Skin Immunology Flashcards
what is a cytokine?
a protein sent by one cell and recognised + responded to by another
what is hypersensitivity?
an overreaction to an antigen
what forms the keratin layer?
terminal differentiation of keratinocytes to corneocytes
what are three structural proteins in the keratin layer and epidermis?
filaggrin
involucrin
keratin
what is another name for the keratin layer?
the stratum corneum
what is the immunological role of keratinocytes?
sense pathogens via cell surface receptors and help mediate an immune response
what can activate a keratinocyte?
UV
sensitisers
what three immune components can keratinocytes produce?
AMPs
cytokines
chemokines
what do AMPs do?
directly kill pathogens
in which disease have high levels of AMP been found in the skin?
psoriasis
what do cytokines and chemokines do?
recruit and regulate the cells of the immune system
what type of cell is a langerhans cell?
dendritic
antigen presenting cells
what is the main resident immune cell of the skin?
langerhans cells
what characterises the langerhans cells?
the birbeck granule
what T cells are found in a health epidermis?
CD8 mainly
what T cells are found in a health dermis?
CD4 and CD8
what T cells are found in psoriasis?
TH1
TH17
what T cells are found in atopic dermatitis?
TH2
TH17
where are T cells produced?
bone marrow
where are T cells sensitised?
thymus
what are CD4 T cells?
T helper cells
what are the two types of CD4 cells?
TH1
TH2
what do TH1 cells do?
activate macrophages
what do TH2 cells do?
help B cells make antibodies
what are CD8 T cells?
cytotoxic T cells
what do CD8 cells do?
kill infected cells
what are the two types of dendritic cells found in the dermis?
dermal
plasmacytoid
what do dermal dendritic cells do?
play a role in antigen presentation
secrete cytokines and chemokines
where are plasmacytoid dendritic cells found?
dermis of diseased skin
what do plasmacytoid dendritic cells do?
produce IFNa
where is the MHC found?
chromosome 6
what cells have MHC I?
almost all cells
what do MHC I molecules do?
present endogenous antigens to CD8 cells
where are MHC II found?
APC’s
what do MHC II molecules do?
present exogenous antigens to CD4 cells
name three factors that can affect the skins immune response?
transplants
UV
ageing
