48] Structural analysis of murine class I major histocompatibility complex antigens

Abstract

This chapter describes the murine major histocompatibility complex (MHC), or H-2 as a cluster of loci coding for proteins involved in the processes of cell-mediated immunity. On the basis of this evolutionary homology the MHC loci have been divided into classes. The chapter outlines the methods used to obtain structural information about the H-2 Class I antigens. It discusses that there are two groups of Class I genes. Class I genes located in the left-hand side of the MHC encode the cell-surface molecules that represent the “classical” transplantation antigens known to mediate graft rejection. These antigens are to be found on virtually all nucleated cells in the mouse. The Class I genes found to the right-hand portion of the MHC, known as the Qa and Tla region, encode cell surface antigens that are distributed in a tissue-specific fashion. The Class I genes to the left-end of the MHC are particularly notable for their extensive polymorphism, whereas those to the right-hand end are far less polymorphic. The chapter reviews that there are structural differences among the H-2 Class I antigens but they do have certain features in common. Currently, the classical transplantation antigens are the best characterized of the Class I antigens although structural data on antigens of the Qa and the Tla regions can be expected to accumulate in the near future.