Introduction to Immunology – PST05103 Pharmaceutical Microbiology
NTA Level 5 • Semester 1 • PST05103 Introduction to Immunology Pharmaceutical Microbiology • Source Session/Topic 45 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 45: Introduction to Immunology Total Session Time: 60 minutes Pre-requisites • Human anatomy and physiology Students Learning Tasks By the end of this session students are expected to be able to: • Explain e terms used in immunology and immunization • Describe types of immunity Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |5 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Presentation |Common Terminologies used in | | | | |Immunity | |3 |10 minutes |Presentation |The Immune System | |4 |25 minutes |Presentation |Types of Immunity | |5 |5 minutes |Presentation |Key Points | | 6|5 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing STEP 2: Common Terminologies Used in Immunology (10 minutes) • Immunity o Immunity is the ability of the body to defend itself against diseases • Immunology o Immunology is the study of immunity • Immune response o A response generated against a potential pathogen • Granulocytes o Are leukocytes that contain densely staining granules • Monocytes o Are small leukocytes that circulate in the blood • Phagocytosis o Is a process whereby cells of the immune system known as phagocytic cell e.g. a neutrophil, recognize, ingests and destroys a pathogen • Antigens o Are substances that are capable of stimulating the immune system to produce specific immune response against them • Antibodies o Are specific substances produced by the immune system in response to exposure to an antigen STEP 3: The Immune System (10 minutes) • The immune system is the system of specialized cells and organs that protect the body from diseases • The immune system functions to protect the body against bacterial and viral infections and destroy cancer cells and foreign substances • When the immune system is weakened, its ability to defend the body also weakens. This allows pathogens to grow and flourish in the body, and cause diseases • The immune system also performs surveillance of tumour cells, and immune suppression has been reported to increase the risk of certain types of cancer • The immune system protects the body from infection through various lines of defence. • The immune system is a complex system of structures and processes that work together to protect the body • The immune system is made up of two components derived from the central (bone marrow and thymus) and peripheral (spleen, lymph nodes and lymphatic channels, tonsils, adenoids, Peyer's patches, and appendix) lymphoid organs; o The molecular component ▪ This component uses specific and nonspecific molecules to protect the body against foreign substances and pathogens ▪ Molecules of the immune system; • Immunoglobulins • Lymphokines o The cellular components ▪ This component consists of immune cells that protect the body ▪ Cells of the immune system are white blood cells • Granulocytes • Lymphocytes • Monocytes • Macrophages STEP 4: Types of Immunity (25 minutes) • There are basically two types of immunity, innate immunity and acquired immunity • Innate immunity o It is an immunity that an individual is born with, it is pre- existing in the body o It is the first line of defence o It is non-specific and non-adaptive ▪ It produces the same responses for all potential pathogens o Innate immunity includes; ▪ Physicochemical barriers (e.g. skin, saliva, lysozymes etc.) • These physical barrier kills or prevent entry of pathogens ▪ Cells (e.g. macrophages, neutrophils, basophils, mast cells etc.) • These cells attack and kills foreign organisms and toxins ▪ Processes • Processes such as inflammatory reactions and phagocytosis limit spread of infection o These components protect the body for the first few days of an infection o Sometimes innate immunity is enough to clear the pathogen • Acquired immunity o This is the type of immunity that is not present at birth o It is the second line of defence which involves building up memory of encountered infections so can mount an enhanced response specific to the pathogen or foreign substance o Acquired immunity is adaptive o It involves ▪ Antibodies • which generally target foreign pathogens roaming free in the bloodstream ▪ T cells • which are directed especially towards pathogens that have colonised cells and can directly kill infected cells or help control the antibody response o Acquired immunity has two components; humoral immunity and cell- mediated immunity o Humoral immunity is mediated by antibodies while cell-mediated immunity is mediated by immune cells o Acquired immunity is either active or passive o Active acquired immunity; ▪ It is induced after contact with a foreign substance or pathogen (antigen) ▪ After exposure the body actively produces antibodies and immune cells that will fight against the pathogens ▪ Active acquired immunity is acquired either artificially e.g. by injection of antigen (e.g. vaccines) or naturally e.g. after a clinical or subclinical infection ▪ Advantage: • Produces long term immunity ▪ Disadvantages; • Slow onset of immunity • Requires prolonged contact with antigen o Passive acquired immunity ▪ Passive acquired immunity is naturally acquired from the mother or artificially produced e.g. by injection of an antibody containing preparation ▪ Advantage: • Immediate action ▪ Disadvantages • Short lived • Hypersensitivity reaction STEP 5: Key Points (5 minutes) • Immunity is the ability of the body to defend itself against invading pathogens or toxin • The immune system consists of innate and acquired components of the immunity • The innate component is pre-existing, comprised of physical barriers such as skin and mucous membrane together