Immunology - Part 1

4PY019 Pharmacy Stage 1 Immunology- Part 1 Dr Abhishek Gupta Senior Lecturer Physiology and Pharmacology a.gupta@wlv.ac.uk Session Learning objective - Understand various cells associated with the immune system - Gain an overview of the immune system- innate immunity - Gain an insight into the inflammatory response including the role of chemical mediators The Immune system- Introduction • Pathogen: an organism that causes disease to its host – – – – – Virus- HIV, Influenza virus, Corona virus Bacteria- S aureus, P. aeruginosa, E. coli Protozoa- Plasmodium, Leishmania Fungi- Candida Helminths- Hookworm, Tapeworm • Antigen: the protein or polysaccharide found on the surface of a pathogen – A substance that induces a specific immune response – More appropriately called an immunogen • Foreignness • Immunogenic i.e. able to trigger an immune response • Reactive: Initiate antibody production to react The Immune system- Introduction • Immune response – Recognition • ‘Our own side’ is referred to as self, and everything else as non-self – Response • Disposal: kill or eliminate the threat from the invader • Communication: coordinate the activities of the various recognition and disposal elements Playfair, J and Bancroft, G., 2007 WBCs in immune response- Recap • Eosinophils: participate in damaging parasitic invaders like parasitic worms. 60-70% • Basophils: this contain secretory vesicles containing histamine and are realised during inflammation and infection. 1-4% • Neutrophils: They attract foreign antigens and engulf and destroy them (phagocytosis). 0-1% • Monocytes: immature cells for the first 24 hours, then become macrophages (in tissues) which engulf bacteria, dead cells and debris • Lymphocytes: two types B Lymphocytes and T Lymphocytes 20-30% 2-6% Source: Patton, K. 2020 Some Inflammatory cells and factors • • • • • • Neutrophils Monocytes Macrophages at tissue level Plasma Factor XII (Hageman Factor) Mast cells (also known as a mastocyte or a labrocyte) Dendritic cells https://tmsforacure.org/overview/ https://www.drugtargetreview.com/news/28263/impai red-dendritic-cancer/ Inflammatory mediators • • • • • • Histamine Prostaglandins Leukotrienes Bradykinins Cytokines Interferons Cytokines • A group of low molecular weight regulatory proteins secreted in response to stimuli • When secreted by lymphocytes- Lymphokines • When secreted by monocytes or macrophages- Monokines • Cytokines= Lymphokines + Monokines • Many cytokines referred to as Interleukins Production of blood cells- Recap Source: Spence and Mason, 1992 REC: Reticulo endothelial system https://www.brainkart.com/article/Immunity_26731/ Innate response • The innate immune system is nonspecific, meaning anything that is identified as foreign is a target for the innate immune response. • The innate immune system is activated by the presence of antigens and some of their properties. • The innate immune system includes: - Physical Barriers: such as skin, guts and eyelashes - Defence Mechanisms such as stomach acid, bile, bacteria in Gut and tears - General Immune Responses such as inflammation, complement and non-specific cellular responses. - The inflammatory response actively brings immune cells to the site of an infection by oedema Think about the inflammation and how and why this happens? Inflammatory response-I • Recognition of the antigen – Mast cells • Response: – Dilation of local blood vessels to increase blood supply to the affected area – Increase in permeability of capillary endothelium so that phagocytic blood cells can infiltrate to the affected tissue – Once these phagocytic cells arrive at the tissue, they help in disposal of pathogens • Phagocytosis – Communicate to attract and produce more immune cells Inflammatory response • Signs and symptoms – Inflammation – Elevated temperature – Redness – Pain – May cause fever References • • • • • • • • Kuby, J. (1997) Immunology. 3rd ed. Freeman and Company. Playfair, J. and Bancroft, G. (2007) Infection and Immunity. 3rd ed. Oxford University Press. Waugh, A. and Grant, A. (2014) Ross and Wilson Anatomy and Physiology in Health and Illness.12th ed. Edinburgh: Churchill Livingston Elsevier Moini, J. (2020) Anatomy and Physiology For Health Professionals. 3rd ed. Jones & Bartlett Learning Totorta, G. and Derrickson, B. (2011) Principles of Anatomy and Physiology. 13th ed. Wiley & Sons. Web links for extra reading (Optional): • Antibodieshttps://courses.lumenlearning.com/suny-mcc-biology2/chapter/antibodies/ • NET https://www.youtube.com/watch?v=TIFmtnSdolM Opsonisation: – https://www.ncbi.nlm.nih.gov/books/NBK534215/ – https://www.news-medical.net/life-sciences/Overview-of-Opsonization.aspx Membrane attack complex: – https://royalsocietypublishing.org/doi/10.1098/rstb.2016.0221 – https://www.youtube.com/watch?v=vH5l95hsi7U