A. Polymorphisms at each locus can potentially double the number of different MHC molecules expressed by an individual.
B. Pathogens can evade the immune system by mutating the immunodominant epitope, which results in loss of affinity for the specific MHC allele.
C. Pathogens do not cause evolutionary pressure to select MHC alleles that confer protection against them.
D. The DRα chain and its mouse homolog, Eα, are monomorphic.
6.13 True or False: Classical MHC class I molecules are highly polymorphic, as opposed to MHC class Ib, which are oligomorphic.
6.14 Matching: Match the following MHC class Ib genes with their appropriate description:
Section references.
6-1 Antigen presentation functions both in arming effector T cells and in triggering their effector functions to attack pathogen-infected cells.
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Vyas, J.M., Van der Veen, A.G., and Ploegh, H.L.: The known unknowns of antigen processing and presentation. Nat. Rev. Immunol. 2008, 8:607–618.
6-2 Peptides are generated from ubiquitinated proteins in the cytosol by the proteasome.
Basler, M., Kirk. C.J., and Groettrup, M.: The immunoproteasome in antigen processing and other immunological functions. Curr. Opin. Immunol. 2013, 25:74–80.
Brocke, P., Garbi, N., Momburg, F., and Hammerling, G.J.: HLA-DM, HLA-DO and tapasin: functional similarities and differences. Curr. Opin. Immunol. 2002, 14:22–29.
Cascio, P., Call, M., Petre, B.M., Walz, T., and Goldberg, A.L.: Properties of the hybrid form of the 26S proteasome containing both 19S and PA28 complexes. EMBO J. 2002, 21:2636–2645.
Gromme, M., and Neefjes, J.: Antigen degradation or presentation by MHC class I molecules via classical and non-classical pathways. Mol. Immunol. 2002, 39:181–202.
Goldberg, A.L., Cascio, P., Saric, T., and Rock, K.L.: The importance of the proteasome and subsequent proteolytic steps in the generation of antigenic peptides. Mol. Immunol. 2002, 39:147–164.
Hammer, G.E., Gonzalez, F., Champsaur, M., Cado, D., and Shastri, N.: The aminopeptidase ERAAP shapes the peptide repertoire displayed by major histocompatibility complex class I molecules. Nat. Immunol. 2006, 7:103–112.