fighting infection-bacteria Flashcards
what allows bacteria to enter and proliferate
break in epethial surface
what activates complement pathway and mannon binding lectin pathway leading to cell lysis
liposaccharides on the bacteria
three effects of complement
1) mast cell activation
2) opsonisation
3) chemotaxis
opsonisation
targeted for destruction by phagocytes
after complementation has begun what happens
mast cell degranulation causes increased blood flow and leaky blood vessels causing oedema and local irritation
after mast cell degranulation occurs what happens next
neutrophils get drawn to sea by complement, bacterial products and chemokine –> adhere to endothelia cell and marginate into infected area
which cells are phagocytksed and killed by neutrophils
opsonised bacteria
dendritic cells
engul and internalise bacteria- they migrate to the lymph node via the lymphatics
how are naive cells recruited to the lymph nodes
recruited by dendritic cells
interaction between dendritic cells and T helper cell in lymph nodes
dendritic cells present bacterial peptide to T helper cell receptor on their MHC II molecules which activate the T cells
Dendritic cells can activate
T helper 1/2 cells
activated T helper 2 cells cause
B cells to become plasma cells and produce antibodies–> initially ism and then class switching occurs and IgG and igA
early antibody production
IgM–> 5 binding sites on IgM= enhance binding efficiency
opsonised bacteria engulfed by
phagocyte and killed
after infection..
bacterial debris is removed by neutrophils or by antibodies as soluble immune complexes