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Unformatted text preview: Discussion = 20% Midterm 30% Final 50% Exams are open book, open note, essay format Graded on a curve improvement from midterm to final taken into account with final grade Discussion section graded on: Attendance (mandatory) Participation Homework (old exam problems) Today's lecture is an overview: Text is not required and will not be tested on. Lecture notes at course reader store plus the supplement also at CR store. Midterm 3 (100pt) questions Final 5 (100pt) questions Discussion: discuss lectures and do homework problems Just need to do it, but not necessarily correct Book won't really help, we don't ask what's in the notes. WE give you data sets and we interpret the data. Not memorization. Also, no computers. Class is graded on a curve. Reader is old exam questions. Important to do the homework. Introduction to immune systems. Innate immunity is acquired. Acidity prevents organisms from LR4 will recognize those. Oops lost some stuff. Innate response is characterized by...when you are exposed to a certain organism a second time, an innate response will be the same but the acquired will give you an enhanced response. The response would be much slower otherwise. The secondary immunity response is the hallmark of acquired immunity. Orgs less evolved than sharks don't have this. Only recognizes organic molecules. Must be able to differentiate different forms of non-self. Acquired can recognize the difference between staph and e. coli. Generated immunity, we're talking about a generated immunity. Every different bact, virus, etc gives a different immune response. This diveristy is: dif orgs, genetic changes - antigenic drift changes the coat proteins, B and T cells are lymphocytes. They have very specific receptors. The receptor on B cells is antibody molecules. You can find them on the cell surface or in secreted forms. T cells are much more refined. The receptor is only on the cell surface. It binds to other cells on your body. B cells can see bact in your blood, but a T cell can only recognize an antigen that is presented on your cells. History, DNM names. Do know Koch. Koch, took blood from guinea pig inoculated. Transfer blood to another guinea pig and it would protect. He identified soluble immune response. There were two main theory groups. Instructional theory learns to recognize a specific antigen (prolly not right). Selective, if antigen happens to recognize then good, if not, oh well. Side chain theory: starting to get correct. an agent binds to a side chain receptor on a cell. Release of recetpor, gets greater response of more receptors. The repertoire of Ab exists independently of antigens (pretty close to correct). Agent selects particular side chain it reacts with. Landsteiner: Ochemist. Synthesized organic molecules not in nature. Induced antibody responses. How can you have that many Ab to respond to that many Ag? Doubt on selective theories. Pauling said it's probably a blank. But it doesn't explain how it gets amplified response and how does it not recognize self versus self. Why is it intolerant to another organism. KNOW THIS! Clonal selection Only certain cells make Ab (B cells). Every one of these cells makes a different ab. Each cell produces Ab of a single specificity. Specificity is generated randomly. Any cell making self-reactive abs is eliminated. This theory was generated about Ab but also holds true to B cells. Cells react to antigen proliferate, you expand clones of B cells that are reacting. Then you get more of THAT cell. This explains memory response. Some cells become Ab producers (plasma cells). Other cells become long-lived memory cells. True for both B and T cells. Doesn't take in account for how it takes into account the diveristy. the Genes that make receptors is that code a lot of different proteins. They can recombine to make different genes. Depending on where you join, you'll make a different codon. Different junctional joining of gene segments create different genes. Somatic mutations also make more diverse Ab. Some proteins are aborted but sometimes they join up and make different proteins. It sets the immune system apart from much of the rest of the body. How is the immune system organized? generated from bone marrow stem cells. It's a blod generated immune system. Theere are lymphoid tissues, primary and secondary. Primary is where you generate lymphoid cells. Also the thymus (located above the heart). The generated lymphoid cells usually go to the secondary. the effectors of the immune system occur in secondary lymphoid tissue. Not a blood response, it's a tissue response. There are key cells. APC include Macrophages and dendritic cells. They recognize antigens and engulf them. Then they chop them up and present it. APCs allow T cells to respond. MHC lead to rejection in transplants. Without surface expression of the peptide, the T cell response would not occur. They also express soluble proteins called cytokines. They're also linked to the adaptive immunity. Effector community: T cells and B cells. B cells can bind to ag and pull it out of the system. It can neutralize viruses. They can help phagcytes engulf antigens. Important Ab can bind to Ag to complement and kill the bacteria. B cells don't react to bacteria. They only react to MHC molecules They come in two flavors, CD4 and CD8 T cells. You'll see a lot of CD 4, CD8, CD 10 etc. CD4 T cells respond to Ag by secreting cytokines. They are helper cells. CD8 cells are killer cells they will kill cells that have Ag on their surface. If CD8 sees a cell with a virus, it will kill the cell to prevent more viruses made or it can kill tumor cells. B cells help T cells become better killer cells. Clonal expansion diagram. Also general immune system structure. Cytokines = protein secreted by the cell. Not a hormone. Growth factors are a cytokine but not all cytokines are growth factors. Cells and organs of the immune system are connected by blood and lymph. Most widely distributed organ in the body. Different organs can talk to it via cytokines and receptors. Two basic aspects = antigen elimination and inflammation. White blod cells. Granuloctyes are WBCs. We won't really talk about RBCs and they just carry oxygen. Granulocytes have granules. Neutrophils are phagocytic and short-lived. Mast cells and basophils release soluble media. Monocytes and macrophages are WBCs but also APCs. There is also the Dcs that have wild processes that are found in the skin and mucous membranes. They contact the Ag and move to the lymph node and are important in getting the immune system going. They are not very specific. Antigen specific cells are the lymphoid cells. They are responsible for different antibodieis peptides. T cells are formed in the thymus. CD4 helper cells and CD8 killer cells. Lymphatic system is very thin walled vessels. If you have inflammation or you dong, fluiod can escape your circulatory system. You often get fluid coming out of the tissue. You NEED to have it go back into the circulatory system. Lymphatics do this. It gets picked up by theses inuses in the body that form larger ducts. As your muscles move, it pushes your lymphatic system to pump the fluid back into the circulatory system. Throughout this system are little lymphnodes. It's a new system to trap antigens back in your body. It screens your body continually. The organs that are important: bone marrow, thyums where T cells are made, spleen, tonsils and all over the body. The gut is the biggest lymphoid system because it's the nastiest place. Lymph node crosssection. It has a definitive architecture. It has cortex and paracortex and medulla. In the paracortex wis where your T cells. Fluid comes in from lyphattaics in the afferent lyphatic vessel. It leaves through the efferent lymphatic vessel. When an antigen comes through, it's treated like a filter. The antigens go through the B and T cells where the immune response is activated. These gerinal centers are where B cells are proliferating (clonal expansion). Bone marrow, is where teh stem cells are. There's more architecture. Some stem cells, B cells, plasma cells,. B cells are made here and often differentiate into plasma cells. A lot of the generation of the immune cells is in the bone marrow. Thyums is dark in a newborn and atrophies and gets fatty deposits in older people. Most of your immune cells are generated when you're younger. Spleen. It's a big lymph node. It removes old RBC and recycles the hemoglobbin. We just need to know it's a big lymph Gut: Gut associated lymphoid tissue (GALT). The villi are fingers which allows a lot of exposure for absorbing nutrients. You see lymphoid tissue of B and T cells organized under the villi. also M cells at the bottom of the crypt. That's where youg et your immune response. M cells like this: figure in book. Ag transoported by M cells activates B cells in follicle. B cells differentiate into IgA producing plasma cells Plasma cells mirate to submucosa an secrete IgA. We want to make secretable Ab. ...
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This note was uploaded on 12/31/2009 for the course MIMG 185 taught by Professor Zack during the Fall '06 term at UCLA.
- Fall '06