TFEB and TFE3 cooperate in the regulation of the innate immune response in activated macrophages

Abstract

The activation of transcription factors is critical to ensure an effective defense against pathogens. In this study we identify a critical and complementary role of the transcription factors TFEB and TFE3 in innate immune response. By using a combination of chromatin immunoprecipitation, CRISPR-Cas9-mediated genome-editing technology, and in vivo models, we determined that TFEB and TFE3 collaborate with each other in activated macrophages and microglia to promote efficient autophagy induction, increased lysosomal biogenesis, and transcriptional upregulation of numerous proinflammatory cytokines. Furthermore, secretion of key mediators of the inflammatory response (CSF2, IL1B, IL2, and IL27), macrophage differentiation (CSF1), and macrophage infiltration and migration to sites of inflammation (CCL2) was significantly reduced in TFEB and TFE3 deficient cells. These new insights provide us with a deeper understanding of the transcriptional regulation of the innate immune response.

Enhanced translation expands the endo-lysosome size and promotes antigen presentation during phagocyte activation

“…4a, b). These results are consistent with observations by Pastore et al, who also observed delayed nuclear entry of these proteins in response to LPS-induced macrophage activation (Pastore et al, 2016). Strikingly, mRNA levels of TFEB and TFE3 target genes (i.e.…”

“…5, 2018; Our results suggest that biosynthesis plays a major role in LPS-induced lysosome expansion in macrophages. Activation of TFEB and TFE3 transcription factors drives expression of lysosomal genes thereby stimulating lysosome function under various stresses including starvation, phagocytosis, protein aggregation and macrophage activation (Gray et al, 2016;Liu et al, 2017;Martina et al, 2014;Pastore et al, 2016;Polito et al, 2014;Raben and Puertollano, 2016;Sardiello et al, 2009;Settembre et al, 2012Settembre et al, , 2013. Thus, we next investigated whether the observed rapid lysosome expansion was driven by TFEB-and TFE3-mediated transcriptional upregulation of lysosome genes.…”

“…To further exclude the role of TFEB in lysosome expansion during macrophage activation, we measured tubulation and lysosome volume in RAW macrophages deleted for the genes encoding TFEB and/or TFE3 using CRISPR-based technology (Pastore et al, 2016).…”

Lysosome enlargement during inhibition of the lipid kinase PIKfyve proceeds through lysosome coalescence

“…To do this, RAW macrophages deleted for TFEB, TFE3 or both (Pastore et al, 2016) were treated with vehicle or apilimod for 1 h and manually assessed for the average diameter and number of swollen vacuoles using differential interference contrast (DIC) optics. As suspected, RAW cells carrying deletions for TFEB and/or TFE3 were not impaired in apilimod-induced vacuolation, with vacuole number and size comparable to wild-type RAW cells (Supplemental Fig.…”

“…For example, in macrophages and dendritic cells, lysosomes are transformed from individual puncta into a highly tubular network (Saric et al, 2016;Vyas et al, 2007;Swanson et al, 1987). In addition, nutrient depletion, protein aggregation, and phagocytosis activate a family of transcription factors that can enhance expression of lysosome genes and adjust lysosome activity (Gray et al, 2016;Pastore et al, 2016;Sardiello et al, 2009;Tsunemi et al, 2012;Medina et al, 2011;Settembre et al, 2012;Roczniak-Ferguson et al, 2012). This is best understood for the related transcription factors, TFEB and TFE3, which are recruited to the surface of lysosomes and subject to phosphorylation by various kinases including mTORC1 to modulate their nucleo-cytoplasmic transport (Li et al, 2016b;Martina et al, 2012;Peña-Llopis et al, 2011;Martina et al, 2014Martina et al, , 2016Roczniak-Ferguson et al, 2012).…”