Lecture 3 Flashcards
What are 4 examples of cell associated receptors?
-Toll-like receptors
-Nod-like receptors
-CARD-family receptors
-cGAS
What are PAMPS?
Pathogen Associated Molecular Patterns
The PAPMP LPS is also known as?
An endotoxin that can cause septic shock
True or false: Multiple TLRs cannot be recognized by different structures in the same pathogen
False
Multiple TLRs can be recognized by different structures in the same pathogen
What does LPS recognition require?
TLR4 and binding receptors CD14
What are CD (cluster of designation)
Identifies cell surface molecules
-act as receptors/ligands
How does signaling work?
PAMP–>PRR–>ADAPTOR–>SIGNAL
What are chemokines and cytokines directed to do?
Alarm and destroy
What is the MyD88 dependent pathway?
MyD88 is used as the adaptor protein that triggers NFkB pathway which makes inflammatory cytokines (IL-1/IL-6/TNFalpha)
What is the MyD88 independent pathway?
TRIF is used as the adaptor protein to trigger the IRF3 pathway which makes interferons (IFN)–>fight against virus infection
What are IRF’s?
Interferon regulatory factors
-proteins that regulate transcription of interferons
What are membrane associated receptors?
TLRs
What are cytosolic receptors?
-Nod-like receptor
-CARD-family sensors (RIG-I)
What is a nod-like receptor and what does it recognize?
-Can sense bacteria infection in the cytoplasm and induced NFkB inflammation
-bacterial infection
What do TRIF adaptors always lead to?
IRF7
What can recognize cytoplasmic DNA?
(cGAS) Cyclic gMP-AMP synthase
True or false: Macrophages can make cytokines and chemokines
True
What are the 4 ways that cytokines/chemokines alarm?
- MBP and CRP opsonize pathogens and activate complement through Lectin & Classical pathway
- Activate more immune cells –>IFN alpha & beta (interferons make resistance to viral replication/activate NK cells/alert non-infected cells)
- Recruit other cells (chemokines)–>provide directional signals for leukocytes to site of infection
- Systemic effects
What is TNFalpha?
Increases vascular permeability
-prevents pathogens from entering the blood through platelet activating factor
-TOO MUCH LEADS TO SEPTIC SHOCK/SYSTEMIC INFLAMMATION
What are the 2 ways that innate system destroys microbes/infected cells?
- Phagocytosis
- Cytotoxicity
What 2 front line defenders are used in phagocytosis?
- Neutrophils
- Macrophages
What frontline defender is used in cytotoxicity?
Natural killer cells
True or false: Natural killer cells are always ready to kill but their effector function is decreased when stimulated with cytokines
False
Their effector functions are increased 20-100 fold when stimulated with cytokines
(Goku going super saiyan)
How do NK cells recognize and kill virally infected cells?
By using Inhibitory and Activating receptors
1. Inhibitory receptors tell them NOT to kill a target cell (negative signal)–>has MHC I
2. Activating receptors tell them to KILL a target cell (positive signal)–>no MHC I
