| First Author | Rowe JH | Year | 2012 |
| Journal | J Immunol | Volume | 189 |
| Issue | 2 | Pages | 876-84 |
| PubMed ID | 22711893 | Mgi Jnum | J:189796 |
| Mgi Id | MGI:5447002 | Doi | 10.4049/jimmunol.1103227 |
| Citation | Rowe JH, et al. (2012) Innate IFN-gamma is essential for programmed death ligand-1-mediated T cell stimulation following Listeria monocytogenes infection. J Immunol 189(2):876-84 |
| abstractText | Although best characterized for sustaining T cell exhaustion during persistent viral infection, programmed death ligand-1 (PDL-1) also stimulates the expansion of protective T cells after infection with intracellular bacterial pathogens. Therefore, establishing the molecular signals that control whether PDL-1 stimulates immune suppression or activation is important as immune modulation therapies based on manipulating PDL-1 are being developed. In this study, the requirement for PDL-1 blockade initiated before infection with the intracellular bacterium Listeria monocytogenes in reducing pathogen-specific T cell expansion is demonstrated. In turn, the role of proinflammatory cytokines triggered early after L. monocytogenes infection in controlling PDL-1-mediated T cell stimulation was investigated using mice with targeted defects in specific cytokines or cytokine receptors. These experiments illustrate an essential role for IL-12 or type I IFNs in PDL-1-mediated expansion of pathogen-specific CD8(+) T cells. Unexpectedly, direct stimulation by neither IL-12 nor type I IFNs on pathogen-specific CD8(+) cells was essential for PDL-1-mediated expansion. Instead, the absence of early innate IFN-gamma production in mice with combined defects in both IL-12 and type I IFNR negated the impacts of PDL-1 blockade. In turn, IFN-gamma ablation using neutralizing Abs or in mice with targeted defects in IFN-gammaR each eliminated the PDL-1-mediated stimulatory impacts on pathogen-specific T cell expansion. Thus, innate IFN-gamma is essential for PDL-1-mediated T cell stimulation. |
