Lecture 13

Question 1

List the 4 factors the establishment of an infection depends on.

Answer 1

Characteristics of the microorganism, number of organisms, mode of transmission, stability of organism

Question 2

Almost all infections begin at an _____________.

Answer 2

epithelial surface

Question 3

When does adaptive immune response become important?

Answer 3

When innate immunity can’t deal with the infection within a couple of day.

Question 4

List the 5 major classes of pathogens?

Answer 4

Viruses, bacteria, fungi, protozoa, worms

Question 5

Cytokines made in the later stages of an infection influence differentiation of ________ toward ___ or ____ cells.

Answer 5

CD4 T cells; TH1; TH2

Question 6

Pathogens influence cytokines that affect ___ differentiation into ___or ___.

Answer 6

TH0; TH1; TH2

Question 7

The distinct subset of ______ cell can regulate each other’s regulation.

Answer 7

CD4 T

Question 8

IL-10 from TH2 causes __________ of TH1 development by suppressing ____ production by DC.

Answer 8

inhibition; IL-12

Question 9

IFN-gamma from TH1 causes inhibition of ___ development

Answer 9

TH2

Question 10

T cell subset produce __________ that regulate the development of other subsets. For ex. ___ (1.) inhibits ____ (2.) and vice versa. So, most responses are dominated by either ___ (1.) or ____ (2.) and are not __________ responses.

Answer 10

cytokines; TH1; TH2; balanced

Question 11

To initiate extravasation, most of the antigen-specific T cells cease production of ___________ and express ______, which binds to ______ that is induced on activated endothelial cells.

Answer 11

L-selectin; VLA-4; VCAM-1

Question 12

In the absence of a previous inflammatory response, activated T cell enter all tissues via _________: ________ interaction.

Answer 12

P-selectin; PSGL-1

Question 13

Effector T cells that recognize pathogen antigens in tissue:
Produce…
Activate… (2)
Express…
Action on…

Answer 13

cytokines
endothelial cells and adhesion molecules on T cells
E-selectin, VCAM
effector T cells

Question 14

Effector T cells change their adhesion molecules so they can migrate to the site of an __________. So, adhesion molecules _________ trafficking.

Answer 14

Infection; regulate

Question 15

______________ organs are the site of antigen-specific B cell activation.

Answer 15

Peripheral lymphoid

Question 16

What is protective immunity?

Answer 16

The resistance to a pathogen that results from infection or vaccination.

Question 17

Immunological memory is __________ after infection or vaccination. It needs to be maintain be repeated exposure to infectious virus. The memory response had an approximate half-life of between __ to __ years.

Answer 17

long-lived; 8; 15

Question 18

Antigen-specific memory B cells differ both quantatively and qualitatively from ________ cells.

B cell frequency : ___ fold increase.

Antibody affinity : ______ (higher/lower)

Isotypes : __, __, __

Answer 18

naïve B; 100; higher; Ig G,A,E

Question 19

Affinity maturation is a form of ____________ (somatic evolution) where B cells, using their surface antibodies (____), compete for limiting amounts of antigen. The B cell compete with each other and with free antibody produced by ___________. The B cells with the highest __________ will be able to bind to ______ and remain __________.

Answer 19

somatic selection; BCRs; plasma cells/plasmablasts; binding affinity; antigen; activated

Question 20

Long-lived Memory B cells have high _________ and high levels of ___ so they are efficient at acquiring _______ (signal 1) and ready to get ______ (signal 2)

Memory B cells have ___ on their surface so they can activate or participate in activation of ___ (memory) cells.

Answer 20

affinity antibody; MHC; antigens; T help

B7; TH2

Question 21

Naive T cells require contact with ____________ and the cytokines ___ and ____ for survival. Most activated T cells become effector T cells and are short-lived and die by __________. Or some are activated effector cells become long-lived memory cells that need cytokines ____ and ____ for survival.

Answer 21

MHC self peptides; IL-7; IL-15; apoptosis; IL-7; IL-15

Question 22

Memory T cells need ___________ to proliferate.

Answer 22

MHC self peptide

Question 23

Naive B cells either become _________ which eventually dies by ________ or become ___________.

Answer 23

plasma cells; apoptosis; memory B cells

Question 24

When antigens have both epitopes that were “seen” before and new epitopes, the memory responses to the epitopes seen before will _______ and there may be no ________ for new epitopes.

Answer 24

dominate; responses

Question 25

How do infectious organisms cause disease?

Answer 25

By evading the body’s initial immune defenses and triggering an adaptive immune response. When a pathogen breaches physical barriers, the adaptive immune system responds by recognizing and targeting specific antigens on the pathogen. During this process, B and T cells are activated to produce antibodies and cytotoxic cells that neutralize or destroy the invaders. Following the resolution of infection, most effector cells die, but memory cells remain, providing long-term immunity and a faster, more efficient response if the same pathogen is encountered again.

Question 26

What is the result of an immune response?(4)

Answer 26

There are no pathogens remaining.
Sometimes, the infection is contained but not eliminated.
Sometimes the pathogen or immune response (or both) leave significant tissue damage.
Often long-life journey.

Question 27

What governs whether a Th0 differentiates into TH1 or TH2?

Answer 27

Pathogens influence the cytokines.

Question 28

Differential expression of adhesion molecules can direct what?

Answer 28

Different subsets of effector T cells to specific sites: the selective expression of different homing receptors that bind to tissue-specific addressins (P-selectin)

Question 29

What is affinity maturation?

Answer 29

A form of somatic selection where B cells compete for limiting amounts of antigen to bind to and remain activated.

Question 30

What 2 components does protective immunity consist of?

Answer 30

Preformed immune reactants : Abs, effector T cells
Long-lived immunological memory

Question 31

Give a way CD8 cells that can be activated in the absence of CD4 cells.

Answer 31

Activated by dendritic cells.