Cytokines Flashcards
(51 cards)
3 ways to categorize Immune signals
1) Cell-contact dependent OR cell-contact independent
2) Mediated by germ-line encoded receptors OR mediated by V(D)J generated receptors
3) Pro-inflammatory OR Anti-inflammatory
Germline-encoded receptors (characteristics)
- The gene segments that encode the receptor are already arranged in the genome of all cells
- Each cell of the body expresses the same transcript from this gene
- Heritable
Receptors produced by somatic recombination (characteristics)
- The gene segments that you inherit are unarranged
- Arrangement only occurs in select lineages
- Prior to clonal expansion, each cell has a different arrangement of each gene segment, and thus each expresses a different transcript
- Sequences express are not necessarily the receptor sequences expressed in your mother and father
Innate lineages are activated following the interaction of pathogen associated products with __________ ___________ ___________
Pattern Recognition Receptors (PRRs)
Example of a PRR
Toll-Like Receptors
Most well characterized PAMPs are those derived from:
Bacterial and viral pathogens (least characterized are from fungal and helminth pathogens)
Intracellular TLRs
3, 7, 8 and 9
Extracellular TLRs
1, 2, 4, 5, 6, 10
Principle Cell Sources of TNF
Macrophages, T-Cells
Principal cell sources of Interleukin (IL-1)
Macrophages, endothelial cells, some epithelial cells
Principal Cell sources of IL-6
Macrophages, endothelial cells, T-cells
Part 1: Pathogen Encounter (Cytokines and receptors)
PAMP, PPR, IL-1, IL-6, TNFα
Part 2: Neutrophil Influx (Cytokines and receptors)
IL-8, G-CSF, GM-CSF, Chemokines
G-CSF and GM-CSF
Granulocyte and Granulocyte-monocyte colony stimulating factor - released from Macrophages and Th cells - induce proliferation in the bone marrow
IL-8
Interleukin-8 - Circulating PMNs (Chemotatic - causes PMN migration toward injury)
Four families of Chemokines
CC chemokines: Two cys residues that are adjacent
CXC chemokines: Two cys residues separated by one amino acid
C chemokines: One cys residue
CX3C: Two cys residues separated by three amino acids
Function of Chemokines
Formation of gradient to which PMNs are attracted
There are greater than ______ different chemokines
40
4 stages of PMN extravasation
Stage 1: Rolling
Stage 2: Integrin activation by chemokines
Stage 3: Stable adhesion
Stage 4: Migration through endothelium
Part 3 Of Immune Response
T-Cell activation
Germline genes in T-cell activation
MHC, CD28, CD80, CD86 (B7)
CTLA-4
Serves to negatively regulate response - competes with B7 to provide a “stop” signal through CD28
IL-2
A cytokine that provides autocrine, cell-contact independent, pro-proliferative feedback to the Th cell producing it
Part 4: T cell differentiation into:
TH1 cells
TH2 cells
TReg cells
