BCG therapy downregulates HLA-I on malignant cells to subvert antitumor immune responses in bladder cancer.

ABSTRACT: Patients with high-risk, nonmuscle-invasive bladder cancer (NMIBC) frequently relapse after standard intravesical bacillus Calmette-Guérin (BCG) therapy and may have a dismal outcome. The mechanisms of resistance to such immunotherapy remain poorly understood. Here, using cancer cell lines, freshly resected human bladder tumors, and samples from cohorts of patients with bladder cancer before and after BCG therapy, we demonstrate 2 distinct patterns of immune subversion upon BCG relapse. In the first pattern, intracellular BCG infection of cancer cells induced a posttranscriptional downregulation of HLA-I membrane expression via inhibition of autophagy flux. Patients with HLA-I-deficient cancer cells following BCG therapy had a myeloid immunosuppressive tumor microenvironment (TME) with epi

SUBMITTER: Rouanne M 

PROVIDER: S-EPMC9197524 | biostudies-literature | 2022 Jun

REPOSITORIES: biostudies-literature