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Langerin+ CD8α+ Dendritic Cells Drive Early CD8+ T Cell Activation and IL-12 Production During Systemic Bacterial
Kelly A Prendergast1,2, Naomi J Daniels3, Troels R Petersen1
1Malaghan Institute of Medical Research, Wellington, New Zealand.
Frontiers in Immunology
|June 6, 2018
Summary
Langerin+ CD8α+ dendritic cells are crucial for initiating adaptive immunity against bloodstream bacterial infections. Their depletion impairs T cell responses and early control of infections like tuberculosis.
Area of Science:
- Immunology
- Microbiology
- Infectious Diseases
Background:
- Bloodstream infections (bacteremia) cause significant illness and death, yet immune responses remain incompletely understood.
- Langerin+ CD8α+ dendritic cells (DCs) in the spleen are known to prime CD8+ T cells and produce IL-12, key for fighting infection.
Purpose of the Study:
- To investigate the role of langerin+ CD8α+ DCs in adaptive immunity against blood-borne bacterial infections.
- To determine the impact of depleting this specific dendritic cell subset on the immune response to Mycobacterium bovis bacille Calmette-Guerin (BCG).
Main Methods:
- Used genetically modified mice lacking langerin+ CD8α+ DCs.
- Administered intravenous Mycobacterium bovis bacille Calmette-Guerin (BCG) infection.
- Assessed bacterial load, IL-12p40 levels, and CD8+ T cell responses (activation, proliferation, IFN-γ production).
Main Results:
- Depletion of langerin+ CD8α+ DCs led to increased bacterial numbers in the spleen.
- Reduced serum IL-12p40 levels were observed in mice lacking these DCs.
- Delayed CD8+ T cell activation, proliferation, and IFN-γ production occurred without langerin+ CD8α+ DCs.
Conclusions:
- Langerin+ CD8α+ dendritic cells are essential for initiating CD8+ T cell responses and IL-12 production during bacteremia.
- This dendritic cell subset plays a critical role in the early control of systemic bacterial infections.
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