Lecture 6: Antigen Recognition, Processing, Presentation

Front 1

True or false: in some cases, T cells bind antigens not presented by ther cells, but rather floating in solution

Back 1

False; they require presentation

Front 2

What are the types of APC?

Back 2

1) Monocytes/macrophages
2) B cells
3) Dendritic cells

Front 3

What APC takes up materials by pinocytosis?

Back 3

Dendritic cells

Front 4

True or false: B cells recognize denatured protein antigen, whereas T cells recognize initial, in-tact antigen

Back 4

False; the opposite is true.

Front 5

What T cell marker is associated with MHC class I?

Back 5

CD8+; this is associated with killing cells; want to kill cell when it has endogenous antigen, which is implied by MHC class I

Front 6

What T cell marker is associated with MHC class II?

Back 6

CD4+

Front 7

How does Ig opsonization improve phagocytosis for macrophages? C3b opsonization?

Back 7

When opsonization occurs with an Ig, the macrophage binds the Fc domain and then eats the cell. There is also a C3b receptor.

Front 8

True or false: strong immunogens bind MHC molecules worse than weak immunogens

Back 8

False; they bind better, which is logical

Front 9

True or false: one MHC molecule recognizes one epitope

Back 9

False; each MHC molecule can recognize a range of epitopes; this increases the repertoire of MHC molecules

Front 10

What family of proteins is responsible for transporting antigen peptides into teh RER? What specific proteins?

Back 10

The ABC protein family; TAP-1 and TAP-2 are the specific proteins

Front 11

What does li tand for? What does li do?

Back 11

The invariant chain; li is attached to MHC class II until it reaches the lysosome; li is swapped for antigen peptide

Front 12

True or false: MHC class II molecules are synthesized in the RER, then they go directly to the lyosome to combine with antigens

Back 12

False; they first go to the golgi apparatus, which directs them to teh lysosome

Front 13

True or false: antigens that bind to MHC class II never enter the RER

Back 13

True; they enter the cell in a phagosome, which fuses with a lysosome; this is the lysosome where combination with MHC class II occurs

Front 14

What is one factor that leads to an increase in MHC class II molecules on the cell surface?

Back 14

Interferon-gamma

Front 15

CD4 is a ligand for what? Seen on what cell type? What is the basic function?

Back 15

This is a ligand for MHC class II; involved in cell-cell adhesion and signal transduction

Front 16

CD8 is a ligand for what?

Back 16

Class I MHC molecules

Front 17

What cell is ICAM-1 seen on? What does it bind?

Back 17

ICAM-1 is seen on APCs; it binds LFA-1.

Front 18

What cell type is CD2 seen on? What does it bind?

Back 18

It is seen on T cells, which makes sense since CD4 and CD8 are on T cells. It binds LFA-3

Front 19

What are lr genes also called? What do they encode?

Back 19

Also called immune response genes.

Front 20

True or false: immune response genes are inherited at the class I loci of the MHC

Back 20

False; class II loci

Front 21

What genes dictate the specificity of the MHC molecules?

Back 21

The immune response (lr) genes

Front 22

What is the theory of determinant selection?

Back 22

Some antigens cannot be recognized because a matching MHC does not exist; may have correct T cell, but it cannot be activated