A 10 Acute Cutaneous Inflammation Flashcards
What does SALT stand for, and what is it associated with?
- skin associated lymphoid tissue.
- Cutaneous adaptive immune response.
What are the known PAMP’s?
- Bacterial lipopolysaccharide
- Peptidoglycan
- Lipoteichoic acids
- Mannans & Glucans
- Bacterial DNA
Langerhans has what unique organelle?
Birbeck granule
Helper T cells have what function & what receptor?
-Get other immune cells involved
-CD4
(think “4 Helps, but double is death!” 8)
Cytotoxic T cells have what function & receptor?
- Kill marked cells
- CD8
What cell presents antigens to T cells waiting in lymph nodes?
Langerhans
What tells T cells to go to the skin?
T-cells bound to CLA (cutaneous lymphocyte antigen)
Helper T Cell Subset Th1: what function?
Intracellular pathogens (like viruses)
Helper T cell subset Th2: what function?
Helminth infections
Helper T cell subset Th17: what function?
Autoimmune
Helper T cell subset Treg: what function?
Immune suppression
Immediate Hypersensitivity reactions involve which immune cells?
-Mast cells (rls histamine)
-
Which cells can be involved in antigen presenting?
- Macrophages
- Dendritic cells
- B cells
- Keratinocytes (though not as efficiently)
How long until Triple Response of Lewis occurs?
3-10 seconds
What are 3 phases of Triple Response of Lewis?
- Erythema=Capillary dilation
- Flare=Nearby arterioles
- Wheals=Up vascular permeability
All gram-negative bacteria have what PAMP?
Lipopolysaccharides
What 3 groups of molecules (not cells) serve as the “bridge” from innate immune response to adaptive immune response in the skin?
- co-stimulators, cytokines, chemokines: recruit & activate lymphocytes
- MHC Class II: presented along w/ the antigen to T-cells
- Co-stimulatory molecule: CD-80 & CD-86
Which type of T cell has the CLA antigen bound to it?
Memory T cells
What is the primary purpose of CLA-positive T cells?
Cutaneous Immunosurveillance
What is the mechanism of Type I (Immediate) Cutaneous Hypersensitivity reaction?
IgE’s bound to mast cells become cross-linked, causing mast cell degranulation -> inflammation or anaphylaxis
What is the mechanism of Type 2 Cutaneous Hypersensitivity Reactions?
-“Antibody-dependent.”Antibodies attach to antigens which have (mistakenly) collected on skin cells. Killer T cells and complement activation produce cytotoxicity. (Ex, hemolytic anemia, transfusion rxn, some autoimmune disorders, POSSIBLY vitiligo)
What is the mechanism of Type 3 Cutaneous Hypersensitivity reactions?
“Immune Complex Disorders.” Antibodies and antigens form Immune Complexes in the blood. Deposit in vessel walls, esp. small vessels in skin. Complement Activation, platelet aggregation, and Lysosomal Enzyme Release causes vascular damage. (ex, lupus erythematosis & dermatomyositis)
What is the mechanism of Type 4 Cutaneous Hypersensitivity Rxn?
- Antigen presented to T-cell by antigen-presenting cell.
- Cytokines rls’d, amplifying T-cell and macrophage recruitment (seen in allergic contact dermatitis, tuberculosis, leprosy)
What are 3 skin immune system cells/chemicals that are suppressed by UV light?
- Langerhans
- Thy1+
- Dendritic epidermal T cells
