%0 Figure %A Prendergast, Kelly A. %A Daniels, Naomi J. %A R. Petersen, Troels %A Hermans, Ian F. %A R. Kirman, Joanna %D 2018 %T image_1_Langerin+ CD8α+ Dendritic Cells Drive Early CD8+ T Cell Activation and IL-12 Production During Systemic Bacterial Infection.TIF %U https://frontiersin.figshare.com/articles/figure/image_1_Langerin_CD8_Dendritic_Cells_Drive_Early_CD8_T_Cell_Activation_and_IL-12_Production_During_Systemic_Bacterial_Infection_TIF/6225896 %R 10.3389/fimmu.2018.00953.s001 %2 https://frontiersin.figshare.com/ndownloader/files/11343149 %K langerin %K dendritic cell %K diphtheria toxin %K bacille Calmette–Guerin %K systemic infection %X

Bloodstream infections induce considerable morbidity, high mortality, and represent a significant burden of cost in health care; however, our understanding of the immune response to bacteremia is incomplete. Langerin+ CD8α+ dendritic cells (DCs), residing in the marginal zone of the murine spleen, have the capacity to cross-prime CD8+ T cells and produce IL-12, both of which are important components of antimicrobial immunity. Accordingly, we hypothesized that this DC subset may be a key promoter of adaptive immune responses to blood-borne bacterial infections. Utilizing mice that express the diphtheria toxin receptor under control of the langerin promoter, we investigated the impact of depleting langerin+ CD8α+ DCs in a murine model of intravenous infection with Mycobacterium bovis bacille Calmette–Guerin (BCG). In the absence of langerin+ CD8α+ DCs, the immune response to blood-borne BCG infection was diminished: bacterial numbers in the spleen increased, serum IL-12p40 decreased, and delayed CD8+ T cell activation, proliferation, and IFN-γ production was evident. Our data revealed that langerin+ CD8α+ DCs play a pivotal role in initiating CD8+ T cell responses and IL-12 production in response to bacteremia and may influence the early control of systemic bacterial infections.

%I Frontiers