Lecture 4 9/5/23 Flashcards
What are the mechanisms of immune cell communication?
-complement
-pattern-recognition receptors
-cytokines
-chemokines
-major histocompatibility complex
What are pathogen-associated molecular patterns (PAMPs)?
molecules that can be recognized by the body as being foreign
What are damage-associated molecular patterns (DAMPs)?
molecules released by damaged/dead cells
What are pattern recognition receptors (PRRs)?
proteins capable of recognizing PAMPs and DAMPs
Which cells primarily express PRRs?
antigen-presenting cells
What is required to trigger inflammation?
the binding of either PAMPs or DAMPs to PRRs
What are the steps that occur once a PRR binds to a PAMP or DAMP?
-inflammation
-interferon production
-sickness behavior
-start of adaptive immune process
What are the four major sub-families of PRRs?
-toll-like receptors (TLRs)
-C-type lectin receptors (CLRs)
-NOD-like receptors (NLRs)
-RIG-1-like receptors (RLRs)
Which PRR sub-family is most important?
TLRs
Why are some PRRs located on the surface of cells?
to recognize extracellular pathogens
Why are some PRRs located within the cytoplasm of cells?
to recognize intracellular bacteria and nucleic acids from microbes/microbe fragments
What bacterial component is recognized by TLR4?
bacterial cell wall lipid/lipopolysaccharide (gram-neg)
What is the location of TLR4?
extracellular
What is recognized by Lectin?
fungal polysaccharide
What is the location of Lectin?
extracellular
What bacterial component does TLR5 recognize?
flagella
What is the location of TLR5?
extracellular
What is recognized by RLRs?
viral RNA
What is the location of RLRs?
intracellular
What is recognized by NLRs?
bacterial peptidoglycan (gram-pos)
What is the location of NLRs?
intracellular
What is recognized by TLR3, TLR7, TLR8, and TLR9?
microbial nucleic acids
What is the location of TLR3, TLR7, TLR8, and TLR9?
endosomal
What are cytokines?
proteins that control the immune responses
What are some of the ways that cytokines can impact cell behavior?
signal for cells to:
-divide
-stop dividing
-produce other signaling molecules
-express new receptors
-die
What is an autocrine effect?
when cytokines act on the same cell that produced them
What is a paracrine effect?
when cytokines act on nearby cells
What is an endocrine effect?
when cytokines spread throughout the body and can act on target cells in distant locations
What is pleiotropic?
when one cytokine stimulates multiple types of cells
What is redundant?
when multiple cytokines have the same function
What is synergistic?
when two cytokines work together to carry out a function
What is antagonistic?
when one cytokine inhibits the action of another cytokine
What are the types of cytokines?
-interferons (IFN)
-interleukins (IL)
-tumor necrosis factor (TNF)
-chemokines
Which type of cytokine is the most important?
interferons
When are interferons produced?
in response to viral infecton
How do interferons function?
by interfering with viral RNA and protein synthesis (antiviral)
What are the type 1 interferons?
-IFN-alpha
-IFN-beta
-IFN-omega
What is the type 2 interferon?
IFN-gamma
What is the type 3 interferon?
IFN-lambda
What is a pro-inflammatory cytokine?
a type of signaling molecule that promotes inflammation
Which cells secrete pro-inflammatory cytokines?
-macrophages
-mast cells
-dendritic cells
Which cytokines fall into the pro-inflammatory cytokine category?
-IL-1
-IL-6
-TNF-alpha
-IFN-gamma
What is the main role of chemokines?
to attract other immune cells
How does the CXCL-8 chemokine impact neutrophil emigration?
-CXCL-8 induces expression of selectins and integrins on endothelial cells
-expression of these molecules promotes adhesion and migration of neutrophils
What is the downfall of chemokines?
they are involved in the pathogenesis of inflammatory and/or autoimmune diseases
What is Humira?
a drug that targets and inhibits TNF in order to suppress inflammatory reactions in rheumatoid arthritis
How can FIP potentially be treated?
injection treatments of interferons to destroy the virus causing the infection
