Physiology: Skin Immunology Flashcards
What does the skin produce that can directly kill pathogens?
Antimicrobial peptides
Which type of hypersensitivity is important in autoimmunity and transplantation?
Type II
Name the reaction following skin testing in type III hypersensitivity
Arthus reaction
How is type IV hypersensitivity mediated?
TH1 cells
What is the immunological function of the keratin layer of skin?
Forms a non-specific, physical barrier to pathogens
What is the function of dermal dendritic cells?
Antigen presenting and secreting cyto/chemokines
Which CD4+ TH cells are associated with atopic dermatitis?
TH2 and TH17
How is type III hypersensitivity mediated?
IgG
How is type II hypersensitivity mediated?
IgM
What does the skin produce that recruits and regulates immune cells?
Cytokines and chemokines
Where does IgE bind to during a type I hypersensitivity reaction?
FcεR1 receptor on mast cells
Which types of T cells are present in the dermis?
CD4+ and CD8+ T cells (+ others e.g. NK cells)
What are MHC class I molecules?
Molecules found on almost all cells that present endogenous antigens to cytotoxic T cells
Which type of T cell is found in the epidermis?
CD8+ T cells
What are MHC class II molecules?
Molecules found on antigen presenting cells that present exogenous antigens to TH cells
Which CD4+ TH cells are associated with psoriasis?
TH1 and TH17
Define autoimmunity
Reaction to host tissue causing chronic inflammation
What is the function of the major histocompatibility complex?
Controls the immune response through the recognition of self and non-self
What is an Arthus reaction?
Local vasculitis associated with deposition of immune complexes and activation of complement (type III hypersensitivity)
How is type I hypersensitivity mediated?
IgE
Which chromosome is the major histocompatibility complex found in?
Chromosome 6
What are plasmacytoic dendritic cells?
Immune cells found in diseased skin that produce IFN⍺
Define hypersensitivity
Overreaction to an antigen
What are Langerhans cells?
Dendritic (APC) cell that is the main resident immune cell of the skin
