Anti-TNF Agents Restrict Adherent-invasive Escherichia coli Replication Within Macrophages Through Modulation of Chitinase 3-like 1 in Patients with Crohn’s Disease

Abstract

Background & Aims The mechanism of action of anti-TNF agents could implicate macrophages modulation in Crohn’s disease (CD). As CD macrophages are defective to control CD-associated adherent-invasive E. coli (AIEC), anti-TNF agents could limit AIEC replication within macrophages. We assessed the effect of anti-TNF agents on AIEC survival within monocytes-derived macrophages (MDM) from CD patients and attempted to identify the implicated proteins. Methods Peripheral blood monocyte-derived macrophages (MDM) were obtained from 44 CD patients including 22 with and 22 without anti-TNF agents. MDM were infected with AIEC-LF82 reference strain. Proteomic analysis was performed before and 6h after AIEC-LF82 infection. Results AIEC-LF82 survival was lower in MDM from CD patients receiving anti-TNF agents compared to those who did not (-73%, p=0.006). After AIEC-LF82 infection, the levels of CD82 (p=0.007), ILF3 (Interleukin enhancer-binding factor 3; p=0.001), FLOT-1 (Flotillin-1; p=0.007) and CHI3L1 (Chitinase 3-like 1; p=0.035) proteins were different within CD-MDM depending on anti-TNF exposure. FLOT-1 (ϱ=- 0.44; p=0.038) and CHI3L1 (ϱ=0.57, p=0.006) levels were inversely and positively correlated with AIEC survival within MDM from CD patients with or without anti-TNF, respectively. We observed a dose-dependent decrease of AIEC-LF82 survival after adjunction of anti-TNF within MDM inducing increase of FLOT-1 and decrease of CHI3L1 mRNA levels. Neutralization of intra-macrophagic CHI3L1 protein using anti-CHI3L1 antibodies reduced AIEC survival within macrophages 6h after infection (p<0.05). Conclusion Anti-TNF agents are able to restrict replication of pathobiont, such as AIEC, within macrophages by modulating FLOT-1 and CHI3L1 expressions in CD patients.

AcrAB efflux pump impacts on the survival of adherent-invasive Escherichia coli strain LF82 inside macrophages

“…Adherent-Invasive Escherichia coli (AIEC) is a group of pathogenic E. coli isolated at high frequency in patients suffering of Chron’s disease (CD), a severe intestinal inflammatory disease 34 . Several molecular and cellular studies support a role of AIEC in CD by promoting inflammation via stimulation of the immune system 35 – 37 . The AIEC phenotype relies on the ability of the bacteria to adhere and invade intestinal epithelial cells and to survive and replicate extensively inside macrophages without inducing cell death 38 – 40 .…”

Stratifying macrophages based on their infectious burden identifies novel host targets for intervention during Crohn’s disease associated adherent-invasiveEscherichia coliinfection

“…While clomipramine significantly reduced both intracellular burden of LF82 and the number of cells infected with LF82, trametinib significantly inhibited TNF release. Intriguingly in the case of both inhibitors, they decoupled intracellular proliferation and cytokine release which have been shown to be interdependent during AIEC infection (Bringer et al, 2012;Douadi et al, 2022). Kinase inhibitors such as trametinib can block cell proliferation, arrest the cell cycle and induce cell death as well as blocking extracellular signal-regulated kinase (ERK) signalling, which plays a role in cytokine secretion during AIEC infection (Hedl and Abraham, 2012;Hoffner, MSN, ANP-BC, AOCNP and Benchich, MSN, NP-C, AOCNP, 2018).…”

“…A hall mark of AIEC infection is replication to high levels within infected macrophages, where it can stall cell death pathways, a likely contributory factor in granuloma formation (Meconi et al ., 2007; Dunne et al ., 2013). With a paucity of information regarding the key drivers for the success of infection in the host-pathogen relationship, the treatment of AIEC infection in the context of CD has proved challenging, although recent progress has been made (Boucher and Barnich, 2022; Douadi et al ., 2022; Gerner et al ., 2022; Titécat et al ., 2022). However, while AIEC replicates and persists to high levels in some infected macrophages this does not occur in all infected cells.…”

The roles of FLOT1 in human diseases (Review)

“…Anti-TNF agents can limit AIEC survival within macrophages, and anti-TNF agents can induce the increase of FLOT1 and decrease mRNA levels of CHI3L1, which can promote the clearance of AIEC. Moreover, the levels of FLOT1 are negatively correlated with AIEC survival in CD patients treated with anti-TNF agents ( 96 ). FLOT1 in lipid rafts is an important part of the phagocytic lysosomal membrane of macrophages, thus FLOT1 plays an important role in anti-fungal immunity ( 97 ).…”