Stress depresses interferon production by leukocytes concomitant with a decrease in natural killer cell activity

Area of Science:

• Immunology
• Psychoneuroimmunology
• Stress Research

Background:

• Stressful events can impact immune function.
• Medical students experience significant academic stress.
• Interferon (IFN) and natural killer (NK) cells are key immune components.

Purpose of the Study:

• To investigate the effects of examination stress on IFN production.
• To assess the impact of examination stress on NK cell activity and numbers.
• To correlate self-reported distress with immune changes during examinations.

Main Methods:

• Collected peripheral blood leukocytes (PBLs) from 40 medical students during examinations and 6 weeks prior (baseline).
• Measured IFN production by concanavalin A stimulated leukocytes.
• Assessed NK cell activity and numbers using three distinct assays (MOLT-4 cell lysis, anti-Leu-7+ percentage, large granular lymphocyte percentage).
• Collected self-report data on distress levels.

Main Results:

• Significantly lower IFN levels were observed during examinations compared to baseline.
• Significant decrements in NK cell activity and numbers were recorded during examinations across all three assays.
• Self-reported distress was significantly higher during examinations.

Conclusions:

• Commonplace academic stress, like examinations, can suppress key immune responses, including IFN production and NK cell function.
• These findings suggest a link between psychological stress and immune suppression.
• The results have implications for understanding stress-associated illnesses and immunosuppressive disorders.