Slide 1Slide 2Slide 3Slide 4Slide 5Slide 6Slide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Slide 25Slide 26Slide 27Slide 28Slide 29Slide 30Slide 31Slide 32Slide 33Slide 34Slide 35Slide 36Slide 37Slide 38Slide 39Slide 40Slide 41Slide 42Slide 43Slide 44Slide 45Slide 46Slide 47Slide 48Slide 49Slide 50Slide 51Slide 52Slide 53Slide 54Slide 55Slide 56Average = 77.7 = B-A = 95+ C+ = 65-71A- = 90-94 C= 55-64B+ = 85-89 C- =<54B = 77-84B- = 72-76Adaptive Immunity: 2 BranchesHumoral Cell-mediatedOverview of Immune SystemMHC interactionsResponse to Ag (humoral system)Response to Ag (CMI system)Electrophoresis of serum proteinsGeneric AbRibbon diagram of a monoclonal abIgGVariability of residues in different abs. The 3 hypervariable regions are termed complementarity-determining regions (CDR)Side-view of Angiotensin II bound to Fab.Van der Waals surface contactsA peptide fomr the HIV protease with an anti-protease FabAb classesAntigenic determinants of AbsThe Ig superfamilyB cell developmentGene arrangements(human chromosome 22)(human chromosome 2)(human chromosome 14)Circular DNA isolated from thymocytes undergoing TCR rearrangement (these rearrange just like Ab genes)From Hozumi and Tonegawa, 1976, PNAS USA 73: 3628Kappa gene expressionH-gene expressionRecombination signal sequencesSecreted vs. membrane forms of IgMClass switching by alternative processingClass switching by alternative processingSecretory pathwayNucleotide addition during joiningWhen ss DNA is generated: Extra nucleotides can also be added:Somatic variationAllelic exclusion (only in B and T cells)Model of allelic exclusionClass switchingcis-acting