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Biology subjects

Agardy, D. A.

Publications and source records attributed to Agardy, D. A..

3 recordsLinked to original sources

Tissue resident CD4+ memory T-cells mark response to immune checkpoint inhibition in high-grade glioma

Background: Immune checkpoint inhibitors (ICI) are efficacious in many solid tumors, but response in glioma is restricted to a small subgroup. The determinants of response and resistance to ICI remain poorly understood. Methods: Here we exploit a syngeneic hypermutated high-grade glioma model with dichotomous response to combined PD-1 and CTLA-4 inhibition to unravel determinants of tumor-infiltrating T-cells driving response. Tumor-infiltrating T-cells from ICI-responsive and non-responsive tumors were analyzed by single-cell RNA and T-cell receptor sequencing and tumor-reactive T-cell receptor clonotypes were functionally validated to characterize their transcriptional phenotypes. We verify our findings in IDH1 wildtype glioblastoma patients treated with neoadjuvant pembrolizumab. Results: ICI response was associated with intratumoral clonal expansion of tumor-reactive cytotoxic T-cells and increased infiltration of CXCR6+ CD4+ tissue resident memory T-cells (Trm). CD4 stem-like memory T-cells in responding tumors demonstrated elevated interferon responses, following trajectories toward clonally expanded Trm, versus trajectories toward exhaustion in non-responsive tumors. In responsive tumors, CD4+ Trm interacted with infiltrating CXCR3+ tumor-reactive and clonally expanded, yet transcriptionally versatile cytotoxic T-cells. Probing the post neoadjuvant ICI high-grade glioma patient tissue dataset, we confirmed increased CXCR6 expression in CD4+ T cells and the association of CD4+ Trm with prolonged overall survival. Conclusion: These findings identify CD4 tissue-resident memory T-cells as determinants of ICI response in IDH1 wildtype high-grade glioma and warrant their further investigation to improve immunotherapy outcomes.

cancer biology↗

Inflammatory endothelial cells promote infiltration of antigen-licensed cytotoxic T cells in malignant gliomas after irradiation

Insufficient T cell infiltration into malignant gliomas fundamentally limits the efficacy of adoptive T cell therapy. Here we show that fractionated irradiation overcomes this barrier by reprogramming the tumor endothelium towards an immune-recruiting interface. Using complementary murine glioma models combined with adoptive T cell transfer, antigen-specific vaccination, and single-cell transcriptomic and T cell receptor profiling, we demonstrate that irradiation enhances the accumulation, clonal expansion, and effector differentiation of tumor-specific CD8+ T cells. Irradiated tumors showed increased T cell receptor clonality and local enrichment of proliferative effector CD8 T cells with enhanced cytotoxic, interferon-responsive, and oxidative metabolic programs. Mechanistically, irradiation triggers a conserved interferon-driven endothelial program marked by antigen presentation and upregulation of adhesion molecules, including ICAM-1 and VCAM-1. This radiation-induced endothelial activation program preferentially seen in inflammatory endothelial subsets was conserved in human glioblastoma and linked to T cell recruitment and maintenance of activated CD8 T cell states. Functionally, irradiation synergized with adoptive T cell transfer and antigen-specific vaccination to promote glioma-specific T cell accumulation and effector differentiation, improving tumor control and survival. Together, these findings identify radiation-induced endothelial activation as a key regulator of T cell trafficking across the brain tumor vasculature highlighting the vascular niche as a critical determinant of immunotherapy efficacy and a rational target for combination strategies in glioblastoma.

immunology↗

Macrophage-derived VEGF-C decreases hematogenous metastatic dissemination by normalizing the tumor vasculature

Expression of pro-lymphangiogenic vascular endothelial growth factor C (VEGF-C) in primary tumors correlates with the occurrence of proximal lymph node metastasis in most solid cancer types. However, the role of VEGF-C in regulating tumor cell dissemination to distant organs is currently unclear. Perivascular tumor-associated macrophages (TAMs) are key regulators of hematogenous cancer cell spreading, forming tumor microenvironment of metastasis (TMEM) doorways for breast cancer cells to intravasate tumor blood vessels and fuel distant metastases. Using an experimental breast cancer (BC) model, we show here that TAMs expressing VEGF-C decrease cancer cell dissemination to the lung while enhancing lymph node metastasis. These TAMs express podoplanin and associate with normalized tumor blood vessels expressing VEGFR3. Further clinical data reveal that VEGF-C+ TAMs correlate inversely with malignant grade and with the occurrence of TMEM complexes in a cohort of BC patients. Thus, our study displays an apparently paradoxical role of VEGF-C expressing TAMs in redirecting cancer cells to preferentially disseminate to the lymph nodes, at least in part, by normalizing tumor blood vessels and promoting lymphangiogenesis.

cancer biology↗