Innate vs Acquired Flashcards
What is the link between the innate and acquired immune systems?
Macrophages. They phagocytose the invaders and present them to T0 cells
What do macrophages secrete that turns a To into a Th1 cell?
IL-12
What does the Th1 cell secrete after it has been converted from a To cell?
Interferon gamma which feeds back to the macrophage (along with NK and other cells in the IIS) and IL-2 which also feeds back on itself
What effect does gamma interferon (secreted by Th1) have on macrophages?
It enhances its activity within the innate immune system
What is the IL-12 gamma interferon axis?
Macrophage secretes IL-12 which turns T0 cells into Th1 cells. They then secrete gamma interferon which stimulates the macrophage
What other effect does the IL-2 secreted by the Th1 cell have besides enhancing itself?
It activates cytotoxic T cells which kill cells infected with the pathogen
How does a cytotoxic T cell know a cell has a pathogen?
It attaches to a MHC1 on the surface of the cell
What is MHCII?
It is a surface protein on all APCs that shows the antigen (of an exogenous pathogen) to the rest of the immune system
What are the antigen presenting cells?
Macrophages
B cells
Dendritic cells
What kind of cells in the body have MHCI?
All nucleated cells
What cytokine will convert T0 to Th2?
What cell produces this cytokine?
IL-4
It is produced by an unknown cell in the immune system
What cytokines does Th2 secrete and what cell do they in turn act on?
IL-4 and IL-5
They act on B cells
Once a B cell is activated by Th2 what does it become? What does it then produce?
A plasma cell
It produces immunoglobulins