YIJC [H2] EXT A_Infectious Disease (N)(S)(vf)

1 2025 JC2 H2 BIOLOGY LECTURE NOTES EXTENSION TOPIC A: INFECTIOUS DISEASE Learning Outcomes: (a) describe the specific (adaptive) immune system, including active, passive, naturally acquired and artificially acquired immunity, and the non-specific (innate) immune system (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 immunoglobulin G, IgG, as an example (d) explain how somatic recombination, hyper -mutation and class switching result in millions of different antibody molecules (e) discuss how vaccination can control disease (including the eradication of small pox), limited to vaccination stimulates immunity without causing the disease and vaccination of a high enough proportion of the population can break the disease transmission cycle (f) discuss the benefits and risks of vaccination (g) explain how viruses, including influenza virus and HIV, cause diseases in humans through the disruption of host tissue and functions (including HIV and helper T cells, influenza virus and epithelial cells of the respiratory tract) (h) explain the mode of transmission and infection of bacterial pathogens, using Mycobacterium tuberculosis as an example (i) describe the modes of action of antibiotics, including penicillin, on bacteria References: 1. Peter Wood, Understanding Immunology, 3rd Edition: • Chapters 1 – 10 & 14 2. Campbell & Reece, Biology, 11th Edition: • Chapter : Viruses, Pg. 427 – 439 (or corresponding chapter in previous editions) 3. Janeway, et. al., Immunobiology, 6th Edition: 4. Alberts et. Al., Molecular Biology of the Cell, 4th Edition • Chapter 24: The Adaptive Immune System, Pg. 1363 – 1420 Note: Some of these textbooks are available in our library. You may wish to borrow them to supplement your reading when necessary. H2

2 LECTURE OVERVIEW 1) Introduction 3 1.1 Pathogens 4 1.2 The Immune System 5 2) Immune Response 8 2.1 Innate Immunity (Non-Specific) 2.1.1 First Line of Defence: Barriers to Infection 2.1.2 Second Line of Defence: Cellular Defence 2.2 Antigen Presentation 2.3 Adaptive Immunity (Specific) 2.3.1 Cell-Mediated Immunity 2.3.2 Humoral Immunity 11 12 12 17 19 24 28 3) Antibodies 32 3.1 Structure and Function of Antibodies 32 3.2 Generation of Antibody Diversity 36 4) Immunological Memory 40 5) Human Health and Diseases 45 5.1 Viral Diseases 5.1.1 How Influenza Infections Cause Diseases 5.1.2 How HIV Infections Cause Diseases 5.2 Bacterial Diseases (Tuberculosis) 45 47 48 50 6) Medical Interventions 53 6.1 Antibiotics 6.1.1 Inhibition of Protein Synthesis 6.1.2 Inhibition of Nucleic Acid Synthesis 6.1.3 Inhibition of Cell Wall Synthesis 53 54 55 55 6.2 Vaccination 6.2.1 Immune Response 6.2.2 Benefits and