1. What is your immune System like? Write a sentence for each metaphor ....
starter

2. Big picture Immune system diseases Non specific immunity
Disease survival mechanisms
Physical & chemical barriers
Infectious Disease
Inflammatory
Transmission
Epidemiology
Non-specific Cellular response
Specific immunity
Vaccination
Public Health
Immunological surveillance
B cells
T cells
Clonal Selection theory
Big picture

3. Learning outcomes
Explain the role of lymphocytes, B cells in the immune system
Identify The need for immunological memory
Apply the Importance of primary and secondary responses

4. Specific (s) or non-specific (ns)
Third line of defence
Specific (only acts on particular pathogen)
First immunological surveillance occurs to find/ discover pathogen
Then clonal selection needs to occur to find the corresponding lymphocyte to combat the pathogen
Line of defence
Specific (s) or non-specific (ns)
Mechanism employed
Function
3rd S
Antibodies production from B cells from bone marrow
Make antibodies (humoral response)and are found in the lymphoid organs (except the thymus)
3rd S
Response by T cells from thymus gland
Cellular immunity but also with the regulation of the humoral response

5. B lymphocytes (b cells)
Lymphocytes respond specifically to antigens on foreign cells, cells infected by pathogens and toxins released by pathogens.
An antigen is a complex molecule – recognisable as self or foreign/ non-self
Antigen triggers production of antibodies
Antibody is a y-shaped molecule with a specific receptor (binding site)

6. Specific Immunity Antibody-Antigen Interaction
Antigen - any agent capable of eliciting an immune response
Isolated molecules
Molecules on surface of cell or virus *
A specific antibody molecule will be able to recognize a specific (epitope ) antigen
Antibody binds to antigen

7. B Cells Antigen-specific B cell receptor
National Cancer Institute
Understanding Cancer and Related Topics
Understanding the Immune System
B Cells
Antigen-specific B cell receptor
Class II MHC and processed antigen are displayed
Antigen
B cells work chiefly by secreting soluble substances known as antibodies. They mill around a lymph node, waiting for a macrophage to bring an antigen or for an invader such as a bacteria to arrive. When an antigen-specific antibody on a B cell matches up with an antigen, a remarkable transformation occurs.
The antigen binds to the antibody receptor, the B cell engulfs it, and, after a special helper T cell joins the action, the B cell becomes a large plasma cell factory that produces identical copies of specific antibody molecules at an astonishing pace--up to 10 million copies an hour.
Antibodies
B cell
Lymphokines
Plasma cell
Antigen-presenting
bacteria
Activated helper T cell
NCI Web site:

8. B Cell activation
B cells play three important roles in the immune response:
they produce antibodies in response to specific antigens
they perform the role of antigen-presenting cells
they develop into memory B cells.

9. B CELL ANTIBODIES
Each B cell can a produce a specific antibody that can recognise a specific antigen from a pathogen or toxin. The antibody will bind to the antigen, forming an antigen–antibody complex.
the antigen–antibody complex has two modes of action:
It may inactivate the pathogen/toxin (neutralisation), rendering it susceptible to phagocytosis.
It may stimulate a response, resulting in cell lysis.

10. Agglutination
Antibodies can cause microbes to stick together
This makes it easier for phagocytes to engulf them

11. Inactivate
Antibodies can bind to pathogen
Causing them to become inactive / rendering them harmless

12. Neutralisation
Some pathogens make us ill by producing toxins
Some antibodies work by neutralising these toxins

13. Stimulate cell lysis
The binding of an antibody to the surface of a pathogen can set of a chain reaction with blood proteins, which...
... causes the pathogen to swell up an burst.

14. Need a little help from my friends ....
B cells can identify specific antigens and present them to T cells.
T cells can then destroy the pathogen.

15. Signal 1 antigen & antigen receptor
* T Helper Cells
Signal 2 - T cell help Th Th B Y
1. T cell antigen receptor
2. Co-receptor (CD4)
Signal 1 antigen & antigen receptor
3.CD40 Ligand

16. More About T-Lymphocytes
Help the humoral response by involvement in the maturation of B cells and by triggering the production of antibodies by B-cells
Helper T-cells:
B-cell
Antigen
SIGNAL
Helper T-cell

17. Self vs. Non-self What would happen if your body was under attack?
Try this .....
ABO testing

18. ABO blood groups
Check out what happens if the blood are from different systems
Called tissue typing
Agglutination / clumping – blocking vessels eventually!

19. Clonal selection theory
The body has a large number of lymphocytes each with a single type of membrane receptor specific for one antigen.
When a receptor is activated by the binding of an antigen, the lymphocyte repeatedly divides resulting in a clonal population of lymphocytes.
Cell division

20. 5,5,1 Write 5 sentences to summarise the lesson
Now condense into 5 key terms
Now 1picture/image

21. Summary slide Specific defences Immune surveillance
A range of white blood cells constantly circulate monitoring the tissues.
If tissues become damaged or invaded, cells release cytokines which increase blood flow resulting in specific white blood cells accumulating at the site of infection or tissue damage.
Recognition of self and non self through specific surface proteins (antigens)
Lymphocytes respond specifically to antigens on foreign cells, cells infected by pathogens and toxins released by pathogens.

22. Summary slide
specific defences
B lymphocytes
Each B lymphocyte clone produces a specific antibody molecule that will recognise a specific antigen surface molecule on a pathogen or a toxin.
Antigen-antibody complexes may inactivate a pathogen or toxin or render it more susceptible to phagocytosis.
In other cases the antigen-antibody complex stimulates a response which results in cell lysis.
B lymphocytes activated by antigen presenting cells and T lymphocytes produce a clone of B lymphocytes that secrete antibodies into the lymph and blood where they make their way to the infected area.

23. Summary slide Specific defences Immunological memory cells
Some T and B lymphocytes produced in response to antigens by clonal selection survive long term as memory cells.
A secondary exposure to the same antigen rapidly gives rise to a new clone of lymphocytes producing a rapid and greater immunological response.