| First Author | Shedlock DJ | Year | 2003 |
| Journal | J Immunol | Volume | 170 |
| Issue | 4 | Pages | 2053-63 |
| PubMed ID | 12574376 | Mgi Jnum | J:126911 |
| Mgi Id | MGI:3762298 | Doi | 10.4049/jimmunol.170.4.2053 |
| Citation | Shedlock DJ, et al. (2003) Role of CD4 T cell help and costimulation in CD8 T cell responses during Listeria monocytogenes infection. J Immunol 170(4):2053-63 |
| abstractText | CD4 T cells are known to assist the CD8 T cell response by activating APC via CD40-CD40 ligand (L) interactions. However, recent data have shown that bacterial products can directly activate APC through Toll-like receptors, resulting in up-regulation of costimulatory molecules necessary for the efficient priming of naive T cells. It remains unclear what role CD4 T cell help and various costimulation pathways play in the development of CD8 T cell responses during bacterial infection. In this study, we examined these questions using an intracellular bacterium, Listeria monocytogenes, as a model of infection. In CD4 T cell-depleted, CD4(-/-), and MHC class II(-/-) mice, L. monocytogenes infection induced CD8 T cell activation and primed epitope-specific CD8 T cells to levels commensurate with those in normal C57BL/6 mice. Furthermore, these epitope-specific CD8 T cells established long-term memory in CD4(-/-) mice that was capable of mounting a protective recall response. In vitro analysis showed that L. monocytogenes directly stimulated the activation and maturation of murine dendritic cells. The CD8 T cell response to L. monocytogenes was normal in CD40L(-/-) mice but defective in CD28(-/-) and CD137L(-/-) mice. These data show that in situations where infectious agents or immunogens can directly activate APC, CD8 T cell responses are less dependent on CD4 T cell help via the CD40-CD40L pathway but involve costimulation through CD137-CD137L and B7-CD28 interactions. |
