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Irradiation Suppresses IFNγ-Mediated PD-L1 and MCL1 Expression in EGFR-Positive Lung Cancer to Augment CD8+ T Cells Cytotoxicity
- Source :
- Cells, Vol 10, Iss 2515, p 2515 (2021), Cells, Volume 10, Issue 10
- Publication Year :
- 2021
- Publisher :
- MDPI AG, 2021.
-
Abstract
- Tumor cells express immune checkpoints to exhaust CD8+ T cells. Irradiation damages tumor cells and augments tumor immunotherapy in clinical applications. However, the radiotherapy-mediated molecular mechanism affecting CD8+ T cell activity remains elusive. We aimed to uncover the mechanism of radiotherapy augmenting cytotoxic CD8+ T cells in non-small-cell lung cancer (NSCLC). EGFR-positive NSCLC cell lines were co-cultured with CD8+ T cells from healthy volunteers. Tumor cell viability and apoptosis were consequently measured. IFNγ was identified secreted by CD8+ T cells and PBMCs. Therefore, RNAseq was used to screen the IFNγ-mediated gene expression in A549 cells. The irradiation effect to IFNγ-mediated gene expression was investigated using qPCR and western blots. We found that the co-culture of tumor cells stimulated the increase of granzyme B and IFNγ in CD8+ T, but A549 exhibited resistance against CD8+ T cytotoxicity compared to HCC827. Irradiation inhibited A549 proliferation and enhanced apoptosis, augmenting PBMCs-mediated cytotoxicity against A549. We found that IFNγ simultaneously increased phosphorylation on STAT1 and STAT3 in EGFR-positive lung cancer, resulting in overexpression of PD-L1 (p &lt<br />0.05). In RNAseq analysis, MCL1 was identified and increased by the IFNγ-STAT3 axis (p &lt<br />0.05). We demonstrated that irradiation specifically inhibited phosphorylation on STAT1 and STAT3 in IFNγ-treated A549, resulting in reductions of PD-L1 and MCL1 (both p &lt<br />0.05). Moreover, knockdowns of STAT3 and MCL1 increased the PBMCs-mediated anti-A549 effect. This study demonstrated that A549 expressed MCL1 to resist CD8+ T cell-mediated tumor apoptosis. In addition, we found that irradiation suppressed IFNγ-mediated STAT3 phosphorylation and PD-L1 and MCL1 expression, revealing a potential mechanism of radiotherapy augmenting immune surveillance.
- Subjects :
- PD-L1
Lung Neoplasms
QH301-705.5
medicine.medical_treatment
T cell
CD8-Positive T-Lymphocytes
CD8+ T cells
Article
B7-H1 Antigen
STAT3
Interferon-gamma
Immune system
STAT1
medicine
Cytotoxic T cell
Humans
Biology (General)
Cell Proliferation
A549 cell
biology
irradiation
Radiotherapy
Chemistry
General Medicine
Immunotherapy
Granzyme B
medicine.anatomical_structure
MCL1
non-small-cell lung cancer
biology.protein
Cancer research
Myeloid Cell Leukemia Sequence 1 Protein
CD8
Subjects
Details
- Language :
- English
- ISSN :
- 20734409
- Volume :
- 10
- Issue :
- 2515
- Database :
- OpenAIRE
- Journal :
- Cells
- Accession number :
- edsair.doi.dedup.....2c4e7eaded409d48d120831dd08ca7fd