Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
26 Cards in this Set
- Front
- Back
|
What and how does the Innate Immune system recognize Ag?
|
- Use pattern recognition receptors (PRRs) to recognize pathogen associated molecular patterns (PAMPs)
|
|
|
Where are receptors of the innate immune system encoded? number of receptor types?
|
- germline
- <1000 |
|
|
Where are receptors of the adaptive immune system encoded? number of receptor types?
|
- somatic recobination
- 10^12 |
|
|
What are some important types of PRRs?
|
- TLR
- mannose receptor - N-formyl methionyl receptor - scavenger receptor |
|
|
What does TLR-4 recognize?
|
- LPS on gram - bacteria
|
|
|
What does the engagement of TLRs stimulate?
|
- production of cytokines (TNF, IL-1/12), enzymes, chemokines (IL-8), adhesion molecules (E-selectin), costimulatory molecules (CD80/86)
- involved in antimicrobial activities of activated macros |
|
|
What are the 3 epithelial barrier components to the innate immune?
|
1) epithelium physical barrier
2) antibiotics produced within skin 3) intraepithelial lymphocytes (alpha/beta and gamma/episilon T) kill microbe/infected cells |
|
|
What are the steps to get leukocytes (PMN) from the blood to infection site? (inflammation)
|
- macrophage w microbe releases IL-1 and TNF
- vasculature expresses E/P selectins - PMN bind weakly and roll - macrophages/endothelial cells produce chemokines - chemokines increase PMN affinity for integrins - PMN binds and stops rolling - PMN cytoskeleton re-organizes - Chemokines stimulate PMN motility - Histamines/leukotrienes increase vascular permeability - PMN to infection site |
|
|
Microbe binding to mannose receptor causes?
|
- phagocytosis of microbe
- killing of microbe |
|
|
Binding of Microbe to TLR causes?
|
- phagocytosis: ROS/NO killing of microbe
- Cytokines (TNF, IL-12) leads to inflammation and enhances adaptive |
|
|
Binding of Cytokines (IFN-y) to Cytokine receptor causes?
|
- phagocytosis (ROS/NO kills microbe)
- Cytokines: inflammation, enhances adaptive |
|
|
What are the 2 ways Natural Killer cells attack microbes?
|
1) direct killing of host cell
2) facilitated killing |
|
|
What is facilitated killing?
|
- Macrophages with phagocytosed microbe releases IL-12
- NK cell activated to release IFN-y - Macrophage induced to kill microbes better |
|
|
What are the mechanisms for indirect killing by NK cells?
|
- relies on inhibitory and activating receptor
- Inhibitor receptor on NK cells engages with Class I MHC on cell = not killed - Virus inhibits class I MHC on infected cell, nothing for inhibitory receptor to bind to = cell killed - activator receptor on NK cell with Activating ligand on cell (cell killed if inhibitory receptor not engaged) |
|
|
What do gamma/episilon T cells recognize?
|
- shared microbial lipids
|
|
|
What do NK-T cells recognize?
|
- hybrid between 2 cell types
- recognize microbial lipids on class I MHC, CD1 |
|
|
What do B-1 B cells recognize?
|
- microbial CHO
- mainly in mucosa |
|
|
What do Marginzal Zone B cells recognize?
|
- polysaccharide rich microbes
|
|
|
What are the 3 ways the complement system can be activated?
|
1) alternative (microbe)
2) classical (Ab) 3) Lecting (mannose binding lectin) |
|
|
What are the 3 goals of the complement system?
|
1) inflammation [C3a/5a]
2) opsonization of microbe [C3b] 3) lysis of microbes [C9] |
|
|
What are the 5 most important cytokines of the innate system?
|
1) TNF
2) IL-1 3) Chemokines 4) IL-12 5) IFN-y |
|
|
What happens when TNF is overproduced?
|
- lowers bp and can lead to septic shock
|
|
|
What do mannose-binding lecting do?
|
- recognizes microbial CHO
- coats microbes via C |
|
|
What do C-reactive proteins do?
|
- coats microbes via C
|
|
|
How does the innate system activate the adaptive system?
|
- APC from innate take Ag to peripheral lymphoid organ and present Ag (signal 1)
- B7 on APC binds to CD28 on T cell and produce cytokines (signal 2) |
|
|
How does the adaptive system enhance the innate?
|
- T cells release IFN-y which increases macrophage activity
- Ab secreted increase complement activation |
