240 likes | 424 Views
2. Stress and Immunosuppression. The purpose is toShow that the human immunesystem is weakened during varioustypes of stresses(2 studies will demonstrate this). 3. Types of Stresses and Examples: . Physical (traffic accident)Chemical (drug induced)Emotional (depression) Acute (short term)
E N D
1. 1 Stress and Immunosuppression
By,
Atman Shah
shahatma@msu.edu
2. 2 Stress and Immunosuppression The purpose is to…
Show that the human immune
system is weakened during various
types of stresses
(2 studies will demonstrate this)
3. 3 Types of Stresses and Examples: Physical (traffic accident)
Chemical (drug induced)
Emotional (depression)
Acute (short term)
Chronic (long term)
4. 4 Common Features of All Stresses…
Are to activate 2 neuroendocrine pathways:
1) Sympathetic Adreno-Medullary (SAM) system.
2) Hypothalamic-Pituitary-Adrenal (HPA) axis.
5. 5 Maintain Homeostasis
6. 6
7. 7 Adrenaline is produced when we are frightened or excited. It prepares the body for "fight or flight."
8. 8 Excessive Cortisol Secretion
9. 9 Cortisol is a key anti-stress hormone.
10. 10 Various studies have been done to show the link between stress and a compromised immune system.
The studies that follow aim to show how cellular immunity (which includes phagocytic, natural killer, and cytotoxic T cells) decreases as a result of various types of stresses.
11. Paik, et. al. Behavioral Medicine 2000; 26:139-141. 11 Stress due to an exam…… Experiment at the Catholic University, in Korea:
28 male/14 female undergraduate students were selected and agreed to participate.
They were all free of any disease or illness.
12. Paik, et. al. Behavioral Medicine 2000; 26:139-141. 12 Method:
13. Paik, et. al. Behavioral Medicine 2000; 26:139-141. 13 Results: From the blood samples on the day of the exam, they found:
Lowered levels of Interferon gamma (IFN-?), which is normally released by T lymphocytes and natural killer (NK) cells.
Lowered T-helper 1 (Th1) cellular immunity.
14. Paik, et. al. Behavioral Medicine 2000; 26:139-141. 14
15. 15 Few Drawbacks:
The experiment had a small sample size (42 people).
The neuroendocrine state (.i.e. HPA axis) was not examined.
16. 16 Conclusions of this study… Although the neuroendocrine status was not monitored, the cytokine profiles were taken which served as an indirect link to the immune system.
There was a significant decrease in the number of macrophages, interferons, lymphocytes and natural killer (NK) cells.
17. 17 Final Conclusion
Seeing the decline in specific immune cells does show an inhibited immune system, during stress due to an exam.
18. 18 Another Study…
The next study will demonstrate what physical and emotional stresses can do to the immune system and how it can affect the reactivation of certain viruses.
19. 19 Space Flight: before, during & after
20. Stowe, et. al. Psychosomatic Medicine 2001; 63:891-895. 20 NASA sponsored study…..
To study the relation between elevated stress hormones and the reactivation of Epstein-Barr Virus (EBV) in astronauts.
To study the effects of stress due to space flight on levels of neuroendocrine hormones and immune cells.
21. Stowe, et. al. Psychosomatic Medicine 2001; 63:891-895 21 Method: Concentration of (EBV) anti-viral antigen/antibodies and stress hormones were measured in blood samples taken from 28 astronauts.
Blood samples were taken:
Ten days before launch
Landing day
Three days after landing
Urine samples for detecting hormones.
22. Stowe, et. al. Psychosomatic Medicine 2001; 63:891-895 22 Results: There was significant rise (8- to 64-fold increase) in the levels of EBV antigens in blood samples taken before, during and after the flight. (chronic stress, may have triggered the replication)
The levels of anti-EBV antibodies continued to decrease from before to after flight.
11 astronauts showed evidence of EBV reactivation, and each showed increases in urinary epinephrine and norepineprine (stress hormones).
23. 23 Conclusions of this study… There was a decrease in the virus specific antibodies in all the astronauts.
Reactivation of EBV occurred in 11 of the 28 astronauts.
Urinary cortisol and catecholamines were elevated after flight.
Stresses due to space flight lead to decreased virus specific T-cell immunity and reactivation of EBV.
24. 24 Final Conclusion: Both studies showed the effects of different types of stresses.
Exam stress (acute stress) and space flight (chronic stress) had similar decline in immune cells.
The immune system was down regulated in both studies.
25. 25 The End