B Cells and T Cells - 11/12/23 Flashcards
What is a lymphocyte?
A type of WBC that is specific to a pathogen
What is a Self-Antigen?
An antigen that belongs to the body’s cells and isn’t foreign
What is an Antigen made of?
glycoprotein or glycolipid
How many lymphocytes are in the body? And what do they recognise?
- Over 10 million
- A different antigen shape
Why is foetal infection rare?
There is a physical barrier preventing blood mixing
What are properties of B lymphocytes? [2]
- It becomes mature in bone marrow
- Involved in humoural response - releasing antibodies into body fluids
Where does B-Lymphocytes mature?
Bone Marrow
What are properties of T-Lymphocyte cells? [2]
- It becomes mature in Thymus gland (moves to here from bone marrow)
- Involved in cell-mediated immunity involving body cells
Where do T-Lymphocytes mature?
In Thymus gland
Explain Cell Mediated Immunity. [2]
- When you respond to cells in own body that’s been infected by non-self pathogens (or cells from same species)
- Because the cells are genetically different - they have different antigens on cell surface
What are the different types of T-Cells?
- Killer T Cell
- Helper T Cell
- Memory T Cell
- Supressor T Cell
What do Killer T Cells do?
Destroy pathogen infected cells
What does Helper T Cells do? [2]
- Boosts immune response by:
- Stimulating B-Cells to make antibodies
- Activate killer T Cells to divide
What does Memory T Cell do?
Remembers antigen for protection in future infections
What are examples of the specific cells that T-Lymphocyte cells target?
- Phagocytes/macrophages that engulfed a pathogen then presented its antigen on cell membrane
- Body cells infected with virus that presents viral antigen on cell membrane
- Transplanted cell of same species with different antigens on membrane
- Cancer cells with unusual antigens on membrane
What do T-Lymphocytes specifically target on a cell?
Antigen
Why is T-Lymphocyte response a specific response?
Because each lymphocyte specifically recognises an individual pathogen
What are Cytokines, and what are they released by?
- Cytokines are chemical messengers that stimulate response in all T-cells
- They are released by Helper T Cell
Which cell in T-Cells can the B-Cell not work without?
The helper T cell
What does helper T cells alert to both T and B cells?
The prescence of a pathogen
What can memory cells help to do when exposed to a pathogen? [3]
- They can replicate themselves when exposed to an invading pathogen
- Remain in lymph nodes searching for pathogen
- Faster immune response
How are T-Cells activated?
- It has receptor proteins on surface which binds to complementary antigens
- This mean T-cell is activated
- It divides and produces clones
What happens in Cell Mediated Immunity? [4]
Helper T cells:
- Help B cells develop into plasma cells so they can secrete antibodies
- Help B cells develop into memory B cells
- Activate cytotoxic T cells
- Activate phagocyte
What are B cells covered with?
Antibodies
When the B cells binds to antigen by antibody, what does this form?
Antigen-Antibody Complex
What happWhat do Plasma cells do?
They release antibodies