antibacterial response Flashcards
first line of defence in innate immnunity
mechanical
chemical
microbiological
What are defensins
anti-microbial peptides capable of killing by penetrating microbial membrane thus disrupting their integrity.
they are active against bacteria, fungi and many viruses
how many types of defensins are there and what are they
there are 2 types:
alpha- defensins
beta -defensins
alpha-defensins are secreted by neutrophils and by Paneth cells
beta- defensins are secreted by a broad range of epithelial cells, in particular those in resp tract the skin and the urogenital tract
if these barriers are crossed what happens
complement activation by microbial cell wall component
complements being the PRR
peptidoglycan (gram positive ) and LPS (gran negative ) bacteria activates complement by alternative pathway
if a bacteria expresses mannose on their surface then it binds to mannose binding lectin and activates the lectin pathway
what are the 3 terminal step in the complement system
inflammation
lysis
opsonization
how many tlrs are there in mammals
9
which TLR bind to peptidoglycan and lps
TLR2 - peptidoglycan
TLR4 - LPS
structure of TLR
leucine rich repeat motif
cysteine rich flanking motif
TiR domain
the leucine and cysteine regions are extracellular and responsible for ligand binding
what does PRR and PAMPS interaction lead to
phagocytosis and cytokines
fucntion of antibodies
neutralise bacterial toxins
trigger classical complement pathway by binding of IgM
opsonisation
what is toxin neutralisation
it is when antibodies protect the cell by binding to the toxins
an example of bacteria that has adapted to survive inside macrophages
mycobacterium tuberculosis
the innate immune responses to intracellular bacteria consists of which type of cells and what is the interaction mediated by
phagocytes and NK cells
mediated by IL-12 and IFN-gamma
