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Introduction to & The Lymphoid system Objectives:

• To know the historical perspective of immunology • To be familiar with the basic terminology and definitions of immunology • Cells of Immunology - introduction • To understand types of immune responses : "Body Defenses Against Disease" 2nd Ed 1978 Encyclopaedia • To know about the lymphoid system Britannica Films

• To understand T and functions Your Immune System: Natural Born Killer - Crash Course #32

Videos to get you warmed up (^^) Edward jenner

• In 1798 Edward Jenner began the science of Immunology. After he noticed that Milkmaids who contracted cowpox (a mild disease) were subsequently immune to small pox.

• Louis Pasteur Introduced Weakened Virulence (attenuated: weakened, non-virulent strain whose exposure can confer resistance to disease.)

Louis Pasteur

Bacterial culture > Normal healthy chicken > No disease or death > produce IMMUNE chicken .

Fresh Bacterial ‘No culture ‘> IN IMMUNE chicken > Live chicken. Or > IN NORMAL chicken > Dead chicken.

Edward How we conquered the Louis Pasteur - deadly smallpox virus - Jenner Story Simona Zompi Mini Biography Basic terminology & Definitions of immunology

Immunoglobulin (Ig) or (Ag)

Noninfectious that Any substance that binds • Secreted from . induce reactions, specifically to a component of • Consist of a heavy or light most commonly IgE-mediated adaptive . polypeptide chain. type 1 reactions.

Immunology Immune Immunity Immune system Immune The study of mechanisms Refers to People survived Is the collection of cells, response that humans and other protection tissues and molecules ravages of epidemic animals use to defend The reaction of the against that function to defend diseases when faced their bodies from immune system . us against infectious with the same disease invading organisms such microbes (, against foreign again. as bacteria, viruses, Virus , parasite Fungus). substances. fungi, parasites or toxins Where & what are antigens? Immune system abnormalities

• (bacteria, Hypersensitivity due to viruses and parasites ) & exposure to Allergen. Susceptible to Allergen :non-infectious their related products by Antigen like virus, (, polysaccharides, antigens that induce bacteria, fungi and hypersensitivity reactions, lipids) parasite. • Environmental substances. most commonly IgE- • Drugs. mediated type I reactions • Organs (kidney transplant ) , tissues, cells.

Immunology - Disorders of the Immune deficiency Introduction to immune response Antibodies part 1

Antigens.... Types of immune responses: Innate and Adaptive. Humoral vs. Cell-Mediated Types of Immunity

Adaptive Innate Specific Nonspecific Response of an antigen specific B Shorter duration and T to an antigen Adaptive Innate Immunity Immunological memory No memory Immunity (Non Specific) “ recognition” (Specific) ,Natural

The cells of innate and adaptive immunity are recruited to sites of infection and injury, and activated to get rid of the infectious agents and Humeral Cell Mediated dead tissues. Immunity Immunity This process is called (B cells) (T cells) Phases of adaptive immune responses.

Overview of the Immune System

Clusters of differentiation (CD): A molecule with a CD designation has characteristic cell surface are often associated with cell’s function. (They are the Cellular markers for the cells)

Cell surface markers: CD3, CD4, CD8, CD19, CD28, CD16, CD56 9 Innate Immunity (Natural Immunity) Mediated by cells and proteins that fight against microbes. It has 4 major components:

Phagocytic leukocytes Natural Killer (NK) cell: Complement System: Epithelial barriers of ( and the skin, GI tract and ) ~Specialised in identifying ~The complement systems respiratory tract: ~Neutrophils respond rapidly to cells that are infected by consists of about foreign stimuli and injury. Their a virus or that have become 20 proteins in normal Prevent microbe entry. reaction is part of acute tumor cell. human . (Have to be breached for inflammation. a microbe to establish ~Macrophages are after ~They do this by looking for ~Synthesised mainly in function.. E.g. by cuts entering the tissue and are present changes in cell surfaces. If the . and burns) under epithelia, CT & in all natural killer cells find cells organs.This reaction is chronic with a changed surface, ~Heat labile i.e. it’s Immunology - Innate inflammation. they dissolve them using Immunity (Complement inactivated in 56C for System Overview) Macrophages also help to repair cytotoxins. 30 minutes. damaged tissue Note: Antigen+= complex, We add the complement in order to remove the complex

Complement Functions

4-Cell Lysis: 1-: 2-Opsonization: 3-: Dissolve the cell walls of Attracts other Enhancing Clustering & binding bacteria which leads to loss immune cells from of of pathogens of fluids & minerals and then death. the blood, such as: antigens together. Fight viruses directly by macrophages and destroying the virus’s neutrophils envelopes or indirectly by destroying cells infected by viruses. Adaptive Immunity (acquired immunity after exposure to antigens)

-Consists of highly speicialized cells which have the ability to destroy invading pathogen & toxic molecule. -Includes both: 1- 2-Cellular Immunity -Highly specific to a specific pathogen -Antigen is any substance that elicits the adaptive immune response.

-Mediated by T and B lymphocytes following exposure to specific antigen & characterised by immunological memory

-B-Lymphocytes secretes antibodies

-T-Lymphocytes secretes Immunology -

12 1- Humoral Immunity: (antibodies)

5-If the body is re-exposed to 1-The Humoral the antigen, immune 2-These cells 4--As this 3- B cells mature these memory B- response begins then undergo a response into plasma cells cells will with the process of clonal declines, a pool that secrete recognise the recognition of expansion and of memory cells antibodies antigen and antigens by naive differentiation. remain behind. respond much B cells more quickly and effectively.

*Antibodies are the effector products of humoral immunity. • Naive and their effector products make up the second branch of the adaptive immune 2- Cellular Immunity system • (T and B lymphocytes) T cells type: T-helper CD4 1 T-cytotoxic CD8 • is called into action against pathogens that overcome innate immune defences

Components of the adaptive immune system are normally silent; however, when activated, these components “adapt” to the presence of infectious agents by activating, proliferating, and creating potent mechanisms for neutralizing or eliminating the microbes.

14 Innate and Adaptive Innate vs Adaptive You can use this table to revise from once you Immune Systems Immunity finish studying both types of immuniy.

15 Cells of immune response are organized into 3 functional groups: • Lymphocytes: come from distinct lineage of stem cells and are responsible for the adaptive response

• Antigen presenting cells: are capable of bringing antigens to lymphocytes to initiate the adaptive response

• Effector cells: actually do the killing of microbes once an adaptive response is underway

16 Lymphatic System The Lymphatic System, Part 1 Lymphoid system provides suitable environment for development, maturation and proper functioning of cells of immune system Cells and organs of immune System lymphatic vessels Primary Lymphoid Organs circulating lymph Thymus Primary lymphoid Bone organs marrow Lymphatic system Spleen

Lymph nodes Secondary lymphatic Tonsils tissues MALT (Mucosa Associated Lymphoid)

Peyer’s patches Immunology T-cell Lymphoid cells intro (part 1/5) Lymphoid series comprise of two main populations T cells B cells T-Lymphocyte Differentiation • Originate in Bone Marrow migrate to Thymus for development • T cell precursors differentiate into mature T cells in thymus • Stem cells lack antigen receptors. • All T- Cells have CD3 as a cell marker. • T cell passage take place in thymus and differentiate into T cells expressing either markers (CD4 or CD8). • T-Helper cell CD3/CD4 Lymphoid system provides suitable environment for development, maturation and proper functioning of cells • T-Cytotoxic Cell CD3/CD8 of immune system T-Cells

T-Helper T-Cytotoxic CD3/CD4 (CD3/CD8)

About 35% of peripheral Perform cytotoxic T-Helper-1 T-Helper-2 blood T cells functions by killing:

Help CD8 cells Help macrophages Allograft cells virus-infected to become Help B cells Tumor (transplant) cells activated in cell mediated (CD20) to develop immunity during into antibody inflammatory producing plasma response cells B Lymphocyte Immunology - Adaptive Immunity (B cell , (CD20 or CD19) Hypermutation and Class Switching Overview)

Originate Display Found

• During • They display • Pre B cells: embryogenesis: Surface: found in Bone fetal liver • IgM Marrow • final • IgD • Mature B cells: destination: found Migrate to They both serve as an circulating Bone Marrow antigen receptor bloodstream * They do not require thymus for maturation One way to memorize Antibodies them: A person named Ig G.A.M.E.D a lot Immunoglobulins (Ig) are grouped into 5 classes: • IgG • IgM • IgA • IgD • IgE oIg are o They differ in size, amount of CHO and biologic functions after binding to specific antigens Immunology - Antibodies (Function)

Video 15 Ig Antibodies and Video 16 Antibody Immunoglobulin Function Immunoglobulin Immune Function Thank you! Girls Team: Boys Team: Noura AlTawil Ibrahim Al-Beeshi Nourah AlKharraz Abdulnasser Alwabel Kayan Kaaki Torki Alnaser Hissah AlMuzini Sara AlHussein Abdulelah Abukhalaf Nojood AlHaidari Nasser Almuqbil Farah Mendoza Majed Alasbali Atheer AlNashwan Faisal Alqahtani Ruba Alsaaran Munira AlSalman Mohammed Alfawaz Malak AlYahya

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