BMS3020 L16 Inflammation, Host Immunity and Pathogen Evasion 9/11/18
BMS3020 CHRONIC DISEASE
LECTURE 16 – Introduction of Inflammation, Host Immunity
against Infections and Mechanisms of Pathogen Evasion
Historic Definition of Inflammation:
- Inflammation is characterised by redness (rubor), heat (calor), swelling (tumor), pain (dolor) and
dysfunction of the inflamed organs (functio laesa)
- First four features were described in ancient times by Celsus
- Functio laesa was added by Rudolf Virchow in 1858
- Infection is not a synonym for infection even though most infections cause inflammation
Inflammation
- First response of the body to harmful stimuli e.g. infection, wounding, sun etc.
- Activation of vascular system, immune system and other local cell types
Acute: Chronic:
- Resolve quickly - Prolonged inflammation or never resolved
- Harmful stimuli removed - Harmful stimuli remain or new stimuli
- Initial tissue destruction - Simultaneous tissue destruction and
- Followed by healing healing
- Could lead to serious consequences
including cancer
Infectious Agents:
- Pathogen, opportunistic or commensal
- Infectious diseases are caused by diverse living agents that replicate in their hosts
- The interaction between host and microorganism(s) are determining factor for pathogenesis
- Virus – requires cellular components to replicate
- Bacteria, fungus, parasites – have their own organelles and structures
- Endogenous retrovirus or retroviral elements are contained in animal genomes – ancient viruses
which can become activated in humans – implicated in autoimmune and age-related diseases
- Reading item for ERV related human rheumatoid diseases
Phases of Viral Infection
Entry into host:
- Limited number of possible routes of entry – ones in orange are epithelium infection
- Respiratory - Conjunctivital
- Skin - Congenital (mother to child)
- Gastro-intestinal - Blood (insect bite, transplacental)
- Urogenital
- Route of entry does not necessarily correlate with the disease
induced by a virus e.g. some viral diseases remain localised, others
manifest in systemic symptoms
- Virus Tropism: Not the entry site – virus can be neurotropic i.e. cause
disease in the nervous system, but it can enter from anywhere – Determined by multiple factors
interacting in both host and virus
1
BMS3020 CHRONIC DISEASE
LECTURE 16 – Introduction of Inflammation, Host Immunity
against Infections and Mechanisms of Pathogen Evasion
Historic Definition of Inflammation:
- Inflammation is characterised by redness (rubor), heat (calor), swelling (tumor), pain (dolor) and
dysfunction of the inflamed organs (functio laesa)
- First four features were described in ancient times by Celsus
- Functio laesa was added by Rudolf Virchow in 1858
- Infection is not a synonym for infection even though most infections cause inflammation
Inflammation
- First response of the body to harmful stimuli e.g. infection, wounding, sun etc.
- Activation of vascular system, immune system and other local cell types
Acute: Chronic:
- Resolve quickly - Prolonged inflammation or never resolved
- Harmful stimuli removed - Harmful stimuli remain or new stimuli
- Initial tissue destruction - Simultaneous tissue destruction and
- Followed by healing healing
- Could lead to serious consequences
including cancer
Infectious Agents:
- Pathogen, opportunistic or commensal
- Infectious diseases are caused by diverse living agents that replicate in their hosts
- The interaction between host and microorganism(s) are determining factor for pathogenesis
- Virus – requires cellular components to replicate
- Bacteria, fungus, parasites – have their own organelles and structures
- Endogenous retrovirus or retroviral elements are contained in animal genomes – ancient viruses
which can become activated in humans – implicated in autoimmune and age-related diseases
- Reading item for ERV related human rheumatoid diseases
Phases of Viral Infection
Entry into host:
- Limited number of possible routes of entry – ones in orange are epithelium infection
- Respiratory - Conjunctivital
- Skin - Congenital (mother to child)
- Gastro-intestinal - Blood (insect bite, transplacental)
- Urogenital
- Route of entry does not necessarily correlate with the disease
induced by a virus e.g. some viral diseases remain localised, others
manifest in systemic symptoms
- Virus Tropism: Not the entry site – virus can be neurotropic i.e. cause
disease in the nervous system, but it can enter from anywhere – Determined by multiple factors
interacting in both host and virus
1
