Stress--mechanisms of immunosuppression

Area of Science:

• Veterinary Immunology
• Animal Physiology
• Stress Physiology

Background:

• Stress is an adaptive response to homeostatic threats (stressors).
• Stressor effects are modified by intrinsic and extrinsic factors like genetics and immune status.
• The General Adaptation Syndrome model is outdated; four pathways modulate the immune system.

Purpose of the Study:

• To clarify the definition and modifiers of stress in animals.
• To review the known pathways involved in stress and immune modulation.
• To highlight the knowledge gaps in stress-induced immunosuppression in domestic fowl.

Main Methods:

• Literature review of stress definitions and mechanisms.
• Discussion of neuroendocrine and neuroimmune pathways.
• Identification of research needs in avian stress immunology.

Main Results:

• Stress is defined as an adaptive response to stressors.
• Four pathways (autonomic nervous system, hypothalamic-adrenal axis, extra-adrenal, neuroimmunological) are implicated in immune modulation.
• Mechanisms of stress-induced immunosuppression resistance in domestic fowl are poorly understood.

Conclusions:

• Accurate definition of stress is essential.
• Multiple complex pathways mediate stress responses.
• Further research is needed to link stressors, physiological responses, and disease susceptibility in domestic fowl.