Topic 10 Defense Against Infectious Disease

10.1 Types of Defense (4h)
Describe the process of clotting.
Limit this to the release of clotting factors from platelets and damaged cells resulting in the formation of thrombin. Thrombin catalyses the conversion of soluble fibrinogen into the fibrous protein fibrin which captures red blood cells.
Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity.
This is intended to be a simple interoduction to the complex topic of immunity. The idea of a polyclonal response can be introduced here.
Define active immunity, passive immunity, natural immunity and artificial immunity.
Active immunity -- immunity due to the production of antibodies by the organism itself after the body's defense mechanisms have been stimualted by invasion of foreign micro-organisms.
Passive immunity -- immunity due to the acquisition of antibodies from another organism in which active immunity has been stimulated, including via the placenta or in colostrum.
Natural immunity -- immunity due to infection.
Artificial immunity -- immunity due to inoculation with vaccine.
Explain antibody production.
Limit the explanation to antigen presentation by macrophages and activation of helper T-cells leading to activation of B-cells, which divide to form clones of anitbody secreting plasma cells and memory cells.
State that cytotoxic T-cells destroy cancer cells and body cells infected with viruses.
Describe the production of monoclonal antibodies; one use of them in diagnosis and one use in treatment.
Production should be limited to the fusion of tumour and B-cells and their subsequent proliferation and production of antibodies. Detection of antibodies to HIV is one example in diagnosis. Others are detection of a specific cardiac isoenzyme in suspected cases of heart attack and detection of HCG in pregnancy test kits. Examples of the use of these antibodies for treatment include targeting of cancer cells with drugs attached to monoclonal antibodies, emergency treatment of rabies or cancer, blood and tissue typing for transplant compatibility and purification of industrially made interferon.
Outline the principle of vaccination.
Emphasize the role of memory cells here. The primary and secondary responses can be clearly illustrated by a graph. Precise details of all the types of vaccine (attenuated virus, inactivated toxins, etc) for specific diseases are not required.
Discuss the benefits and dangers of vacciation against bacterial and viral infection, including the MMR vacine (combined measles/mumps/rubella) and two other examples.