Physiology: Skin Immunology

Question 1

What does the skin produce that can directly kill pathogens?

Answer 1

Antimicrobial peptides

Question 2

Which type of hypersensitivity is important in autoimmunity and transplantation?

Answer 2

Type II

Question 3

Name the reaction following skin testing in type III hypersensitivity

Answer 3

Arthus reaction

Question 4

How is type IV hypersensitivity mediated?

Answer 4

TH1 cells

Question 5

What is the immunological function of the keratin layer of skin?

Answer 5

Forms a non-specific, physical barrier to pathogens

Question 6

What is the function of dermal dendritic cells?

Answer 6

Antigen presenting and secreting cyto/chemokines

Question 7

Which CD4+ TH cells are associated with atopic dermatitis?

Answer 7

TH2 and TH17

Question 8

How is type III hypersensitivity mediated?

Answer 8

IgG

Question 9

How is type II hypersensitivity mediated?

Answer 9

IgM

Question 10

What does the skin produce that recruits and regulates immune cells?

Answer 10

Cytokines and chemokines

Question 11

Where does IgE bind to during a type I hypersensitivity reaction?

Answer 11

FcεR1 receptor on mast cells

Question 12

Which types of T cells are present in the dermis?

Answer 12

CD4+ and CD8+ T cells (+ others e.g. NK cells)

Question 13

What are MHC class I molecules?

Answer 13

Molecules found on almost all cells that present endogenous antigens to cytotoxic T cells

Question 14

Which type of T cell is found in the epidermis?

Answer 14

CD8+ T cells

Question 15

What are MHC class II molecules?

Answer 15

Molecules found on antigen presenting cells that present exogenous antigens to TH cells

Question 16

Which CD4+ TH cells are associated with psoriasis?

Answer 16

TH1 and TH17

Question 17

Define autoimmunity

Answer 17

Reaction to host tissue causing chronic inflammation

Question 18

What is the function of the major histocompatibility complex?

Answer 18

Controls the immune response through the recognition of self and non-self

Question 19

What is an Arthus reaction?

Answer 19

Local vasculitis associated with deposition of immune complexes and activation of complement (type III hypersensitivity)

Question 20

How is type I hypersensitivity mediated?

Answer 20

IgE

Question 21

Which chromosome is the major histocompatibility complex found in?

Answer 21

Chromosome 6

Question 22

What are plasmacytoic dendritic cells?

Answer 22

Immune cells found in diseased skin that produce IFN⍺

Question 23

Define hypersensitivity

Answer 23

Overreaction to an antigen

Question 24

What are Langerhans cells?

Answer 24

Dendritic (APC) cell that is the main resident immune cell of the skin