- Poster presentation
- Open Access
CD8α+ dendritic cells dictate immune responses against murine AML
© Kline et al; licensee BioMed Central Ltd. 2013
Published: 7 November 2013
Spontaneous T cell responses generated against a variety of solid malignancies are often subverted by immune evasion mechanisms active in the tumor microenvironment. In contrast, the mechanisms that regulate T cell activation versus tolerance to hematopoietic malignancies, such as acute myeloid leukemia (AML), have not been well-characterized. Our recent work in a murine AML model has demonstrated that following a systemic introduction of leukemia cells, T cells specific for leukemia-derived antigens underwent abortive proliferation and were deleted from the host. This deletional tolerance in mice with established AML was reversible upon administration of an agonistic anti-CD40 antibody to activate host dendritic cells (DCs), and argued that these cells may play a dominant role in tolerance induction to AML. Investigation of the DCs populations which engulfed AML cells in vivo, and which were likely promoting T cell tolerance, led to the critical observation that AML cells were phagocytosed exclusively by CD11c+CD8α+ DCs (CD8α+ DCs). CD8α+, but not CD8α- DCs purified from mice following an intravenous inoculation of AML cells, were able to cross-present leukemia-derived antigens to T cells in vitro, providing strong evidence that CD8α+ DC generate T cell tolerance to AML. Ongoing work utilizing mice deficient in particular DC subsets is focused on identifying a functional link between CD8α+ DCs and T cell tolerance. Additionally, the receptors expressed selectively on CD8α+ DCs which facilitate phagocytosis and cross-presentation of leukemia derived antigens are under investigation.
This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.