Flashcards
Antigen Presentation
Cards in this deck (14)
- 1where does MHC I present antigens from?the intracellular fluid e.g. viruses
- 2where does MHC II present antigen from?the extracellular fluid e.g. bacteria
- 3state the structure of a MHC Ialpha peptide only, 3 genes A,B,C
- 4state the structure of a MHC IIalpha and beta peptides, 3 genes - DR,DP,DQ
- 5where does the antigen sit on a MHC molecule?peptide binding groove
- 6which cells express MHC I?all nucleated cells
- 7explain the MHC I pathway (6 steps)1. proteosomal degradation - virus proetins broken to peptides
2. peptides transferred to ER by TAP
3. MHC I synthesised and assembled in ER using chaperones
4. peptides loaded onto empty MHC
5. complex transported via golgi to surface
6. can now be detected by CD8+ t cells - 8which cells express MHC II?only APC's
- 9explain the MHC II pathway ( 6 steps)1. MHC II is synthesised in the ER, binding of cytoplasmic fragments is prevented (CLIP in PBG)
2. foreign antign is endocytosed and lysosomes fuse with primary endosomes
3. antigen is digested to peptide
4. MHC and endocytic pahways merge (CLIP replaced)
5. complex transported to cell surface
. can be detected by CD4+ t cells - 10what are dendritic cells and what do they present to?professional APC's that present antigen to naive T cells which stimulates a response in secondary lymphoid tissues
- 11what do macrophages and B cells present antigen to?Th1 or TH2 in reaction to an infection
- 12explain how immature dendritic cells become interdigitating dendritic cellsimmature DCs migrate to epithelial surfaces and encounter antigen, then migrate to lymph nodes and process antigen, then take up residence in LN paracortex as IDC and present the antigen to T cells
- 13name 3 facts about MHC genespolygenic, co-dominantly expressed and polymorphic
- 14what does a lack of diversity in MHC lead to?susceptibilty to infection, reduced response to vaccination, increased risk of autoimmune diseases
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- (LYM) Flashcards on Antigen Presentation, created by becki_fernandes on 29/04/2013.
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