3- Principles of Adaptive Immunity

Question 1

What is the main difference between innate and adaptive immunity?

Answer 1

Innate is non-specific with no memory, and adaptive is slow and creates a memory using B and T cells.

Question 2

What is an antigen (Ag)?

Answer 2

A particle that has a specific sequence to which an immunoglobulin or T-cell receptor can bind to.

Question 3

What is an antigen receptor?

Answer 3

Receptors that bind antigens. They are either immunoglobulins or T-cell receptors.

Question 4

What are B cell receptors?

Answer 4

Immunoglobulins on the outside of the B cell to which bind matching antigens.

Question 5

What are T cell receptors?

Answer 5

Receptors on the surface of T cells which bind to specific antigens.

Question 6

Which region of the immunoglobulin (Ig) molecule binds the antigen?

Answer 6

The variable region- there is a different sequence for each Ig

Question 7

Which gene segments code the variable regions of the heavy and beta chain?

Answer 7

V, D and J

Question 8

Which gene segments code the variable region of the light and alpha chain?

Answer 8

V and J

Question 9

What is the purpose of the V, D and J segments?

Answer 9

They create the diversity in the Ag receptor binding site!

Question 10

What is clonal selection?

Answer 10

Multiplying the specific lymphocytes for a pathogen so that we can have an effective defense for that pathogen in the future.

Question 11

Which cells carry the antigen to the naive T cells to bind to the TCR?

Answer 11

Dendritic cells

Question 12

How are pathogen Ag’s delivered to the lymph node for the adaptive immune response?

Answer 12

Dendritic cells carry the Ag’s on MHC-II’s to the lymph node and wait for the corresponding T cell.

Question 13

What are the Major Histocompatibility Complexes (MHC)?

Answer 13

They are molecules in every nucleated cell that present antigens to T cells.

Question 14

Which class of MHC recognizes intracellular pathogens?

Answer 14

MHC-I

Question 15

Which class of MHC recognizes extracellular pathogens?

Answer 15

MHC-II

Question 16

What type of T cell corresponds to MHC-I’s?

Answer 16

CD8 Tc cells

Question 17

What type of T cells correspond to the MHC-II’s?

Answer 17

CD4 Th cells

Question 18

What cells have MHC-I molecules?

Answer 18

All nucleated cells. Basically everything except RBC’s (don’t have a nucleus).

Question 19

What cells have MHC-II molecules?

Answer 19

Professional antigen-presenting cells (APC’s_. These are dendritic cells, macrophages and B cells.

Question 20

What are the 5 Ig molecules?

Answer 20

IgA, IgD, IgE, IgG, and IgM. (GAMED)

Question 21

Which 2 Ig’s are on the B cell surface?

Answer 21

IgD and IgM

Question 22

What is the first antibody (Ab) to be secreted in an immune response?

Answer 22

IgM

Question 23

What are the 3 Ab’s that float around in the blood/lymph?

Answer 23

IgM, IgA and IgG

Question 24

What is neutralization?

Answer 24

It’s when Ab’s bind tightly to an important site on a pathogen and stop its ability to grow and infect.

Question 25

Which Ab acts as an opsonin?

Answer 25

IgG

Question 26

What is somatic hypermutation?

Answer 26

It’s when nucleotide substitution in the variable regions of IgM happen to bind the pathogen more tightly.

Question 27

What happens after the primary immune response with a pathogen?

Answer 27

Memory cells are created

Question 28

Since memory cells are created after a primary infection, what happens during the secondary infection?

Answer 28

The pathogen is recognized and killed quickly.