Prevention and treatment of cancers by tumor antigen-expressing Staphylococcus epidermidis

Sep 24, 2026

Uploaded by Miles

A recent Science study reported genetic engineering of Staphylococcus epidermidis to express tumor cross-reactive antigens that trigger T-cell responses and show anticancer effects after topical delivery. This article discusses both direct local effects and indirect systemic effects from exposure to engineered S. epidermidis. It also explains how gut, bladder, and skin microbiota can shape anticancer immunity through immune-tonus modulation and specific cross-reactive T-cell responses, and summarizes experimental evidence supporting therapeutic potential alongside cancer therapies.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages3

Reading Time8 min

AccessFree to download

Editorial

Abstract

Immunological rationale and microbiome context

Engineered S. epidermidis models and therapeutic effects

Authors and publication information

ONCOIMMUNOLOGY 2023, VOL. 12, NO. 1, 2212547 [https://doi.org/10.1080/2162402X.2023.2212547](https://doi.org/10.1080/2162402X.2023.2212547) EDITORIAL Prevention and treatment of cancers by tumor antigen-expressing Staphylococcus epidermidis Oliver Kepp a,b, Laurence Zitvogelc,d,e,f, and Guido Kroemera,b,g aMetabolomics and Cell Biology Platforms, Gustave Roussy Cancer Center, Université Paris Saclay, Villejuif, France; bCentre de Recherche des Cordeliers, Equipe labellisée par la Ligue contre le cancer, Université de Paris, Sorbonne Université, Inserm U1138, Institut Universitaire de France, Paris, France; cGustave Roussy Comprehensive Cancer Institute, Villejuif, France; dUniversité Paris Saclay, Faculty of Medicine, Le Kremlin-Bicêtre, France; eEquipe labellisée par la Ligue contre le Cancer, INSERM U1015, Villejuif, France; fDepartment of Biology, Center of Clinical Investigations in Biotherapies of Cancer (CICBT) BIOTHERIS, Villejuif, France; gInstitut du Cancer Paris CARPEM, Department of Biology, Hôpital Européen Georges Pompidou, AP-HP, Paris, France ABSTRACT In a recent paper in Science, Chen et al. reported the genetic engineering of S. epidermidis expressing tumor cross-reactive antigens that trigger T cell responses and exhibit anticancer effects after topical administration. Here we discuss direct local effects and indirect systemic effects of exposure to engineered S. epidermidis strains. KEYWORDS Immunotherapy; Microbiome; Immunity Main text Oncogenesis and tumor progression are influenced by multiple extratumoral factors including the gut microbiota 1. Bacteria may improve immunosurveillance by two major effects. First, bacteria can contribute to the conditioning of a general (bodywide) or local (intestinal or tumoral) environment that nonspecifically favors the activity of anticancer immune effectors (or reduces the activity of immunosuppressive cells), hence exerting an adjuvant effect that improves the immune tonus2. Second, bacterial proteins can induce specific T cell immune responses against antigenic peptides that are cross-reactive with tumor-associated antigens3. It appears plausible that both effects can concur to reduce tumorigenesis or to ameliorate anticancer immune responses in conjunction with chemotherapy or immunotherapy1. Although much emphasis has been placed on the central role of the intestinal microflora, which is the most diverse and quantitatively abundant microbiota, other microbial communities including those of the bladder and the skin may play an important role in determining anticancer immune responses as well4,5. In a fascinating paper that was recently published in Science, Chen et al. demonstrate that, in mice, Staphylococcus epidermidis can be genetically manipulated to express tumor antigens and then used to prevent or treat cancers expressing such antigens6. S. epidermidis is part of the normal human skin microbiota and is usually not pathogenic, meaning that only patients bearing intravenous catheters or compromised immune systems develop clinically relevant infections by this Grampositive bacterium. Nonetheless, even in the absence of clinical signs of skin inflammation and barrier breaches, S. epidermidiscan elicit antigen-specific CD4+ and CD8+ T cell responses7. In their paper, Chen et al. set out to develop a method for the genetic manipulation of S. epidermis6. Using this method, the authors engineered S. epidermidis strains that expressed different variants of ovalbumin (OVA)-derived MHC class I-(OT1) or MHC class II-restricted (OT2) peptides, showing that the combination of soluble OT1 peptide and cell wall-attached OT2 was particularly efficient in inducing immune responses that restrained the growth of OVA-expressing B16F10 melanomas implanted under the skin ofC57Bl/6 mice. The absence of either OT1 or OT2 from S. epidermis, the absence of OVA from B16F10 melanomas or the depletion of CD8+ T lymphocytes precluded the anticancer effects obser

FAQs

What is the core idea behind using engineered Staphylococcus epidermidis against cancers?

Engineered S. epidermidis expresses tumor cross-reactive antigens that trigger specific T-cell responses. These responses can restrain tumor growth and reduce metastasis in experimental models.

How can bacteria influence anticancer immunity through non-specific and specific mechanisms?

Bacteria can condition general or local environments to favor anticancer immune effectors or reduce immunosuppressive cells. They can also provide bacterial proteins that induce specific T-cell responses against cross-reactive antigenic peptides.

Why does the engineered strain’s antigen design matter in the reported experiments?

Anticancer effects depend on the presence of OT1 and OT2 peptide variants in S. epidermidis and the matching antigen in tumor cells. Removing either peptide, removing tumor antigen, or depleting CD8+ T lymphocytes prevents the observed anticancer outcomes.

Sep 24, 2026

Uploaded by Miles