Exam 2 -Adaptive Immunity

Question 1

epitope

Answer 1

part of antigen which is recongnized by BCR, TCR, or Abs, can be multiple on one antigen

Question 2

Makes a good antigen

Answer 2

large (more epitopes)
Comple/Heterogenecity (vs. repeating subunits)
Proteins (elicit strong response) vs polymers/lipids = weak

Question 3

response generated by polymers

Answer 3

weak

Question 4

lipid antigen response

Answer 4

none, they are haptens (need complex)

Question 5

Problem with encapsulated bacteria

Answer 5

covered in polysachharrides, immune system is not easily induced

Question 6

Bacterial response vs fungal

Answer 6

fungal is stronger b/c they have many antigens whereas bacteria have just one with many epitopes

Question 7

site of lymphocytic origin and maturation

Answer 7

primary lymphoid tissue

Question 8

produces T cells

Answer 8

Thymus

Question 9

Produces B cells

Answer 9

Bone marrow

Question 10

Secondary lymphoid tissue

Answer 10

sites where lymphocytes encounter antigen (lymph, spleen, clusters of lymphoid tissue (MALT-tonsils) and GALT (gut)

Question 11

ALT

Answer 11

associated lymphoid tissue

Question 12

Development of Lymphocytes

Answer 12

Stem cell in bone marrow –> B or T progenitor cell –> matures in bone or thymus respectively, mature cells enter blood –> secondary lymph tissue to look for antigen –> enter back into circulation if they do not find antigen

Question 13

Naive lymphocytes

Answer 13

have antigen receptors, but have not yet encountered their antigen

Question 14

Activated Lymphocytes

Answer 14

have found and bound their antigen to their receptor, and have recieved a co-stimulatory signal (allowing them to expand and differentiate into effector and memory cells)

Question 15

Effector lymphocytes

Answer 15

short-lived descendants of activated lymphocytes,armed with the ability to carry a out a specific immune function such as secreting antibodies, cytokines, or killing infected cells

Question 16

Memory Lymphocytes

Answer 16

long-lived descendant of activated lymhocytes; can quickly become effector cells upon second exposure-they remain in the body after infection is cleared so next time the response is rapid –> effector cells

Question 17

T Cell development and Education

Answer 17

In the thymus, progenitor cell matures into a naive T cell and expresses TCR which is specific for ONE antigen (recombinatin), T cells then mature in the thymus as self anitgens are selected against (+ are weak and kept and - are strong and destroyed apoptosis); lastly the T cells express a glycoprotein (CD4 or CD8)

Question 18

Genes for specific TCR

Answer 18

specific to one epitope so made with genetic recombination and deletion of autoimmune clones; T cell then to get activated they are processed or presented and gets a costim signal; once activated they prolif

Question 19

+ T cells

Answer 19

allowed to stay; only weakly bind self antigens

Question 20

• T cells

Answer 20

killed via apoptosis b/c they strongly bind self antigens

Question 21

T cells Express what once mature

Answer 21

a glycoprotein, either CD4 or CD8

Question 22

Needs to happen for T cells to be activated

Answer 22

Antigens to T cells processed and presented; and costimulatory signal required

Question 23

Most T cells become

Answer 23

effector cells

Question 24

CD8+ cells mostly become

Answer 24

cytotoxic T cells

Question 25

CD4+ cells mostly become

Answer 25

Helper T cells (TH1 or TH2)

Question 26

Cells which do not become effector T cells

Answer 26

Memory CD4+ and memory CD8+ cells

Question 27

Negative Selection of B cells

Answer 27

B cells that react strongly to self antigen (autuimmune clones) are deleted in bone marrow via apoptosis

Question 28

B cell receptor

Answer 28

expresses IgM (immunoglobin protein) on surface as receptor; has two antigen binding sites (for the same antigen-NOT different) and binds free soluble antigens such as protein, polysach, or lipids

Question 29

T Cell Receptor

Answer 29

A single antigen binding site; binds PROCESSED antigens (cut up into pieces) that are presented TO THEM by MHC receptor (NOT soluble antigen); These antigens are mostly proteins and internal linear peptides produced during processing of antigen and bound by MHC

Question 30

T cell receptors have ____ binding sites

Answer 30

one binding site for antigen

Question 31

B Cell Receptors have _____ binding sites

Answer 31

two antigen binding sites for the same antigen; expressed as IgG

Question 32

B Cell receptors bind

Answer 32

Free soluble protein, lipid, or polysachs

Question 33

T cell receptors bind

Answer 33

Processed protein which is presented to them by MHC-commonly internal linear peptides

Question 34

Number of eptiopes recognized by a one BCR or TCR

Answer 34

one!

Question 35

Number of receptors on a single T/B cell

Answer 35

50,000 BCRs/TCRs

Question 36

Population of T and B cell responds to _____ epitopes

Answer 36

100 million; but NOT 100million receptor genes

Question 37

How do B and T cells detect so many epitopes?

Answer 37

gene rearrangement of cassetes; segements of genes are randomly cut and sliced during development and via genetic recombination form a functional receptor gene; thus autoimmune cells must be removed (maturation)

Question 38

Major Phases of T and B cells

Answer 38

Selection and activation of naive lymphocytes, and expansion/proliferation and differentiation into effector cells

Question 39

Selection

Answer 39

upon entry into immune system each antigen or processed antigen is recognized by a genetically distinct lympocyte with the correct receptor

Question 40

Activation

Answer 40

signals from another cell type are needed to go further

Question 41

Expansion

Answer 41

upon activation, the lymphocyte proliferates and differentiates into a larger population of identical cells which can react to the same exact type of antigen!

Question 42

Helper T cell Role

Answer 42

secrete cytokines that activate other cells in the immune system

Question 43

Helper cells come from

Answer 43

Naive CD4 T cells

Question 44

TH1 secretes

Answer 44

IL-2 and IFN gamma to activate CD8+ cells