Critical Cover

Science's STKE  03 Dec 2002:
Vol. 2002, Issue 161, pp. tw456
DOI: 10.1126/stke.2002.161.tw456

Variation in the ability to cope with infection among individuals helps ensure the success of a given population. Extensive polymorphism in the genes of the major histocompatibility complex (MHC) are consistent with control of resistance, either through the presentation of different foreign peptides by MHC proteins, the selection of distinct repertoires of T cells during development, or through both processes. Messaoudi et al. observed a great divergence in the response to viral infection in two strains of mice carrying a four-amino acid difference in one MHC gene, but which were otherwise genetically identical. T cells in both strains focused on the same dominant viral peptide, which bound with equal affinity to each MHC variant. However, T cells responsible for better viral clearance in the resistant strain showed greater diversity of T cell receptor usage and improved recognition of antigen. Thus, MHC polymorphism may influence different responses to infection through the repertoire of T cells they select.

I. Messaoudi, J. A. G. Patiño, R. Dyall, J. LeMaoult, J. Nikolich-Žugich, Direct link between mhc polymorphism, T cell avidity, and diversity in immune defense. Science 298, 1797-1800 (2002). [Abstract] [Full Text]