Foundations of Immunology II

Question 1

What cells are HLA Class I expressed on? Class II?

Answer 1

HLA Class 1 is expressed on almost all nucleated cells except trophoblasts and sperm cells

HLA Class II is expressed on antigen presenting cells, such as B-cells, dendritic cells and macrophages

Question 2

What are the chain of HLA Class I and II? Are they polymorphic?

Answer 2

HLA Class I is made of a polymorphic a-chain and a non-polymorphic b2-chain.

HLA Class II has a polymorphic a and b chain

Question 3

What T-cells correlate with what class of HLA molecules?

Answer 3

HLA Class 1 molecules present to CD8 cells, while HLA Class II present to CD4 cells

Question 4

What is cross presentation and how does it occur?

Answer 4

Cross-presentation is when an antigen is presented by both classes of HLA molecules. This typically happens when a dendrite or other APC presents to a CD4 cell.

Question 5

Where to lymphocytes concentrate antigens?

Answer 5

Lymph nodes