name the 6 functions of the skin
- protection and defense
- signal reception
- thermoregulation
- communication
- secretion
- absorption
name the 3 layers of skin and their characteristics
- epidermis
- keratinocytes
- restricts extracellular passage and enforces uptake via cytoplasm - dermis;
- connective tissues, fibroblasts, hair follicles and sweat glands
- highly vascularized for immunization, temperature regulation and carrying nutrients into the skin - hypodermis;
- blood vessels and adipocytes
name the 3 innate immune cells in the skin and their function
- keratinocytes; PRR expression –> NFkB signalling and b-defensins
- fibroblasts; express cytokines and receptors
- adipocytes; production of cathelicidin AMP
describe the function of Langerhans cells in steady state, allergy and inflammation
steady state; induce tolerance and Tregs, and produce IL-10
allergy; migrate to LN and induce CTL tolerance
inflammation; produce IL-23 and T cells, induce IL-17 production (pro-inflammatory response) and cytotoxic and memory T cells
what is the role of AMP in psoriasis and atopic dermatitis
p; increased AMP production –> seldom bacterial infections
a.d.; decreased AMP production –> high susceptibility to infection and dysbiosis
name the 4 histopathological features of psoriasis
- acanthosis
- papillomatosis
- hypogranulosis
- parakeratosis
what is the function of microbiota in the skin?
interaction with keratinocytes and immune cells –> homeostasis
induce TLR2 response and interact with DC (IL-17)
dysbiosis –> inflammation
describe the immune pathogenesis of atopic dermatitis
- Th2/22 (early) and Th1/17 (late)
- cytokines; IL-4/5/13/22/31/33 and TSLP
- treatment; targeting type-2 immunity
describe the immune pathogenesis of psoriasis
- Th1/17/22
- cytokines; IL-17A/22/23 and TNF
- treatment; anti-TNF/17A/23
