Immunology 01 PDF

Immune Systems BIOL233W2 Prof HMG Lattorff SU1 | Introduction to the Immune System Lecture 1 | What is Immunology Lecture 2 | Different types of pathogens and diseases caused Lecture 3 | Overview of the Immune System Lecture 4 | Malfunctioning of the Immune System SU1 | Learni...

Immune Systems BIOL233W2 Prof HMG Lattorff SU1 | Introduction to the Immune System Lecture 1 | What is Immunology Lecture 2 | Different types of pathogens and diseases caused Lecture 3 | Overview of the Immune System Lecture 4 | Malfunctioning of the Immune System SU1 | Learning Outcomes Define & use the following terms correctly: Immunology Immune system Host Pathogen Vaccine Immunity Adaptive (acquired) immunity Innate immunity Natural immunity Artificial immunity SU1 | Immunology Immunology is a discipline of medicine/biology that studies the functioning of the immune system. Immune System is a complex network of cells, organs, molecules, and pathways that are interconnected and function together to provide protection against foreign substances/pathogens SU1 | Immune system Immune System is a complex network of cells, organs, molecules, and pathways that are interconnected and function together to provide protection against foreign substances/pathogens Main function is to protect the host against foreign substances or “invaders” Pathogens - living organisms, e.g., viruses, bacteria, parasites, or other microorganisms that can cause disease. These are also known as foreign substances. Foreign substances - Substances that are not of the host and/or can potentially harm the host, e.g., disease causing agents, cancer cells. SU1 | Immunity Immunity is the state of being insusceptible or resistant to a noxious agent or process, especially a pathogen or infectious disease. Immunity may occur naturally or be produced by prior exposure or immunization. SU1 | History of Immunology Prehistoric times disease was a punishment by gods for "bad deeds" or "evil thoughts" Classical Greek times Hippocrates (Father of medicine) attributed disease to imbalance in one of the four humors (blood, phlegm, yellow bile, or black bile) First written concept of immunity, 430 BC, the plague in Athens (Greece): caring for the sick was allowed for people who had Hippocrates, 460-370 BC recovered (survived) from the disease, as they were not attacked a second time SU1 | History of Immunology First immunotherapy 120 BC: induce active immunity for snake venom by drinking the blood of animals which fed on venomous snakes first clinical description of immunity 9th century, description of exposure to smallpox confers immunity (phrase immunity was not used) Miasma theory Until 19th century, belief that miasma, a noxious form of "bad air” caused disease like cholera or black death (plague) SU1 | History of Immunology Prevention of smallpox 1718, dried crusts made from smallpox pustules of patients inhaled or inserted into the skin (variolation) Smallpox “vaccine” Edward Jenner (1798), workers exposed to milder form of smallpox (cowpox) were immune to smallpox (severe form) à cowpox (milder form) pustules fluid injection protected against smallpox (severe form) Smallpox eradication 1980 WHO certified that smallpox eradicated (first and so far only disease to be completely eradicated) SU1 | History of Immunology Germ theory of disease Louis Pasteur showed that particles in the air spoil nutrient broth, not the air itself Louis Pasteur, 1822-1895 Pasteur developed several vaccines, attenuated microorganisms (Fowl cholera (1879), Anthrax (1881), Rabies (1885) – first human vaccine) Koch’s postulates Robert Koch published four criteria for establishing causality between specific microorganisms and diseases Robert Koch, 1843-1910 SU1 | History of Immunology Koch’s postulates 1. The microorganism must be found in abundance in all organisms with the disease but should not be found in healthy organisms. 2. The microorganism must be isolated from a diseased organism Robert Koch, 1843-1910 and grown in pure culture. 3. The cultured microorganism should cause disease when introduced into a healthy organism. 4. The microorganism must be re-isolated from the inoculated, diseased experimental host and identified as being identical to the original specific causative agent. SU1 | different types of immunity SU1 | different types of immunity SU1 | different types of immunity SU1 | different types of immunity SU1 | different types of immunity Innate immunity is present in all metazoans, immune responses: inflammatory responses and phagocytosis Adaptive immunity, involves advanced lymphatic cells which distinguish between specific "non-self" substances in the presence of "self" SU1 | different types of immunity Maternal passive immunity antibody-mediated immunity mother's antibodies (MatAb) passed through placenta to the fetus, occurs around 3rd month of gestation IgG only antibody isotype that can pass through placenta Passive immunity also provided through transfer of IgA antibodies in breast milk transferred to gut of nursing infant protecting against bacterial infections, until newborn can synthesize own antibodies SU1 | different types of immunity Naturally acquired active immunity as result of an infection person exposed to live pathogen à develops a primary immune response à leads to immunological memory disorders of immune system function can affect formation of active immunity, such as immunodeficiency (both acquired and congenital forms) and immunosuppression SU1 | different types of immunity SU1 | different types of immunity Artificially acquired passive immunity short-term immunization induced by transfer of antibodies can be administered in several forms; as human or animal blood plasma, as pooled human immunoglobulin for intravenous (IVIG) or intramuscular (IG) use, and in the form of monoclonal antibodies (MAb). Lasts for short period, does not help build immune memory SU1 | different types of immunity Artificially acquired active immunity induced by a vaccine, a substance that contains antigen vaccine stimulates a primary response against the antigen without causing symptoms of the disease SU1 | different types of immunity four types of traditional vaccines Inactivated vaccines composed of micro-organisms that have been killed with chemicals and/or heat and are no longer infectious, examples: flu, cholera, plague, hepatitis A, likely to require booster shots Live, attenuated vaccines composed of micro-organisms cultivated under conditions which disable their ability to induce disease, responses more durable, may require booster shots, examples yellow fever, measles, rubella, mumps. Toxoids inactivated toxic compounds from micro-organisms in cases where these (rather than the micro-organism itself) cause illness, examples tetanus and diphtheria. Subunit, recombinant, polysaccharide, and conjugate vaccines composed of small fragments or pieces from a pathogenic (disease-causing) organism, example: Hepatitis B virus SU1 | different types of immunity In addition, newer types of vaccines Outer Membrane Vesicle (OMV) vaccines contain outer membrane of bacterium without any of internal components or genetic material, stimulate immune response effective against the original bacteria without risk of an infection Genetic vaccines deliver nucleic acid coding for an antigen into host cells, which produce that antigen, stimulating an immune response, this category of vaccine includes DNA vaccines, RNA vaccines, and viral vector vaccines, difference is in the chemical form of nucleic acid and its delivery into host cells