工程菌介导的唾液酸酶递送重塑肿瘤免疫微环境

he tumor microenvironment is composed of a variety of cellular and non cellular components, which affect the occurrence, development and metastasis of tumor tissues, and hinder the recognition and killing of tumor tissues by immune cells. Sialic acid, as a molecule upregulated in a variety of tumor models, inhibits the activation of immune cells by binding to siglec receptors on immune cells. In this study, an engineered strain slpnanh encoding sialidase (nanH) was designed with attenuated Salmonella typhimurium ΔppGpp as the carrier. Through plasmid construction technology, the engineered strain slpnanh was constructed using pBAD vector carrying nanH, which has high sialidase activity. In vitro, crystal violet staining and scratch experiments showed that it could inhibit the proliferation and migration of MC38 cell line. The slpnanh developed in this study has a good effect in the treatment of MC38 tumor cell line mediated by bacteria, and has a broad prospect of clinical application.