Effector Memory CD4 T cells engage the innate immune system through CD40 and TNFR to trigger cytokine storm and autoimmune pathology II

Introduction: DCs sense and respond to a variety of pathogen-dependent and independent features. We found that DCs can directly sense the presence of immunological memory in the form of effector memory T cells via TNFRSF signaling. Expression of CD40L and TNF by effector memory T cells specifically led to a robust inflammatory signature in interacting DCs. Method: Bone marrow derived DCs (BMDCs) were differentiated in the presence of GMCSF for 7 days. WT naïve T cells were polarized to Th0 (platebound anti-CD3 and anti-CD28 and soluble IL-2) for 5 days, followed by 2 days of rest in low IL-2 containing media to mimic generation of effector memory T cells. CD11c+ BMDCs were sorted via AutoMacs and activated with effector memory T cells (ratio of 1:4) in the presence or absence of soluble anti-CD3 (200ng/mL) for 3 hours. Cells were pretreated with blocking and neutralizing antibodies for CD40L and TNF (20ug/mL for 30 minutes) when indicated. Cells were blocked with FC block and stained with flourophores to distinguish DCs from T cells. DCs were FACS sorted and lysed in Trizol. Conclusion: Effector memory T cells activate interacting BMDCs via CD40 and TNF signaling. When these pathways are blocked, BMDCs fail to upregulate the transcriptional program associated with effector memory T cell induced activation. Overall design: mRNA profiles of BMDCs stimulated with Th0 cells via CD3 in the presence or absence of TNF and CD40L blocking antibodies for 3 hours by Illumina sequencing in duplicate.