Tumor-specific antibodies elicited by engineered bacteria promote bladder cancer immunotherapy in preclinical mouse models
(1) Rouanne M (2) Chen N (3) Mariuzza DL (4) Yang Z (5) Li F (6) de Los Santos-Alexis K (7) Savage TM (8) Vincent RL (9) Mendelsohn CL (10) Danino T (11) Arpaia N
Rouanne et al. engineered probiotic E.coli (EcN) using a synchronized lysis integrated circuit to release human CXCL13 at critical population densities, without impeding normal bacterial growth. EcN CXCL13 release promoted B cell and splenocyte migration in vitro and high tumor expression after delivery into mouse bladders. In orthotopic bladder cancer models, EcN-colonized tumors selectively elicited GC responses in tdLNs. EcN boosted anti-PD-1-induced antitumor activity, tumor-specific antibody responses, and long-term survival in “cold” advanced bladder cancer models, and generated immune memory. Efficacy depended on CD8⁺ T and CD4⁺ TFH cells.
Contributed by Paula Hochman
(1) Rouanne M (2) Chen N (3) Mariuzza DL (4) Yang Z (5) Li F (6) de Los Santos-Alexis K (7) Savage TM (8) Vincent RL (9) Mendelsohn CL (10) Danino T (11) Arpaia N
Rouanne et al. engineered probiotic E.coli (EcN) using a synchronized lysis integrated circuit to release human CXCL13 at critical population densities, without impeding normal bacterial growth. EcN CXCL13 release promoted B cell and splenocyte migration in vitro and high tumor expression after delivery into mouse bladders. In orthotopic bladder cancer models, EcN-colonized tumors selectively elicited GC responses in tdLNs. EcN boosted anti-PD-1-induced antitumor activity, tumor-specific antibody responses, and long-term survival in “cold” advanced bladder cancer models, and generated immune memory. Efficacy depended on CD8⁺ T and CD4⁺ TFH cells.
Contributed by Paula Hochman
ABSTRACT: The intratumoral microbiome has recently emerged as a potential hallmark of cancer, with implications for response or resistance to therapy. Bacteria can either promote or inhibit cancer growth. However, intratumoral bacteria can also be engineered using synthetic biology to remodel the tumor microenvironment. Here, we engineered the probiotic bacterium Escherichia coli Nissle 1917 (EcN) to express the human chemokine CXCL13 (C-X-C motif chemokine ligand 13), a critical component of germinal center (GC) formation. Antibody affinity maturation and class switching are fundamental aspects of adaptive immune response. Both occur primarily in the GCs of secondary lymphoid organs for defense against pathogens. Immune checkpoint blockade (ICB) efficacy is primarily driven by T cells; however, recent studies in mice and humans have shown that humoral immune responses act as critical partners for ICB-mediated antitumor activity. Using orthotopic models of bladder cancer, intravesically delivered engineered CXCL13-expressing EcN colonized bladder tumors and elicited GC responses in bladder tumor-draining lymph nodes after intravesical delivery. When combined with programmed cell death protein 1 (PD-1) blockade, engineered EcN improved antitumor activity in two aggressive, fast-growing, and immunologically cold orthotopic mouse models of bladder cancer. Mechanistically, this antitumor effect was dependent on the presence of CD8(+) T cells and CD4(+) T follicular helper cells; combination therapy increased tumor-specific antibody responses and promoted long-term survival and protective immunity upon tumor rechallenge. Thus, we demonstrate that synthetically engineered CXCL13-expressing EcN can enhance the efficacy of PD-1 checkpoint blockade immunotherapy by amplifying tumor-specific humoral immunity.
Author Info:
(1) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA.
(2) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA. (3) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA. (4) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. (5) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA. (6) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. (7) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. (8) Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA. (9) Department of Urology, Columbia University, New York, NY 10032, USA. (10) Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA. Department of Biomedical Engineering, Columbia University, New York, NY 10027, USA. Data Science Institute, Columbia University, New York, NY 10027, USA. (11) Department of Microbiology & Immunology, Columbia University, New York, NY 10032, USA. Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA.
Citation: Sci Transl Med 2026 Jul 22 18:eadv7600 Epub07/22/2026
