Q32

Criteria	Marks
Demonstrates an extensive understanding of the innate and adaptive immune response including phagocytosis, inflammatory response, stimulation and role of B and T cells; relates body’s responses to innate and adaptive immunity against H. pylori	7
Demonstrates a thorough understanding of the innate and adaptive immune response including phagocytosis, inflammatory response, stimulation and role of B and T cells	5–6
Demonstrates a sound understanding of the innate and adaptive immune response	3–4
Demonstrates some understanding of the immune response	2
Provides some relevant information	1

Sample answer:

Damaged cells cause chemicals to be released, causing inflammation. Dilation of blood vessels as a part of inflammatory response increases blood flow which facilitates movement of phagocytes including macrophages and neutrophils into the infected area. Phagocytes process bacterial antigens and present them to the helper T-cells which triggers the adaptive immune response through release of cytokines. This results in activation of T and B cells. Cytotoxic T-cells specific to H. pylori directly attack the bacteria while the memory T-cells stay in the system to induce a rapid secondary immune response. Suppressor T-cells help with the regulation of the immune response. Plasma B-cells produce antibodies specific to H. pylori while memory B-cells remain in the system for secondary immune response. The antibodies can neutralise the antigens directly or tag it for destruction by phagocytes.

Both innate and adaptive immune responses work together to eliminate H. pylori. Innate response is rapid and provides immediate defence against H. pylori whereas adaptive response is slow but provides lifelong immunity through specific memory cells.