15964384
Description
Flashcards by Sophie Byrne, updated more than 1 year ago
|
Created by Sophie Byrne
over 5 years ago
|
|
| Question | Answer |
| Why do pathogens invade host cells? | Intracellular = privileged envt - Immune sys protection - No Abs or complement - Nutrient and tissue access |
| 4 examples of invasive pathogens | Salmonella enterica Mycobacterium tuberculosis Candida albicans Shigella spp |
| How does Mtb invade host cells? | Phagocytosed by resident alveolar macrophages Mtb arrests vacuole - phagosome can't fuse w/ lysosome --> no acidification --> Mtb not killed Nutrients delivered to arr vac by Golgi Waste removed |
| How does Salmonella enterica invade cells? | Pathogen-dependent phagocytosis: T3SS inserted into epithelial cell (M cell or enterocyte in gut) Releases effectors into host cell Effectors cause rearracgeent of actin cytoskeleton --> cup-like structure Bacterium taken up by host cell Enclosed in vacuole - shrinks and solidifies SP12 T3SS activated - secretes effectors - controls nutrient delivery by Golgi to cell May exit cell via basal membrane - other body tissues |
| How does Shigella invade host cells? | Similar to Salmonella mechanism M cell actin cytoskeleton remodelling using T3SS effectors Taken up by PDP Lyses vacuole once in host cell No flagellum - uses host actin to propel self - uses lots of host cell ATP May travel through double memb b/w cells May exit via basal memb Phagocytosis - may exit macrophage by inducing apoptosis Access to other host tissues |
| How does Candida albicans become invasive? | Change in pH, [CO2], temp Morpho change to hyphal form Hyphae dig into tissues (facilitated by phospholipases secreted at tip e.g. caPLB1) Reach blood vessel and break off/yeast budding off tip Spreads round body to other tissues and organs e.g. kidneys |
Want to create your own Flashcards for free with GoConqr? Learn more.