Innate Immunity Flashcards
What is innate immunity
First line of defence
What are some innate immune mechanisms in the oral cavity
- barrier functions
- saliva
- initiation of innate immunity
- recognition of threats
- signalling pathways
- cytokines and chemokines
Is innate immunity specific or non specific
Non specific
How does the immune system initially respond to a threat
Tissue Homestasis, a balance of healthy and unhealthy bacteria
What are commensal organisms
They inhabit everyone’s oral cavity, the immune system needs to respond to these to have a low immune response to prevent infection
After what period of time would an innate immune response occur
After about 4 days
What is the innate immune system
The first line of defence
What does the epithelium of the innate immune response produce
Produces Antimicrobial peptides
Produces cytokines/chemokines
What are non professional immune cells
Epithelial/endothelial cells + fibroblasts
What are the innate cell subsets and complement
- phagocytic cells (macrophages, neutrophils)
- antigen-presenting cells (dendritic cells)
Main role is phagocytosis
What is the function of a chemokines
Cell recruitment
What is the function of cytokines
Cell activation/proliferation
What is the role of the epithelium in the oral cavity
Physical barrier, produces different compounds such as Antimicrobial peptides, Immunoglobins, Lactoferrin, lysozyme and cystatins
Epithelium provides structural/mechanical support
What are Antimicrobial peptides
Small (<50 amino acids)
They are host defence peptides and they are effective in low concentrations
What are some examples of Antimicrobial peptides
- beta defensins
- human neutrophil peptides
- cathelicidins
- psoriasin proteins
What is the role of Antimicrobial peptides
- directly kill microbes (bacterial lysis)
- modulates host immunity (recruits immunocytes ect)
What is secretory immunoglobulin A
Secretory piece will absorb to the saliva forming a protective layer
What is the main role of secretory immunoglobulin A
Attaches to and neutralises microbes
What is lactoferrin
Transport iron ions but has an Antimicrobial activity, present in saliva and produced by neutrophils
What is lyzosome
Present in saliva amd produced by macrophages/neutrophils, target cell walls of bacteria
What are cystatins
Anti protease activity and supports remineralisation of the teeth
What are antigens
Cells involved in immune responses that have receptors for components of micro organisms
What is a toll like receptor
They can be present on the plasma membrane of the cell and there are different types on the surface and inside the cell, they recognise bacterial and fungal components on the plasma membrane and internalised toll like receptors recognise internalised viruses and internalised bacteria
What are the two main toll like receptor
TLR 2 and TLR 4 they recognise a lot of bacteria and fungi
What do dectin and glucan receptors recognise
Fungal recognition
What do NOD like receptors recognise
Bacterial recognition
What do protease activated receptors (PARs) recognise
Microbial and allergen recognition
What are the main roles of PRM receptors
Promote phagocytosis of microbes and promote activation of immune cells
What is the importance of cytokines
They instruct a target cell what to do, they are important in T cell differentiation
What are cytokines
Small proteins (<80kDa in size)
Signalling molecules that coordinate an immune response
What is an autocrine function of a cytokine
Alter behaviour of the cell from which they were secreted
What is a paracrine function of cytokines
Alter behaviour of neighbouring cells
What does the endocrine function of cytokines do
Enter circulation and alter behaviour of distant cells
What does PRR stand for
Pattern Recognition Receptors (recognise antigens)
What do cytokines and chemokines do in terms of receptor signalling
Shapes the type of the immune response
What are chemokines
Small signalling molecules important in signalling and predominantly involved in cell recruitment
What is the difference between cytokines and chemokines
Cytokines tell the immune cells what to do, chemokines tell the immune cells where to go
What are the 4 classes of chemokines
- C chemokines (2 members)
- CC chemokines (31 members)
- CXC chemokines (18 members)
- CX3C chemokines (1 member)
What is the role of bradykinin
Important role in regulating blood pressure
