Primary Immune Response

Question 1

Describe the cellular response.

Answer 1

1. Cells with antigens on their surface bind to complementary receptor proteins on a specific helper T cell
2. Cytotoxic T cells are activated when Th cells release cytokines and are replicated by mitosis (clonal selection) and the detect antigens on infected body cells
3. Tc cells release perforin proteins which punch holes in infected cell membranes causing cell lysis
4. Memory T cells remain in circulation so that upon re entry of the pathogen they can react quicker.

Question 2

Describe the humoral response.

Answer 2

1. Cells with antigens on their surface bind to complementary receptor proteins on a specific helper T cell
2. This activates the Th cell which releases cytokines which activate B cells which reproduce by mitosis (clonal selection)
3. Plasma cells make and release monoclonal antibodies
4. monoclonal antibodies agglutinate pathogens by binding to complementary antigens (forming antigen-antibody complexes)
5. Immobilised pathogens and destroyed by phagocytosis
6. Memory B cells remain in circulation so that upon re entry of the pathogen they can react quicker.