APC-MHC immune responses
Cells expressing MHC I
CNS macrophages
Microglia
Astrocytes
Endothelial Cells
- Remember that these cells are presenting "self antigen" that has infected the cell
Co-receptors necessary
B7, CD8, CD28
Cytokine Released
CD8 T-cell releases Fas-L which can bind to FasR on these cells...
and kill them
MHC II
Only on antigen presenting cells
CD4 cells
Co receptors
CD40, CD4
Th1 response
Inflammatory response
CD4 T-cell releases inflammatory cytokines like IFN-y which activate immune cells and macrophages (M1) to kill intracellular pathogens
Co receptors
CD40, CD4
Th2 response
Non-inflammatory response: humoral immunity activated
CD4 T-cell releases IL-4, IL-6, IL-10 onto B-cell, which converts B-cell into plasma cell. Plasma cell has no MHC or BCR, only produces antibody for the antigen. (EC pathogens)
Cytokines involved
T-cell release IFN-y, TNF-a, IL-1B
Cytokines involved
T-cell releases IL-4, IL-6, IL-10
Cells that express MHC I
CNS Macrophage
Microglia
B cell
Dendritic cells
- All APCs
If antigen is MBP
Autoimmunity developed against OLs which express MBP
- Leads to multiple sclerosis
- Indirect MS: impair NG2 progenitor development b/c of cytokines
Release of cytokines like TNF-a and IFN-y kill OLs --> demyelination
If antigen is MBP
Autoimmunity developed against OLs which express MBP
- Leads to multiple sclerosis
- Direct MS: antibodies created to kill OLs since they express MBP
Antibody functions
Neutralization of bacterial toxins
Opsonization - coating of pathogen to signal for phagocytosis
Activate NK cell mediated death
Activate of mast cell/IgE mediated killling
Th1 response vs Th2 response
New Note
