The presence of lymph node (LN)-like vasculature in tumors, characterized by expression of peripheral node addressin and chemokine CCL21, is correlated with T-cell infiltration and positive prognosis in breast cancer and melanoma patients. However, mechanisms controlling the development of LN-like vasculature and how it might contribute to a beneficial outcome for cancer patients are unknown. Here we demonstrate that LN-like vasculature is present in murine models of melanoma and lung carcinoma. It enables infiltration by naïve T-cells that significantly delay tumor outgrowth after intratumoral activation. Development of this vasculature is controlled by a mechanism involving effector CD8 T-cells and NK cells that secrete LTα3 and IFNγ. LN-like vasculature is also associated with organized aggregates of B-lymphocytes and gp38+ fibroblasts that resemble tertiary lymphoid organs that develop in models of chronic inflammation. These results establish LN-like vasculature as both a consequence of and key contributor to anti-tumor immunity.

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In the context of solid tumors, there is a positive correlation between the accumulation of cytotoxic CD8+ tumor infiltrating lymphocytes (TILs) and favorable clinical outcomes. However, CD8+ TILs often exhibit a state of functional exhaustion limiting their activity, and the underlying molecular basis of this dysfunction is not fully understood. Here, we show that TILss found in human and murine CD8+ melanomas are metabolically compromised with deficits in both glycolytic and oxidative metabolism. While several studies have shown that tumors can outcompete T cells for glucose, thus limiting T cell metabolic activity, we report that a down-regulation of the activity of enolase 1, a critical enzyme in the glycolytic pathway, represses glycolytic activity in CD8+ TILs. Provision of pyruvate, a downstream product of enolase 1, bypasses this inactivity and promotes both glycolysis and oxidative phosphorylation resulting in improved effector function of CD8+ TILs. We found high expression of both enolase 1 mRNA and protein in CD8+ TILs, indicating that the enzymatic activity of enolase 1 is regulated post-translationally. These studies provide a critical insight into the biochemical basis of CD8+ TILs dysfunction.

Purpose Although tyrosine kinase inhibitors (TKI) can be effective therapies for leukemia, they fail to fully eliminate leukemic cells and achieve durable remissions for many patients with advanced BCR-ABL+ leukemias or acute myeloid leukemias (AML). Through a large-scale synthetic lethal RNAi screen, we identified pyruvate dehydrogenase, the limiting enzyme for pyruvate entry into the mitochondrial tricarboxylic acid cycle, as critical for the survival of chronic myeloid leukemia cells upon BCR-ABL inhibition. Here we examined the role of mitochondrial metabolism in the survival of Ph+ leukemia and AML upon TK inhibition. Experimental Design Ph+ cancer cell lines, AML cell lines, leukemia xenografts, cord blood, patient samples were examined. Results We showed that the mitochondrial ATP-synthase inhibitor oligomycin-A greatly sensitized leukemia cells to TKI in vitro. Surprisingly, oligomycin-A sensitized leukemia cells to BCR-ABL inhibition at concentrations 100–1000-fold below those required for inhibition of respiration. Oligomycin-A treatment rapidly led to mitochondrial membrane depolarization and reduced ATP levels, and promoted superoxide production and leukemia cell apoptosis when combined with TKI. Importantly, oligomycin-A enhanced elimination of BCR-ABL+ leukemia cells by TKI in a mouse model and in primary blast crisis CML samples. Moreover, oligomycin-A also greatly potentiated the elimination of FLT3-dependent AML cells when combined with a FLT3 TKI, both in vitro and in vivo. Conclusions TKI therapy in leukemia cells creates a novel metabolic state that is highly sensitive to particular mitochondrial perturbations. Targeting mitochondrial metabolism as an adjuvant therapy could therefore improve therapeutic responses to TKI for patients with BCR-ABL+ and FLT3ITD leukemias.

Multiple Sclerosis (MS) is a disease characterized by immune-mediated destruction of central nervous system (CNS) myelin. Current MS therapies aim to block peripheral immune cells from entering the CNS. While these treatments limit new inflammatory activity in the CNS, no treatment effectively prevents long-term disease progression and disability accumulation in MS patients. One explanation for this paradox is that current therapies are ineffective at targeting immune responses already present in the CNS. To this end, we sought to understand the metabolic properties of T cells that mediate ongoing inflammation in the demyelinating CNS. Using experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice, a well-studied model of MS, we showed that the CD4+ and CD8+ T cells that invade the EAE CNS are highly glycolytic. This elevation of glycolysis is mediated by upregulated expression of the glycolytic machinery, and is essential for inflammatory responses to myelin. Surprisingly, we found that an inhibitor of glyceraldehyde-3 phosphate (GAPDH), 3-bromopyruvic acid (3-BrPa), blocks IFN-γ but not IL-17A production in immune cells isolated from the EAE CNS. Indeed, in vitro studies confirmed that the production of IFN-γ by differentiated Th1 cells is more sensitive to 3-BrPa than the production of IL-17A by Th17 cells. Finally, in transfer models of EAE, 3-BrPa robustly attenuates the encephalitogenic potential of EAE-driving immune cells. These data are one of the first to demonstrate the metabolic properties of T cells in the demyelinating CNS in vivo.