front 1 What are the 3 functions of the innate immune system? | back 1 Physical/chemical barriers, cellular responses, activation of adaptive immunity |
front 2 Why is MHC necessary? | back 2 T cells can’t recognize free antigen → need MHC to present peptide→ enables T cell activation |
front 3 Similarities between BCR and TCR? | back 3 Both are antigen-specific and generated by gene rearrangement |
front 4 Differences between BCR and TCR? | back 4 BCR binds free antigen (no MHC); TCR requires processed antigen + MHC |
front 5 What is self-MHC restriction? | back 5 T cells only recognize antigen on self-MHC |
front 6 Where are MHC molecules expressed? | back 6 Most cells (Class I), APCs (Class II) |
front 7 Where are TCRs expressed? | back 7 Only on T cells |
front 8 Components of MHC Class I? | back 8 α chain + β2-microglobulin |
front 9 Components of MHC Class II? | back 9 α chain + β chain |
front 10 Similarity between Class I & II? | back 10 Both have peptide-binding groove and present antigens to T cells |
front 11 Key difference between Class 1 and 2? | back 11 Class 1 = 1 chain + β2m; Class 2 = 2 chains |
front 12 Where is MHC Class I found? | back 12 All nucleated cells |
front 13 Where is MHC Class II found? | back 13 APCs (Dendritic cells, macrophages, B cells) |
front 14 What is the binding groove? | back 14 Site where peptide binds on MHC |
front 15 Why is the binding groove important? | back 15 Determines which peptides can be presented |
front 16 Steps of antigen presentation? | back 16 Breakdown → load on MHC → move to surface → T cell recognition |
front 17 What is the central dogma? | back 17 DNA → RNA → Protein |
front 18 What is an Allele? | back 18 Different versions of a gene |
front 19 What is an Allotype? | back 19 Protein product of allele |
front 20 What is a SNP? | back 20 a polymorphism of a single nucleotide (not quite same as mutation) |
front 21 What is Co-dominance? | back 21 Both alleles expressed equally |
front 22 What is a Haplotype? | back 22 Linked genes inherited together |
front 23 What is a Syngeneic Haplotype? | back 23 Genetically identical |
front 24 What is Congenic Haplotype? | back 24 Identical except one locus |
front 25 What is Polygeny? | back 25 Multiple genes → one protein |
front 26 What is a Polymorphism? | back 26 Many versions of a protein due to multiple alleles |
front 27 Where are MHC genes located? | back 27 Chromosome 6 |
front 28 What is HLA? | back 28 Human MHC known as Human Leukocyte Antigen complex |
front 29 What does Complex I encode? | back 29 HLA-A, B, C |
front 30 What does Complex II encode? | back 30 HLA-DP, DQ, DR |
front 31 What does Complex III encode? | back 31 Complement + inflammatory cytokines |
front 32 Complex I presents to which cells? | back 32 CD8 T cells |
front 33 Complex II presents to which cells? | back 33 CD4 T cells |
front 34 Why is co-dominance important? | back 34 Increases antigen presentation diversity |
front 35 How are MHC genes inherited? | back 35 As haplotypes from each parent and expressed co-dominantly |
front 36 What is MHC diversity? | back 36 Many alleles in population |
front 37 Why is MHC diversity important? | back 37 Protects against many pathogens |
front 38 What is MHC promiscuity? | back 38 One MHC binds many peptides |
front 39 Heterozygote advantage? | back 39 More alleles = better protection |
front 40 Balancing selection? | back 40 natural selection that maintains multiple alleles in a population keeping MHC diversity high |
front 41 Directional selection? | back 41 Favors one allele, reducing diversity |
front 42 What are anchor residues? | back 42 Key amino acids that bind MHC |
front 43 Why are anchor residues important? | back 43 to determine which peptides fit in the groove |
front 44 Anchor residues are more important in which class? | back 44 Class I because of more restrictive binding |
front 45 MHC are related to promiscuity? | back 45 They relate to promiscuity because Class 2 have less strict binding making them more promiscuous. |
front 46 How does MHC activate T cells? | back 46 Signal 1 = MHC + peptide → TCR |
front 47 What else is needed for T cells activation? | back 47 Signal 2 (costimulation) + Signal 3 (cytokines) |
front 48 What are the 3 signals for T cell activation? | back 48 MHC + peptide (Signal 1), Costimulation (Signal 2) and Cytokines (Signal 3) |