INFECTIOUS DISEASES A

1 EJC H2 Biology T2W8 Infectious Diseases Part I Extension Topic A: Infectious Diseases (Part 1) 1. Introduction Immunology is the study of the body’s defence against infection at cellular and molecular levels. The following are the questions we would address in this topic: How does the body prevent pathogens from entering the body? When infection occurs, how does the body eliminate the pathogen? How does the body develop long -lasting immunity to many infectious diseases we encountered once before? 2. Learning Outcomes a. Describe the specific (adaptive) and non -specific (innate) immune systems including active and passive, natural and acquired immunity. b. Outline the roles of B lymphocytes, T lymphocytes, antigen -presenting cells and memory cells in specific primary and secondary immune responses. c. Explain the relationship of the molecular structure of antibodies to their functions, using IgG as an example. d. Explain how genetic recombination during development results in millions of different antibody molecules (including somatic recombination, hyper-mutation and class switching). 3. References Judith Owen, Jenni Punt, Sharon Stranford. Kuby Immunology, 7th Edition. Murphy KM, P Travers, M Walport (Eds.) Janeway’s Immunobiology. 8 th Edition. Pommerville, Jeffrey C. Alcamo’s Fundamentals of Microbiology: Body Systems.

2 EJC H2 Biology T2W8 Infectious Diseases Part I Contents 1. Introduction ............................................................................................................... 1 2. Learning Outcomes.................................................................................................... 1 3. References ................................................................................................................. 1 4. Pathogens, Antigens and Epitopes ............................................................................ 3 5. Overview of the Components of the Immune System .............................................. 3 6. Immune Response - Innate Immunity ...................................................................... 5 7. Antigen Presentation ................................................................................................. 8 8. Immune Response - Adaptive Immunity ................................................................. 10 a. Activation of T Cells & Role of T Cells in Adaptive Immunity ................................ 10 b. Activation of B Cells & Role of B cells in Adaptive Immunity ................................ 13 c. Antibodies (or Immunoglobulins) ................................ ................................ ........ 17 9. Mechanisms to Generate Huge Variety of Antibodies ............................................ 20 a. Somatic Recombination / V(D)J Recombination ................................ .................. 20 b. Somatic Hypermutation ................................ ..........