Innate Immunity 2 Flashcards
The oral mucosa and innate immune cells produce…
Cytokines and chemokines which orchestrate the immune response
What are cytokines
Small proteins that act as signalling molecules to co ordinate immune response
Can be autocrine, paracrine and endocrine
What are chemokines
Small proteins that are involved in directing cells to the site of infection
What is the difference between chemokines and cytokines
Chemokines direct cells to the site of infection and cytokines tell cells what to do when they arrive at the site of infection
What is the most abundant cell type at the oral mucosa
Neutrophils are the most abundant, they increase in number during inflammation
What do cell adhesion molecules control
They control interactions between immune cells and endothelial cells
How are neutrophils attracted to the site of infection
Neutrophils are attracted along a CXCL8 gradient to the site of infection
What are the 3 main families of adhesions
- selectins
- intergrins
- immunoglobulin superfamily
Promote cell to cell interactions
What are cell adhesion molecules important for
Promote cell to cell interactions, important for immune trafficking
What is the role of neutrophils
They are phagocytic granulocytes
Their primary function is to engulf and destroy invading pathogens
What is degranulation
Main function of neutrophil
Granules in cell containing numerous ntimicrobial peptides and enzymes
Released upon activation of receptors
What are Neutrophil extracellular traps
- activation induces neutrophils to release proteins and some genetic material
- trap pathogens
What is the role of macrophages
- circulate in blood as precursors called monocytes
- migrate into tissues and differentiate into macrophages
- early responders to infection
Primary function is phagocytosis
What are some other innate immune cells at oral mucosa
- Natural killer cels and innate lymphoid cells
- mast cells - degranulation
- dendritic cells - main function is to present antigen to T cells
- eosinophils and basophils - similar function to neutrophils
- all can migrate to tissue in similar manner to other cells
What ways can phagocytosis occur
- degradation and removal of the pathogenic threat
- antigen presentation
- safely break down and dispose of apoptotic cells
What are the two types of antigen presenting cells
Non professional (epithelial cells/fibroblasts/endothelial cells)
Professional (macrophages and dendritic cells)
What are the non professional antigen presenting cells
Epithelial cells/fibroblasts/endothelial cells
What are the professional types of antigen presenting cell
Macrophages and dendritic cells
What are granules
Vesicles containing preformed mediators
Give some examples of granules
- proteinases
- Antimicrobials
- chemical mediators eg histamine
In response to
MPAMPS
Complement proteins
Cytokines
What are the 4 enzymatic cascade systems for plasma factors
- complement
- kinins
- coagulation factors
- fibrinolytic system
What is complement
A collection of soluble proteins that are present in circulation
What is opsonisation
Coating of pathogens by antibodies or complement proteins
What are the 3 pathways for complement
1) classical
2) alternative
3) mannose binding lectin pathway (MBL)
What is the classical pathway
Antibody attaches to microbe
What is the alternative pathway
Attaches to microbial cell wall
Explain MBL pathway
Attaches to carbohydrates on pathogen surface
What are anaphylatoxins
Glycoproteins such as complement components C3, C4 and C5 that drive immune responses
What is the function of anaphylatoxins
- promote immune cell recruitment
-increase adhesion of cells - induces granulation
- promotes cytokine production
- induces antigen presentation
- regulate adaptive immune responses
