Acetyltransferase fromAkkermansia muciniphilablunts colorectal tumourigenesis by reprogramming tumour microenvironment

Abstract

ObjectiveThe protein post-translational modification (PTM) in host cells can be rewritten by bacterial enzymes and represents an unprecedented mechanism in the communication between intestinal flora and the host. AlthoughAkkermansia muciniphilahas been widely investigated as a probiotic and blunts colitis-associated tumourigenesis in mice, there is little understanding regarding whetherA. muciniphilais involved in the PTM of colorectal cancer (CRC). This study investigates whether and howA. muciniphilaengages in the PTM of host CRC.DesignThe secreting extracellular vesicles fromA. muciniphilaand purified Amuc_2172 were used for different tumourigenesis mice models. Amuc_2172-induced immune activity of CD8+cytotoxic T lymphocytes (CTLs) were evaluated in vitro and in vivo. The acetyltransferase activity and downstream target genes of Amuc_2172 were investigated.ResultsAmuc_2172, a general control non-derepressible 5-related acetyltransferase ofA. muciniphila, was accessible to colorectal cells by macropinocytosis and functioned as an acetyltransferase of Lys14 on histone H3 (H3K14ac). Elevated H3K14ac onHspa1aloci promoted the transcription and secretion of heat-shock protein 70 (HSP70) in cancer cells. High level of HSP70 promoted the immune activity of CTLs in vitro and in vivo. Moreover, bioengineered nanoparticles provided a safe and reliable drug delivery strategy of Amuc_2172 for CRC treatment in an allograft mice model.ConclusionAmuc_2172 reprogrammed tumour microenvironment by inducing HSP70 secretion and promoting CTL-related immune response in the process of tumourigenesis.