Adaptive Immunity I

Question 1

What are the 3 ways adaptive immunity differs from innate immunity?

Answer 1

1. Lymphocytes have a single receptor, but with unlimited number of possibilities.
2. Delayed onset of response.
3. Immune Memory.

Question 2

Where are class I MHC antigens found and what are their purpose?

Answer 2

Found in the membrane of most all nucleated cells. Function to hold a peptide fragment from an Intracellular protein for presentation to T-Cells.

Question 3

Where are class II MHC antigens found and what are their purpose?

Answer 3

Found only on Anitgen Presenting Cells. Function to hold a peptide fragment from an extracellular protein for presentation to T-Cells.

Question 4

Which type of T-cells recognize peptides from MHC class I molecules? What co-receptors?

Answer 4

Recognized by Cytotoxic T-Cells with CD8+ receptors.

Question 5

Which type of T-cells recognize peptides from MHC class II molecules? What co-receptors?

Answer 5

Recognized by Helper T-Cells with CD4+ receptors.

Question 6

What are the characteristics of immature Dendritic Cells?

Answer 6

1. Efficient phagocytes
2. Express low amounts of MHC class 1 and no Class II
3. Receptors recognize inflammatory chemokines

Question 7

What are the characteristics of mature Dendritic Cells?

Answer 7

1. Innate receptors and phagocytic activity are down regulated.
2. High levels of MHC I and II molecules.

Question 8

How do dendritic cells mature and activate? What can they then activate?

Answer 8

Maturation occurs through an infection event. Can activate naive T cells.

Question 9

What ensymatic system creates peptides that bind to MCH I molecules? MHC II?

Answer 9

MHCI=proteasome peptides

MHC II= Endosomal proteases.

Question 10

What is cross-presentation of Exogenous antigens and how is it done?

Answer 10

Dendritic cells can take exogenous antigens and redirect them to the endogenous presentation pathway. This allows for more MHC I molecules.