Cutaneous Immunology Flashcards
What are the two main “branches” of innate immunity?
Cellular vs non-celullar
What cells make up cellular innate immunity?
Macrophages, neutrophils, NK cells, mast cells, eosinophils, lymphocytes (especially cytotoxic T-cells)
What are some important components of non-cellular innate immunity?
Antimicrobial peptides - cathelicidins and defensins
Cytokines (IL-1, IL-10, IL-12, IFNa, IFNb)
Complement
TLR
What are the 3 primary complement pathways?
Classical, alternative, and mannose-binding lectin pathways
What is the difference between classical complement and alternative/mannose-binding lectin pathway activation?
Classical requires antibodies (It is activated by Antigen-Ab complexes [IgM or IgG])
Which IgG does not activate complement?
IgG4
In what order (strength) do IgG’s activate complement?
IgG3>IgG1>IgG2
What are the purposes of the complement cascade?
- opsonization, C3b>>C5b
- Lyse pathogen (membrane attack complex)
- increase chemotaxis (c3a, c5a) known as anaphalaxins.
What is the alternative pathway activated by?
Viral or bacterial products
What is the mannose-binding lectin pathway activated by?
Microbial carbohydrates like mannose and other monosaccharides on the bacterial wall
What cells are Toll-like receptors mostly expressed on?
Dendritic cells and macrophages
What pathway does activation of TLR activate?
NF-kB (Nuclear factor kappa beta)
Which TLR does NOT use MyD88 for intracellular signaling?
TLR3
Which TLR is activated by triacylated lipoproteins?
TLR1/TLR2
Which TLR is activated by diacylated lipoproteins?
TLR2/TLR6
Which TLR is activated by flagellin?
TLR5
Which TLR is activated by imidazoquinolines (imiquimod) and ssRNA?
TLR7/TLR8
Which TLR is activated by CpG DNA?
TLR9
Which TLR is activated by dsRNA?
TLR3
Which TLR is activated by LPS?
TLR4
Which TLR is affected by retinoids?
TLR2
Which TLR is involved in inflammatory acne?
TLR2 (As expected, this TLR is also affected by retinoids)
Which dermatologic medication affects TLR7?
Imiquimod (synthetic TLR7 analog)
Which complement fragment is the most potent anaphylatoxin?
C5a