B Elements of immune system

Question 1

What is an antigen

Answer 1

From antibody generation, an antigen is something that stimulates an immune response

Question 2

What are some examples of structures that can be antigens?

Answer 2

Proteins, polysaccharides, lipids, but also metals such as nickel

Question 3

What is immune tolerance?

Answer 3

Control mechanisms to stop the immune system from reacting towards the hosts own tissue

Question 4

What are the main differences between innate and adaptive immune system?

Answer 4

Fast, non-specific, no memory vs slow, highly specific, memory

Question 5

What are the precursor to all immune cells?

Answer 5

Hemopoietic stem cells

Question 6

Which lineages of immune cells is there?

Answer 6

Granulocyte progenitor and lymphoid progenitor

Question 7

Which are the granulocytes?

Answer 7

Eosinophils, basophils, neutrophils

Question 8

Where do production of all immune cells begin?

Answer 8

Bone marrow

Question 9

Bone marrow

Answer 9

Production of stem cells. B lymphocyte maturation

Question 10

Thymus

Answer 10

T-lymphocyte maturation

Question 11

Naïve cells

Answer 11

Mature cells that are not yet activated by contact with antigen

Question 12

Effector cells

Answer 12

Activated lymphocytes

Question 13

Basic structure of lymph node

Answer 13

Cortex, germinal centers, medulla

Question 14

Cortex (lymph node)

Answer 14

Aggregates of B-lymphocytes in follicles

Question 15

Germinal centers

Answer 15

Activated B-lymphocytes

Question 16

Paracortex

Answer 16

Surrounds the cortex, T-cells are here

Question 17

Medulla

Answer 17

Macrophages and plasma cells

Question 18

Plasma cells

Answer 18

Fully differentiated B-lymphocytes, have no BCR but only produce antibodies

Question 19

Name the immune cells of the innate immune system

Answer 19

Granulocytes (neutrophil, basophil, eosinophil), mast cells, compliment proteins, monocytes/macrophages, dendritic cells, NK cells

Question 20

Name the immune cells of the adaptive immune system

Answer 20

B-lymphocytes / plasma cells, T-lymphocytes (CD4+ T-cells/Helper T-cell & CD8+ T-cells / cytotoxic T-cell), NK cells

Question 21

Antigen presenting cells

Answer 21

Macrophages, dendritic cells, B-lymphocytes , (t-lymphocyte?)

Question 22

Basics of T-cell receptor (TCR)

Answer 22

Only recognize epitope from partially degraded proteins coupled to a MHC. One alpha chain and one beta chain. Also need a co-stimulatory signal from either CD4 or CD8, which also dictate which MHC class they can interact with

Question 23

Basics of B-cell receptor (BCR)

Answer 23

What later becomes the antibodies; when a BCR it has a transmembrane portion making it stick to the surface of B-lymphocytes. Two heavy chains and two light chains. One constant region and one variable; variable with CDRs decide which epitope it can bind to. Different amount of Fc depending on which subset.

Question 24

Humoral immunity

Answer 24

Antibody mediated immunity. Responds directly to microbes. B-lymphocytes responsible

Question 25

Cell-mediated immunity

Answer 25

Activation of T-lymphocytes by a cell from the innate immune system, by interacting with MHC class I or II

Question 26

How many types of antibodies are there in humans?

Answer 26

Five

Question 27

Basic structure of an antibody

Answer 27

2 heavy chains, 2 light chains. Variable regions which are the ones that bind to the epitope and vary. Constant regions are the same in the same type of antibody (i.e IgG all have the same c-region but different v-regions depending on target). Paratope that can bind to epitope

Question 28

Epitope

Answer 28

Small part of an antigen that the antibody recognize and bind to. Several different antibodies can recognize different epitopes on the same antigen.

Question 29

PRRs

Answer 29

Expressed by macrophages, neutrophils and DCs, recognize different conserved structures in pathogens known as PAMPs

Question 30

Cytokines

Answer 30

Proteins secreted from immune cells to communicate with other immune cells with the correct receptor.

Question 31

Chemokines

Answer 31

Attracts immune cells with correct receptor; move towards place with highest concentration of chemokine.

Question 32

Describe how an inflammation works.

Answer 32

Bacteria enter wound - macrophages recognize PAMPs with their PRRs Macrophages release cytokines and chemokines which causes vasodilation and increased adhesive properties for other immune cells and opens up epithelium slightly, making it possible to move into the tissue. Immune cells are attracted by chemokines and move to the area with bacteria, start eating them