Myocardial Infarction Primes Autoreactive T Cells through Activation of Dendritic Cells

Publication date: 21 March 2017
Source:Cell Reports, Volume 18, Issue 12
Author(s): Katrien Van der Borght, Charlotte L. Scott, Veronika Nindl, Ann Bouché, Liesbet Martens, Dorine Sichien, Justine Van Moorleghem, Manon Vanheerswynghels, Sofie De Prijck, Yvan Saeys, Burkhard Ludewig, Thierry Gillebert, Martin Guilliams, Peter Carmeliet, Bart N. Lambrecht
Peripheral tolerance is crucial for avoiding activation of self-reactive T cells to tissue-restricted antigens. Sterile tissue injury can break peripheral tolerance, but it is unclear how autoreactive T cells get activated in response to self. An example of a sterile injury is myocardial infarction (MI). We hypothesized that tissue necrosis is an activator of dendritic cells (DCs), which control tolerance to self-antigens. DC subsets of a murine healthy heart consisted of IRF8-dependent conventional (c)DC1, IRF4-dependent cDC2, and monocyte-derived DCs. In steady state, cardiac self-antigen α-myosin was presented in the heart-draining mediastinal lymph node (mLN) by cDC1s, driving the proliferation of antigen-specific CD4⁺ TCR-M T cells and their differentiation into regulatory cells (Tregs). Following MI, all DC subsets infiltrated the heart, whereas only cDCs migrated to the mLN. Here, cDC2s induced TCR-M proliferation and differentiation into interleukin-(IL)-17/interferon-(IFN)γ-producing effector cells. Thus, cardiac-specific autoreactive T cells get activated by mature DCs following myocardial infarction.

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Van der Borght et al. demonstrate that myocardial infarction induces the priming of autoreactive CD4⁺ T cells specific for cardiac self-antigen α-myosin in the heart-draining lymph node through the maturation and migration of conventional dendritic cells. Using ex vivo co-culture systems, cDC2s are shown to be superior in presenting α-myosin.


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