Chapter 26 (cont f-08)

Chapter 26 (cont f-08) - Chapter 32 (cont.) Chapter Immune...

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Unformatted text preview: Chapter 32 (cont.) Chapter Immune System Fall 2008 Today we will Today Review B-cells & T-cells Structure of How attack Humoral immunity & cell-mediated Humoral immunity immunity Medical care and protection ? Immune sys malfunctions Review Review B-cells Bone marrow Form antibodies Proteins Proteins Y shaped shaped Attached Join w/specific antigens Join Antibodies attach to invaders in the Antibodies blood or extracellular fluid or lymph blood Macrophages engulf all Offspring: plasma cells & memory B Offspring: cells cells Plasma cell = antibody factory Plasma produce free antibodies produce Associated with HUMORAL IMMUNITY Review Review T-cells – Start development in bone Start marrow marrow – Fully develop in thymus Cytotoxic T-cells & Helper Tcells – Both have T-cell receptors T-cell Both aka antigen receptors aka antigen Always attached to cells – Cytotoxic T-cells attack infected cells attack Offspring: Offspring: – Memory Cytotoxic T-cells & – Memory Helper T-cells – Helper T cells Associated with Associated CELL-MEDIATED IMMUNITY CELL-MEDIATED B-cell Antibodies Antibody can ID foreign antigen Antibody When a microbe invades a B cell antibody already exists to fight it Therefore millions of different Therefore antibodies exist in body all of the time antibodies – BUT initially just a handful of any one type BUT just How possible? Antibody differentiation Antibody WE KNOW B-cells are formed in bone marrow from precursor (stem) cells An antibody is a protein and is part of a B-cell antibody Antibody differentiation Antibody B-cells are formed in bone marrow from precursor cells An antibody is a protein and is part of a B-cell The genetic code for making any protein is found in DNA for antibody protein, its the DNA in precursor cells An antibody protein is made from more than one gene Antibody differentiation Antibody B-cells are formed in bone marrow from precursor cells An antibody is a protein and is part of a B-cell The code for making any protein in found in DNA Thus the code for any given antibody comes from the DNA in precursor cells Genes making up antibodies are randomly selected Can form lots & lots & lots of different antibodies Antibody differentiation Antibody B-cells are formed in bone marrow from precursor cells An antibody is a protein and is part of a B-cell Like The code for making any protein in found in DNA an enzyme’s active site Each antigen binding site has Thus the code for any given antibody comes fromunique shape and charge the DNA in precursor cells Permits only particular antigens to fit Any Protein has code made up one or more genes. Genes making up antibodies are randomly selected Can form lots & lots & lots of different antibodies The immune system does not The design antibodies or T-cell design receptors expressly to bind to antigens on invading microbes it just makes lots & lots of it Different ones ones Antigens reside on the surface of microbes and are not considered to be a part of a microbe. A microbe can have different antigens attached to it. Why doesn’t your immune system destroy your cells? Why Your cell’s plasma membrane is Your uniquely tagged uniquely tagged Major Histocompatibility Complex (MHC) – Are proteins (glycoproteins) Why doesn’t your immune system destroy your cells? destroy And the answer is: And They try to T hey but When the embryo produces an immature B-cell having an antibody which identifies the antigens on its own cells as being the enemy, the body responds by destroying the immature B-cell carrying the antibody. HUMORAL IMMUNITY B-cells and antigens B-cells There are millions of different pre-existing antibodies in bloodstream/interstitial fluid p d a 1 11 BUT there are few of any given type @ z 1 HUMORAL IMMUNITY B-cells and antigens B-cells There are millions of different pre-existing antibodies in bloodstream/interstitial fluid * ** ** ** ** * * Remember, only a few of these antibodies initially made * An invader with a specific antigen enters bloodstream and binds to a specific antibody B-cell & Antigen Cont. B-cell It clones B-cell & Antigen Cont. B-cell Thus we now have many more antibodies that can bind to that specific antigen B-cells & Antigens Cont. B-cells These cloned cells now differentiate into plasma cells and memory B-cells A factory the plasma cells produce millions upon millions of antibodies which are released into the bloodstream Memory B-cells are also produced play a role in future immunity of body ALL WORK TOGETHER ALL ALL WORK TOGETHER ALL virus ALL WORK TOGETHER ALL virus ALL WORK TOGETHER ALL ecap Antibodies Destroy By: Antibodies Binding to invader and this action causes invader to become inactive and Free antibodies coating the surface of an Free invading cell rendering it inactive invading Clumping of invaders >> macrophage: Clumping endocytosis endocytosis Employing “complement system” Employing – A+A union attracts blood proteins to antibody stem; A+A this attracts phagocytes > destruction OR creates holes in plasma membrane > destruction holes Listen please Cytotoxic T-cells destroy by Cytotoxic After binding to an infected cell, the Cytotoxic T-cell secrete an enzyme which makes a hole in infected cells plasma membrane; the Cytotoxic T-cell then inserts other enzymes into the infected cell which initiate adverse chemical reactions, destroying the infected cell preventing the virus from reproducing Cytotoxic T-cells destroy by Cytotoxic a e ym nz E on ti c After binding to an infected cell, the cytotoxic T-cell secrete an enzyme which makes a hole in infected cells plasma membrane; the cytotoxic T-cell then inserts other enzymes into the infected cell which initiate adverse chemical reactions, destroying the infected cell preventing the virus from reproducing B & T Memory Cells Memory When memory cell senses reinvasion, they stimulate plasma cell formation, dumping oodles of antibodies into the bloodstream If we have memory cells, then why do we repeatedly suffer from colds and flu? Medicine and Immune Response Medicine Our immune system not invincible – Maybe overwhelmed by size of invasion – Maybe overcome by toxins – Maybe fooled – Invader mutates too fast Augmented by Antibiotics & Vaccinations Augmented Antibiotics Antibiotics Are drugs that retard the growth and multiplication of many invaders multiplication – penicillium Antibiotics Are drugs that retard the growth and multiplication of many invaders multiplication – penicillium – But NOT viruses HELP w/viral infections on the way Info only – neuraminidase inhibitors Block viruses from escaping host cell Antibiotics Are drugs that retard the growth and multiplication of many invaders multiplication – penicillium – But NOT viruses HELP w/viral infections on the way – neuraminidase inhibitors Block viruses from escaping host cell FUNCTION: Give body time to respond Problem: mutating microbe >> ineffective Problem: antibiotic antibiotic Vaccinations Vaccinations Defined as: injection/intake of weakened Defined or killed microbes to confer immunity or Do: causes body to react to an invasion; creates memory cells creates Vaccinations Vaccinations Defined as: injection/intake of weakened Defined or killed microbes to confer immunity or Do: causes body to react to an invasion; creates memory cells creates Jenner & cowpox (1796) Polio-diphtheria-typhoid fever-measlesplague-smallpox and cancer plague-smallpox cancer Immune System Malfunctions Mal 5 groups 1. 2. 3. 4. 5. Allergies Autoimmune diseases SCIDs Acquired immune deficiencies Cancers Cancers Allergies are immune responses to antigens that are not harmful harmful – Pollen, dust, mold spores, Pollen, bee stings, animal dander bee Many parasites enter Many same way so stopping response not good response runny nose; runny mucus secretion; sneezing; congestion congestion Autoimmune Diseases Autoimmune The body mounts an attack against a The particular cell type that it should recognize as “self” cell as Autoimmune Diseases Autoimmune The body mounts an attack against a particular The cell type that it should recognize as “self” cell cell Why? Why? – Not understood – Hypothesis: some invaders have antigens like our normal cells; some antibodies produced to combat invader then also attack “self” “self” Anemia-diabetes-MS-rheumatoid arthritis No known cure SCID SCID Severe Combined Immune Deficiency – Few or no immune cells are formed due to Few defective gene defective Therefore NO defense against infection SCID SCID Severe Combined Immune Deficiency – Few or no immune cells are formed due to Few defective gene defective Therefore NO defense against infection “bubble boy” SCID SCID Severe Combined Immune Deficiency – Few or no immune cells are formed due to defective Few gene gene Therefore NO defense against infection “bubble boy” Therapy Info only Remove bone marrow to culture dish Add virus w/needed gene attached All injected into bloodstream Virus infects cell and combines DNAs New cells now have “good” gene New Some able to have normal life Some AIDS AIDS Acquired Immune Deficiency Disease – Organism eventually cannot fight infection Destroys “helper T-cells” – In humans: Human Immunodeficiency Virus (HIV) Transmitted by – body fluids body Blood, semen, vaginal secretions, breast milk, needle Blood, sharing, blood transfusions sharing, – via direct contact w/broken skin or with mucus membranes Does not live long outside body – No cures: high rate of mutation but partially effective treatments Disable HIV Treat the infection e.g. cancer or pneumonia Cancer Cancer Cancer is a disease characterized by the unchecked growth of malignant malignant tumor cells tumor – Primarily a genetic problem but can be caused Primarily by viruses by Cancer Cancer Cancer is a disease characterized by the unchecked growth of malignant tumor cells malignant – Primarily a genetic problem but can be caused by viruses Tumor: a population of cells that is unregulated Tumor: population thus grows at an abnormal rate thus – Benign (polyp) – Malignant Malignant Cancer Cancer Cancer is a disease characterized by the unchecked growth of malignant malignant – Primarily a genetic problem but can be caused by viruses tumor cells Tumor: a population of cells that is unregulated thus grows at an abnormal rate Tumor: population – Benign (polyp) – Malignant Malignant Cancer cells form every day in body Cancer – NKC and Cytotoxic T-cells destroy MANY of NKC them them Destroy “self” cells??????????? – New proteins formed (as a result of unregulate growth) that New IDs cancer cell as “non-self” IDs Cancer Cancer Cancer is a disease characterized by the unchecked growth of malignant malignant – Primarily a genetic problem but can be caused by viruses tumor cells Tumor: a population of cells that is unregulated thus grows at an abnormal rate Tumor: population – Benign (polyp) – Malignant Malignant Cancer cells form every day in body Cancer – NKC and Cytotoxic T-cells destroy MANY of them Destroy “self” cells??????????? – New proteins formed (as a result of unregulate growth) that IDs cancer cell as “non-self” – Some produce no new antigens, are not attacked, and grow Some unchecked unchecked – Some mutate and are resistant to attack Treatments: radiation-chemotherapy-surgery Lecture test Monday Lecture and The BIG lab test also next week The BIG amen amen ...
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This note was uploaded on 06/02/2011 for the course BIOL 110 taught by Professor Duwel during the Fall '08 term at South Carolina.

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