Immunology

Question 1

What are the two types of immunity?

Answer 1

Innate and adaptive

Question 2

Describe Innate/natural immunity.

Answer 2

Antigen independent - rapid
- 1st line - intact skin , mucous membranes, normal microbiota
- 2nd line - natural killer and phagocytic WBCs, inflammation, fever, antimicrobial substances
- No memory capacity

Question 3

Describe Adaptive/ acquired immunity.

Answer 3

Antigen Dependent - slower
- 3rd line - specialised lymphocytes, T and B cells, antibodies
- Memory capacity

Question 4

What are the molecular triggers of immunity?

Answer 4

• PAMPs containing LPS and dsRNA produced during viral infection.
• Cytokine production mobilises defence mechanisms - TNF, IL-1 &6 - inflammatory cytokines released in early response to bacterial infection.
• Cytokines initiates cell recruitment and local inflammation - development of fever.
• Dysregulated production of inflammatory cytokines in associated with inflammatory/auto-immune disease.

Question 5

What are the Pattern recognition receptors(PRRs)?

Answer 5

• TLR-Toll like receptors
• NLR - nucleotide-binding domain leucine rich
• RLR - RIG-I- like receptors
• CDS cytosolic DNA sensors

Question 6

What are PAMPs?

Answer 6

Pathogen associated molecular patterns
- Nucleic acid
- Proteins
- Cell wall lipids

Question 7

What are DAMPs?

Answer 7

Damage associated molecular patterns
Tissue damage and activate innate immunity
- Stress-induced proteins
- Crystals

Question 8

Describe PRR.

Answer 8

• Germ-line encoded the same in every cell
• Leukocytes express many types
• Recognise key patterns components

Question 9

Describe Lymphocyte receptors.

Answer 9

• Random modular design during development
• Each lymphocyte has many copies of one receptor and recognise almost anything.

Question 10

Describe how PRRs activate destruction process.

Answer 10

• Phagocytes, macrophages, neutrophils
• Innate immune response combats microbes by: recruiting phagocytes and leukocytes that destroy the microbes via inflammation and blocking viral replication or killing virus-infected.

Question 11

What are cytokines?

Answer 11

Small proteins released by cells that affect interactions and communications between cells and bind to cytokine receptors.

Question 12

What do cytokines regulate?

Answer 12

Innate and adaptive systems during inflammation.

Question 13

Describe the inflammatory response.

Answer 13

1. Bacteria and pathogens enter wound.
   2.Platelets release blood clotting proteins at wound site constriction.
2. Mast cells secrete factors mediating dilation and of blood vessels - delivery of blood, plasma and cells to wound increases.
3. Neutrophils secrete factors that kill and degrade pathogens
4. Neutrophils and macrophages remove pathogens by phagocytosis.
5. Macrophages secrete cytokines that attract immune cells to the site activating tissue repair cells.
6. Response continues until foreign material is eliminated and wound repaired.

Question 14

What is the process of adaptive immunity?

Answer 14

• Critical when innate is ineffective.
• There are 2 process - cell mediated and humoral response.
• Recognises specific ‘on self’ antigens.
• Develops an immunological memory to quickly eliminate a specific pathogen in future infections.

Question 15

What are the major cells included in adaptive immunity?

Answer 15

• APCs
• Antigen specific T cells
• B cells differentiate into plasma cells to produce antibodies.

Question 16

What are the two types of Lymphocytes (adaptive)?

Answer 16

T cells
- develop in bone marrow, mature in thymus - helper CD4+, Cytotoxic CD8+, regulatory
B cells
- develop in bone marrow
- produces antibodies - binds to target antigen on pathogen neutralising, labelling and killing it - IgM, IgG, IgE, IgA, IgD