4.1.1.f+g Specific Immune Response

What is the specific immune response?

What is the specific immune response?

Response specific to one type of pathogen only, after it has entered the body. The response is antigen specific. This is to produce antibodies and provide long-term immunological protection and memory from the pathogen.

Where are T lymphocytes produced?

bone marrow

Where are T lymphocytes matured?

Thymus gland

What are the different types of T cells that T lymphocytes can differentiate to form?

T helper

T killer

T memory

T regulator

What is the function of the T helper cells?

- Release interleukins to stimulate the clonal expansion and differentiation of B lymphocytes

What is the function of the T killer cells?

- Attack and kill host-body cells that display the foreign antigen as they have been attacked.

- Uses perforin to make holes in the cell, causing it to burst.

What is the function of the T memory cells?

Remains in the blood for a long time to provide long-term immunological memory

What is the function of the T regulator cells?

Inhibits immune response after the pathogen has been successfully removed to prevent autoimmunity

Where are B lymphocytes produced?

Bone marrow

Where are B lymphocytes matured?

Bone marrow

What are the different types of B cells that B lymphocytes can differentiate to form?

B plasma

B memory

B effector

What is the function of the B plasma cells?

Produce and release antibodies

What is the function of the B memory cells?

Remain in the blood for a number of years and provide immunological memory as it remembers the same pathogen for faster antibody production in further infections

What is the function of the B effector cells?

Form plasma clones

What is clonal selection?

Activation of the specific B and T cells

How do macrophages use the cytokines produced to signal to other cells in the immune response?

- Release monokines

- Some monokines attract neutrophils by chemotaxis

- Some monokines stimulate B cells to differentiate and release antibodies

How do T helper cells and macrophages use the cytokines produced to signal to other cells in the immune response?

- Release interleukins to stimulate clonal expansion and differentiation of B and T lymphocytes

What is a further example of cell signalling via cytokines in the immune response?

- Many cells can release interferon

- Inhibits virus replication

- Stimulates activity of T killer cells

Explain the process of the cell-mediated immune response

1. Macrophage engulfs a pathogen by phagocytosis and displays the pathogen's antigen on its cell surface to form an antigen-presenting cell (APC)

2. The APC interacts with a specific T helper cell which causes it to release interleukin-1

3. The interleukin-1 stimulates the T helper cells to release interleukin-2 which stimulates the clonal expansion and differentiation of T killer cells

4. The T killer cells detect the antigen on the cell surface of the infected cell and produce perforin.

5. This forms holes in the cell and allows water to move into the cell, causing lysis of the cell.

6. Exposure to a specific antigen means T-memory cells are also produced

Explain the process of the humoral immune response

1. Macrophage engulfs a pathogen by phagocytosis and displays the pathogen's antigen on its cell surface to form an antigen-presenting cell (APC)

2. The APC interacts with a specific T helper cell which causes it to release interleukin-1

3. The interleukin-1 stimulates the T helper cells to release interleukin-2 which stimulates the clonal expansion and differentiation of B effector cells into B plasma cells

4. The plasma divide and produce many antigen-specific antibodies

5. The antibodies attach to the antigen of the pathogen and destroy it by neutralisation or agglutination

6. Exposure to a specific antigen means B-memory cells are also produced