1. Unit 4 - Immunology and Public Health

2. Unit 4 – Immunology and Public Health
1. The Immune System
2. Infectious Diseases and immunity
Non-specific defences
Specific cellular defences
Transmission and control
Active Immunisation and Vaccination and the evasion of immune responses

3. By the end of this section you will be able to …..
1. The Immune System b) specific cellular defences
By the end of this section you will be able to …..
describe the role of T lymphocytes in recognising self and non-self
explain what is meant by an autoimmune disease in relation to lymphocyte regulation
state what is meant by the term ‘allergy’ and give examples of common allergic reactions

4. Decide if each card is TRUE or FALSE
Crohns disease, type 1 diabetes, Graves disease, psoriasis and rheumatoid arthritis are examples of autoimmune diseases.
Crohns disease, type 1 diabetes, Graves disease, psoriasis and rheumatoid arthritis are examples of autoimmune diseases.
Chicken pox, CJD, legionnaires’ disease and meningitis are examples of autoimmune diseases.
Chicken pox, CJD, legionnaires’ disease and meningitis are examples of autoimmune diseases.
An autoimmune disease is caused by an overactive immune response in which the body’s own cells are destroyed.
An autoimmune disease is caused by an overactive immune response in which the body’s own cells are destroyed.
Autoimmune diseases can be caught from close contact with infected people.
Autoimmune diseases can be caught from close contact with infected people.
The statements on the left are true. The statements on the right are false.
Creutzfeldt-Jakob disease (CJD) is a rare and fatal condition that affects the brain. It causes brain damage that worsens over time.
Treatment of autoimmune disease only serves to alleviate the symptoms, it does not cure the disease.
Treatment of autoimmune disease only serves to alleviate the symptoms, it does not cure the disease.
Autoimmune diseases can be easily cured with a combination of antibiotics and anti-viral drugs.
Autoimmune diseases can be easily cured with a combination of antibiotics and anti-viral drugs.
There is no known prevention for autoimmune disease.
There is no known prevention for autoimmune disease.
Children can be vaccinated against autoimmune diseases – this prevents them from getting ill in later life.
Children can be vaccinated against autoimmune diseases – this prevents them from getting ill in later life.

5. Rheumatoid arthritis
In rheumatoid arthritis, cytokines cause inflammation which will attack the bone and cartilage in joints, causing them to be replaced with fibrous tissue which leaves the joint less mobile than before.

6. Type 1 diabetes
Destruction of Beta cells

7. Graves disease

8. Psoriasis
skin condition that causes red, flaky, crusty patches of skin covered with silvery scales

9. Inflammation of the lining of the digestive system (IBD)
Crohns diseases

10. Multiple Sclerosis

12. Confusing self and non-self
T-lymphocytes have specific surface proteins that should be able to read the surface antigens of a cell and tell if it is self or non-self.
However, sometimes T-lymphocyte regulation can fail
T-lymphocytes fail to distinguish between the surface proteins of the body’s own cells and surface proteins on foreign cells and therefore attacks body cells.
The immune response against our own self cells is called autoimmunity.
Rheumatoid arthritis
Type 1 diabetes
Multiple sclerosis.

13. Confusing self and non-self

14. Allergies
B-lymphocytes sometimes over-react to harmless substances like dust, pollen and feathers etc. or even medicines such as penicillin.
The hypersensitive B-lymphocytes release antibodies which cause mast cells to release histamine.
Some allergies are so severe that they can trigger anaphylactic shock where the histamine causes such a huge drop in blood pressure it can be life threatening.

15. Can you now ….
describe the role of T lymphocytes in recognising self and non-self
explain what is meant by an autoimmune disease in relation to lymphocyte regulation
state what is meant by the term ‘allergy’ and give examples of common allergic reactions