Selected Grantee Publications
Deep Analysis of CD4 T Cells in the Rhesus CNS During SIV Infection
Elizaldi et al., PLOS Pathogens. 2023.
https://pubmed.ncbi.nlm.nih.gov/38060615/
Systemic HIV infection results in chronic inflammation that causes lasting damage to the central nervous system (CNS), despite long-term antiretroviral therapy (ART). Researchers studied neurocognitive outcomes in male and female rhesus macaques infected with simian immunodeficiency virus (SIV) using an ART regimen simulating suboptimal adherence; one group received no ART, and the other received ART with periodic interruptions. Using single-cell transcriptomic profiling, the researchers also identified molecular programs induced in the brain upon infection. They found that acute infection led to marked imbalance in the CNS CD4/CD8 T‑cell ratio, which persisted into the chronic phase. The studies provide insight into the role of CD4 T cells in the CNS during HIV infection. Supported by ORIP (P51OD011107, K01OD023034), NIA, NIAID, and NCI.
IL-21-IgFc Immunotherapy Alters Transcriptional Landscape of Lymph Node Cells Leading to Enhanced Flu Vaccine Response in Aging and SIV Infection
Pallikkuth et al., Aging Cell. 2023.
https://pubmed.ncbi.nlm.nih.gov/37712598/
Aging is associated with increased risk of seasonal flu disease burden and serious flu-related complications, particularly for people with HIV. In this study, investigators aimed to elucidate the immunomodulation following flu vaccination in aging male and female rhesus macaques infected with simian immunodeficiency virus (SIV). Their results suggest that IL-21 treatment at the time of flu vaccination modulates the inductive lymph node germinal center activity to reverse SIV-associated immune dysfunction. The authors identified IL-21 as a potential candidate molecule for immunotherapy to enhance flu vaccine responses in affected populations. Further studies could examine the overall benefit of IL-21 immunotherapy on mucosal lung immunity and protection against infection. Supported by ORIP (R24OD010947), NIA, and NIAID.
Exosome Cell Origin Affects In Vitro Markers of Tendon Repair in Ovine Macrophages and Tenocytes
von Stade et al., Tissue Engineering Part A. 2023.
https://pubmed.ncbi.nlm.nih.gov/36792933/
The underlying pathogenesis of rotator cuff tendinopathy reflects a combination of intrinsic and extrinsic factors, and recent work suggests that cell-to-cell communication drives the severity of tendon changes. Researchers are interested in the role of extracellular vesicles in tendon mechanical resilience, tissue organization, and anti-inflammatory macrophage phenotype predominance in response to tendon injury. In this study, investigators demonstrated how exosomes differ functionally based on cell source. This work suggests that control of exosome composition could lead to more effective therapies for certain tissues. Supported by ORIP (K01OD022982) and NCATS.
Lipid Droplets and Peroxisomes Are Co-Regulated to Drive Lifespan Extension in Response to Mono-Unsaturated Fatty Acids
Papsdorf et al., Nature Cell Biology. 2023.
https://www.nature.com/articles/s41556-023-01136-6
Investigators studied the mechanism by which mono-unsaturated fatty acids (MUFAs) extend longevity. They found that MUFAs upregulated the number of lipid droplets in fat storage tissues of Caenorhabditis elegans, and increased lipid droplets are necessary for MUFA-induced longevity and predicted remaining lifespan. Lipidomics data revealed that MUFAs modify the ratio of membrane lipids and ether lipids, which leads to decreased lipid oxidation in middle-aged individuals. MUFAs also upregulate peroxisome number. A targeted screen revealed that induction of both lipid droplets and peroxisomes is optimal for longevity. This study opens new interventive avenues to delay aging. Supported by ORIP (S10OD025004, S10OD028536, P40OD010440), NIA, NCCIH, NIDDK, and NHGRI.
Allelic Strengths of Encephalopathy-Associated UBA5 Variants Correlate Between In Vivo and In Vitro Assays
Pan et al., eLife. 2023.
https://pubmed.ncbi.nlm.nih.gov/37502976/
The UBA5 gene is associated with developmental and epileptic encephalopathy 44 (DEE44), an autosomal recessive disorder, in humans. The link between UBA5 variants and severity of DEE44, however, is not established. Investigators developed humanized fly models carrying a series of patient UBA5 variants. These flies showed differences in survival rates, developmental progress, life span, and neurological well-being. The severity of these defects correlated strongly with functional defects of UBA5 variants, allowing the classification of UBA5 loss-of-function variants into mild, intermediate, and severe allelic strengths in patients. This study provides resources for systematic investigation of the mechanistic link between UBA5 variants and DEE44 and for developing diagnostic approaches. Supported by ORIP (R24OD022005, R24OD031447, U54OD035865) and NCATS.
Effects of Pulsatile Intravenous Follicle-Stimulating Hormone Treatment on Ovarian Function in Women With Obesity
Luu et al., Fertility and Sterility. 2023.
https://pubmed.ncbi.nlm.nih.gov/37276947/
By performing intravenous (IV) administration of pulsatile recombinant follicle-stimulating hormone (FSH), researchers established conditions for effective hypothalamic suppression in women with normal and high body mass index (BMI). In women with obesity, the treatment resulted in E2 and inhibin B levels comparable to those in normal-weight women. This work offers a potential strategy to mitigate some of the adverse effects of high BMI on fertility, assisted reproduction, and pregnancy outcomes. Supported by ORIP (K01OD026526), NIA, and NICHD.
Host-Derived Growth Factors Drive ERK Phosphorylation and MCL1 Expression to Promote Osteosarcoma Cell Survival During Metastatic Lung Colonization
McAloney et al., Cellular Oncology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37676378/
Mortality from osteosarcoma is closely linked to lung metastasis, even though the lung appears to be a hostile environment for tumor cells. Using female mice, researchers assessed changes in both host and tumor cells during colonization. Their findings suggest that the mitogen-activated protein kinase (MAPK) pathway is significantly elevated in early and established metastases, which correlates with expression of anti-apoptotic genes (e.g., MCL1). The authors conclude that niche-derived growth factors drive increased MAPK activity and MCL1 expression in osteosarcoma, promoting metastatic colonization. This gene is a promising target for future therapeutic development. Supported by ORIP (K01OD031811), NCI, and NCATS.
Intestinal Microbiota Controls Graft-Versus-Host Disease Independent of Donor–Host Genetic Disparity
Koyama et al., Immunity. 2023.
https://pubmed.ncbi.nlm.nih.gov/37480848/
Allogeneic hematopoietic stem cell transplantation is a curative therapy for hematopoietic malignancies and non-malignant diseases, but acute graft-versus-host disease (GVHD) remains a serious complication. Specifically, severe gut GVHD is the major cause of transplant-related mortality. Here, the authors show that genetically identical mice, sourced from different vendors, had distinct commensal bacterial compositions, which resulted in significantly discordant severity in GVHD. These studies highlight the importance of pre-transplant microbiota composition for the initiation and suppression of immune-mediated pathology in the gastrointestinal tract, demonstrating the impact of non-genetic environmental determinants to transplant outcome. Supported by ORIP (S10OD028685), NIA, NCI, and NHLBI.
SALL1 Enforces Microglia-Specific DNA Binding and Function of SMADs to Establish Microglia Identity
Fixsen et al., Nature Immunology. 2023.
https://doi.org/10.1038/s41590-023-01528-8
Microglia function is thought to play a role in neurodevelopmental, psychiatric, and neurodegenerative diseases. Using knockout mice, investigators explored functional interactions between spalt-like transcription factor 1 (SALL1) and SMAD4, which demonstrated that interactions are mediated by a conserved microglia-specific SALL1 super-enhancer and result in direct activation of regulatory elements. The concerted interactions induce a microglia lineage determining program of gene expression. These findings indicate that expression of SALL1 and associated genes could contribute to phenotypes of aging and neurodegenerative diseases. Supported by ORIP (S10OD026929), NIA, NIMH, and NINDS.
Phytochemical Compound PB125 Attenuates Skeletal Muscle Mitochondrial Dysfunction and Impaired Proteostasis in a Model of Musculoskeletal Decline
Musci et al., Journal of Physiology. 2023.
https://physoc.onlinelibrary.wiley.com/doi/10.1113/JP282273
Age-related musculoskeletal decline contributes to disability and cardiometabolic diseases and is linked to impaired mitochondrial function and disrupted proteostasis. Using male and female Hartley guinea pigs, investigators tested a purported phytochemical activator of nuclear factor erythroid 2-related factor 2, which helps promote redox homeostasis, proteome maintenance, and mitochondrial energetics. They reported that the activator, PB125, improved mitochondrial respiration and attenuated disease- and age-related declines in skeletal muscle protein synthesis. This study provides insights for the development of interventions in humans. Supported by ORIP (T32OD010437) and NIA.