Browsing by Subject "Oxidative phosphorylation"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Inhibiting Glycolysis Enhances T Follicular Helper Cell Differentiation and Survival upon Human Immunodeficiency Virus Infection
    (2020-01) Rane, Sushmita Shirish; Yu, Quigui (Andy); Guo, Haitao; Lu, Tao
    Human immunodeficiency virus (HIV) primarily infects T helper (Th) cells. Decrease in the number of Th cells is the hallmark of HIV infection. Latent reservoirs of human immunodeficiency virus (HIV) are the leading barrier towards eradication of HIV infection. T Follicular helper (Tfh) cells are a subset of Th cells that function to provide aid to B cells for their maturation, affinity selection and antibody class switch. Several studies have shown that Tfh cells are a major reservoir of latent as well as productive hiv infection. But in contrast to the fate of other Th cell subsets, the frequency of Tfh cells was shown to have increased during HIV infection which could not be attributed to their reduced susceptibility to HIV infection. The hypothesis was that Tfh cells possess a unique metabolic phenotype that protects them from HIV induced cell death. Transcriptome analysis of Th subsets from human donors and showed that Tfh cells rely less on glycolysis for their energetic requirements and instead have increased transcription of fatty acid synthesis genes. This finding was corroborated by seahorse extracellular flux assay. The results shoId that glycolysis was not essential for Tfh cell differentiation in-vitro. The observed increase in Tfh cell frequency could not be attributed to increased Tfh differentiation upon HIV infection since HIV infection inhibited the differentiation of both non-Tfh and Tfh cells. The results found that bypassing the glycolytic pathway by providing Tfh cells with Galactose in the medium protected ex-vivo infected primary tonsillar cells from HIV induced cell death. This protection could be partly explained by the induction of Baculovirus IAP repeat containing 5 (BIRC5) when the cells utilized Galactose instead of Glucose. The studies together show that Tfh cells have an oxidative metabolic phenotype which protects them from HIV induced cell death in part by induction of BIRC5 expression.
  • Thumbnail Image
    Item
    Modulation of oxidative phosphorylation and mitochondrial biogenesis by cigarette smoke influence the response to immune therapy in NSCLC patients
    (Elsevier, 2023-04) Wang, Yuezhu; Smith, Margaret; Ruiz, Jimmy; Liu, Yin; Kucera, Gregory L.; Topaloglu, Umit; Chan, Michael D.; Li, Wencheng; Su, Jing; Xing, Fei; Biostatistics and Health Data Science, Richard M. Fairbanks School of Public Health
    The treatment regimen of non-small cell lung cancer (NSCLC) has drastically changed owing to the superior anti-cancer effects generated by the immune-checkpoint blockade (ICB). However, only a subset of patients experience benefit after receiving ICBs. Therefore, it is of paramount importance to increase the response rate by elucidating the underlying molecular mechanisms and identifying novel therapeutic targets to enhance the efficacy of IBCs in non-responders. We analyzed the progression-free survival (PFS) and overall survival (OS) of 295 NSCLC patients who received anti-PD-1 therapy by segregating them with multiple clinical factors including sex, age, race, smoking history, BMI, tumor grade and subtype. We also identified key signaling pathways and mutations that are enriched in patients with distinct responses to ICB by gene set enrichment analysis (GSEA) and mutational analyses. We found that former and current smokers have a higher response rate to anti-PD-1 treatment than non-smokers. GSEA results revealed that oxidative phosphorylation (OXPHOS) and mitochondrial related pathways are significantly enriched in both responders and smokers, suggesting a potential role of cellular metabolism in regulating immune response to ICB. We also demonstrated that all-trans retinoic acid (ATRA) which enhances mitochondrial function significantly enhanced the efficacy of anti-PD-1 treatment in vivo. Our clinical and bioinformatics based analyses revealed a connection between smoking induced metabolic switch and the response to immunotherapy, which can be the basis for developing novel combination therapies that are beneficial to never smoked NSCLC patients.
  • Thumbnail Image
    Item
    The onset of circulation triggers a metabolic switch required for endothelial to hematopoietic transition
    (Cell Press, 2021) Azzoni, Emanuele; Frontera, Vincent; Anselmi, Giorgio; Rode, Christina; James, Chela; Deltcheva, Elitza M.; Demian, Atanasiu S.; Brown, John; Barone, Cristiana; Patelli, Arianna; Harman, Joe R.; Nicholls, Matthew; Conway, Simon J.; Morrissey, Edward; Jacobsen, Sten Eirik W.; Sparrow, Duncan B.; Harris, Adrian L.; Enver, Tariq; de Bruijn, Marella F.T.R.; Pediatrics, School of Medicine
    Hematopoietic stem cells (HSCs) emerge during development from the vascular wall of the main embryonic arteries. The onset of circulation triggers several processes that provide critical external factors for HSC generation. Nevertheless, it is not fully understood how and when the onset of circulation affects HSC emergence. Here we show that in Ncx1-/- mouse embryos devoid of circulation the HSC lineage develops until the phenotypic pro-HSC stage. However, these cells reside in an abnormal microenvironment, fail to activate the hematopoietic program downstream of Runx1, and are functionally impaired. Single-cell transcriptomics shows that during the endothelial-to-hematopoietic transition, Ncx1-/- cells fail to undergo a glycolysis to oxidative phosphorylation metabolic switch present in wild-type cells. Interestingly, experimental activation of glycolysis results in decreased intraembryonic hematopoiesis. Our results suggest that the onset of circulation triggers metabolic changes that allow HSC generation to proceed.