Opsonization and Phagocytosis - can Flashcards
What are Opsonins?
Macromolecules attached to the surface of a microbe and can be recognized by receptors on neutrophils and macrophages. *Most microorganisms will NOT be phagocytes without opsonins.
What are the receptors for Opsonins?
- Fcy on phagocytes
- Cr and leukocytes intergrein Mac-1
In regards to IgG receptors,____ regions react with organisms.
Fab
_______ is the signal for macrophages to phagocytose the neutrophils.
The loss of CD16
_______ is most important for phagocytosis of IgG coated particles and microorganisms.
RII
What are the Chemotactic factors?
C3a & C5a
What are the main complement derived opsonins?
C3b & C3bi
Monocytes are found where vs macrophages?
Monocytes in blood, move to tissue and become macrophages *Phagocytic function
What is the major phagocytic cell of the innate immune system?
Neutrophils
What factors increase PMN #s?
stress
injury
infection
Increased cytokines
2 main methods of destruction of bacteria?
- oxidative mechanism
- Non-oxidative (Enzymes & pH change)
What kinds of receptors are found on macrophages?
Similar to neutrophils:
- LPS receptor (CD14)
- Toll like receptors
- Fe receptors
- Complement receptors
- IFNy receptor
- Chemokine receptors
5 kinds of phagocytic cells…GO!
- neutrophils
- Macrophage/monocyte
- Eosinophils
- Basophils
- Dendritic cells
3 Tactics used by pathogens to avoid being killed by phagocytes…Go!
- Kill or be killed (Cytotoxicity)
- Inhibit opsonization or inactivate phagocytosis
- capsule
- M protein
- Disrupt signaling - Survive intracellular killing
- inhibit phagosome-lysomsome fusion
- Escape from phagosome
- survive lysosomal enzymes.
