Skin immunity

Question 1

Cutaneous immunity

Answer 1

Innate-physical barrier, epidermal production of protective proteins, local cytokine production, blood derived cells

Question 2

first barrier

Answer 2

physical barrier including stratum corneum, barrier proteins like filaggrin, block microbes from penetrating the skin

Normal skin flora are competitive for spots to bind to skin

Question 3

2nd barrier

Answer 3

microbe encounters constitutively expressed anti microbial proteins in the stratum corneum

Defensins are the most common proteins

Question 4

3rd barrier

Answer 4

after the stratum corneum, the microbe separates tight junctions and activates TLRs inducing immune reaction

New AMPs are produced and blood borne immune cells are activated

Question 5

Immune activativation

Answer 5

TLRs induce the production of cytokines aka TNFa, and IL1

blood borne ccells including DCs, PMNs, mast cells, T cells can all be activated,

DCs esp produce IL23

IL23 and IL17

IL17 induces further changes in the epidermis, including thickening and induced AMP production, promotes increased recruitment of new cells

Question 6

Psoriasis

Answer 6

3% of the population
men=women
Genetic predisposition
Painful
70% report itch
not otherwise healthy

have a risk of MI (like increased cholesterol)

Causes psoriatic arthritis, depressions, diabetes mellitus, crohns, economic disability

Thickened cornified layer
IL23 upregulated T17 immunity

Question 7

treatments of psoriasis

Answer 7

Topical: corticosteroids, vitA and vitD derivatives

Phototherapies: UVB, psoralen and UVA

Systemic therapies: Methotrexate, cyclosporin, Retinoids

Question 8

clinical presentation of psoriasis

Answer 8

clinical changes in resident cell population in the skin

Scale: abnormal keratinocyte maturation, abnormal keratin expression (keratin16)

Thickness: rapid keratinocyte proliferation increase in cell markers (Ki67)

Redness: cutaneuous vascular proliferation and dilation

Question 9

IL23 and IL 17 inhibition in psoriasis

Answer 9

IL23 inhibition attenuates IL17 production, but basal levels are maintained

IL17 anitbodies fully block IL17 Ab