front 1 What are the two major compartments of the cell? | back 1 Cytosol and nucleus and vesicular system (ER, Golgi, vesicles, lysosomes) |
front 2 Why are these two compartments kept separate? | back 2 Separate intracellular vs extracellular problems and prevent incorrect protein interactions |
front 3 How is material moved between them? | back 3 Transport proteins (energy required) |
front 4 Relationship between MHC I and endogenous antigens? | back 4 MHC I presents intracellular proteins (viral, tumor, self) |
front 5 How does antigen presentation work under healthy conditions? | back 5 Self-antigens are presented |
front 6 How does antigen presentation work during infection? | back 6 Foreign antigens are presented → immune response |
front 7 Self vs non-self antigen? | back 7 Self = body proteins; Non-self = pathogens |
front 8 Is self-antigen presentation bad? | back 8 ❌ No → normal monitoring process, monitors cell health and maintain tolerance |
front 9 What is ERAD? | back 9 Misfolded ER proteins → sent to cytosol → degraded by proteasome |
front 10 What is the proteasome? | back 10 Degrades proteins into peptides |
front 11 What is the immunoproteasome? | back 11 Modified version → better peptides for MHC I |
front 12 What causes the switch? | back 12 IFN-γ (inflammation) |
front 13 What is a Constitutive proteasome? | back 13 Normal version in healthy cells |
front 14 In what cellular compartments do various stages of MHC class I presentation take place? | back 14 Cytosol → protein breakdown, ER → peptide loading, and Surface → presentation |
front 15 Role of TAP (Transporter Associated w/ Antigen processing)? | back 15 Moves peptides from cytosol → ER |
front 16 Role of calnexin? | back 16 Helps MHC I fold properly and stabilizes the alpha chain before peptide loading |
front 17 What are the components of the peptide loading complex? | back 17 Tapasin, peptide editing, ERp57, Calreticulin and (MHC Class 1 and β2M) |
front 18 Function of Tapasin? | back 18 Links MHC I to TAP + peptide editing |
front 19 What is peptide editing? | back 19 helps select high-quality peptides improving the stability of MHC 1 complex. |
front 20 Function of ERp57? | back 20 Protein folding helper (Chaperone) |
front 21 Function of Calreticulin? | back 21 Stabilizes MHC I during loading |
front 22 Function of MHC I + β2M? | back 22 Form presentation complex |
front 23 What is ERAP? | back 23 an ER aminopeptidase and it trims peptides to correct size for MHC 1 |
front 24 What is immunodominance? | back 24 Few peptides dominate T cell response |
front 25 What is the purpose of presentation of self-antigen? | back 25 Allows external antigens → MHC I→ activates CD8 T cells |
front 26 Is this presentation bad or normal? | back 26 This is a normal process |
front 27 Purpose of Cross-presentation? | back 27 It allows for exogenous antigens to be presented on MHC 1 which is important in activating CD8 T cells against viruses and tumors. |
front 28 Three major APCs? | back 28 Dendritic cells, macrophages, B cells |
front 29 Which APCs initiates adaptive immunity? | back 29 Dendritic cells |
front 30 What do dendritic cells do in antigen presentation? | back 30 Capture antigen → go to lymph node → activate T cells |
front 31 Relationship between MHC class 2 and exogenous antigen? | back 31 MHC Class 2 presents exogenous (external) antigens |
front 32 How do exogenous antigens enter cells? | back 32 Endocytosis or phagocytosis |
front 33 Purpose of invariant chain? | back 33 1. Blocks binding groove 2. Sends MHC II to endosome |
front 34 What is CLIP? | back 34 fragment of invariant chain that temporarily occupies a binding groove |
front 35 What is HLA-DM? | back 35 Intracellular APCs that removes CLIP + loads real antigen |
front 36 What presents lipid antigens? | back 36 CD1 family molecules |
front 37 How are CD1 family molecules similar to MHC I? | back 37 its structure, using a binding groove to present antigen and expressed on the cell surface |
front 38 How are CD1 family molecules similar to MHC II? | back 38 presenting exogenous antigens and antigens being processed in vesicular/ endosomal compartments. |
front 39 What cell type do CD1 family present to? | back 39 NKT cells |
front 40 CD8 T cell function? | back 40 Kill infected/cancer cells |
front 41 CD4 T cell function? | back 41 Help immune response (activate macrophages, B cells, regulate) |
front 42 Difference between MHC I vs MHC II? | back 42 MHC I → intracellular → CD8 and MHC II → extracellular → CD4 |