Immunity Flashcards
Name some natural barriers against microbes
On the skin, we have low pH and free fatty acids. In the stomach and lungs, we have mucus containing lysozymes, lactoferrin and antimicrobial peptides as well as cilia that can push things away
Name some ways pathogens evade these barriers
They can use pili or adhesins to attach to host cells.
What is an unique feature of the neutrophil?
It can do NETosis, in which it releases DNA and oxygen radicals to trap bacteria and viruses.
What does the NF-kappaB pathway produce?
Proinflammatory cytokines such as IL-1beta
What is sepsis?
When the immune system goes into overdrive; the white blood cells cause a cytokine storm which causes a hyperinflammatory state. This leads to epithelial damage, which can lead to fluid leakage which in turn leads to swelling and low blood pressure; this leads to organ failure.
Why are different immune cells important for clearing virus infections vs bacterial /fungal infections?
Since different pathogen has different life styles, as well as size, there need to be different strategies. For example, while most bacteria is small enough to be phagocytosed, there are parasites that are way too big. Similarly, viruses are obligatory intracellular pathogens, while bacteria can be both extracellular and intracellular
What type of immune response is generally connected to (extracellular) bacteria?
B-cells are very important as antibodies can opsonize, neutralize bacteria and activate complement and other immune cells with Fc receptor such as macrophages. For T-cells Th1 cells are most active and will activate B-cells and macrophages.
What type of immune response is generally connected to viruses?
Here CTL cells are responsible for cleared the cells. Th cells are still responsible for activating them.
What type of immune response is generally connected to parasites?
Th2 - respons which causes mast cells to degranulate and release factors that damage the worm. B-cells can also produce antibodies against worm that will opsonize.
