The induced response to infection (1) Flashcards
What do cellular receptors of innate immunity do?
They distinguish ‘non-self’ from ‘self’
What do macrophages carry?
A battery of phagocytic and signalling receptors
What do toll-like receptors do?
Sense presence of 4 main groups of pathogenic microorganisms
What receptor recognises LPS?
TLR4
What does recognition of LPS by TLR4 do to macrophages?
Changes macrophage gene expression
What does genetic variation in TLR do?
Associated with resistance or susceptibility to disease
What happens when resident macrophages are activated?
A state of inflammation is initiated at site of infection
How do inflammasomes amplify innate immune system?
They increase production of IL-1beta
Which cells are first effector cells recruited to sites of infection?
Neutrophils
What do inflammatory cytokines do?
They recruit neutrophils from blood to infected tissue
What happens to neutrophils after they consume pathogens?
They destroy themselves and release cytokines
What do inflammatory cytokines do?
They raise body temperature, activate liver to make acute-phase response
How many phases to human immune response?
3
What happens during the immediate innate immune response?
Pathogen invades tissue and proliferates.
Pathogen is recognized by preformed soluble effector molecules and resident effector cells in the infected tissue
Pathogen is either eliminated or the induced innate response is triggered
How long is the immediate innate immune response?
0 - 4 hours
What happens during the induced immune response?
Pathogen invades tissue and proliferates
Activation of cells resident in the infected tissue. Recruitment of effector cells to the infected tissue. Inflammation, fever, the acute phase response.
Soluble effector molecules and effector cells recruited to infected tissue recognize and attack pathogen.
Pathogen is either eliminated or survives and instigates the adaptive immune response
What are innate recognition receptors that recognize pathogens?
Pathogen Recognition Receptors (PRRs)
Which cells express PRRs?
Macrophages, NK cells, and other cells of innate immunity
What do PRRs recognize?
Carbohydrates, lipids, proteins nucleic acids typically found on pathogenic surfaces
How do innate immune cells recognize self and non-self cells?
Pathogen Associated Molecular Patterns (PAMPs)
Damage Associated Molecular Patters (DAMPs)
What are PAMPs?
Shared molecular structures on microbial surfaces (eg. LPS)
What do DAMPs?
Damage to self-cells
How many receptors are there for PAMPs/DAMPs?
> 100
What do PRRs recognize?
PAMPs and DAMPs