T Cells

Question 1

What are T cells?

Answer 1

White blood cells involved in the cell mediate response and it matured in the thymus (chest) but produced in bone marrow
It is specific as they respond to antigens on surface of antigen presenting cells

Question 2

What are APC?give 4 examples

Answer 2

Antigen presenting cell
Any cell that present a non self antigen on their surface

1-infected body cells will present with antigen on their surface
2-a macrophage will have these after having engulfed pathogen and destroyed it and it can be excreted out by exocytosis or will present on their surface
3-transplant organs have antigen which body sees as non self as it is foreign to the body
4-cancer cells will have abnormal antigen shapes which body doesn’t see as foreign because it is the body cells replicating uncontrollably.

Question 3

Why is it called cell mediated For the T cells?

Answer 3

T cells only respond to antigens which are presented on cells (APC),not produce antibodies and release them into body fluid which is what B cells do.

Question 4

Give the response of cell mediation

Answer 4

1-Once a pathogen has been engulfed/destroyed by phagocyte the antigen (APC)are the positioned in the SA macrophage (phagocyte)
2-helper T cells (type of T cells) have receptors which attach to the antigen of the APC
3-once attached the help them to be divide by mitosis to replicate and make a large number of clones to destroy infected cells in body
4-cloned helper T cells differentiate into different cells
Some may become:
-some stay as helper to cells and activate B lymphocytes
-stimulate macrophages to perform in phagocytosis
-some become cytotoxic T cells (killer T cells)
-memory Tc cells (helper cells) are produced and activated if antigen is encountered again.

Question 5

What are cytotoxic cells?

Answer 5

Cells which destroy abnormal or infected cells

Question 6

What do the cytotoxic cells do to destroy infect cells or abnormal ones?

Answer 6

The TCR and CD8 on the cytotoxic cell have a complementary shape to MHC and it release of a protein perforin which embeds in cell surface membrane and makes a pore(whole) In infected cell so that any substance can enter or leave cell cause cell death

Question 7

Why is the process of cytotoxic common in viral infections?

Answer 7

Because the viruses infect the body cells,body cells are sacrificed to prevent viral replication

Question 8

Why do you have a sore throat when you have a cold?

Answer 8

The cytotoxic T cells are destroying infected body cells in your throat