CSIM 1.12 Introduction to Immunology 1

Question 1

What are the types of immunodeficiency?

Answer 1

Primary immunodeficiency
• Congenital
Secondary immunodeficiency
• Caused by disease, drugs, or otherwise environment

Question 2

What are the features of the innate immune response?

Which cell mediates this and how?

Answer 2

White blood cells, most importantly macrophages and neutrophils, detect a foreign object and release chemical messengers which cause:
• Increased blood flow (red, hot)
• Increased vascular permeability (swelling)
• Stimulation of local nerves (pain)

Question 3

Where are macrophages and what do they do?

Answer 3

They are stationed in tissue

They sense foreign antigens using receptors and perform phagocytosis

Present antigens

Question 4

What is the benefit of increasing vascular permeability in an immune inflammatory response?

Answer 4

To allow and recruit more white blood cells into the area

Question 5

Name the granulocytes and their activated functions

Answer 5

Neutrophils
• Phagocytosis and activation of antibacterial mechanisms (contain receptors)

Eosinophils
• Killing of antiBODY-coated parasites (e.g. worms and helminths)

Basophils
• Circulating counterpart of tissue mast cells

Question 6

Which receptors do eosinophils carry?

Answer 6

They carry receptors for IgE, and are involved in the destruction of IgE-coated parasites

Question 7

What adverse role do eosinophils have?

Answer 7

Contributes to the response to allergens

Question 8

Which cells are activated in immediate hypersensitivity, and which receptor is this mediated by?

Answer 8

Basophils

IgE receptors

Question 9

Which cells are specialised types of phagocytes known as ‘mononuclear phagocytes’? What are their activated functions?

Which receptor is expressed by these cells?

Answer 9

Dendritic cells
• Antigen uptake and presentation in peripheral sites

Myeloid receptor CD14
• Acts as a recognition molecule for a range of bacterial envelope molecules

Question 10

Which antigens/particles do dendritic cells take up?

Answer 10

• Particulate antigens
  
  • Pieces of tissue
  • Senescent cells
  • Bacteria

Question 11

What are dendritic cells activated by?

Answer 11

• CD14 activation

* Cytokines from T-cells

Question 12

What is the main role of dendritic cells when not perpetuating an immune response

Answer 12

‘Clean up’ cells scavenging cell debris and senescent cells

Question 13

Where do dendritic cells come from?

Answer 13

Lymphoid AND myeloid progenitor calls of the bone marrow

Question 14

Which types of dendritic cells are the most efficient at presenting antigens to T-cells?

Answer 14

Langerhans cells

Tissue dendritic cells

Question 15

What are the main three types of lymphocytes?

Answer 15

• B cells
  
  • T cells
  • Natural killer cells

Question 16

Compare and contrast B and T lymphocytes in terms of cell origins and cell products

Answer 16

ORIGINS (this is where the B and T come from)
• B cells - arise in bone marrow
• T cells - arise in bone marrow but must mature in thymus

PRODUCTS
• B cells - produce antibodies and some cytokines
• T cells - produce cytokines (not antibodies)

Question 17

Natural killer cells are formed where?

Answer 17

The bone marrow

Question 18

What is meant by the ‘innate’ and ‘adaptive’ immunity

Answer 18

Innate Immunity:

As soon as something enters the immune system attacks by identifying foreign antigens

Adaptive Immunity:

Adaptive immunity refers to antigen-specific immune response. The antigen first must be processed. Once an antigen is recognised, immune cells specifically designed to attack that antigen proliferate. Adaptive immunity also includes “memory” making future responses more efficient.

Question 19

What do natural killers do?

Answer 19

Part of the innate immune response which are cytotoxic, produce cytokine and express immunoglobulin receptors

Question 20

Where are natural killer cells found?

Answer 20

• Spleen
  
  • Lymph nodes
  • Bone marrow

Question 21

What are complement proteins?

Answer 21

A series of proteins which:
  •  Activate inflammation
  •  Recruit phagocytes
  •  Pathogen opsonisation
  •  Lysis of pathogens (MAC)

Question 22

What are cytokines

Answer 22

Proteins produced by cells which induce a response by binding to cell receptors, can be AUTOcrine and paracrine