1 / 41

Antigen Processing & Presentation

Antigen Processing & Presentation. Hugh B. Fackrell. Antigen Processing & Presentation. Assigned Reading Content Outline Performance Objectives Key terms Key Concepts Short Answer Questions. Assigned Reading. Chapter: 10 pp 249-262 Janis Kuby’s Immunology 3rd Ed.

oliana
Download Presentation

Antigen Processing & Presentation

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Antigen Processing & Presentation Hugh B. Fackrell

  2. Antigen Processing & Presentation • Assigned Reading • Content Outline • Performance Objectives • Key terms • Key Concepts • Short Answer Questions

  3. Assigned Reading • Chapter: 10 pp 249-262 • Janis Kuby’s Immunology 3rd Ed

  4. Self MHC Restriction of T Cells Role of Antigen Presenting Cells Two Presentation Pathways Cytosolic Pathway: Endogenous Antigens Endocytic Pathway: Exogenous Antigens Clinical Applications Content Outline

  5. MHC antigens codominate 53

  6. Mixed Lymphocyte Reaction 38

  7. Self MHC Restriction of T Cells • CD4+ & CD8+ cells • Antigen must be in cleft of MHC • MHC polymorphism • ~500 antigens/cleft

  8. Haplotype Restricted Cytotoxicity 56

  9. “Antigen Pulse” • “Antigen pulsed” macrophages • T helper (CD4+) cells can only be stimulated by macrophages with the same MHC Class II • Cytotoxic (CD8+) T cells can only be stimulated by macrophages with the same MHC Class I

  10. T Cell Activation

  11. MHC I: Biological function 44

  12. MHC II: Biological function 47

  13. MHCII: Biologogical function (2) 46

  14. MHCII: Function 50

  15. Role of Antigen Presenting Cells • Immunize with native protein • Boost with native protein • B cell & T cell response • Boost with denatured antigen • T cell response only • 2 different mechanisms APC for cell mediated & humoral

  16. Antigen Presenting Cells • Professional APC • Dendritic cells • Macrophages • B Cells • Non Professional APC • Fibroblasts • Glial cells • Thymic epithelial cells • Vascular endothelial cells

  17. Dendritic cells • Lot MHC-II • co-stimulate • activate T helpers

  18. Macrophages • Engulf microbe first • digest antigen • bind to MHC-II • co express with B7 membrane protein

  19. B Cells • Constitutively express MHC-II • activated • then express B7

  20. Two Presentation Pathways • Cytosolic- • MHC-I • endogenous antigens • Endocytic - • MHC-II • exogenous antigens

  21. Cytosolic Pathway: Endogenous Antigens • Ubiquitin & ATP • Bind to peptide • proteasomes • Bind ubiquitin • peptide transport • Assembly of peptides in MHC-I • Rough Endoplasmic reticulum • Export to membrane

  22. TAP proteins • Transports associated with Antigen Processing • TAP-1 TAP-2 • Transfer Peptides from proteosome to RER

  23. TAP-1 TAP-2

  24. Calnexin & MHC-1

  25. Assembly in RER • TAP-1 TAP-2 transport into ER • Bind to Calnexin MHC-I • Add peptide to MHC-I • Release calnexin • Transport to Gogli

  26. Endogenous PathwayMHC-i

  27. Endocytic Pathway: Exogenous Antigens • endocytic vesicles • peptide transport • Assembly of peptides in MHC-II

  28. Endocytic Route • From Outside- phagocytosis • From Inside • Make MHC-II • Bind Invariant chain • CLIP- digests invariant chain • Fuse • MHC-II & clipped I & peptide • peptide displaces clipped I chain

  29. Invariant chain & MHC-II

  30. Exogenous PathwayMHC-II

  31. Clinical Applications

  32. Performance Objectives

  33. Key Terms • antigen presenting cells[253],professional antigen presenting cells[253], • nonprofessional antigen presenting cells[253],cytosolic pathway[255],, • endocytic pathway[258], ubiquitin [255], proteosome[255],

  34. Transportors associated with antigen processing (TAP) [256], • molecular chaperones[257], calnexin[ 257], invariant (Ii) chain [258], • CLIP [259],

  35. Key Concepts • Describe self MHC restriction. • Compare the cytosolic pathway for antigen presentation with the endocytic pathway for antigen presentation • Compare professional with non professional antigen presenting cells.

  36. Draw a flow diagram comparing cytosolic and endocytic pathways for processing antigens [Fig 10-4] • Describe peptide generation by proteasomes. • Describe transport of antigenic peptides from the cytosol to the Rough Endoplasmic reticulum

  37. Draw a concept map for the separate antigen presenting pathways for endogenous and exogenous antigens. • Describe the assembly of MHC-II molecules within the rough endoplasmic reticulum. • Describe the development of a viral vaccine that uses the cytosolic pathway.

  38. Short Answer Questions

  39. Describe the development of a vaccine that used the endocytic pathway. • Name thee types of professional APCs. • For each type indicate whether it expresses MHC-II molecules and a co-stimulatory signal constitutively or must be activated before doing so. • Describe the role of ubiquitin in the processing of endogenous antigens.

  40. Describe the role of calnexin in the assembly of MHC-I. • T cells can react only with protein fragments. • What is this process called? • How does it occur? • Which pathway leads to antigen interaction with MHC-I molecules? • Which pathway leads to interaction with MHC-II molecules?

  41. DONE!!!

More Related