Innate Immunity 2 Flashcards
What is the primary function of neutrophils?
To engulf and destroy invading pathogens (phagocytosis)
What is the primary function of a macrophage?
Phagocytosis and presentation of antigen to adaptive immune cells
starts as a monocyte then differentiates into macrophage at tissue
What is degranulation?
Degranulation is cellular process that releases antimicrobial cytotoxic or other molecules from secretory vesicles called granules
What are granules?
Granules are VESICLES containing preformed mediators;
- Proteinases
- Antimicrobial Peptides (AMPs)
- Chemical mediators (histamine)
When can degranulation occur?
in response to:
- Microbial antigens
- Complement proteins
- Cytokines/other inflammatory mediators
What is phagocytosis?
Degradation and removal of pathogenic threat, results in antigen presentation. It can also safely break down and dispose of apoptotic cells
What are the two types of of antigen presenting cell (APC)
Non-Professional: Epithelial cells/fibroblasts/endothelial cells
Professional: Macrophages/Dendritic cells
How does antigen presentation occur?
extracellular organism is phagocytised by an APC, the antigens bind to MHC (major histocompatibility complex) and move to the surface of that cell presenting antigens - which go onto activate T cells…
How does phagocytosis and antigen presentation link innate and adaptive immunity?
Phagocytosis occurs by APCs (innate) and MHC presents the antigens on the cells surface allowing communication to T and B cells (adaptive)
What are the 4 enzymatic cascade systems found in plasma (plasma factors?)
- Complement
- Kinins
- Coagulation factors
- Fibrinolytic system
what is the complement system?
Helps the body clear pathogens and damaged cells through INFLAMMATION or OPSONISATION
How many pathways of complement system are there and what is the function of each one?
3;
Classical pathway - antibody attached to microbe
Alternative pathway - proteins bind to microbial cell wall
Mannose binding lectin pathway (MBL) - carbohydrate on pathogen surface
What are the 3 main processes involved in innate immunity?
- Degranulation
- Phagocytosis
- Antigen Presentation
what are anaphylatoxins?
Complement peptides are fragments that are produced as part of the activation of the complement system
Why are anaphylatoxins important?
- promote immune cell recruitment
- induces granulation
- promotes cytokine production
- induces antigen presentation
