Module 3: The Immune Response

Question 1

Adaptive immune response stages

Answer 1

-antigen recognition
-lymphocyte activation
-elimination of pathogens or non-self perceived antigens
-apoptosis of immune cell
-establishment of immunological memory

Question 2

Antigen recognition

Answer 2

-after pathogen has entered body and evaded immune responses
-PAMPs are seen by antigen-presenting cells such as dendritic cells

Question 3

Lymphocyte activation

Answer 3

-requires series of cellular interactions which lead to T cell and B cell differentiation and clonal expansion

Question 4

Contraction

Answer 4

-once the pathogen is eliminated, the vast majority of activated lymphocytes undergo apoptosis, and the immune response gradually declines

Question 5

Memory

Answer 5

-the few adaptive immune cells that survive the contraction phase differentiate into memory cells, when re-exposed to the same antigen, there memory cells proliferate quickly to generate an immune response that is much faster and more robust than the first response to the pathogen

Question 6

Role of MHC molecules

Answer 6

-display antigenic peptides on the surface of cells, which can then be recognized by the TCR and its co-receptors

Question 7

Classification of MHC molecules

Answer 7

-MHC class I
-MHC class II

Question 8

Antigen presenting cells function

Answer 8

-t cells are not able to recognize extracellular pathogens by themselves so they require an intermediate to present them antigens

Question 9

Professional APCs

Answer 9

-macrophage
-b cell
-dendritic cells

Question 10

Non-professional APCs

Answer 10

-fibroblasts
-glial cells
-rarely needed for this specific function and normally only for a short period of time

Question 11

Antigen processing by the exogenous pathway steps

Answer 11

-engulfment
-proteolytic processing
-formation of MHC-antigen complex
-cell surface expression
-recognition by helper T cells

Question 12

Engulfment

Answer 12

-APCs engulf foreign antigens by endocytosis, forming a endosome

Question 13

Proteolytic processing

Answer 13

-foreign antigens inside endosome are broken down into fragments

Question 14

Formation of MHC-antigen complex

Answer 14

-vesicle fuses with vesicles containing MHC molecules, forming MHC-antigen complexes

Question 15

Cell surface expression

Answer 15

-MHC-antigen complex is transported to the plasma membrane, where it will be displayed on the surface of the cell

Question 16

Recognition by helper t-cell

Answer 16

-t cell receptor on surface of helped t-cell binds to the MHC-antigen complex on the cell surface of the APC, which will initiate an adaptive immune response

Question 17

Lymphocyte activation

Answer 17

-mediates efficiency of the specific immune response
-macrophages
-dendritic cells
-b-cells
-helper t cells
-cytotoxic t cells

Question 18

Cytokine networks

Answer 18

-balance humoral and cell-mediated immunity
-chemokines
-interleukins
-interferons
-tumor necrosis factor
-growth factors

Question 19

Steps of T cell dependent B cell activation signalling pathway

Answer 19

-peptide-MHC class II complex
-signal 1: TCR-peptide:MHC complex
-expression of co-stimulatory molecules
-signal 2: co-stimulation
-signal 3: cytokines
-outcome of 3 signals

Question 20

Immune synapse structure

Answer 20

-interaction between a T cell and APC

Question 21

Immune synapse function

Answer 21

-effective activation of T cell
-synapse holds signal proteins together to form stronger connection

Question 22

Memory B-cells

Answer 22

-memory occurs when there is a second encounter with an antigen

Question 23

Natural passive immunity

Answer 23

-acquired by fetus or newborn
-short lived immunity
-no immunological memory

Question 24

Artificial passive immunity

Answer 24

-acquired by injection of serum containing antibodies
-immunity is temporary
-no immunological memory

Question 25

Natural active immunity

Answer 25

-acquired through infection by a pathogen
-immunological memory has a significant chance of being developed

Question 26

Artificial active immunity

Answer 26

-acquired through vaccination
-no symptoms present
-immunological memory has a significant chance of being developed

Question 27

Clonal expansion

Answer 27

-production of large quantity of identical cells from the same original cell

Question 28

Interferons

Answer 28

-induce antiviral state by inhibiting replication of viruses

Question 29

Interleukins

Answer 29

-regulate immune and inflammatory responses by affecting proliferation and differentiation of immune cells

Question 30

Tumor necrosis factors

Answer 30

-implicated in tumor regression and systemic inflammation which can lead to septic shock

Question 31

Chemokines

Answer 31

-call in cells to the region of infection or injury and play a key role in inflammation, immune responses and hematopoiesis.

Question 32

Growth factors

Answer 32

-stimulate growth, proliferation, healing, and cellular differentiation

Question 33

MHC class 1

Answer 33

-on every cell except red blood cells
-bodies way of telling cells that everything is okay
-if cell is infected, the news will be displayed on MHC class 1

Question 34

MHC class 2

Answer 34

-on B cells, macrophages, dendritic cells etc
-bodies way of telling cells that something weird is floating around that needs to be attended to
-induces CD4 cells