Gender differences in macrophage antiviral function following exercise stress.

Area of Science:

• Immunology
• Exercise Physiology
• Virology

Background:

• Male mice exhibit increased susceptibility to herpes simplex virus-1 (HSV-1) respiratory infections after exhaustive exercise, while moderate exercise offers protection.
• Female mice show better survival rates against HSV-1 infection compared to males, despite similar responses to exercise stress.
• Immune mechanisms underlying these gender-specific responses, particularly macrophage antiviral resistance, remain underexplored.

Purpose of the Study:

• To investigate potential gender disparities in macrophage antiviral resistance following both moderate and exhaustive exercise protocols.
• To elucidate the role of macrophage function in sex-based differences in HSV-1 infection outcomes.

Main Methods:

• Male and female CD-1 mice (N=36 each) were allocated to control, moderate exercise, or exhaustive exercise groups.
• Exercise interventions involved daily treadmill running for three consecutive days.
• Moderate exercise lasted 90 minutes, while exhaustive exercise continued until volitional fatigue (approx. 50 minutes).

Main Results:

• Female mice demonstrated superior macrophage antiviral resistance to HSV-1 compared to males in control and moderate exercise groups (P < 0.05).
• Moderate exercise significantly increased macrophage antiviral resistance in both genders.
• Exhaustive exercise markedly reduced macrophage antiviral resistance in both male and female mice (P < 0.001).

Conclusions:

• Altered macrophage antiviral resistance to HSV-1 is a potential contributing factor to observed gender differences in infection susceptibility.
• These findings highlight the differential impact of exercise intensity on immune responses and infection outcomes in males and females.
• Macrophage function represents a key immunological mechanism influencing sex-based variations in respiratory viral infections.