BIOL 460 1st Edition Lecture 7 Outline of Last Lecture I. Allotype Outline of Current Lecture II.Rh factorIII. Ig A, Ig EIV. DegranulationCurrent LectureImmunology- Lecture 8: Nucleotide biosynthesis: When Rh (+) father and Rh(-) mother conceive a child that is Rh (+), ERYTHROBLASTOSIS FETALIS develops where the mother has made antibodies as a result of exposure to Rh (+) during the first delivery. The alpha Rh Ab have Ig G isotype and cross placenta. These already present antibodies during subsequent delivery (2nd child birth) can attack and destroy RBC of fetus. Ig A: found in abundance in external secretions such as- Mucus 5-15 g/day Saliva Tears Breast milk Sperm cellsAnimal sperm cells are more energy consuming and made only during mating season. 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.Ig A in breast milk is responsible for healthy infants in daycare centers. Mothers who are exposed produce Ab specific for the microbes in the daycare center. Breast milk fed child receives these Ab from the mother and are healthier than other children. This is partly due to Ig A in serum persists as a monomer whereas the secreted Ig A is a dimeric with secretory component with a J-chain in the center. During early development Ab can not through intestinal cell walls and needs protection. Ab made for environment made by the mother and passed onto the child through breast milk. Ig A as a dimer. In the epithelial cells there are poly receptors which bind to Ig A and promote phagocytosis and part of the receptor cleaved off.Ig A- on the surface. -binds to bacteria or virus. -attachment to viral or bacterial membranes are affected by Ig A.Ig E- found in low serum level. -also in hypersensitivity i.e. allergic reaction.Role- protection against intestinal parasites. As there are many parasites in III world countries, immune system is working and less sensitive to allergens.- exists as not a free form but on the surface of cells.- In basophils, there are membrane bound internal vesicles called granules that contain histamine.- Mast cells also have Ig E on its surface.Degranulations- granules are released when allergens sit on cells.Degranulation can be triggered by allergen crosslinks FcE receptors (epsilon receptors).Ab against Ab: Alpha Ig E crosslinks with anti Ig E and granulation occurs.papainAlpha Ig E --------------- Fab (Ig E bound as Ag) Fab No granulationSince Fab is not cross linked to Ig E, there are no granulation.Ig D: surface of resting mature B-lymphocytes. Idiotype or Ag specificity is identical. Both Ig M and Ig D have transmembrane domain in membrane bound form. Ig D leaves the plasm cells in pentameric form.In nature, polyclonal Ab formed.Nucleotide biosynthesis:1. Normal pathway- nucleotides synthesized.2. Salvage pathway- anabolic and catabolic pathways and intermesiate molecules used in synthesis.3. Needs enzymes- hypoxanthin,guanine, and phosphoitasyli transferase.4. Enzymes need precursors such as hypoxanthin and thymidine.1975- Milstein and Kohler – production of hydridomas.Myeloma cells lack enzyme for the salvage pathway.HAT- hypoxanthin, aminopoietin (molecule blocks normal pathway.1. Myeloma cells die because no enzymefor salvage pathwayand also no normal pathway allowed.2. Anyway plasma cells die every 2 weks.3. Only hybridoma cells live. Liver makes this Ab.4. One chromosome has HGRT and savage pathway can act as pre- cursors for savage pathway given.5. Bunch of genes for Ab secretion.6. Genes from myeloma cells for terminal illness or uncontrolled proliferation.Monoclonal made to avoid cross reactivity.On the gel sheet deposit one plasma cell and other afterwards.One plasma cell is deposited and wait for 2 weeks for plasma cells to die.Only cells such as hybridomas survive.Only idiotype of the plasma cells