Lecture 13 Flashcards
Hematopoietin Family
Receptor Features: comprised of 1 to 3 subunits
- Subunit expression used to regulate activity
IL-2 Receptor Subuinits (g-sharing)
- a-subunit
- confers ligand specificity; NO transduction
- bg-subunit
- weak binding/ signal transduction
- abg-subunit
- physiologically active
a-subunit
Expressed in activated T-Cells; expressed in activated B-Cells
b-chain bearing
Low-affinity receptors: NO signal transduction (HSC)
- IL-3, IL-5, GM-CSF
High-affinity receptors: YES signal transduction (Myeloid Precursor)
- B-subunit
Interferon Family
Interferes with viral growth; inhibits proliferation and survival of viruses
Interferon-a (Made by multiple cell types)
- Induces ribonucleases (degrades RNA)
- Inhibits protein synthesis (translation)
- Destroys virally infected cells
Interferon-b (made by activated mac/DC and virus-infected cells)
- Induces ribonucleases
- Inhibits protein synthesis
- Destorys virally-infected cells
Interferon-g (made by NK cells and activated T-Cells)
- Drives TH to TH1 (TC development_
- Activates Macs
Interferon-l
Upregulate anti-viral genes
Protein Kinase R
- Activated by dsRNA
- Phosphorylates eIF2a (phosphorylation elongation)
- Blocks initiation of translation
2’,5’-oligoA Synthetase
- Activated by dsRNA
- Activates latent ribonucleases
- Degrades viral mRNA
Mx Proteins
- Inhibits viral transcription
- Detect nucleocapsid proteins
- Prevents virus assembly
Tumor Necrosis Factor Family
Not mainly about tumor necrosis
1. Regulates development and homeostasis
2. Signaling in a variety of tissues
Tumor Necrosis Factor Family (TNF)
- Can be soluble or membrane-bound
- Receptors assemble into trimers
-homotrimers
TNF-a
Macrophage
1. Pro-inflammatory
2. Anti-tumor (apoptosis)
3. Pro-survival
Lymphotoxin-a
Lymphocytes
1. Immune activation
2. MHC expression
3. Increased adhesion
Lymphotoxin-b
Lymphocyte differentiation
BAFF
B-Cell development and homeostasis
APRIL
B-Cell development and homeostasis
CD40L
T-Cell Surface
1. B-Cell differentiation