based on sex.

Purpose of the Study:

• To investigate distinct stroke-modifying mechanisms in female versus male mice.
• To understand sex-dependent immune regulation in stroke.

Main Methods:

• Middle cerebral artery occlusion (MCAO) model in mice for 60 minutes, followed by 96 hours of reperfusion.
• Analysis of infarct size.
• Quantification of regulatory B10 cells and anti-inflammatory microglia/macrophages in brain hemispheres.
• Assessment of spleen cell populations.

Main Results:

• Female mice exhibited smaller infarcts compared to males.
• Increased regulatory CD19+CD5+CD1dhi B10 cells and anti-inflammatory CD11b+CD206+ microglia/macrophages were found in the ipsilateral hemisphere of female mice.
• Female mice had higher total spleen cell numbers but lower B10 cell levels in spleens.
• Male mice did not show these specific immune cell increases in the affected hemisphere.

Conclusions:

• Distinct sex-dependent regulatory mechanisms contribute to diminished stroke severity in females.
• These findings underscore the importance of considering sex in stroke research and the development of immune-modulating therapies.
• Future studies should evaluate immune-modulating interventions in both male and female stroke models.