Single H2Kb, H2Db and double H2KbDb knockout mice: peripheral CD8+ T cell repertoire and antilymphocytic choriomeningitis virus cytolytic responses

Single H2Kb, H2Db and double H2KbDb homozygous knockout (KO) mice were generated and their peripheral CD8+ T cell repertoires compared to that of C57BL/6 (B6) mice. Limited (10 – 20 %, H2Db), substantial (30 – 50 %, H2Kb) and profound (90 %, H2KbDb) reduction of peripheral CD8+ T cells was observed in KO mice, without Vβ diversity alteration. Classical class Ia molecules therefore ensure most but not all of the peripheral CD8+ T cell repertoire education. As expected, H2Kb but also H2Db KO mice developed choriomeningitis following intracranial infection by lymphocytic choriomeningitis virus with the same kinetics, lethality and CD8+ cell implication as wild‐type B6 mice. By contrast, H2KbDb (class Ia–Ib+) KO mice survived. Choriomeningitis of H2Db KO mice was linked to the development of a subdominant (in normal B6 mice) H2Kb‐restricted cytotoxic T lymphocyte response. Mice expressing a restricted set of histocompatibility class I molecules should represent useful tools to evaluate the immunological potentials of individual MHC class I molecules.