WK 1- INNATE AND ADAPTIVE IMMUNE RESPONSES

Question 1

What is innate immunity

Answer 1

Non specific immune response and present before presence of a pathogen, immune response generated is always the same (despite the pathogen), involves barriers such as physical barriers (skin and mucous), cellular responses and soluble mediators (cytokines, complements, kinins)

Question 2

What is adaptive immunity

Answer 2

Involves formation of antibodies-> is a delayed response, is leukocytes driven and specific to the invading pathogen

Question 3

What does immunogenic mean

Answer 3

Any molecule that on its own can elicit an adaptive immune response

Question 4

What cells are involved in innate immunity

Answer 4

innate lymphoid cells, monocytes, macrophages, natural killer cells, mast cells, dendritic cells, neutrophils

Question 5

What cells are involved in adaptive immunity

Answer 5

leukocytes, mast cells, T cells, dendritic cells, B cells

Question 6

What are antigen presenting cells

Answer 6

aka accessory cells-> take antigen from pathogen and display it with MHC on their surface. Include cells like macrophages, DC and NK cells

Question 7

What is a PAMP

Answer 7

Pathogen associated molecular pattern-> are molecules that a cell possesses, such as lipopolysaccharides and DNA/RNA, that identify a pathogen as being foreign, allowing it to be attacked by the body. They are not found on eukaryotic cells (self-cells)

Question 8

What is a DAMP

Answer 8

Danger associated molecular pattern-> include things such as acidity and toxic molecules, that are released by the body during trauma and can trigger an immune response, just like PAMP

Question 9

What is PRR

Answer 9

Pathogen recognition receptors-> are receptors that a sensor cell possesses (macrophages, DC, mast cells) or that is secreted, that recognise PAMPs and turn on genes associated with inflammation and immune response
(inflammation will aid in removal of the pathogen)

Question 10

What are the 3 types of PRR

Answer 10

1. Extracellular
2. Intracellular
3. Secreted

Question 11

What are examples of extracellular PRRs

Answer 11

1. Manos and Scavenger receptors; cause phagocytosis of pathogen and lysozomal degradation
2. Toll-Like receptors (TLR4); pathogen will bind to the receptor and cause signals to be sent to the nucleus causing release of cytokines (IL-1, IL-6, TNFa), chemokines and interferons that will aid in killing pathogen

Question 12

What are examples of intracellular PRRs

Answer 12

1. NOD receptors; when pathogen binds inside cell it will trigger release of cytokines (such as TNFa, IL-1, IL-6) which cause inflammation and destruction of pathogen, or they will trigger apoptosis

Question 13

What are examples of secreted PRRs

Answer 13

1. Complements; secreted by the liver, when they interact with pathogens they will trigger the complementary cascade

Question 14

What is the complementary cascade

Answer 14

Is part of the innate immune system and involves soluble proteins travelling in blood in their inactive form-> when they bind to a pathogen they will become activated and cause the complementary cascade to occur and result in: opsonization, creation of membrane attack complex that cause the pathogen to lyse, and initiation of an immune response through recruiting immune cells

Question 15

What are the 3 pathways that form the complementary cascade

Answer 15

Classical, Lectin and Alternative pathways

Question 16

Describe the classical pathway of the complementary cascade

Answer 16

Plays a role in the adaptive immune response-> it is activated when antibodies bind to antigen of a pathogen

Question 17

Describe the lectin pathway of the complementary cascade

Answer 17

Initiated by mannos binding lectin protein binding to carbohydrates on the cell surface of a pathogen

Question 18

Describe the alternative pathway of the complementary cascade

Answer 18

Triggered by C3b directly binding to a pathogen

Question 19

What protein/complement factor do all 3 pathways converge on

Answer 19

C3b

Question 20

What is opsonisation

Answer 20

Process by which complement coats the outside of a cell surface of a pathogen, tagging it for phagocytosis

Question 21

What are 4 types of acute phase proteins

Answer 21

1) serum amyloid protein
2) C-reactive protein
3) fibrinogen
4) mannose binding lectin

Question 22

What cytokine acts on the liver to stimulate production of acute phase proteins

Answer 22

IL-6

Question 23

What are examples of primary lymphoid tissue

Answer 23

Thymus (T cells) and bone marrow (B cells)

Question 24

What are examples of secondary lymphoid tissue

Answer 24

Spleen, lymph nodes, MALT

Question 25

What are membrane attack complexes

Answer 25

groups of complement proteins create a hole in a pathogen, allowing for inward movement of fluid and for the pathogen to eventually lyse

Question 26

What is an opsonin

Answer 26

anything that can form a bridge between a phagocyte and a microbe–> allows for opsonisation
eg. C3b

Question 27

What are antigens

Answer 27

Surface markers present on all cells that allow the body to recognise them as being self or non-self–> antigens include blood grouping antigens (RhD, ABO), MHC and toxins

Question 28

What are antibodies

Answer 28

Are functional proteins that allow for the binding of antigens an complements. Antibodies can be found bound to a cell or in body fluids. Eg. IgM, IgA, IgE, IgD, IgG

Question 29

What do antibodies do

Answer 29

Antibodies bind to antigens and enhance the immune response through; preventing attachment of pathogens, enhancing phagocytosis, neutralising toxins