AUTHOR=Tajpara Poojabahen , Sobkowiak Michał Jacek , Healy Katie , Naud Sabrina , Gündel Beate , Halimi Asif , Khan Zara Ahmad , Gabarrini Giorgio , Le Guyader Sylvie , Imreh Gabriela , Reisz Julie A. , Del Chiaro Marco , D’Alessandro Angelo , Heuchel Rainer , Löhr J Matthias , Özenci Volkan , Sällberg Chen Margaret 

TITLE=Patient-derived pancreatic tumor bacteria exhibit oncogenic properties and are recognized by MAIT cells in tumor spheroids

JOURNAL=Frontiers in Immunology

VOLUME=Volume 16 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2025.1553034

DOI=10.3389/fimmu.2025.1553034

ISSN=1664-3224

ABSTRACT=IntroductionTumor-residing microbiota poses a new challenge in cancer progression and therapy; however, the functional behavior of patient tumor-derived microbes remains poorly understood. We previously reported the presence of tumor microbiota in intraductal papillary mucinous neoplasms (IPMNs), which are precursors of pancreatic cancer.MethodsWe examined the metabolic and pathogenic potential of clinical microbiota strains obtained from IPMN tumors using various pancreatic cell lines and 3D spheroid models.ResultsOur findings revealed that several strains from IPMNs with invasive cancer or high-grade dysplasia, such as E. cloacae, E. faecalis, and K. pneumoniae, induced a cancer metabolite signature in human pancreatic cells when infected ex vivo. Bacterial invasiveness was significantly correlated with DNA damage in spheroids derived from normal and tumor-derived pancreatic cells, particularly in strains derived from advanced neoplasia IPMN and under hypoxic conditions. Additionally, microbial metabolites activate human mucosal-associated invariant T (MAIT) cells and restrict the infection, both extra- and intracellularly, in hypoxic tumor conditions and in synergy with antibiotics.DiscussionImmune sensing of tumor microbiota metabolites may have clinical implications in cancer management.