Immune System Presented by Kazzandra Anton, Rhea Chung, Lea Sado, and Raymond Tanaka
Content Standards 35.1 In innate immunity, recognition and response rely on traits common to groups of pathogens 35.2 In adaptive immunity, receptors provide pathogen-specific recognition 35.3 Adaptive immunity defends against infection of body fluids and body cells
Immune System The body s defence system against infectious organisms and foreign invaders, such as: Pathogens - a bacterium, fungus, virus, or other disease causing agent. Foreign Molecules - molecules that aren t originated from the body (can be non-pathogenic)
Innate Immunity Non-Specific Immune Response Two types of Innate Defenses: 1. Barrier Defenses: Skin Mucous Secretions 2. Internal Defenses: Phagocytic Cells Natural Killer Cells Antimicrobial Proteins Inflammatory Response
Barrier Defenses Skin has thick layer of dead cells in the epidermis. Mucous: Mucous membranes lines the digestive, respiratory, urinary, and reproductive tracts It creates mucus, a fluid that traps pathogens and other particles Secretions from oil and sweat glands give human skin a ph level ranging from 3-5. This allows the surface of your skin to be acidic enough to prevent growth of a lot of bacteria
Internal Defenses Phagocytic cells rely on Toll-like Receptors or TLR s to recognize pathogens. These TLR s potentially trigger the internal innate system. TLR s recognize a molecular pattern characteristic of pathogens
Phagocytic Cells 1. Neutrophils Circulate in the Blood Attracted to infected tissues which they engulf and destroy 2. Macrophages Known as big eaters Also engulfs pathogenic cells They can be stationary or mobile in the body 3. Dendritic Cells Mainly populate tissues that contacts the environment Stimulates the adaptive immunity 4. Eosinophils Often found under epithelia Defends against multicellular organisms such as parasites
Natural Killer Cells (NK Cells) A type of lymphocyte. Roam around the body and search for virus infected and cancerous cells. Unlike macrophages, NK cells do not engulf the infected cells but instead releases a chemical that lead to cell death.
Antimicrobial Peptides & Proteins Pathogen recognition triggers production of varies peptides and proteins that attack the pathogen. Interferons are proteins that are secreted from infected cells to induce nearby cells to produce substances that inhibit viral replication.
Inflammatory Response Cytokines are released from activated macrophages and neutrophils Mast cells releases histamine to allow nearby blood vessels to dilate and become permeable. Phagocytes are then allowed to enter the injured site from the now permeable blood vessels and digest the pathogens.
Our bodies defence systems Adaptive Defenses
T-Cells (thymus)
T-Cells (thymus)
WHAT IS A B-CELL!? B-cell: Lymphocytes (white blood cell) that mature in bone marrow. Membrane-bound Antibodies: Also known as surface immunoglobulin.
Important B-Cell INFO A substance that activates a response from a T-cell or B-cell in considered an antigen. Antigen-binding site is where the antigen binds with the antigen receptor. Antigen binding sites are also variable regions. Variable regions differentiate as the B-cell matures in the bone marrow. When the B-cell is fully matured, it is completely different from other B-cells, making it easier to bind with different antigens.
B-cell activation 1. An antigen is detected by a B-cell antigen receptor via binding with the antigen s epitope, which is a small accessible portion of an antigen. In some cases, a helper T-cell is required to activate a B-cell.
Humoral Immune Response 1. B-cell binds with an antigen. 2. The B-cell begins to divide, making clones of itself. (clonal selection) 3. Cells divide into effector cells (plasma cells) or memory cells. Effector cells: Short-lived, help combat the antigen NOW! Memory cells: Lives for decades, prepared to fight off the same antigen if it were to reappear.
Immune Disorders Allergies: exaggerated (hypersensitive) responses to certain antigens called allergens Autoimmune Disease: when the immune system is active against particular molecules of the body Human Immunodeficiency Virus (HIV): when the body lacks one or more components of the immune system
Allergies Immunoglobulin E (IgE): proteins designed to attach to foreign substances to remove them from your body Anaphylactic Shock: severe, potentially life-threatening allergic reaction Treatment: Epinephrine auto injector
Autoimmune Disease What triggers the disease? Environmental Factors: Drugs Viruses Bacteria Food Pollutants Hormones Stress Genetic Factors: Gender Heritability Race There is NO DEFINITE CURE for Autoimmune Diseases but there are some treatments that include: Healthy diet Regular exercise Limited sun exposure Plenty of rest Vitamin supplements Drugs that reduce the immune response like Corticosteroids Medical intervention therapy hormone replacement blood transfusion if the blood is infected anti-inflammatory medication for joint problems immunosuppressive medication physical therapy
Common Autoimmune Disease There are over 100 known types of autoimmune diseases Rheumatoid Arthritis: chronic inflammation in the joints Lupus: inflammation caused by the immune system attacking the body s tissues and organs Crohn s Disease: inflammation of the bowel Psoriasis: rapid build up of skin cells causing scales and itchy, dry patches Multiple Sclerosis: the immune system attacks the protective covering of nerves Vasculitis: inflammation of the blood vessels
Human Immunodeficiency Virus There is no known cure but the infectee can receive treatment called antiretroviral therapy (ART) to slow the progress of the disease and prolong their life span