4P - Immune exoproteome, soluble proteome and immune-related gene expression profiles of anti-PD-1 therapy in stage IIIB/IV Non-Small Cell Lung Cancer: relevance of immunosuppressive factors

Background

This study intended to evaluate the immunological status of patients with stage IIIB/IV non-small cell lung cancer (NSCLC) comparing samples at diagnostics (DX), after chemotherapy (CT) and undergoing immune checkpoint blockade (ICB) immunotherapy.

Methods

Comprehensive immunophenotyping (>200 parameters defining T, B, NK, NKT-like cells, monocytes, dendritic cells, and myeloid-derived suppressor cells) was performed using peripheral blood from 44 stage IIIB/IV NSCLC patients. Immune related gene expression quantification for 103 targets, including 9 reference genes, was performed by RT-qPCR. Additionally, 103 immune-related plasmatic factors (cytokines, chemokines, growth factors and soluble immune checkpoints) were quantified using xMAP (Luminex®) technology.

Results

Most important finding consists in myeloid-derived suppressor cells (MDSCs) significant increase in all NSCLC patients compared to CTRL, particularly monocytic Myeloid-Derived Supressor Cells (M-MDSC). Similarly, type 2 myeloid dendritic cells (mDC2) demonstrated the same results for ICB patients. Particular T cells subsets (CD8, activated CD8, memory CD45RA+ and Tregs), transitional B cells, CD56bright NK cells and NKT-like cells were found significantly increased in ICB patients. Gene expression analysis revealed associations with genes involved in the T cell response, MHC class I expression, metabolism, adhesion molecules and vascular endothelial growth factors. Concerning the soluble factors associated with M-MDSC, a significant increase in VISTA/B7-H5 was observed in NSCLC patients under immunotherapy. A significant increase in IL-10 was observed, thus promoting the differentiation of Treg cells by cDC2. Using unsupervised machine-learning clustering analysis algorithms we were able to identify a global signature associated with checkpoint inhibitor blockade therapy and response to treatment (RECIST1.1).

Conclusions

In conclusion, this study suggests the importance of an extensive evaluation of cellular and soluble immune factors, which may prove useful in the selection and monitoring of patients undergoing immunotherapy in lung cancer.

Legal entity responsible for the study

The authors.

Funding

FCT - Portuguese Foundation for Science and Technology.

Disclosure

All authors have declared no conflicts of interest.