Intravesical Pseudomonas aeruginosa mannose-sensitive Hemagglutinin vaccine triggers a tumor-preventing immune environment in an orthotopic mouse bladder cancer model.
Cancer Immunol Immunother
; 71(6): 1507-1517, 2022 Jun.
Article
in En
| MEDLINE
| ID: mdl-34718847
Bacillus Calmette-Guerin (BCG) immunotherapy can prevent recurrence and progression in selected patients with non-muscle-invasive bladder cancer (NMIBC); however, significant adverse events and treatment failure suggest the need for alternative agents. A commercial anti-infection vaccine comprises a genetically engineered heat-killed Pseudomonas aeruginosa (PA) expressing many mannose-sensitive hemagglutination (MSHA) fimbriae, termed PA-MSHA, which could be a candidate for bladder cancer intravesical therapy. In an immunocompetent orthotopic MB49 bladder cancer model, we characterized the antitumor effects and mechanisms of PA-MSHA compared with those of BCG. Three weekly intravesical PA-MSHA or BCG treatments reduced tumor involvement; however, only PA-MSHA prolonged survival against MB49 implantation significantly. In non-tumor-bearing mice after treatment, flow-cytometry analysis showed PA-MSHA and BCG induced an increased CD4/CD8 ratio, the levels of effector memory T cell phenotypes (CD44, CXCR-3, and IFN-γ), and the proportion of CD11b+Ly6G-Ly6C-IA/IE+ mature macrophages, but a decrease in the proportion of CD11b+Ly6G-Ly6C+IA/IE- monocytic myeloid-derived suppressor cells (Mo-MDSCs) and the expression of suppressive molecules on immune cells (PD-L1, PD-1, TIM-3, and LAG-3). Notably, PA-MSHA, but not BCG, significantly reduced PD-1 and TIM-3 expression on CD4+ T cells, which might account for the better effects of PA-MSHA than BCG. However, in tumor-bearing mice after treatment, the increased proportion of Mo-MDSCs and high expression of PD-L1 might be involved in treatment failure. Thus, modulating the balance among adaptive and innate immune responses was identified as a key process underlying PA-MSHA-mediated treatment efficacy. The results demonstrated mechanisms underlying intravesical PA-MSHA therapy, pointing at its potential as an alternative effective treatment for NMIBC.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Urinary Bladder Neoplasms
/
Carcinoma, Transitional Cell
/
Mycobacterium bovis
Type of study:
Diagnostic_studies
Limits:
Animals
/
Humans
Language:
En
Journal:
Cancer Immunol Immunother
Journal subject:
ALERGIA E IMUNOLOGIA
/
NEOPLASIAS
/
TERAPEUTICA
Year:
2022
Document type:
Article
Country of publication:
Germany