L1: Psychoneuroimmunolgy Flashcards
PNI
The study of the effect of the mind and brain on health and resistance to disease
Ader & Cohen Studies
Rats: conditioned to associated saccharin-laced water with immunosuppressant drug
After, giving them only saccharin, no drug water → immunosuppression
1st line of defense
Skin, mucous membrane, gut microbiome
2nd line of defense
innate immune cells, inflammatory response (macrophages, NK cells, neutrophils) + mast cells (produce histamine → inflammation)
3rd line of defense
Specialized lymphocytes, humoral and cell mediated immunity
humoral immunity
antibody-mediated immunity, acts before cells get infected, protect against bacterial & viral reinfection, B-cells produce antibodies that recognize specific antigens
cell-mediated immunity
after cells are infected, slower acting, T cells release chemicals that target and destroy infected cells, Th, cytotoxic (CD8), Tregs
IL-2 release leads to
T cells
B cell growth factor leads to
b cells
immunocompetence
The overall ability of the immune system, at any given time, to defend the body against the harmful effects of foreign agents
Immune deficiency (or immunocompromised)
an inadequate immune response; may occur naturally, due to disease, or as a side effect of drugs
approx x% of people have allergies
40%
work by gradual exposure so immune system gets used to the allergen
allergy shots
autoimmune disorders
Line between self and invader blurred, body begins to attack itself
More than 80 types
autoimmune disorders treated by
anti-inflammatories and immunosuppressant drugs
med students during exams study
Found that stress of exams impact how well immune system responds - less Th cells and lower Th/suppressor t cells ratio
Pittsburg Cold Studies (2005)
Found a correlation between number of stressful life events and the likelihood of getting a cold
chronic stress influenced likelihood more than acute stress → more immunosuppressed
Diathesis-Stress model 2 factors that produce disease
Predisposition (diathesis) to the diseases
Can be biochemical (exposure to virus), genetic or other vulnerabilities developed in childhood
Experiencing stress
Protective factors can mitigate the impact of stress
what are glucocorticoids
cortisol, stress hormones
impacts of glucocorticoids on the immune system
Shrink thymus gland, halt formation of new lymphocytes, antibodies
Block release of interleukins and interferons making circulating lymphocytes less responsive
Remove lymphocytes from circulation, kill T lymphocytes
Glucocorticoids shrink which gland?
thymus
lonely participants cold study
Lonely participants no more likely to get the virus then less lonely participants but loneliness predicted greater self-reported cold symptoms severity among those infected, did not predict mucus weight
stress impact on cancer
some evidence that stress may impact the growth and spread of cancer, but little evidence that it impacts onset
theories of how stress effects cancer
stress weakens the immune system preventing it from detecting and destroying developing cancer cells
stress hormones could promote growth and spread of tumors
could increase risk through chronic inflammation
behavioral influences (smoking, not exercising…)
