22 - Coordinated Response to Infection Flashcards
How does C’ activate B cells?
Through stimulation of B-cell CR2
Example of a bacterium that inhibits C’ stimulation of B cells
Neisseria meningitidis group B
Factor released by macrophages that stimulates T cells and NK cells
IL-12
Monocyte ligand of ICAM-1
MAC1, CD18 (dimer, CD18 is beta chain)
Neutrophil ligand of ICAM-1
Gp150/95, CD18 (dimer, CD18 is beta chain)
Necessary condition for classical C’ activation
Adaptive immune response against pathogen.
Need to have Ig bound to target for C1q to bind and initiate classical.
APC co-stimulatory molecules
CD80/86
CD80/86 ligand on T cells
CD28
What does T cell do when presented with antigen and co-stimulated with CD80/86-CD28 interaction?
Release IL-2, upregulate IL-2R, proliferate.
Express CD40L
Differentiate
Possible outcomes of failed CD80/86-CD28 interaction
1)
2)
1) T cells not co-stimulated undergo apoptosis or become angergised (if CD80/86 not displayed, for example).
2) CTLA4 could be stimulated on T cell, which suppresses T cell proliferation
CTLA4
Inhibitory molecule expressed by activated T cells.
Binds CD80/86 more avidly than does CD28.
Inhibits T cell proliferation if bound.
Alternative name for CR2
CD21 (on B cells)
Th17 basic role
Increase neutrophil invasion of tissue, inflammation
Cytokine necessary for survival of memory T cells
IL-15
TLR 1/2, 2/6 ligands 1) 2) 3) 4)
1) Peptidoglycan
2) Lipoarabinomannan
3) Zymosan
4) Lipoproteins
