how does the immune system response to chronic stress, which specific immune cells are involved and how are they affected? be specific
Chronic stress can affect immune system in multiple ways.
* Signaling from the brain: Due to the signaling from the sympathetic nervous system to bone marrow and thymus, the fibers influence immune responses by secreting substances which can bind to receptors on while blood cells.
* Lymphocytes have beta adrenergic receoptors that respond to stress conditions. Natural killer cells have high density of these receptors, B-cells have high density but low affinity receptors, T-cells have low density of the receptors.
Stress is immunosuppressive due to the following reasons:
* Reduced natural killer cell cytotoxicity
* Reduced or suppressed immunoproliferation
* Suppression of Th1 cell stimulating cytokine production leads to an imbalance in Tn1:Th2 ratio. Decreased Th1 cell functions make the individual more prone to infectious diseases.