BLS 342 1st Edition Lecture 1Outline of Last LectureI. Maturation of Immune CellsII. Cancer begins with Cell DamageIII. How Cancer DevelopsIV. Cancer CellsV. Growth Factors and CancerVI. Density Dependent Inhibition of GrowthVII. Anchorage Independent GrowthVIII.Telomeres and ImmortalityIX. Metastasis and AngiogenesisX. Cancer ProgressionOutline of Current LectureI. Evidence for Immune Reaction to TumorsII. How does Cancer Escape DetectionIII. Cancer VaccinesIV. Antibodies that Stimulate Cell KillingV. Conjugated AntibodiesVI. Antibodies that Block ReceptorsCurrent LectureEvidence for Immune Reaction to Tumors: your immune system is used to fightcancerCheck for tumors: if it isn’t there anymore that means that the immune system saw the tumor and destroyed it Some tumors regress unexpectedly There is an increased incidence of primary and secondary malignancies in immunodeficient patients-Immunodeficiency: a condition in which your body cannot produce enough of the substances or cells that it would normally produce to fight infection•There are T cells and antibodies floating around that are specific to the cancer•The young and the very old (lifetime exposure to hormones, your immunes system stats to shut down) have an increased occurrence of tumors— we can be immunized against tumors•If they are sitting at 1— their risk is a little higher than the general population. Anythingpast 1, they have a high instance of cancer and it correlates to being on the immunosuppressive drugs.How Does Cancer Escape Detection?Before the cell transformed and became cancer it was just a normal cell— your immune system is trained to not recognize our cells Tumor cells can look like normal cells— DNA starts to become mutated unless it starts to affect the protein because then it gets recognized If there is a different surface protein, the macrophage begins to recognize and destroy itCancers that don’t produce a strong immune response survive— the cancer cells that are best achieve the ability to hide from the immune system Weak or non-immunogenic cells survive and reproduce, however sometimesthe strong immunogenic cells can survive as well (cancer divides so quickly that it overwhelms the immune system and avoids being destroyed) Benign tumors can have a capsule as well as Malignant tumors (allows the tumor to keep growing)— cancer cells surround themselves with dense connective tissue that shields them from immune attack Some cancer cells produce molecules that destroy T cells—Cancer cells canshut off your immune systemElimination: immune system recognizes and destroys the cancer Equilibrium: when the cancer is mutating at a fast enough rate while your immune system is recognizing it and destroy them Escape: Arrows mean activation, curve arrows mean block (its secreting some protein messenger— cancer is block it and turning it off) Cancer cells rely on proteins from nearby healthy cells to hide from the immune system— cancer cells have blood vessels grow into itAntibodies recognize specific antigen, if they stick to a protein that has cancer it takes away the disguise and sticks to it— the macrophages come and destroy it Cancer cells produce proteins that suppress the immune system— new drugs that can suppress the suppressors are being tested• We can train T cells to recognize proteins that are linked to cancer cellsCancer Vaccines: Cancer cells + killer t cells + dendritic cells = trained immune cells that kill or shrink the cancerA few cancers cells are removed from the patient along with a few immune cells— the immune and cancer cells are cultured together The immune cells will take antigens from the cancer cells, they now recognize the cancer The immune cells are put back in the patient so they can recognize the tumor and alert the rest of the body We can produce anticancer antibodies in the lab:These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.•Antibodies have a nice y shape•The tips recognize the foreign protein•Macrophage, located at the other end recognize whenever a cell is coveredby antibodiesAntibodies that stimulate cell killing:These antibodies function by targeting proteins on the surface of cancer cells The antibodies themselves mark the cancer cell for destruction by the immune system Rituxan:specifically recognizes CD 20 proteinsDoesn’t distinguish between cancerous and noncancerous cells— it’ll cause the killing of all B cells in the system Allows the normal ones to come backConjugated Antibodies: this approach uses antibodies to target toxic molecules to the cancer cells•Antibody targets the cell and brings the radioactivity right to the cancer cell•An antibody has an amino protein attached to it and it causes the cancer cells to be recognized because they have escaped apoptosis-Radiolabelled: small radioactive particles attached-Chemolabelled: powerful chemotherapy drugs attached-Immunotoxins: cell toxins attachedAntibodies that Block receptors: these antibodies function is a blockade of growth signalTratuzumab: recognizes breast cancer cells that produce too much of the protein HER 2 (are ‘HER 2 positive)Breast cancer? : test to see if a woman has a higher than normal HER 2 protein If they are at a high risk of reoccurrence you can put them on Herceptin to try to prevent the reoccurrence
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