Linkage of bacterial protein synthesis and presentation of MHC class I-restricted Listeria monocytogenes-derived antigenic peptides.

The processing and MHC class I-restricted presentation of antigenic peptides derived from the p60 protein of the facultative intracellular bacterium Listeria monocytogenes is tightly linked to bacterial protein synthesis. We used non-linear regression analysis to fit a mathematical model of bacterial antigen processing to a published experimental data set showing the accumulation and decay of p60-derived antigenic peptides in L. monocytogenes-infected cells.

Role of tripeptidyl peptidase II in the processing of Listeria monocytogenes-derived MHC class I-presented antigenic peptides.

The effective control of the infection of mice with the facultatively intracellular bacterium Listeria monocytogenes requires CD8 T cells which recognize bacterial antigenic peptides presented in the context of host MHC class I molecules. It is generally accepted that bacterial antigens are processed by the proteasome, a proteolytic cytoplasmic multiprotein complex. We observed that presentation of the L.

Adoptive CD8 T cell control of pathogens cannot be improved by combining protective epitope specificities.

Adoptive transfer of CD8 T cells has the potential to cure infectious or malignant diseases that are refractory to conventional chemotherapy. A practically important but still unanswered question is whether mixtures of protective CD8 T cells with different epitope specificities mediate more efficient effector cell functions than do the monospecific individual CD8 T cell populations. In this study, we have addressed this issue for models of viral and bacterial infection.

Identification of a cross-reactive HLA-DRB1*0301-restricted CD4 T cell response directed against cholesterol-binding cytolysins from two different pathogens.

Cholesterol-binding cytolysins constitute an evolutionarily conserved family of pore-forming proteins expressed by different gram-positive pathogens. Listeriolysin O, one well-characterized member of the cytolysin family, is also known to induce specific CD4 and CD8 T cell responses upon infection of mice with Listeria monocytogenes. Here we describe an HLA-DRB1*0301-restricted listeriolysin O-derived T cell epitope that is conserved among several members of the cytolysin family.

Cross-presentation of Listeria monocytogenes-derived CD4 T cell epitopes.

Listeriolysin O (LLO) mediates the evasion of Listeria monocytogenes from the phagolysosome into the cytoplasm of the host cell. The recognition of infected cells by CD4 T cells is thought to be limited by the evasion of bacteria from the phagolysosome and also by the direct LLO-mediated inhibition of CD4 T cell activation. To analyze the influence of these immunoevasive mechanisms on the antilisterial CD4 T cell response, the expansion of L.