Selected Grantee Publications
Multimodal Analysis of Dysregulated Heme Metabolism, Hypoxic Signaling, and Stress Erythropoiesis in Down Syndrome
Donovan et al., Cell Reports. 2024.
https://pubmed.ncbi.nlm.nih.gov/39120971
Down syndrome (DS), a genetic condition caused by the presence of an extra copy of chromosome 21, is characterized by intellectual and developmental disability. Infants with DS often suffer from low oxygen saturation, and DS is associated with obstructive sleep apnea. Investigators assessed the role that hypoxia plays in driving health conditions that are comorbid with DS. A multiomic analysis showed that people with DS exhibit elevated heme metabolism and activated stress erythropoiesis, which are indicators of chronic hypoxia; these results were recapitulated in a mouse model for DS. This study identified hypoxia as a possible mechanism underlying several conditions that co-occur with DS, including congenital heart defects, seizure disorders, autoimmune disorders, several leukemias, and Alzheimer's disease. Supported by ORIP (R24OD035579), NCATS, NCI, and NIAID.
CDK4/6 Inhibition Sensitizes Intracranial Tumors to PD-1 Blockade in Preclinical Models of Brain Metastasis
Nayyer et al., Clinical Cancer Research. 2024.
Brain metastases are associated with high morbidity and are often resistant to immune checkpoint inhibitors. In this study, investigators evaluated the efficacy of combining CDKi (abemaciclib) and anti–PD-1 therapy (“combination therapy”) in mouse models for brain metastases, elucidated how combination therapy remodeled the tumor–immune microenvironment (TIME) and T-cell receptor (TCR) repertoires, and investigated the effects of CDKi on T-cell development and maintenance in NOD-scid Il2rgnull (NSG) mice engrafted with human immune systems (“humanized mice”). Results offer a strong rationale for the clinical evaluation of combination CDKi and PD-1 blockade in patients with brain metastases. Supported by ORIP (R24OD026440), NCI, and NIAID.
A Comprehensive Drosophila Resource to Identify Key Functional Interactions Between SARS-CoV-2 Factors and Host Proteins
Guichard et al., Cell Reports. 2023.
https://pubmed.ncbi.nlm.nih.gov/37480566/
To address how interactions between SARS-CoV-2 factors and host proteins affect COVID-19 symptoms, including long COVID, and facilitate developing effective therapies against SARS-CoV-2 infections, researchers reported the generation of a comprehensive set of resources, mainly genetic stocks and a human cDNA library, for studying viral–host interactions in Drosophila. Researchers further demonstrated the utility of these resources and showed that the interaction between NSP8, a SARS-CoV-2 factor, and ATE1 arginyltransferase, a host factor, causes actin arginylation and cytoskeleton disorganization, which may be relevant to several pathogenesis processes (e.g., coagulation, cardiac inflammation, fibrosis, neural damage). Supported by ORIP (R24OD028242, R24OD022005, R24OD031447), NIAID, NICHD, NIGMS, and NINDS.
Human Hematopoietic Stem Cell Engrafted IL-15 Transgenic NSG Mice Support Robust NK Cell Responses and Sustained HIV-1 Infection
Abeynaike et al., Viruses. 2023.
https://www.mdpi.com/1999-4915/15/2/365
A major obstacle to human natural killer (NK) cell reconstitution is the lack of human interleukin‑15 (IL-15) signaling, as murine IL-15 is a poor stimulator of the human IL-15 receptor. Researchers show that immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ (NSG) mice expressing a transgene encoding human IL-15 (NSG-Tg(IL-15)) have physiological levels of human IL-15 and support long-term engraftment of human NK cells when transplanted with human umbilical cord blood–derived hematopoietic stem cells (HSCs). These mice demonstrate robust and long-term reconstitution with human immune cells but do not develop graft-versus-host disease, allowing long-term studies of human NK cells. The HSC-engrafted mice can sustain HIV-1 infection, resulting in human NK cell responses. This work provides a robust novel model to study NK cell responses to HIV-1. Supported by ORIP (R24OD026440), NIAID, NCI, and NIDDK.
Circulating Integrin α4β7+ CD4 T Cells Are Enriched for Proliferative Transcriptional Programs in HIV Infection
Lakshmanappa et al., Federation of European Biochemical Societies Letters. 2021.
https://doi.org/10.1002/1873-3468.14163
HIV preferentially infects α4β7+ CD4 T cells, forming latent reservoirs that contribute to HIV persistence, yet the properties of α4β7+ CD4 T cells are poorly understood. Investigating HIV-infected humans and SHIV-infected rhesus macaques, investigators demonstrated that α4β7+ CD4 T cells in blood are enriched for genes regulating cell cycle progression and cellular metabolism. In contrast, rectal α4β7+ CD4 T cells exhibited a core tissue-residency gene expression program. These features were conserved across primate species, suggesting that the tissue environment influences memory T-cell transcriptional networks. These findings provide an important foundation for understanding the role of α4β7 in HIV infection. Supported by ORIP (K01OD023034, R24OD010976) and NIAID.
Tissue-Specific Transcriptional Profiling of Plasmacytoid Dendritic Cells Reveals a Hyperactivated State in Chronic SIV Infection
Lee et al., PLOS Pathogens. 2021.
https://doi.org/10.1371/journal.ppat.1009674
Persistent immune activation is an obstacle to optimal health for people living with HIV. Using RNA sequencing, researchers investigated the immunostimulatory potential of plasmacytoid dendritic cells (pDCs) in chronic SIV infection in rhesus macaques. They observed that pDCs have highly activated profiles in these animals. In contrast, pDCs from SIV-infected sooty mangabeys (natural hosts for SIV) had expression profiles similar to uninfected animals. In chronically infected rhesus macaques, interferon alpha transcripts were readily detected in lymph node-homing pDCs, but not those from blood. Therefore, pDCs are a major producer of type-I interferon in chronic SIV infection and could be a useful immunotherapy target. Supported by ORIP (R24OD010445, P51OD011132, P51OD011092, S10OD026799) and NIAID.
IL-21 and IFNα Therapy Rescues Terminally Differentiated NK Cells and Limits SIV Reservoir in ART-Treated Macaques
Harper et al., Nature Communications. 2021.
https://doi.org/10.1038/s41467-021-23189-7
Nonpathogenic simian immunodeficiency virus (SIV) infections in natural hosts, such as vervet monkeys, are characterized by a lack of gut microbial translocation, robust secondary lymphoid natural killer cell responses, and limited SIV dissemination in lymph node B-cell follicles. Using antiretroviral therapy-treated, SIV-infected rhesus monkeys—a pathogenic model—researchers showed that interleukin-21 and interferon alpha therapy generate terminally differentiated blood natural killer cells with potent human leukocyte antigen-E-restricted activity in response to SIV envelope peptides. The correlated reduction of replication-competent SIV in lymph node demonstrates that vervet-like natural killer cell differentiation can be rescued in rhesus monkeys to promote viral clearance. Supported by ORIP (P51OD011132, R24OD010947), NIAID, and NCI.
Epidemiological and Molecular Characterization of a Novel Adenovirus of Squirrel Monkeys After Fatal Infection During Immunosuppression
Rogers et al., Microbial Genomics. 2020.
https://pubmed.ncbi.nlm.nih.gov/32614763/
Adenoviruses frequently cause upper respiratory tract infections, often causing disseminated disease in immunosuppressed patients. A novel adenovirus was identified, squirrel monkey adenovirus 1 (SqMAdV-1), as the cause of a fatal infection in an immunocompromised squirrel monkey (Saimiri boliviensis). A nucleotide polymorphism at the stop codon of the DNA polymerase gene results in a 126 amino acid extension at the carboxy terminus. A single adenovirus variant, SqMAdV-3, has similarity to tufted capuchin (Sapajus apella) adenoviruses. The largest group of adenovirus variants detected, SqMAdV-2.0-2.16, has high similarity (93-99%) to the TMAdV, suggesting that squirrel monkeys may be the natural host of the TMAdV. Supported by ORIP (P40OD010938, R24OD018553), and NIAID.