Immunology 1.pdf

MLS department Subject: Immunology Topic: History of Immunology Date:9/9/2024 Helpful Advices Understanding the concepts is not optional Think, rather than memorize Test questions are based on concepts Ask questions Don’t wait until the last minute to study  Grading structu...

MLS department Subject: Immunology Topic: History of Immunology Date:9/9/2024 Helpful Advices Understanding the concepts is not optional Think, rather than memorize Test questions are based on concepts Ask questions Don’t wait until the last minute to study  Grading structure and Class conduct Your overall course grade (100), will be determined by a combination of your performance in the midterm, class activities, and the final exam. 1. Midterm and Class Activities: 50% This includes midterm exam, assignments, quizzes, and any other assessments conducted during the term. 2. Final Exam: 50% 3. Stay Focused: please keep your phones on silent and out of your sight during lectures. Learning Objective What's Immunity? Brief history of immunology The first vaccination What's the immune system? Main function of immune system The first written documentation on immune protection against infection came from the Greek author Thucydides'. In his book “The History of the Peloponnesian war” he describes that when typhoid fever raged through Athens in 430 BC, those who survived the disease could not become ill again. This was, in fact, the first description of the development of immunological memory by the adaptive immune system. Smallpox and Variolation Smallpox is an acute contagious disease caused by the variola virus, It was one of the most fatal diseases known to humanity and caused millions of deaths before it was eliminated. Variolation is the earliest method of vaccination. Material (usually scab or pus)from an infected person was collected and given to healthy person. Variolation of smallpox in ancient China (11 th century) Smallpox The First Vaccination Dr. Edward Jenner, who developed a cowpox-based vaccination against smallpox in 1796. He did this after his observation that milkmaids often developed cowpox - a mild smallpox-like disease but did not get infected by smallpox. So, he choose, the eight-year-old son (James) and made a few scratches on his arms and rubbed into them some material from one of the pocks on milkmaids' hand who caught cowpox. A few days later James became mildly ill with cowpox but was well again a week later. So, Jenner knew that cowpox could pass from person to person as well as from cow to person. Edward Jenner The next step was to test whether the cowpox would now protect the boy from smallpox? Jenner variolated the boy. As Jenner expected, James did not develop smallpox, either on this occasion or on the many subsequent ones when his immunity was tested again. But he did not invent vaccination! Cowpox  In 19th century, the field of modern Immunology was created and developed by Ilya Mechnikov and Paul Ehrlich who received the Nobel prize for medicine in 1908 “in recognition of their work on immunity”. Paul Ehrlich did an experiment in which he vaccinated pregnant mice with toxins and observed that their pups that did not get sick – but only when they were still being breastfed. He concluded therefore that breast milk can transfer immunity from mother to child. These scientific breakthroughs have laid the foundations of most of modern immunology. To understand immunity, we start with : Why? Where? When? Who? What?  Immunity? Immunity, is the ability to resist or eliminate potentially harmful internal and external threats (pathogens, cancer, debris).  Immune System The immune system is a complex network of organs, cells, and chemical signals distributed in blood and tissue throughout the human body, which regulates normal growth and development of the organism while protecting against disease. Why do we need an immune system for? For defend against external and internal threats wound repair and tissue clean up  External Threats 1.Animal fur 3.Bacteria 4.Virus 2.Environmental pollution  Internal Threats 2.Inflammation 1.Cancer  Where is the immune system located? Why? Where? When? Who? What? Where is the immune system located?  When do we get the immune system? Why? Where? When? Who? What?  When do we get the immune system? Immune system starts well before we actually born. and there are influences in the uterus.  Who has an immune system? Why? Where? When? Who? What?  Who has an immune system? We all have an immune system. All vertebrates have immune system, even invertible animals that don’t have back bone, have immune system too.  What are the key players of immune system? Why? Where? When? Who? What?  Key players of immune system? The immune system made of… - Cells - Organs - Tissues - Molecules which can - Identify threat (Identify) - Mount attack (React) - Eliminate pathogen (Regulate) - Remember ….In 10 days!  1. Recognize(Identify) An immune cell needs to be recognized when there is a threat. This involved being able to : - Distinguish between self & non-self - Recognize when self cells become cancerous and need to be destroyed. - Healing damaged tissue - Can receive chemicals ( cytokine, chemokines)from other cells that can influence its activity.  2. Mount(React) Deployment of effector functions which are specific to the type of threat at hand. - kill pathogens or infected cells - stimulation of wound healing - clearance of cellular debris - coordination of the immune response (cytokines, chemokines)signals  3.Regulate Although immune cells are very good at killing infectious organisms, they can also cause damage to self tissue, so immune cells need to be able to regulate themselves and each other to prevent an immune reaction from getting out of control. Before immune cells able to neutralize threat, they need to be “activated”. The activation can happen by receiving multiple signals from other immune cells, it requirements a system of checks and balances, ensuring that immune cell don’t accidentally become activated and cause unnecessary damage to host tissue.  4.Remember Immune cells called T and B lymphocytes (T cell & B cells), have the ability to remember specific threats. Homework! Please read about , Stem cell Phagocytosis