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18 Cards in this Set
- Front
- Back
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HOW IS THE HOST ALERTED TO PRESENCE OF BACTERIA?
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Danger Hypothesis - To respond or not to respond, that is the question.
Danger sensed by: PRRs (Pattern Recognition -R's) which recognize PAMPs (Pathgen Assoc Moleculare Patters/Proteins) Results in discrimination bw Self and Non-self |
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List some examples of:
PRRs (4) PAMPs (3) |
PRRs
CD14, Toll-R's, CR PAMPs LPS, Teichoic acid, Mannans, dsRNA |
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What is special about M-Phages allowing them to respond to infection?
(3) |
CR1 (binds C3b)
CR2 (bindsiC3b) FcR's (bind Fc of Ig's) |
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1. Who has TLRs?
2. How many are there in mammals? 3. How do they work? |
1. Plants, Insects, Vertebrates
2. 9 in mammals 3. Signaling via NF-kB path -- MyD88 -- cytokine release |
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What does _____ recognize?
1. TLR2 2. TLR2+TLR6 3. TLR4 4. TLR5 5. TLR9 |
1. PGs, Lipoproteins
2. Mycoplama lipoproteins 3. LPS 4. Flagellin 5. CpG DNA |
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LPS induces? (3...and what do these do?)
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1. IL1 - *vascular endothelium, *lymphocytes --> Fever
2. IL6 - Chemotactic for leukocytes 3. TNF-a - *vascular endothelium, ^vascular permeability, ^lymph drainage = Fever, Shock |
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WHAT CELLS ARE INVOLVED IN PHAGOCYTOSIS?
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Professionals:
Neutrophils (in blood, come out to inflamm sites - Short Life Span) Macrophages (mature Tissue monocytes - Long Life Span) Monocytes (immature Blood macrophages) |
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The various aliases of macrophages:
1. In Lung 2. In CT 3. In Liver 4. In Kidney 5. In Brain |
1. Alveolar M-Phges
2. Histiocytes 3. Kupffer cells 4. Mesangial cells 5. Microglial cells |
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Are professional phagocytes the only cells that ingest others?
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Nope! Sunyer's Phagocytic B-Cells
(so far seen in fish and mice) more on the horizon |
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WHAT DIRECTS PHAGOCYTES TO SITE OF INFECTION?
(4 big classes) |
1. Anaphylotoxins (C3a, C5a)
2. Cytokines (IL-1, IL-8) 3. Adhesion Molecules (P/E Selectins, Integrins [LFA1-ICAM; VLA4-VCAM] 4. Chemokines (CC - monocyte migrations; CxC - neutrophil migrations) |
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HOW IS PHAGOCYTE RECOGNITION OF BACTERIA AMPLIFIED?
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Opsonins and Acute Phase Proteins
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What are some Opsonins?
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Complement and Antibody
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How are Acute Phase Proteins Induced?
What are some Acute Phase Proteins? What do these Acute Phase Proteins do? |
1. M-phage sees bacteria -- IL-6 -- IL-6 in liver = Acute Phase Proteins
2. SAA, CRP, Fibrinogen, Mannose BP 3. Activate Complement and Opsonize Bacteria |
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HOW DO PHAGOCYTES KILL MICROBES?
(6 Ways) |
1. Ingest Microbe
2. Enzymes (peroxidase, lysozyme, etc...) 3. Defensins (primitive, pore-forming killers. 30aa peptides) 4. Acidification in phagolysosome 5. Respiratory Burst 6. Release of NO |
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What is the mechanism of Respiratory Burst?
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O2 + NADPH ---> O2- Superoxide --> H2O2 -->
OH- Hydroxyl radical ClO- Hypochlorite O2 Singlet Oxygen (restart burst) *SOD takes Superoxide to H2O2 |
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What is the mechanism of NO synth?
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O2 + L-arginine --> NO
*enzyme iNOS (inducible NO Synthase) |
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HOW DO MICROBES AVOID BEING KILLED?
(5 ways) |
1. Kill phagocyte
2. Inhibit phagocytosis 3. Inhibit lysosomal fusion 4. Escape phagosome 5. Develop mech to survive within phagolysosome |
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HOW CAN THE IMMUNE RESPONSE TO BACTERIA BE PATHOGENIC?
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Toxic Shock
Bacteria spread to bloodstream (sepsis) and thus cause SYSTEMIC RELEASE of TNF and other Cytokines --> Vasodilation, ^Vasc Permeability --> DIC --> SIRS, MODS |
