PUBLICATION

Macrophages directly kill bladder cancer cells through TNF signaling as an early response to BCG therapy

Authors
Martínez-López, M.F., de Almeida, C.R., Fontes, M., Mendes, R.V., Kaufmann, S.H.E., Fior, R.
ID
ZDB-PUB-240808-12
Date
2024
Source
Disease models & mechanisms   17(8): (Journal)
Registered Authors
Fior, Rita, Mendes, Raquel
Keywords
BCG immunotherapy, Bladder cancer, Innate immunity, Macrophages, TNF signaling, Zebrafish xenografts
MeSH Terms
  • Animals
  • Apoptosis*/drug effects
  • BCG Vaccine*/pharmacology
  • BCG Vaccine*/therapeutic use
  • Cell Line, Tumor
  • Humans
  • Macrophages*/drug effects
  • Macrophages*/metabolism
  • Signal Transduction*/drug effects
  • Tumor Microenvironment
  • Tumor Necrosis Factor-alpha/metabolism
  • Urinary Bladder Neoplasms*/drug therapy
  • Urinary Bladder Neoplasms*/immunology
  • Urinary Bladder Neoplasms*/pathology
  • Zebrafish*
PubMed
39114912 Full text @ Dis. Model. Mech.
Abstract
The Bacillus Calmette-Guérin (BCG) vaccine is the oldest cancer immunotherapeutic agent in use. Despite its effectiveness, its initial mechanisms of action remain largely unknown. Here, we elucidate the earliest cellular mechanisms involved in BCG-induced tumor clearance. We developed a fast preclinical in vivo assay to visualize in real time and at single-cell resolution the initial interactions among bladder cancer cells, BCG and innate immunity using the zebrafish xenograft model. We show that BCG induced the recruitment and polarization of macrophages towards a pro-inflammatory phenotype, accompanied by induction of the inflammatory cytokines tnfa, il1b and il6 in the tumor microenvironment. Macrophages directly induced apoptosis of human cancer cells through zebrafish TNF signaling. Macrophages were crucial for this response as their depletion completely abrogated the BCG-induced phenotype. Contrary to the general concept that macrophage anti-tumoral activities mostly rely on stimulating an effective adaptive response, we demonstrate that macrophages alone can induce tumor apoptosis and clearance. Thus, our results revealed an additional step to the BCG-induced tumor immunity model, while providing proof-of-concept experiments demonstrating the potential of this unique model to test innate immunomodulators.
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Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
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Mapping