Lecture 15: Overview of the Immune System PDF

Week 1 Tue 10th Sept Lecture Module Introduction Week 2 Mon 16th Sept Lecture 1 Use of mammalian cells Tue 17th Sept Lecture 2 Cell Culture Laboratory Lab layout, Equipment and Materials Week 3 Mon 23rd Sept Lecture 3 Contamination control...

Week 1 Tue 10th Sept Lecture Module Introduction Week 2 Mon 16th Sept Lecture 1 Use of mammalian cells Tue 17th Sept Lecture 2 Cell Culture Laboratory Lab layout, Equipment and Materials Week 3 Mon 23rd Sept Lecture 3 Contamination control Tue 24th Sept Lecture 4 Contamination control Week 4 Mon 30th Sept Lecture 5 Contamination control Tue 01st Oct Lecture 2, 3, 4 and 5 recap and sample assessment questions Week 5 Mon 07th Oct Lecture 6 Nutrient uptake Tue 08th Oct Lecture 7 Nutrient uptake and sample assessment questions Week 6 Mon 14th Oct Lecture 8 Biology of Culture Cells Tue 15th Oct Lecture 9 Cell culture media Week 7 Mon 21st Oct Lecture 10 Cell culture media postponed Tue 22nd Oct Lab 3 data analysis Reading Week Week 8 Mon 04thNov Lecture 10 Cell culture media Tue 05 Nov th Lecture 11 Cell Culture Media Week 9 Mon 11th Nov Lecture 12 Growing mammalian cells Tue 12th Nov Lecture 8, 9, 10 and 11 recap and sample assessment questions Week 10 Mon 18th Nov Lecture 13 Monitoring growth Tue 19th Nov Lecture 14 Cryopreservation of cells and Lecture 12, 13 and 14 recap and sample assessment questions Week 11 Mon 25th Nov Lecture 15 Innate immune response Tue 26th Nov Lecture 16 Adaptive immune response & Bioassays Lecture 15 and 16 recap and sample assessment questions Week 12 Mon 02nd Dec Revision Tue 03rd Dec  Overview of the Immune System Lecture Overview Introduction: Why discuss this topic Main discussion: Innate Immune System Conclusion: Take home message BIOT6012 Mammalian Biotechnology Lecture 15 Slide 2  Overview of the Immune System Introduction Bioassays: Analytical method to determine concentration or potency of a substance by its effect on living cells or tissues. The role of drugs or bioactive peptides often involves mimicking (e.g. monoclonal antibodies) or stimulating components (e.g. interleukins) of the immune system. Useful to have a basic knowledge of the immune system. BIOT6012 Mammalian Biotechnology Lecture 15 Slide 3  Overview of the Immune System What is immunity Study of how the host Protects against disease Study of the Cells of the Immune System and how they react to foreign substances BIOT6012 Mammalian Biotechnology Lecture 15 Slide 4  Overview of the Immune System Lecture 15 Lecture 16 Immune System No time lag Time lag Innate Adaptive Not antigen Antigen specific (Nonspecific) (Specific) specific 1o line of defence 2o line of defence No memory Interactions between the two systems Development of memory BIOT6012 Mammalian Biotechnology Lecture 15 Slide 5  Overview of the Immune System A typical Immune Response INNATE IMMUNITY ACQUIRED IMMUNITY Rapid responses to a Slower responses to broad range of microbes specific microbes External defences Internal defences Skin Phagocytic cells Humoral response (antibodies) Mucous membranes Antimicrobial proteins Secretions Inflammatory response Invading Cell-mediated microbes Natural killer cells response (pathogens) Complement (cytotoxic lymphocytes) BIOT6012 Mammalian Biotechnology Lecture 15 Slide 6  Overview of the Immune System The Innate Immune System – Key Features Also known as native immunity Fully functional even at birth i.e. in place before presence of infection Not specific to a particular pathogen Reacts to structure of microbes First line of defence Does not differ on repeated exposure to pathogen Response is broad and rapid BIOT6012 Mammalian Biotechnology Lecture 15 Slide 7  Overview of the Immune System Innate Immune System External defences Internal defences Mechanical Cellular Chemical - neutrophils, natural killer Biological cells macrophages/monocytes, dendritic cells Extracellular - cytokines, complement, coagulation BIOT6012 Mammalian Biotechnology Lecture 15 Slide 8  Overview of the Immune System External Defences - Anatomical Barriers 1. Mechanical Factors Skin Respiratory Epithelium: Mucociliary escalator Flushing action: saliva, tears, urine As pathogens may 2. Chemical Factors enter the body via Antimicrobial peptides (found in sweat) breaches in HCL in the stomach barriers (i.e. cuts Lysozyme (found in tears / saliva) in skin) Internal 3. Biological Factors Defences are Normal Flora – microbes in many parts of the body required Normal Flora - > 1000 species of bacteria Competes with pathogens for nutrients and space BIOT6012 Mammalian Biotechnology Lecture 15 Slide 9  Overview of the Immune System External Defences - Anatomical Barriers Mucociliary escalator BIOT6012 Mammalian Biotechnology Lecture 15 Slide 10  Overview of the Immune System Internal Defences – Cellular and Extracellular Complement proteins Coagulation proteins Extracellular Cytokines Cellular - Neutrophils - Monocytes /macrophages - Natural Killer cells - Dendritic cells BIOT6012 Mammalian Biotechnology Lecture 15 Slide 11  Overview of the Immune System Internal Defences – Cellular Natural Killer Cells Dendritic cells Important part of the Antigen presenting cells innate immune system Messenger connecting the innate and Kill bacteria and virus adaptive immune responses infected cells and cancer cells Granules contain perforins and proteases Cellular Defences Neutrophils Phagocytosis (eat and Macrophages digest microbes) Phagocytosis of microbes in tissue Antigen presentation Inflammatory response Triggers inflammatory Antigen presentation response Kill 100s of bacteria BIOT6012 Mammalian Biotechnology Lecture 15 Slide 12  Overview of the Immune System Internal Defences –Extracellular Coagulation Proteins Mechanism to stop bleeding after injury to blood vessels Involved in Blood clotting, Inflammation, Apoptosis Pathogens and cytokines increase coagulation proteins which increases inflammation and increases Extracellular Defences apoptosis of infected cells Complement (C’) Proteins Circulating and membrane-associated proteins Cytokines always present in blood plasma Large group of proteins or Can directly induce inflammation (C3a and C5) glycoproteins Coating microbe with C3b which recruits and Secreted by cells of the immune encourages phagocytes system Forming membrane attack complex (C9) – a narrow Regulate and coordinate many of tube inserts into outer membrane of pathogens and the activities of cells of the innate kills them by lysis immunity BIOT6012 Mammalian Biotechnology Lecture 15 Slide 13  Overview of the Immune System Internal Defences –Extracellular Cytokines What cells of the innate immune system release cytokines? Neutrophils – when they encounter a pathogen Macrophages – when they encounter a pathogen NK cells - when they encounter a microbe infected cell or tumour cells Examples of cytokines Interferons (IFN) – discussed next Interleukins (IL) 1-37 - mostly secreted by T-lymphocytes and macrophages Tumour Necrosis Factor (TNF) - produced by macrophages and T- cells BIOT6012 Mammalian Biotechnology Lecture 15 Slide 14  Overview of the Immune System Internal Defences –Extracellular Cytokines Example: INTERFERON (IFN) Key anti-viral secreted proteins Produced by virus infected monocytes and lymphocytes Signal to neighbouring cells to protect them from virus infection IFN stimulates non-infected cells to produce proteins which inhibit virus replication Several IFNs – not all produced by the virus infected cells IFN α and β form part of the non-specific I.R. IFN γ produced by cells of the specific I.R. If we did not have IFNs – most of us may die of influenza virus infection BIOT6012 Mammalian Biotechnology Lecture 15 Slide 15  Overview of the Immune System INTERFERON (IFN) Pre-warned cells How does IFN warn neighbouring cells? inhibit the virus Virus infects Antiviral state neighbouring cells Virus infected cell releases IFN Antiviral state Antiviral state virus Antiviral state BIOT6012 Mammalian Biotechnology Lecture 15 Slide 16  Overview of the Immune System Conclusion Innate Immune System First line of defence – non-specific (same regardless of microbe) External defences - Mechanical - Chemical - Biological Internal Defences Cellular - neutrophils - natural killer cells - macrophages/monocytes Extracellular - cytokines - complement - coagulation BIOT6012 Mammalian Biotechnology Lecture 15 Slide 17