Cortisol Suppresses the Helper T (Th) 1 Response During Stress
During a stress response, cortisol is the hormone that suppresses the helper T (Th) 1 response. 1, 2
Mechanism of Cortisol's Effect on Immune Function During Stress
- Cortisol is a principal stress hormone released through activation of the hypothalamic-pituitary-adrenal (HPA) axis during stress responses 3
- When released during stress, cortisol shifts the immune balance from Th1 (cellular immunity) toward Th2 (humoral immunity) responses 1
- This immunomodulatory effect is part of the body's adaptive response to stress, protecting against potential systemic overshooting with pro-inflammatory cytokines 1
Differential Effects of Stress Hormones on Immune Function
- Cortisol specifically down-regulates Th1-mediated cellular immune responses while selectively up-regulating Th2-cytokines 4
- This shift in Th1:Th2 balance caused by cortisol can increase vulnerability to certain infectious diseases during periods of stress 4
- Academic examination stress studies have demonstrated increased cortisol release correlating with suppressed Th1 cytokines and enhanced Th2 cytokine production 4
Physiological Significance of Cortisol's Immunomodulation
- The cortisol-mediated Th1 suppression represents an important feedback mechanism that protects the organism from excessive inflammatory responses 1
- During acute stress, cortisol initially suppresses early pro-inflammatory responses but may prime immune cells for subsequent challenges 5
- Chronic stress and sustained cortisol elevation can lead to more persistent immunomodulatory effects, potentially contributing to various stress-related disorders 6
Clinical Implications
- The suppression of Th1 responses by cortisol during stress explains the observed increased susceptibility to certain infections during periods of high stress 4
- Understanding this relationship is important for healthcare professionals as it explains the molecular basis for stress-induced alterations in immune function 6
- Dysregulation of this cortisol-mediated immune suppression may contribute to various stress-related disorders and autoimmune conditions 1, 2
Contrast with Other Stress-Related Hormones
- While cortisol suppresses Th1 responses, other stress-related hormones have different effects:
- Catecholamines (epinephrine and norepinephrine) can have both pro- and anti-inflammatory effects depending on context 1
- Growth hormone (option A) generally enhances immune function rather than suppressing it 3
- ACTH (option B) primarily stimulates cortisol release but does not directly suppress Th1 responses 3
- Prolactin (option C) typically enhances immune responses rather than suppressing them 3
Therefore, cortisol (option D) is the correct answer as it is the primary stress hormone responsible for suppressing the helper T (Th) 1 response during a stress response.