ACAAI Review for the Allergy & Immunology Boards | 409 Questions and Answers(A+ Solution guide)

Small-molecule antigen requires covalent linkage to a larger carrier to stimulate adaptive immune response. The process is achieved in collaboration between hapten-specific B cells and carrier-specific T cells. This is the basis of developing conjugated vaccines. - What is the hapten-carrier effect? SEB and SEC from Staphylococcus aureus cause food poisoning. TSST from Staphylococcus aureus and SPE-C from Streptococus pyogenes cause toxic shock syndrome. - What are the common superantigens and related diseases? Natural killer T (NKT) cells recognize lipid antigens, and the CD1 molecule is involved. - Which type of T cell recognizes lipid antigens and what molecule is involved? Protein antigens are T-cell dependent. Polysaccharide, nucleic acid, and lipids are T-cell independent. - Which antigens are T-cell dependent and which are T-cell independent? On the MHC class I molecule, α3 is the binding site for CD8. On the MHC class II molecule, β2 is the binding site for CD4 - What is the binding site for CD4 on the MHC class I molecule? What is the binding site for CD8 on the MHC class II molecule? On the MHC Class I molecule, α1 and α2 make up the peptide binding cleft. On the MHC class II molecule, α1 and β1 make up the peptide binding cleft. - Which chain makes up the peptide binding cleft in MHC class I molecules? Which chain makes up the peptide binding cleft in MHC class II molecules? An MHC class I molecule presents both intracellular antigens (e.g., viral antigen in cytoplasm) and extracellular antigens (via cross-presentation). The loading site is endoplasmic reticulum (ER). - MHC class I molecule presents which type of antigens and where does the antigen-MHC class I loading happen? The MHC class II locus. They are involved in peptide processing for MHC class I however. - In which chromosomal region are the TAP proteins located?The MHC class II molecule presents extracellular antigens (e.g., antigens from phagocytosed bacteria). The loading site is phagolysosome. - MHC class II molecule presents which type of antigen? Where does the antigen-MHC class II loading happen?