Exercise and Mucosal Immunity Flashcards
The mucosal immune system is populated with which immune cells?
B and T cells, Plasma cells and macrophages
what are the Direct and Indirect methods that antibodies kill invading proteins?
Direct: Inhibit nutrient uptake, inhibit viral entry to host cells
Indirect: Attract other immune cells, which then bind to the FC portion of the antibody and kill invading cell
What are the two binding structures called on an Antibody?
Fragment Antibody Binding Segment (FAB)
Fragment Crystallisable portion (FC)
What are these Ig classes known for?
IgG
IgA
IgE
IgG- most abundant in blood and tissues
IgA- Most secretory antibody
IgE- Allergic reactions
Describe the unique structure of IgA antibodies
Released as Diamers- 2 antibodies binded by a J chain
They contain a secretory component that allows them to travel from the blood vessel to saliva
How do IgA antibody diamers travel from the plasma cell to the saliva
Secretory component interracts with plgR which allows the diamer to travel through the epithelial cells. The plgR is then cleaved and the diamer released into the saliva.
Nieman et al., 2003 reported what two things to IgA following exhaustive ultra marathon events?
IgA secretion rate decreased linearly with increased training load.
Post race URI was associated with low IgA
Mcdowell et al., 1992 reported what following acute exhaustive treadmill running?
Decrease in IgA concentration
Bishop et al., 2000 reported significant increases to IgA when participants were dehydrated, but why might this finding be debatable? and what did the authors show next?
As saliva flow rate decreases, the residing IgA will reflect greater quantity. The authors then looked at IgA secretion rate (IgA secretion per minute), wherein no significant differences were reported regardless of hydration
What did Proctor and Carpenter report in rats when the stimulating the sympathetic nervous system?
IgA output increased following ANS stimulation
However, the higher the stimulation, the lower the IgA output.
What effect to IgA concentraion, Salivary flow rate and secretion rate did Bishop et al., 2006 show following caffeine ingestion before 90 min cycling at 70% of VO2max?
Salivary flow rate did not change, however, IgA concentraion increases significantly. Secretion rate also reported significant increases following Caffeine ingestion.
Decreases in IgA concentration following exhaustive exercise in rats was associated with declines in plgR expression. What is the cause of this?
Exercise increases circulating cortisol. Cortisol is known to decrease the expression of plgR.
Cortisol induces what effects on mucosal immunity?
Decreases B cell activation and proliferation
decreases expression of plgR
Why are studies (Neville et al., 2008; Gleeson et al., 1999) reporting relationships between IgA levels and incidence of URI somewhat unreliable?
The data point variations and R squared values are often varied and small, respectively.
What predictive ability when observing changes in IgA % did Neville et al., 2008 report in elite yachstmen?
After weekly IgA measurements, results show that a <40% drop from an athletes individuals IgA secretion rate was associated with a 1 in 2 (50%) chance of contracting URI within 3 weeks.
