[HTML][HTML] Differential effects of PD-L1 versus PD-1 blockade on myeloid inflammation in human cancer
JCI insight, 2020•ncbi.nlm.nih.gov
BACKGROUND PD-1 and PD-L1 have been studied interchangeably in the clinic as
checkpoints to reinvigorate T cells in diverse tumor types. Data for biologic effects of
checkpoint blockade in human premalignancy are limited. METHODS We analyzed the
immunologic effects of PD-L1 blockade in a clinical trial of atezolizumab in patients with
asymptomatic multiple myeloma (AMM), a precursor to clinical malignancy. Genomic
signatures of PD-L1 blockade in purified monocytes and T cells in vivo were also compared …
checkpoints to reinvigorate T cells in diverse tumor types. Data for biologic effects of
checkpoint blockade in human premalignancy are limited. METHODS We analyzed the
immunologic effects of PD-L1 blockade in a clinical trial of atezolizumab in patients with
asymptomatic multiple myeloma (AMM), a precursor to clinical malignancy. Genomic
signatures of PD-L1 blockade in purified monocytes and T cells in vivo were also compared …
Abstract
BACKGROUND
PD-1 and PD-L1 have been studied interchangeably in the clinic as checkpoints to reinvigorate T cells in diverse tumor types. Data for biologic effects of checkpoint blockade in human premalignancy are limited.
METHODS
We analyzed the immunologic effects of PD-L1 blockade in a clinical trial of atezolizumab in patients with asymptomatic multiple myeloma (AMM), a precursor to clinical malignancy. Genomic signatures of PD-L1 blockade in purified monocytes and T cells in vivo were also compared with those following PD-1 blockade in lung cancer patients. Effects of PD-L1 blockade on monocyte-derived DCs were analyzed to better understand its effects on myeloid antigen-presenting cells.
RESULTS
In contrast to anti–PD-1 therapy, anti–PD-L1 therapy led to a distinct inflammatory signature in CD14+ monocytes and increase in myeloid-derived cytokines (eg, IL-18) in vivo. Treatment of AMM patients with atezolizumab led to rapid activation and expansion of circulating myeloid cells, which persisted in the BM. Blockade of PD-L1 on purified monocyte-derived DCs led to rapid inflammasome activation and synergized with CD40L-driven DC maturation, leading to greater antigen-specific T cell expansion.
CONCLUSION
These data show that PD-L1 blockade leads to distinct systemic immunologic effects compared with PD-1 blockade in vivo in humans, particularly manifest as rapid myeloid activation. These findings also suggest an additional role for PD-L1 as a checkpoint for regulating inflammatory phenotype of myeloid cells and antigen presentation in DCs, which may be harnessed to improve PD-L1–based combination therapies.
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