Skin Immunology

Question 1

Keratin layer

Answer 1

Physical barrier
Filaggrin, involucrin and keratin proteins help with structure
Lots of lipids

Question 2

Langerhans

Answer 2

Dendritic cell that interspaces with keratinocytes in epidermis.
Main skin immune cell, specialized.
Antigen presenting cell
Help activae T cells
BIRBECK GRANULE (tennis racket shaped thigs In Langerhans)

Question 3

CD4+

Answer 3

In dermis
Helper cells
Th1 activate macrophages and destroy microorganisms (release IL2, IFNy)
Th2 Help B cells to make antibodies (Il4 IL5 IL6)

Question 4

CD8+

Answer 4

In epidermis and dermis
Cytotoxic T cells
can kill infected cells directly (apoptosis)

Question 5

Keratinocytes

Answer 5

Sense pathogens on skin surface and help mediate an immune response
Releases antimicrobial peptides, cytokines, chemokines

Question 6

Dendritic cells

Answer 6

Two types: dermal and plasmacytoid
dermal : Ag presenting and secreting cyto/chemokines
plasmacytoid : produce IFNa, found in diseased skin

Question 7

MHC1

Answer 7

Found on almost all cells, presents antigen to CD8+

Presents endogenous antigens so that t cells let it pass OR to recognise disease and intiate apoptosis

Question 8

MHC2

Answer 8

Found on antigen presenting cells such as B cells and macrophages
Present to T helper cells
Present EXOGENOUS antigens (from digested microorganism for example)

Question 9

Mast cells

Answer 9

Effector of IgE mediated allergic reaction (releases granules and mediators)
Also activated by trauma/drugs/microrganisms
Kill worms