Immunology Flashcards
Skin provides a barrier and front line defence between us and what?
Pathogens, chemical insults and physical trauma
Factors that contribute to the skin as an immunological system
Structure
Cell types
Cytokines, chemokines, eicosanoids and antimicrobial peptides
Genetics
How does the structure of the skin contribute to the skin as an immunological system?
Has a keratin layer and stratification
Function of cytokines
Proteins which encourage migration between cells
Function of chemokines
Attract migration of cells
What happens to an infection in a normal immune response?
It is controlled
Hypersensitivity
Overreaction to antigen
Immunodeficiency - is the infection controlled?
Infection not controlled and tumours may arise
Autoimmunity
Reaction to host tissue causing chronic inflammation
Stratum corneum
Keratin layer - formed by terminal differentiation of keratinocytes to corneocytes
Important structural proteins in the stratum corneum
Fillagrin, involucrin, keratin
Functions of keratin in the epidermis
Sense pathogens via cell surface receptors and help mediate an immune response
Produce antimicrobial peptides that directly kill pathogens
Produce cytokines and chemokines
How can keratinocytes be activated?
UV light and sensitizers
Main skin resident immune cell
Langerhans cells
Birbeck granule
Tennis racket shaped characterisation of the antigen presenting cells Langerhans cells
Function of Langerhans cells
Process lipid antigen and microbial fragments and present them to effector T cells
Help activate T cells
What type of T cells are mainly found in the epidermis?
CD8+ T cells
What type of T cells are mainly found in the dermis?
CD4+ T cells and CD8+ T cells
CD4+ T cells associated with inflammation
TH1 (psoriasis), TH2 (atopic dermatitis) and TH17 (psoriasis and atopic dermatitis)
Where are T cells produced and sensitised?
Produced in bone marrow, sensitised in the thymus