Exercise and the immune system 1 2.0 Flashcards
How many lines of defence are there in the immune system?
3
What are the components of the first line of defence?
Skin and mucous membranes (protective barrier)
What are the components of the second line of defence?
Macrophages, neutrophils, dendritic cells, NK cells
What do phagocytic cells do?
Eat other cells
What do cytotoxic cells do?
Secrete toxins that kill other cells
Which line of defence is specific?
The third line
Components of the third line of defence?
T cells, B cells (adaptive immune cells)
Which cells are cytotoxic?
NK cells and T cells
Which cells secrete antibodies?
Plasma cells
Where do immune cells start?
Bone marrow
What cell can differentiate into B cells, T cells and NK cells?
Common lymphoid progenitor cell
What cell can differentiate into platelets, erythrocytes, granulocytes and dendritic cells?
Common myeloid progenitor
What is the precursor cell to common lymphoid and myeloid progenitor cells?
Haematopoietic stem cell
What can monocytes differentiate into?
Macrophages
Which immune response occurs first in response to a pathogen?
Innate immune response
What are the four phases of an infection?
Establishment, inductive, effector, memory
How can immune memory capabilities be assessed?
T cell or B cell function
How are T cells used to measure memory capabilities?
Interferon-gamma production by T cells
How are B cells used to measure memory capabilities?
Antibody responses (IgG, IgA response)
How does a hematology blood analyzer work?
Each cell passes through a detector that has a light source, light is shone across the cell, the amount of light that passes around the cell to the forward scatter detector indicates the cell size
What tells you the size of a cell in a hematology blood analyze?
The amount of light going around the cell into the forward scatter detector
What tells you the granularity of the cell in a hematology blood analyzer?
The amount of light reflected off to the side into the side scatter detector
What are the characteristics of lymphocytes in a hematology blood analyzer?
Small (low FSC) and few granules (low SSC)
What are the characteristics of monocytes in a hematology blood analyzer?
Large with few granules
What are the characteristics of neutrophils in a hematology blood analyzer?
Large with many granules
What is done to immune cells before they are put into a hematology blood analyzer?
They are fluorescently labelled by attaching an antibody with a fluorescent tag
What are CD antigens?
Cluster of differentiation antigens–> antigens that are expressed on different immune cells and are used to identify them
Which CD does T cells express?
CD3
Which CD cells do B cells express?
CD19
Which CD do NK cells express?
CD56
Which CD do Th cells express?
CD4
Which CD do cytotoxic T cells express?
CD8
What does CD27 tell you?
The cells age
What does CD62L tell you?
The cells migration ability
What is interferon gamma a marker of?
Cytotoxicity
3 components of open window hypothesis?
Opportunistic infections follow acute strenuous exercise, changes to salivary IgA in the hrs post exercise, changes to immune cell frequency and functional capacity after acute strenuous exercise
What happens to the concentration of blood lymphocytes during exercise?
Increases
What happens to the concentration of salivary IgA during exercise?
It increases
What happens to the concentration of blood lymphocytes in the hours after exercise?
Drops significantly, below level before exercise
What happens to the concentration of salivary IgA in the hours after exercise?
Drops significantly, below level before exercise
1990 LA marathon study condition?
Compared runners who didn’t run LA marathon to those who did
Results of LA marathon study?
More runners (12.9%) became sick in the week after the race than those who didn’t run (2.2%)
What was the odds ratio of becoming sick after running a marathon compared to not running a marathon?
5.9*
Issues with LA marathon study?
The runners were at a mass participation event while the controls were not and this would have increased the likelyhood of getting an infection regardless of if they did exercise
How was the south africa run study better than the LA one?
The controls in the SA one lived with the runners, so the mass participation event aspect was nulified
What were the results of the SA study?
33.3% of runners got URTI symptoms compared to 15.3% of controls
What was observed regarding the majority of URTI symptoms in athletes?
Most of them are not of infectious origin (11/37 reported had a positive diagnosis)
What was observed regarding URTI symptoms and race time in the SA study?
People who ran a faster race were more likely to get URTI symptoms
What did the Mecca study observe?
The longer someone stayed there, the higher risk of URTI they had (URTI was not associated with age, sex, education or smoking)
What does the J shaped curve describe?
Those who undertake an excessive volume of exercises are at a greater risk of infection to those who are sedentary or moderate exercise. Those who are sedentary have a higher risk of infection than those who do a moderate amount of exercise
What did the Swedish study observe regarding the J shaped curve?
People who do higher amounts of physical activity have lower risk of infection compared to people doing medium or none–> contradicts J shaped curve
What was the makeup of the study done on mice to see the effect of exercise on immune response?
Mice were infected with influenza and the split into 3 groups: sedentary, moderate (20-30 mins) and prolonged (2.5 hrs)
What else could have caused the high intensity mice to die more?
The stress of having to do so much exercise
What was observed regarding morbidity in the infected mice that did different amounts of exercise?
The mice that had a prolonged bout of exercise had higher morbidity scores
What were the three groups of monkeys that had polio?
Forced swimming, kept in a cage, kept in water in a straitjacket
What is poliomyeltis?
An acute infection caused by poliovirus.
What was observed in the mice regarding survival?
30 mins per day exercise had 90% survival, sedentary control had ab 50% and prolonged exercise had ab 30%
Issues with the animal studies looking at effect of exercise on immune response?
They cant control for the stress response and other factors that arise in the animals as a result of the studies
Why is salivary IgA used to observe the effect of exercise on immune function?
obtaining it is non invasive
Why is IgA specifically looked at in saliva
It is the most abundant immunoglobulin in the body
