Related Experiment Videos
Thermal stresses reduce natural killer cell cytotoxicity
1Department of Microbiology and Physiology, College of Medicine, National Cheng Kung University, Tainan City, Taiwan, Republic of China.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|September 1, 1995
Summary
Exposure to extreme ambient temperatures (4°C or 35°C) significantly impairs natural killer (NK) cell activity and numbers in mice. These negative effects on immune function persist for at least 16 days, highlighting the impact of thermal stress on immune response.
Area of Science:
- Immunology
- Environmental Physiology
- Stress Biology
Background:
- Natural killer (NK) cells are crucial for innate immunity, responding to cellular stress and infection.
- Ambient temperature is a significant environmental factor that can influence physiological processes, including immune function.
Purpose of the Study:
- To investigate the impact of acute and prolonged exposure to cold and heat stress on splenic NK cell activity, effector-target cell conjugation, and NK cell numbers in mice.
- To assess the physiological responses, such as adrenal cortisol concentration and colonic temperature, to thermal stress.
Main Methods:
- Male C3H/HeNCrj mice were exposed to ambient temperatures of 4°C, 22°C (control), or 35°C for up to 16 days.
- Splenic NK cell activity was measured using a 51Cr release assay.
- Effector-target cell conjugation and NK cell numbers (5E6-positive cells) were quantified.
- Adrenal cortisol concentration and colonic temperature were monitored.
Main Results:
- Both cold (4°C) and heat (35°C) stress led to a significant decrease in splenic NK cell activity, effector-target cell conjugation, and NK cell numbers, starting as early as day 1.
- These reductions in immune cell function persisted throughout the 16-day exposure period.
- Thermal stress increased adrenal cortisol concentration in both cold- and heat-exposed mice.
- Cold stress lowered colonic temperature, while heat stress increased it.
Conclusions:
- Exposure to extreme ambient temperatures, both cold and heat, profoundly suppresses NK cell-mediated immune functions in mice.
- The observed decrease in NK cell activity and numbers indicates a compromised immune defense under thermal stress.
- These findings underscore the vulnerability of the immune system to environmental temperature fluctuations and the prolonged nature of this impairment.