BMS3020 L14 Chronic Inflammatory Diseases 6/11/18
BMS3020 CHRONIC DISEASE
LECTURE 14 – Chronic Inflammatory Diseases
What is Inflammation?
Historic definition:
- The first response of the immune system to an insult (e.g. infection, wounding, UV exposure etc.)
- Characterised by redness (rubor), heat (calor), swelling (tumor), pain (dolor) and dysfunction of
the inflamed organs (functio laesa)
- Examples: measles rash, poison ivy rash, burn from scalding, swollen lymph nodes under the
armpit or under the ear, sunburn due to UV exposure, rosacea (people get from autoimmune
diseases such as SLE)
Modern perspective:
- Inflammation is a complex local response by tissue cells to an insult
- Acute inflammation occurs transiently as the initial insult is eliminated and damaged tissues
undergo healing
- Chronic inflammation may get worse over time (progression) leading to loss of tissue function,
fibrosis and associated co-morbidities, including chronic pain and behavioural disorders such as
dementia and depression, leading to significant reduction in quality of life
- Inflammation activates immune cells which mature, migrate, proliferate, differentiate and make
cytokines – known as inflammatory cell infiltrates
- Pathogen and damage associated molecular patterns (P/DAMPs) are danger signals which
stimulate innate immune cells
- Pattern recognition receptors (PRRs) recognise these P/DAMPs and mediate inflammatory
signalling as part of the early warning systems
- Cytokines and chemokines are critical factors mediating inflammatory responses – soluble factors
that bind to specific receptors and causing signalling and migration
Early Inflammatory Responses in Skin
- The skin is a mucosal surface
- Insults induce Langerhans cells (type of DC) to migrate to draining
lymph nodes through lymphatic vessel under the skin
- Cytokines and growth or differentiation factors activate skin
resident immune cells which start the inflammation process
- Chemokines (CC) attract other cells such as macrophages,
neutrophils and T cells from the blood which contribute
Innate immunity
- Rapid, non-specific responses to danger without antigen
- Infected, dying or stressed cells generate P/DAMPs
- Innate immune cells respond and become activated
- Activated innate immune cells release interferons (type 1: IFN-
α/β, type 2: IFN-γ) and other ) and other cytokines that can activate other
immune cells – immune cell recruitment
- These cells can mature, migrate, proliferate and differentiate
to acquire effector functions
- Some cells acquire regulatory functions (Tregs)
1
BMS3020 CHRONIC DISEASE
LECTURE 14 – Chronic Inflammatory Diseases
What is Inflammation?
Historic definition:
- The first response of the immune system to an insult (e.g. infection, wounding, UV exposure etc.)
- Characterised by redness (rubor), heat (calor), swelling (tumor), pain (dolor) and dysfunction of
the inflamed organs (functio laesa)
- Examples: measles rash, poison ivy rash, burn from scalding, swollen lymph nodes under the
armpit or under the ear, sunburn due to UV exposure, rosacea (people get from autoimmune
diseases such as SLE)
Modern perspective:
- Inflammation is a complex local response by tissue cells to an insult
- Acute inflammation occurs transiently as the initial insult is eliminated and damaged tissues
undergo healing
- Chronic inflammation may get worse over time (progression) leading to loss of tissue function,
fibrosis and associated co-morbidities, including chronic pain and behavioural disorders such as
dementia and depression, leading to significant reduction in quality of life
- Inflammation activates immune cells which mature, migrate, proliferate, differentiate and make
cytokines – known as inflammatory cell infiltrates
- Pathogen and damage associated molecular patterns (P/DAMPs) are danger signals which
stimulate innate immune cells
- Pattern recognition receptors (PRRs) recognise these P/DAMPs and mediate inflammatory
signalling as part of the early warning systems
- Cytokines and chemokines are critical factors mediating inflammatory responses – soluble factors
that bind to specific receptors and causing signalling and migration
Early Inflammatory Responses in Skin
- The skin is a mucosal surface
- Insults induce Langerhans cells (type of DC) to migrate to draining
lymph nodes through lymphatic vessel under the skin
- Cytokines and growth or differentiation factors activate skin
resident immune cells which start the inflammation process
- Chemokines (CC) attract other cells such as macrophages,
neutrophils and T cells from the blood which contribute
Innate immunity
- Rapid, non-specific responses to danger without antigen
- Infected, dying or stressed cells generate P/DAMPs
- Innate immune cells respond and become activated
- Activated innate immune cells release interferons (type 1: IFN-
α/β, type 2: IFN-γ) and other ) and other cytokines that can activate other
immune cells – immune cell recruitment
- These cells can mature, migrate, proliferate and differentiate
to acquire effector functions
- Some cells acquire regulatory functions (Tregs)
1
