In Situ Synthesis of an Immune-Checkpoint Blocker from Engineered Bacteria Elicits a Potent Antitumor Response.
ACS Synth Biol
; 13(6): 1679-1693, 2024 Jun 21.
Article
in En
| MEDLINE
| ID: mdl-38819389
ABSTRACT
Immune-checkpoint blockade (ICB) reinvigorates T cells from exhaustion and potentiates T-cell responses to tumors. However, most patients do not respond to ICB therapy, and only a limited response can be achieved in a "cold" tumor with few infiltrated lymphocytes. Synthetic biology can be used to engineer bacteria as controllable bioreactors to synthesize biotherapeutics in situ. We engineered attenuated Salmonella VNP20009 with synthetic gene circuits to produce PD-1 and Tim-3 scFv to block immunosuppressive receptors on exhausted T cells to reinvigorate their antitumor response. Secreted PD-1 and Tim-3 scFv bound PD-1+ Tim-3+ T cells through their targeting receptors in vitro and potentiated the T-cell secretion of IFN-γ. Engineered bacteria colonized the hypoxic core of the tumor and synthesized PD-1 and Tim-3 scFv in situ, reviving CD4+ T cells and CD8+ T cells to execute an antitumor response. The bacteria also triggered a strong innate immune response, which stimulated the expansion of IFN-γ+ CD4+ T cells within the tumors to induce direct and indirect antitumor immunity.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Salmonella
/
Programmed Cell Death 1 Receptor
/
Immune Checkpoint Inhibitors
Limits:
Animals
/
Humans
Language:
En
Journal:
ACS Synth Biol
Year:
2024
Document type:
Article
Affiliation country:
China
Country of publication:
United States