Listeria monocytogenes-Infected Hepatocytes Are Targets of Major Histocompatibility Complex Class Ib-Restricted Antilisterial Cytotoxic T Lymphocytes

Subclinical infection of BALB/c mice with the intracellular bacterial pathogen Listeria monocytogenes results in the development of protective antilisterial immunity. L. monocytogenes can infect hepatocytes, and antilisterial cytotoxic T lymphocytes (CTL) lyse Listeria-infected hepatocytes in a major histocompatibility complex (MHC) class Ia-restricted manner. It remained to be determined whether L. monocytogenes-infected hepatocytes are susceptible to MHC class Ib-restricted cytolysis. In this study, we showed that hepatocytes express MHC class Ib molecule Qa-1(b) mRNA and protein. We further showed that Listeria-infected hepatocytes are susceptible to MHC class Ib-restricted cytolysis, since C57BL/6-derived Listeria-infected hepatocytes were lysed by BALB/c-derived antilisterial CTL. These results establish that Listeria-infected hepatocytes are susceptible to cytolysis by MHC class Ib restricted Listeria-specific CTL.