Therapeutics and Immunology: Lecture 1: Principles of immunology

Question 1

What are the four disease categories

Answer 1

Transplantation

Autoimmunity

Activating the immune system

Controlling hypersensitivity reactions

Question 2

What are two main immunology core concepts

Answer 2

Innate immune system

Adaptive immune system

Question 3

What is the innate immune system and give examples of it

Answer 3

Body’s first line defence against pathogens
Specific innate microbial detection
Tissue and cellular injury- inflammation

Examples:
Barrier: skin and acid
Sequestration of nutrients
Lysozyme- anti microbial
Dendritic cells, macrophages and neutrophils

Question 4

What is acute inflammation

Answer 4

Innate response to cellular and tissue injury

Involves: PAIN, HEAT, REDNESS ANDS SWELLING

Question 5

What does PAMP stand for

Answer 5

Pathogen associated molecular patterns

Question 6

Describe what is the innate microbial recognition

Answer 6

Body can recognise pathogens such as bacterial cell wall component (gram negative, e.coli)

Familiar with any lethal contaminant in parenteral formulation

Question 7

What is the adaptive immune system and give examples of it

Answer 7

The immune systems memory capabilities of changing frequently and responding to antigens

Examples:
Lymphocyte responses
Expansion of specific T and B cells
Production of antibodies

Question 8

What is the Innate system recognition, specificity, when is it learnt and how

Answer 8

Recognition: Microbes, injury

Specificity: any time, always the same

When: evolutionary and time

How: many mechanisms

Question 9

What is the adaptive system recognition, specificity, when is it learnt and how

Answer 9

Recognition: Anything antigen with priming

Specificity: Memory of encounter

When: LIFE time

How: Antigen recognition

Question 10

What can the adaptive immune system learn to recognise

Answer 10

Any molecule but mainly:

Antibody and proteins (peptides) using T cell receptors

Question 11

How are structural regions recognised by antibodies, describe how

Answer 11

1. Variable regions bind to antigen via mixture of hydrophobic/hydrophillic, electrostatic, hydrogen bonding and van der waal interactions
2. Binding has high affinity and is stable
3. Examples: infectious agents to small organic molecules

Question 12

How are peptide antigens recognised by T cell receptor

Answer 12

An epitope (part of antigen) is recognised by T cell receptors but are often buried

Antigen must be first broken down into peptide fragments

Episode peptide binds to a self molecule known as a MHC (major histamine complex) molecule

T cell receptor binds to a complex of MHC molecule with the epitope peptide and proliferates to target this antigen

Question 13

What do T and B cells do

Answer 13

T- respond to peptides

B- produce antibodies

Question 14

How do lymphocytes recognise and bind to antigens

Answer 14

Using antibody molecule on surface of cell

Question 15

What are the three life stages of lymphocytes

Answer 15

1. Generation and selection
2. Priming, replication and clonal expansion
3. Effector Function

Question 16

Describe the generation of lymphocyte life stage process

Answer 16

Lymphocytes and other blood cells are derived from bone marrow cells but are totally unique

Genome is randomly rearranged to give them each a single antigen receptor

The lymphocytes are then selected for safe and effective function “tolerance”

Question 17

Describe how the lymphocyte learns what to respond to in the life stage process

Answer 17

Recognises one particular peptide in new viruses through the innate signals that activate dendritic cells

These dendritic cells present viral peptides on major histamine complex

Single T cell can replicate 20 or more rounds over 2-3 weeks

Question 18

Describe how the effector cells function in the life stage process

Answer 18

Large number of T effector cells produced after dendritic cells

These are helper and killer T cells

B cells are selected and a large number of them secrete antibodies

Question 19

What are the two mechanism of action of effector cells (antibody and T lymphocytes)

Answer 19

Antibody:
Binding and blocking
Histamine
Phagocytosis

T cell types:
Killers: direct killing of virally infected cells

Helpers: Cytokine release and inflammation, control B cell antibody responses

Question 20

What are the types of antibodies and their roles

Answer 20

IgG and IgA: can bind to toxins and inactivate them or directly block the viral infection

IgG and IgM: activates complement which can punch holes in bacterial cell walls

IgE: release of histamine

Question 21

What are the types of lymphocytes and their roles

Answer 21

CD8- direct killing of virally infected cells

CD4 helpers: trigger inflammation

Question 22

Explain the steps for the central role of a T helper cell

Answer 22

1. Antigen is bond by B cell antibody
2. B cell presents peptide derived from antigen
3. Peptide recognition by CD4 helper on B lymphocytes triggers activation signal to B cells
4. High levels of antibody against same antigen that peptide was derived from is produced

Question 23

What is the main response a dendritic cell can do

Answer 23

Show antigen peptides at specific concentration that can release and set off the immune system