Specific Immune Response

Question 1

What are the ways antibodies cause the death of the pathogen?

Answer 1

Opsonisation - antibody coats the pathogen to make it more recognisable by phagocytes

Neutralisation - antibody neutralise effects of toxins by binding to them

Agglutination - antibody clump microbes so its easier for phagocytosis

Lysis - antibodies break open bacterial cells.

Question 2

What happens in the T helper activation in the humoral response?

Answer 2

1. Bacterium is engulfed by a macrophage and presents its antigens and becomes an APC
2. T helper cell with a complimentary receptor binds with the APC macrophage
3. This activates the T helper cell and divides to form T memory cells and active T helper cells

Question 3

What happens in the effector stage and clonal selection in the humoral response?

Answer 3

1. A pathogen with a complimentary antigen binds to a B cell’s receptor and is engulfed by endocytosis by the B cell. Lymphocyte becomes an APC with antigens presented on MHC.
2. An activated T helper cell (from 1st stage) binds to the B cells antigens with its complimentary receptor (clonal selection) , causing T cell to release CYTOKINES
3. This stimulates the B cell to divide by mitosis to produce B memory cells for immunological memory , and plasma cells (secrete antibodies)

Question 4

What is the process of the cell mediated response

Answer 4

1. A pathogen is engulfed by a macrophageand its antigens become bound to the MHC, becoming an antigen presenting cell
2. A T killer cell with a complimentary receptor binds to the APC.
3. Activated T killer cell releases CYTOKINES which causes the T killer cell to divide/differentiate into ACTIVE T KILLER CELLS and T KILLER MEMORY CELLS.
4. The active T killer cell then binds to infected APC cells and releases chemicals that causes lysis killing the infected cell.

Question 5

What are the similarities/differences between the cell mediated and humoral response?

Answer 5

SIMILARITIES:
Both are specific to an antigen
Both require the formation of APC’s and an MHC
Both involve clonal selection (activated T helper/killer cells which regonise the antigen on APC)
Both involve differentiation of cells

DIFFERENCES:
Humoral response produces antibodies whereas cell mediated produces T killer cells
Cell mediated responds to specific antigens on infected cells and humoral reacts to antigens on foreign cells in bodily fluids