Human Immune Response Cellular and biochemical processes that protect humans from the effects of foreign substances– usually microorganisms and their proteins

Driving Question: How can we explain the immune response in an applicable, familiar way?  Products:  “Cell Wars” Analogy: detailed visual analogy of immune response.  Presentation of Cell Wars Analogy.  Quiz: Tuesday, 4/5.

How do you know your immune response is working? Looks like Sounds like Feels like

What happens during the immune response?  Organism Feels sick/’crummy’: fever, tired, achy  Organ Systems Integumentary, Cardiovascular, Lymphatic, Endocrine  Cells Increased white blood cell (leukocyte) count  Biochemicals Production of immune response proteins – antibodies and inflammatory chemicals

Immune Response – Overview Barriers Mechanical Chemical Non- Specific Response Fever Inflammation Phagocytosis Specific Response Cell Mediated – T cells Humoral Mediated – B cells Memory/Immunity Recognize and Respond Prevent Remember

Results When the human immune response is activated the results include:  Disease symptoms  Allergies and allergic reactions  Acquired immunity from vaccinations  Autoimmune diseases (ie. lupus, ALS, rheumatoid arthritis, multiple sclerosis)  Organ and tissue rejection

Prevention  Barriers act to prevent pathogens from entering the body  Mechanical Barriers  Skin  Mucous membranes, hair, sweat  Chemical Barriers  Enzymes (various organs)  Tears  Saliva

Recognize  Immune system recognizes proteins as ‘self’ or ‘non-self’  Non-self proteins are called antigens and are found on the surface membranes of pathogens  Antigens associated with bacteria, fungi, viruses:  attract neutrophils to begin phagocytosis  provoke an immune response when identified by lymphocytes called helper T-cells

Response

Response - Non-Specific  Non–specific response = same response to any antigen  Response is fast, but inefficient

Response - Non-Specific  Inflammation  Histamine from basophils cause capillaries to dilate and neutrophils leak out to site of infection  Creates a barrier of proteins around infected site to help prevent spread to other tissues  Inflammatory Response Video Inflammatory Response Video

Response - Non-Specific  Fever  Chemicals produced by basophils and eosinophils increase metabolic rate and body temperature  Increased temperature:  increases production of neutrophils and the activity of phagocytes  slows bacterial growth and reproduction

Response - Non-Specific  Phagocytosis  Neutrophils become phagocytes and engulf/digest cells marked with non-self proteins  Monocytes become macrophages and engulf/digest cells marked with non-self proteins macrophage phagocyte

Response – Specific  Specific response is slower, but more efficient, than the non-specific response  Specific response = a response that is different for every antigen (ie. specific to that antigen)  Specific response is carried out by two types of lymphocytes  T-cells develop in thymus gland and do cell-mediated response  B- cells develop in bone marrow and do antibody-mediated response

Response – Specific  Cell-mediated response (T-cells)  Cells attacks cells that are abnormal – virus-infected; cancerous; organ transplants  Cytotoxic (killer) T cells – designed to kill cells infected with a specific non-self antigen  Killer T Cell Video Killer T Cell Video  Antibody-mediated response (B-cells)  Proteins attack extra-cellular antigens  B-cells become plasma cell which produce antibodies  Antibodies are proteins that bind/attach to a specific antigen

Response – Specific  Antibodies are special proteins that can bind to an antigen and mark it for destruction by other specific and nonspecific mechanisms

Response – Specific

Remember  Memory T and B cells remain dormant after 1 st infection  2 nd encounter initiates a response that is faster and stronger than the initial response  Results in ‘immunity’ and can be produced artificially by vaccination

Immune Response - Summary  Immune Response Video Immune Response Video  Immune Response Video Immune Response Video

Autoimmune Disorders

Allergies

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