POI MPC

• Which region of an antibody determines its antigen specificity?

  Variable region
• What process generates the initial diversity in antibodies?

  VDJ recombination
• Which enzyme is critical for VDJ recombination?

  RAG1/RAG2
• Which antibody isotype is primarily responsible for allergic reactions?

  IgE
• During affinity maturation, which process occurs in the germinal centers?

  Somatic hypermutation
• Which antibody isotype is the first produced in a primary immune response?

  IgM
• What is the function of the Fc region of an antibody?

  Complement activation and Fc receptor binding
• What is the main function of IgA in mucosal immunity?

  Neutralization
• Which pathway of complement activation is triggered by antigen-antibody complexes?

  Classical pathway
• Which complement component acts as an opsonin?

  C3b
• What is the function of C5a in the complement system?

  Inflammation and chemotaxis
• Which regulatory protein prevents the formation of the membrane attack complex (MAC)?

  CD59
• Which complement regulatory protein accelerates the decay of C3 and C5 convertases?

  DAF
• What is the main trigger for the lectin pathway of complement activation?

  Mannose-binding lectin binding to microbial carbohydrates
• The terminal complement pathway leads to the formation of which structure?

  Membrane attack complex (MAC)
• Which of the following is a cofactor for Factor I in complement regulation?

  Factor H
• MHC Class I molecules present antigens to which type of T cells?

  CD8+ T cells
• MHC Class II molecules are expressed on which cells?

  Antigen-presenting cells (APCs)
• Which pathway processes endogenous antigens for MHC Class I presentation?

  Cytosolic pathway
• What is the role of TAP proteins in MHC Class I processing?

  Transport of peptides into the endoplasmic reticulum
• Which of the following is true about MHC polymorphisms?

  They increase the range of antigens presented
• MHC Class II molecules are associated with which type of T cell activation?

  Helper T cell response
• What prevents MHC Class II molecules from binding cytosolic peptides?

  Invariant chain (Ii)
• Which cells can cross-present antigens to CD8+ T cells?

  Dendritic cells
• Which HLA molecule is most associated with increased risk of Type 1 diabetes?

  HLA-DR3/DR4
• What is the primary cause of organ transplant rejection?

  MHC polymorphisms
• How are autoreactive T cells eliminated during development?

  Negative selection
• Which cytokine is secreted by regulatory T cells to suppress autoreactive T cells?

  IL-10
• Which MHC class is associated with graft rejection?

  Both MHC Class I and II
• What is the role of the invariant chain in MHC Class II processing?

  Prevents peptide binding in the endoplasmic reticulum