flow-cytometry-based-isolation-therapeutic-evaluation-tumor

Flow Cytometry-Based Isolation and Therapeutic Evaluation of Tumor-Infiltrating Lymphocytes in a Mouse Model of Pancreatic Cancer

Pancreatic cancer is an aggressive malignancy with a dismal prognosis and limited therapeutic options. Adoptive cell therapy, which involves isolating and ...

Pancreatic ductal adenocarcinoma (PDAC) is characterized by poor response to all therapeutic modalities and dismal prognosis. The presence of tertiary lymphoid structures (TLSs) in various solid cancers is of crucial prognostic significance, highlighting the intricate interplay between the tumor microenvironment and immune cells aggregation. However, the extent to which TLSs and immune status affect PDAC prognosis remains incompletely understood. Here, we sought to unveil the unique properties of TLSs in PDAC by leveraging both single-cell and bulk transcriptomics, culminating in a risk model that predicts clinical outcomes. We used TLS scores based on a 12-gene (CCL2, CCL3, CCL4, CCL5, CCL8, CCL18, CCL19, CCL21, CXCL9, CXCL10, CXCL11, and CXCL13) and 9-gene (PTGDS, RBP5, EIF1AY, CETP, SKAP1, LAT, CCR6, CD1D, and CD79B) signature, respectively, and examined their distribution in cell clusters of single-cell data from PDAC samples. The markers involved in these clusters were selected to develop a prognostic model using The Cancer Genome Atlas Program database as the training cohort and Gene Expression Omnibus database as the validation cohort. Further, we compared the immune infiltration, drug sensitivity, and enriched and differentially expressed genes between the high- and low-risk groups in our model. Therefore, we established a risk model that has significant implications for the prognostic assessment of PADC patients with remarkable differences in immune infiltration and chemosensitivity between the low- and high-risk groups. This paradigm established by TLS-related cell marker genes provides a prognostic prediction and a panel of novel therapeutic targets for exploring potential immunotherapy.

Integrating tertiary lymphoid structure-associated genes into computational models to evaluate prognostication and immune infiltration in pancreatic cancer.

Mast cell tryptases, a family of serine proteases involved in inflammatory responses and cancer development, present challenges in structural characterization and inhibitor development. We employed state-of-the-art protein structure prediction algorithms to model the three-dimensional structures of tryptases α, β, δ, γ, and ε with high accuracy. Computational docking identified potential substrates and inhibitors, suggesting overlapping yet distinct activities. Tryptases β, δ, and ε were predicted to act on phenolic compounds, with β and ε additionally hydrolyzing cyanides. Tryptase δ may possess unique formyl-CoA dehydrogenase activity. Virtual screening revealed 63 compounds exhibiting strong binding to tryptase β (TPSB2), 12 exceeding the affinity of the known inhibitor. Notably, the top hit (3-chloro-4-methylbenzimidamide) displayed over 10-fold selectivity for tryptase β over other isoforms. Our integrative approach combining protein modeling, functional annotation, and molecular docking provides a framework for characterizing tryptase isoforms and developing selective inhibitors of therapeutic potential in inflammatory and cancer conditions.

Computational modeling of mast cell tryptase family informs selective inhibitor development.

Pancreatic ductal adenocarcinoma (PDAC) exhibits an immunosuppressive tumor microenvironment (TME) contributing to its therapeutic resistance. Following our previous studies, we report that mast cells infiltrating the PDAC TME foster this immunosuppression and desmoplasia. Mast cell infiltration correlated with human PDAC progression, and genetic or pharmacological mast cell depletion reduced tumor growth and desmoplasia while enhancing survival in mouse PDAC models. Mechanistically, mast cell-derived IL-10 promoted PDAC progression. Strikingly, combining an agonistic anti-OX40 immunotherapy with mast cell blockade synergistically elicited durable anti-tumor immunity, marked by increased infiltration of CD8 T effector cells expressing granzyme B and dramatic survival benefit unachievable with either approach alone. An OX40-associated gene signature correlated with improved survival in human PDAC, supporting therapeutic translation. Our findings establish mast cells as promoters of the suppressive PDAC TME and rational targets for combination immunotherapy. Targeting this mast cell-mediated resistance mechanism could overcome immunotherapy failure in PDAC.

Article	Year
Integrating tertiary lymphoid structure-associated genes into computational models to evaluate prognostication and immune infiltration in pancreatic cancer. Journal of leukocyte biology\| PubMed ID: 38484172	2024
Computational modeling of mast cell tryptase family informs selective inhibitor development. iScience\| PubMed ID: 39280611	2024
Tumor-infiltrating mast cells confer resistance to immunotherapy in pancreatic cancer. iScience\| PubMed ID: 39473974	2024

Xiangqin Zhao

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