Lecture 19 10/26/23 Flashcards
What are the unique features of parasites?
-larger than bacteria and viruses
-have a more diverse and abundant array of antigens
-can change surface antigens through antigenic variation
-may induce stage-specific immune responses
Which parasites are able to bypass the physical barrier of immunity?
-parasites spread through blood-feeding insects
-schistosomes (penetrate intact skin)
What are the characteristics of platelets in parasitic immunity?
-activation results in release of toxic materials
-do not need antibodies to function
-use TLR4 and TLR2
How are neutrophils involved in parasitic immunity?
release NETs to trap and kill parasites
Which parasites can be destroyed by platelets?
-Toxoplasma gondii
-Schistosoma
-Trypanosoma
What are the characteristics of eosinophils?
-specialized pro-inflammatory and anti-parasite cells
-occur in allergic and/or worm-infested individuals
-bone marrow eosinophils are mobilized by IL-5 from Th2
How do eosinophils kill?
-major basic protein
-eosinophil cationic protein
-eosinophil neurotoxin
Which substance is produced by ILC2s in response to parasites?
IL-5
Which substances are able to stimulate ILC2s during parasitic infection?
-thymic stromal lymphopoietin (TSLP)
-IL-25
-IL-33
What are the roles of ILC2s in parasitic infection?
-control eosinophil production
-induce eosinophila and IgE production
How do eosinophils use their Fc receptors?
-bind to antibodies that are coating worms
-release granules directly onto worms
Which substance secreted by ILC2s is involved in tissue repair?
amphiregulin
What aspect of Toxoplasma gondii helps it to evade the immune system?
intracellular cysts are not recognized by the immune system
Which parasite heavily uses antigenic variation?
Trypanosomiasis
What are the characteristics of antigenic variation in Trypanosomiasis?
-parasites encode thousands of variants of their surface glycoproteins
-can change out the proteins expressed to avoid antibody neutralization
