Exercise and Innate Immune Function Flashcards
Explain the graph produced by Nieman et al., 1994 that displays the demargination of leukocytes and then Leukocyte sub-set behaviour in the pursuing hours post exercise.
Immediately following exercise we see a large leukocytosis (mobilisation of immune cells) in the blood. -This is due to the process of demargination, and is linked with an increase of adrenaline stimulated by exercise.
- After 1 hour post exercise, we see a large reduction in lymphocytes and monocytes, but neutrophils still continue to increase.
- Adrenaline in the blood has been removed, and this causes lymphocytes and monocytes to migrate from the blood into the tissues.
- cortisol now being secreted causes a release of further neutrophils into the blood via the bone marrow, causing the increase.
Describe the indirect and direct mechanisms behind demargination?
Indirect- as exercise is initiated, cardiac output increases. The more and more blow flowing through blood vessels pulls leukocytes from the cell walls and free in the vessel.
Direct- Catecholamines inhibit the adhesive capabilities of the leukocytes and the vessel walls
Why is Blannin et al., 1996 study showing reduced total leukocyte counts at rest in trained endurance athletes just an artefact?
Endurance training increases the amount of plasma protein. This draws water out of the tissues into the plasma- causing plasma volume expansion.
More fluid in the blood, cells are diluted and reflect lower cell counts.
Why do we see a post exercise decrease in cell numbers?
Cell death or movement of cells into the tissues
Which monocyte subset preferentially leave blood circulation immediately after exercise?
CD14+CD16- (Classical)
What is the function of a pattern recognition receptors?
They detect pathogens in the body via the patterns they express on their antigens.
Gleeson et al., 2006 reported what to Monocyte toll-like receptor following acute exercise?
TLR1-4 all reduced significantly following exercise up to 1hr
Why is reduced TLR function bad for monocyte function?
A monocyte cannot be activated without the TLR effectively recognising an antigen. Monocyte effector functions are then downregulated.
Decribe the activation of Th cells via macrophages?
Macrophage displays HMC which a Th cell binds to. The Th cell then triggers the appropriate specific immunal response i.e IL-2 Th1 antiviral response
3 main functions of Neutrophils?
Phagocytosis
Degranulation
Oxidative burst
What are chemokines?
Chemical messengers that attract other immune cells to the site they’re needed
Gavrieli et al., 2008 showed that strenous exercise impairs chemotaxis, how?
Leukocyte adhesion to the blood vessels is inhibited, and leukocyte migration through the vessel wall and into the tissues is also inhibited 24hr post exercise
Blannin Et al., 1996 showed what differences between phagocytic activity of neutrophils with chronic trained and untrained athletes?
Phagocytic activity at rest and post exercise were significantly lower with trained athletes. But did increase post exercise for trained athletes.
totally quantities of Elastase, a chemical released during degranulation, increase following exercise, but why is this misleading?
Elastase released per nutrophil cell in the blood massively declines post exercise. This is because of the large neutrophil increase following exercise.
Cedia and woods, 1999 showed what effect to monocyte antigen presentation to T cells, following moderate and Exhaustive exercise?
T cell activation was assessed measuring IL-2 secretion.
Moderate exercise elicited significant reduction in IL-2 secretion 3 hours post exercise.
Exhaustive exercise elicited significant decrease in IL-2 secretion 3-24 hours post exercise.
