Importance of EMT Factor ZEB1 in cDC1 “MutuDC Line” Mediated Induction of Th1 Immune Response

Abstract

The role of Epithelial to Mesenchymal Transition (EMT) factor Zeb1 is well defined in metastasis and cancer progression but it's importance in dendritic cells (DCs) is unexplored until now. For the first time we report here that Zeb1 controls immunogenic responses of CD8α+ conventional Type-I (cDC1) DCs. We found that ZEB1 expression increases significantly after TLR9 stimulation and its depletion impairs activation, co-stimulation and secretion of important cytokines like IL-6, IL-10 and IL-12 in cDC1 MutuDC line. We further confirmed our findings in primary cDC1 DCs derived from bone marrow. Co-culture of these Zeb1 knock down (KD) DCs with OT-II CD4+ T helper cells skewed their differentiation toward Th2 subtype. Moreover, adoptive transfer of activated Zeb1 KD DCs cleared intestinal worms in helminth infected mice by increasing Th2 responses in vivo. Integrative genomic analysis showed Zeb1 as an activator of immune response genes in cDC1 MutuDCs as compared to other pathway genes. In addition, differentially regulated genes in Zeb1 KD RNA-seq showed significant enrichment of Th2 activation pathways supporting our in vitro findings. Mechanistically, we showed that decreased IL-12 secreted by Zeb1 KD DCs is the plausible mechanism for increased Th2 differentiation. Collectively our data demonstrate that Zeb1 could be targeted in DCs to modulate T-cell mediated adaptive immune responses.

NCoR1: Putting the Brakes on the Dendritic Cell Immune Tolerance

“…To determine the role of NCoR1 in DCs, we have developed a stable NCoR1 knockdown (KD) and matched empty vector-transduced control cells using lentiviral short hairpin RNA (shRNA) approach in a CD8α + cDC1 DC line that mimics remarkably the ex vivo isolated cDC1 DCs (Fuertes Marraco et al., 2012, Smita et al., 2018). We found that NCoR1 transcript levels were significantly reduced (≥85%) in NCoR1 shRNA-transduced DCs (Figures 1A and S1A).…”

Angiotensin Inhibition, TGF-β and EMT in Cancer

“…They can have both inductive and repressive features at the same time, depending on whether they induce an epithelial or mesenchymal phenotype [ 116 ]. As they are responsible for the maintenance of the epithelial or mesenchymal phenotype, respectively, they are also expressed to a varying degree, depending on the cell type, in normal tissues [ 117 , 118 ].…”

ZEBs: Novel Players in Immune Cell Development and Function

“…Recently, one study examined the role of ZEB1 in the murine tumorderived DC cell line (MutuDC) [19] previously reported to resemble splenic cDC1s [20]. This study found that knocking down Zeb1 in MutuDCs led to their impaired activation upon stimulation with the toll-like receptor 9 (TLR9) agonist CpG, and CpG-activation of Zeb1-deficient MutuDCs skewed T cell differentiation towards a Th2 rather than a Th1 response; relative to controls, this was evidenced by a slight increase in GATA3 + interleukin (IL)-13 + Th2 cells and reduced T-bet + IFN-g + Th1 cells following DC:T cell coculture [19] (Figure 3). Transient Zeb1-deletion in mouse Flt3Lderived CD11c + CD24 + bone marrow-derived dendritic cells (BMDCs) also resulted in impaired cytokine secretion upon stimulation with CpG compared with WT controls [19].…”

“…This study found that knocking down Zeb1 in MutuDCs led to their impaired activation upon stimulation with the toll-like receptor 9 (TLR9) agonist CpG, and CpG-activation of Zeb1-deficient MutuDCs skewed T cell differentiation towards a Th2 rather than a Th1 response; relative to controls, this was evidenced by a slight increase in GATA3 + interleukin (IL)-13 + Th2 cells and reduced T-bet + IFN-g + Th1 cells following DC:T cell coculture [19] (Figure 3). Transient Zeb1-deletion in mouse Flt3Lderived CD11c + CD24 + bone marrow-derived dendritic cells (BMDCs) also resulted in impaired cytokine secretion upon stimulation with CpG compared with WT controls [19]. Although these results suggest that ZEB1 may play a role in modulating DC activation and the subsequent induction of T cell responses, in this study the effect of deleting Zeb1 on the development of cDC1s was not addressed and remains to be determined.…”

“…Likewise, in DCs, ZEB2 must be absent for normal cDC1 development to take place [7,14]. However, ZEB1 has been reported to be required for normal cytokine production by cDC1s following CpG stimulation [19]. Moreover, a role for TGF-b signaling and miR-200 family regulation remains be investigated in DCs, but as peripheral cDC1s are known to express CD103 (an integrin regulated by TGF-b signaling), hypothetically, this regulatory network might exist.…”