Biology subjects

Karakousi, T.

Publications and source records attributed to Karakousi, T..

5 recordsLinked to original sources

bioRxiv2026

A tumor metabolism-angiogenesis-immune axis governs immunotherapy responses

Despite the clinical success of immunotherapy, long-lasting benefit remains restricted to a subset of patients. Tumor metabolic adaptation is emerging as a key factor limiting immunotherapy efficacy. We previously found that glycolysis-low tumor variants, compared to the parental glycolytic tumors, better respond to neoadjuvant CTLA-4 immune checkpoint blockade (ICB) therapy. Here, we investigated new rational modalities to restore immune sensitivity of glycolytic tumors by studying how lowering the tumor-cell glycolytic capacity reshapes the tumor microenvironment (TME) to favor long-lasting systemic anti-tumor responses upon immunotherapy. We found that lowering glycolysis in cancer cells through LDHA-knock down (KD) results in TME displaying normalized vasculature, reduced angiogenic markers, increased high endothelial venules (HEVs), and enhanced recirculation of CD8+ T cells both in and out of the tumor. By leveraging public transcriptomic data sets from human solid cancers, we confirmed that glycolysis positively correlates with neo-angiogenesis and inversely correlates with features of vascular normalization and immune cytolytic activity. Moreover, a tumor signature that incorporates glycolysis- and angiogenesis-related genes as positive features, and normal vasculature, HEV, and immune cytolytic activity genes as negative features predicted poor outcomes better than the individual features across most human solid tumor types in the TCGA. To determine the therapeutic implication of these interrelated processes, we asked if targeting the vasculature would restore immunotherapy responses in glycolytic tumors. We found that combining low-dose anti-VEGFR2 with CTLA-4 blockade induces tumor regressions and protection from metastases in glycolytic tumors. These therapeutic effects were associated with vasculature normalization and increased abundance of HEVs and concentrations of lymphangiogenic factors in the TME of glycolytic tumors. Moreover, anti-VEGFR2 with anti-CTLA-4 restored recirculation of anti-tumor CD8+ T cells in and out of the TME in glycolytic tumors, with specific increases in intratumoral recruitment and activation of cytolytic CD62LCD44CD8 T cells expressing VEGFR2 and low levels of CTLA-4, suggesting potential novel direct synergistic effects of anti-VEGFR2 and anti-CTLA-4 on CD8+ T cells. Conversely, this combination opposed the beneficial immune and vascular TME features of LDHA-KD tumors, indicating tumor-metabolic-dependent effects. Accordingly, we found that standard combined regimens of anti-VEGF and ICB therapy improve survival with respect to ICB alone in patients with glycolysis-high but not glycolysis-low tumors. Together, these findings indicate that tumor cell glycolysis "primes" the TME for aberrant vascular architecture and T-cell exclusion, and that modulating the tumor vasculature can unravel these mechanisms restoring immune responsiveness. This suggests that tailoring anti-angiogenic and immunotherapy combinations to the tumor glycolytic state and associated vasculature profiles may restore immune surveillance and overcome therapy resistance.

immunology↗

bioRxiv2025

Tertiary lymphoid structures support the development of allergen-specific progenitor CD4+ T cells

Tissue-resident memory CD4+ T cells (TRM) are key sentinels of the adaptive immune response that provide a rapid, robust inflammatory response upon reactivation in non-lymphoid tissues. While CD4+ TRM are highly protective during reinfections or tumor growth, they are also critical mediators of autoimmunity and allergic disease. Using transcriptional analysis and flow cytometry we profiled the heterogeneity of allergen-specific CD4+ TRM in the lungs following house dust mite exposure and observe two distinct populations of cells: a proinflammatory Th2 lineage and a progenitor TCF1+ lineage that can repopulate the Th2 branch. Confocal microscopy revealed that these two subsets occupied distinct anatomical niches in the inflamed lungs, with Th2 cells localized to the airways while TCF1+ cells localized within pulmonary tertiary lymphoid structures (TLS). Spatial transcriptomics affirmed the TLS as a tissue progenitor niche and highlight the transcriptional progression from progenitor to Th2 cell reflected in the TLS:airway axis. Manipulations to promote or ablate TLS development resulted in increased or decreased TCF1 expression among allergen-specific T cells, respectively. Finally, we identify the PD1 pathway as a critical signal localized to the TLS core and demonstrate that TCF1+ cells in the TLS are responsive to anti-PD1 treatment. Together, these data shape our understanding of tissue CD4+ T cell responses across space and time and highlight TLS as a critical therapeutic target that promotes the propagation of chronic inflammatory diseases.

immunology↗

bioRxiv2024

IFNγ-dependent metabolic reprogramming restrains an immature, pro-metastatic lymphatic state in melanoma

Lymphatic vessels play a crucial role in activating anti-tumor immune surveillance but also contribute to metastasis and systemic tumor progression. Whether distinct lymphatic phenotypes exist that govern the switch between immunity and metastasis remains unclear. Here we reveal that cytotoxic immunity normalizes lymphatic function and uncouples immune and metastatic potential. We find that in mice and humans, intratumoral lymphatic vessel density negatively correlates with productive cytotoxic immune responses and identify IFN{gamma} as an intrinsic inhibitor of lymphangiogenesis. Specific deletion of the Ifngr1 in lymphatic endothelial cells (LECs) greatly expanded the intratumoral lymphatic network and drove the emergence of a tip-like endothelial state, promoting lymph node metastasis but not dendritic cell migration. IFN{gamma} inhibits oxidative phosphorylation, which is required for proliferation and acquisition of the pathologic transcriptional state. Our data indicate that IFN{gamma} induces a phenotypic switch in tumor-associated lymphatic vessels to reinforce canonical immune surveillance and block metastasis.

cancer biology↗

bioRxiv2023

Glutamine antagonist DRP-104 suppresses tumor growth and enhances response to checkpoint blockade in KEAP1 mutant lung cancer

Loss-of-function mutations in KEAP1 frequently occur in lung cancer and are associated with resistance to standard of care treatment, highlighting the need for the development of targeted therapies. We have previously shown that KEAP1 mutant tumors have increased glutamine consumption to support the metabolic rewiring associated with NRF2 activation. Here, using patient-derived xenograft models and antigenic orthotopic lung cancer models, we show that the novel glutamine antagonist DRP-104 impairs the growth of KEAP1 mutant tumors. We find that DRP-104 suppresses KEAP1 mutant tumor growth by inhibiting glutamine-dependent nucleotide synthesis and promoting anti-tumor CD4 and CD8 T cell responses. Using multimodal single-cell sequencing and ex vivo functional assays, we discover that DRP-104 reverses T cell exhaustion and enhances the function of CD4 and CD8 T cells culminating in an improved response to anti-PD1 therapy. Our pre-clinical findings provide compelling evidence that DRP-104, currently in phase 1 clinical trials, offers a promising therapeutic approach for treating patients with KEAP1 mutant lung cancer. Furthermore, we demonstrate that by combining DRP-104 with checkpoint inhibition, we can achieve suppression of tumor intrinsic metabolism and augmentation of anti-tumor T cell responses.

cancer biology↗

bioRxiv2021

KEAP1 mutation in lung adenocarcinoma promotes immune evasion and immunotherapy resistance

Lung cancer treatment has benefited greatly from the development of effective immune-based therapies. However, these strategies still fail in a large subset of patients. Tumor-intrinsic mutations can drive immune evasion via recruiting immunosuppressive populations or suppressing anti-tumor immune responses. KEAP1 is one of the most frequently mutated genes in lung adenocarcinoma patients and is associated with poor prognosis and inferior response to all therapies, including checkpoint blockade. Here, we established a novel antigenic lung cancer model and showed that Keap1-mutant tumors promote dramatic remodeling of the tumor immune microenvironment. Combining single-cell technology and depletion studies, we demonstrate that Keap1-mutant tumors diminish dendritic cell and T cell responses driving immunotherapy resistance. Importantly, analysis of KEAP1 mutant patient tumors revealed analogous decrease in dendritic cell and T cell infiltration. Our study provides new insight into the role of KEAP1 mutations in promoting immune evasion and suggests a path to novel immune-based therapeutic strategies for KEAP1 mutant lung cancer. Statement of significanceThis study establishes that tumor-intrinsic KEAP1 mutations contribute to immune evasion through suppression of dendritic cell and T cell responses, explaining the observed resistance to immunotherapy of KEAP1 mutant tumors. These results highlight the importance of stratifying patients based on KEAP1 status and paves the way for novel therapeutic strategies.

cancer biology↗