Zusammenfassung der Ressource
Bacteria immune response
- Breaks epithelial cells
- Bacteria enter tissue
- PRR bind to PAMPs
- PRR - Pattern
Recognition
Receptors found on
surface of
macrophages
- PAMPs -
Pathogen-associated
molecular patterns on
bacteria
- Macrophages
- Engulf bacteria
- Phagocytosis
- Bacteria killed
through oxidative
burst
- Production of reactive
oxygen species
- Bacteria broken
down into little
particles
- Release
proinflammatory
cytokines and
chemokines
- Signal to other
cells there is an
infection
- IL-1, TNF-a and CXCL-8
- Cytokines
- Can be pro or
anti-inflammatory
- Interleukins
- Target leukocytes
- Interferons
- Have antiviral response
- Chemokines
- Mediate chemotaxis
- Mast cells activated
- Mast cells degranulate
- Granules released
into surrounding
tissue
- They release
enzymes and active
components
- Have an effect on blood vessels
- Blood vessels become leaky
- Tight junctions
broken down
- Blood and interstitial fluid
enters tissue
- Neutrophils escape blood
and enter tissue to fight
infection
- Neutrophils
phagocytose
bacteria
- PRRs bind to PAMPs
- Oxidative burst
- Complement proteins
drawn into tissue
- Opsonise pathogen
- Make it more visible
to phagocytes
- Cell lysis
- Form membrane
attack complex
- Punches hole in
pathogen so water
enters and it bursts
- Cell signalling molecule
- Chemotaxis
- Draws in neutrophils
- Activation
- Mast cells
- C Reactive Protein (CRP)
drawn into tissue
- Dendritic cells activated
- Phagocytose pathogen
- Dendritic cells take
pathogen to local
lymph node
- Dendritic cells talk to
T helper cells
- T helper cells
initiate adaptive
immune response
- Pathogen on MHC2
molecule recognised by T
helper/naive CD4 T cells
- CD4 cell activated
- Activated by
interleukin 2
- Proliferation and
clonal expansion
of CD4 cells
- All CD4 cells
recognise
pathogen
- B cells activated
- B cells clonally expand
- Recognises the
antigen and so can
fight off pathogen
- Some B memory cells produced
- Reside in
lymph node
- Antibodies produced
- IgM is produced first
- Isotype switching
- T helper 2 cells
release certain
cytokines
- Tells B cells which
antibodies to
produce
- Antibdies work to
destroy the pathogen
- Neutralisation
- Prevents toxins
from damaging
tissue
- Prevents
pathogens from
entering cells
- Opsonisation
- Highlights pathigen to the phagocyte
- Helps phagocytosis
- Important for
encapsulated bacteria
and some viruses
- Act as signalling
molecules to activate
acute inflammation
- Cause activation of
complement and in turn
mast cells
- Mast cells release chemical
signals that cause inflammation
- Antibody
mediated cell
cytotoxicity
- Cytotoxic T cells and natural
killer cells bind to Fc portion
of the antibody
- Release enzymes
for cytotoxic cell
- Cause apoptosis of cell
- Clear infection and
cells involved in
fighting it
- Back to state of
normality
- Heal wound
- Some T cells
become memory T
cells
- Reside in lymph node
- Naive T cells differentiate
into different types of T cell
- Stimulated by the
release of cytokines by
dendritic cells
- E.g. with bacterial
infection, TH2 response
is helpful - activates
naive B cells to become
plasma cells and
produce antibodies
- Humoral response
- Displays parts of
pathogen on its surface
- On MHC2 proteins
- Contain granules