Biology subjects

Culp-Hill, R.

Publications and source records attributed to Culp-Hill, R..

3 recordsLinked to original sources

bioRxiv2022

Hematopoietic stem cells are a long-term reservoir for trained immunity in a mouse model of chronic autoimmune disease

Trained immunity (TI) has been speculated to serve as a contributor to autoimmune disease (AD) pathogenesis via generation of hyper-inflammatory myeloid cells. Using a mouse model of systemic lupus erythematosus (SLE), we show that hematopoietic stem cells (HSC) constitute a transplantable, long-term reservoir for macrophages that exhibit features of TI, including increased Mycobacterium avium killing, inflammatory cytokine production, and augmented capacity to co-stimulate naive T cells. Strikingly, hematopoietic progenitor cells derived from these HSC exhibit unique molecular features characterized by reduced chromatin accessibility and transcription of metabolic genes, accompanied by reduced glycolysis and central carbon metabolism. Altogether, our data identify HSC as a functional unit of TI in chronic AD, establish increased T-cell costimulatory activity as a potentially pathogenic feature of TI in this setting, and show that macrophages inherit reduced metabolic activity from AD-exposed HSC, suggesting metabolic activation and TI can be decoupled. Our findings thus implicate HSC as a long-term reservoir for TI that could contribute to AD.

immunology↗

bioRxiv2020

Accelerated erythrocyte senescence causes dose-limiting anemia of antimalarial enolase inhibitors

Glycolysis controls cellular energy, redox balance, and biosynthesis. Antiglycolytic therapies are under investigation for treatment of obesity, cancer, aging, autoimmunity, and microbial diseases. Interrupting glycolysis is highly valued as a therapeutic strategy, because glycolytic disruption is generally tolerated in mammals. Unfortunately, anemia is a known dose-limiting side effect of these inhibitors and presents a major caveat to development of antiglycolytic therapies. We developed specific inhibitors of enolase - a critical enzyme in glycolysis - and validated their metabolic and cellular effects on human erythrocytes. Enolase inhibition increases erythrocyte susceptibility to oxidative damage and induces rapid and premature erythrocyte senescence, rather than direct hemolysis. We apply our model of red cell toxicity to address questions regarding erythrocyte glycolytic disruption in the context of Plasmodium falciparum malaria pathogenesis. Our study provides a framework for understanding red blood cell homeostasis under normal and disease states and clarifies the importance of erythrocyte reductive capacity in malaria parasite growth.

pharmacology and toxicology↗

bioRxiv2018

Trisomy 21 drives production of neurotoxic tryptophan catabolites via the interferon-inducible kynurenine pathway

Trisomy 21 (T21) causes Down syndrome (DS), affecting immune and neurological function by unknown mechanisms. We report here the results of a large metabolomics study showing that people with DS produce elevated levels of kynurenine and quinolinic acid, two tryptophan catabolites with potent immunosuppressive and neurotoxic properties, respectively. We found that immune cells of people with DS overexpress IDO1, the rate-limiting enzyme in the kynurenine pathway (KP) and a known interferon (IFN)-stimulated gene. Furthermore, we found a positive correlation between levels of specific inflammatory cytokines and KP dysregulation. Using metabolic flux assays, we found that IFN stimulation causes IDO1 overexpression and kynurenine overproduction in cells with T21, dependent on overexpression of IFN receptors encoded on chromosome 21. Finally, KP dysregulation is conserved in a mouse model of DS carrying triplication of the IFN receptors. Altogether, these results reveal a mechanism by which T21 could drive immunosuppression and neurotoxicity in DS.

physiology↗