Selected Grantee Publications
Potent Antibody-Dependent Cellular Cytotoxicity of a V2-Specific Antibody Is Not Sufficient for Protection of Macaques Against SIV Challenge
Grunst et al., PLOS Pathogens. 2024.
https://pubmed.ncbi.nlm.nih.gov/38252675/
Antibody-dependent cellular cytotoxicity (ADCC) has been correlated with decreased risk of HIV acquisition. Researchers tested the ability of PGT145, an antibody that neutralizes genetically diverse HIV-1 isolates, to protect rhesus macaques against simian immunodeficiency virus (SIV) via ADCC activity. They found that a single amino acid substitution in the V2 core epitope of the SIV envelope increases PGT145 binding and confers sensitivity to neutralization. Peak and chronic phase viral loads were lower, and time to peak viremia was delayed. They concluded that ADCC is insufficient for protection by this antibody, but increasing the affinity of antibody binding could confer partial protection. Supported by ORIP (P51OD011106), NIAID, and NCI.
Macrophages Derived From Human Induced Pluripotent Stem Cells (iPSCs) Serve As a High-Fidelity Cellular Model for Investigating HIV-1, Dengue, and Influenza viruses
Yang et al., Journal of Virology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38323811/
Macrophages can be weaponized by viruses to host viral reproduction and support long-term persistence. The most common way of studying these cells is by isolating their precursors from donor blood and differentiating the isolated cells into macrophages. This method is costly and technically challenging, and it produces varying results. In this study, researchers confirmed that macrophages derived from iPSC cell lines—a model that is inexpensive, consistent, and modifiable by genome editing—are a suitable model for experiments involving HIV and other viruses. Macrophages derived from iPSCs are as susceptible to infection as macrophages derived from blood, with similar infection kinetics and phenotypes. This new model offers researchers an unlimited source of cells for studying viral biology. Supported by ORIP (R01OD034046, S10OD021601), NIAID, NIDA, NIGMS, and NHLBI.
Induction of Durable Remission by Dual Immunotherapy in SHIV-Infected ART-Suppressed Macaques
Lim et al., Science. 2024.
https://pubmed.ncbi.nlm.nih.gov/38422185/
The latent viral reservoir is established within the first few days of HIV infection and remains a barrier to a clinical cure. Researchers characterized the effects of a combined Anktiva (N-803) treatment with broadly neutralizing antibodies (bNAbs) using male and female rhesus macaques infected with simian–human immunodeficiency virus infection. Their data suggest that these agents synergize to enhance CD8+ T-cell function, particularly when multiple bNAbs are used. Taken together, this work indicates that immune-mediated control of viral rebound is not a prerequisite for sustained remission after discontinuation of antiretroviral therapy and that immune-mediated control of viral rebound is achievable, sufficient, and sustainable in this model. Supported by ORIP (P51OD011106, P40OD028116, R24OD011195) and NIAID.
Trade-Offs Shaping Transmission of Sylvatic Dengue and Zika Viruses in Monkey Hosts
Hanley et al., Nature Communications. 2024.
https://pubmed.ncbi.nlm.nih.gov/38538621/
Mosquito-borne dengue (DENV) and Zika (ZIKV) viruses originated in Old World sylvatic (forest) cycles involving monkeys and canopy-living Aedes mosquitoes. Both viruses spilled over into human transmission and were translocated to the Americas, opening a path for spillback into neotropical sylvatic cycles. This article reports that the trade-offs that shape within-host dynamics and transmission of these viruses are lacking, hampering efforts to predict spillover and spillback. The data revealed evidence of an immunologically mediated trade‑off between duration and magnitude of virus replication, as higher-peak ZIKV titers are associated with shorter durations of viremia, and higher natural killer cell levels are associated with lower peak ZIKV titers and lower anti-DENV-2 antibody levels. Furthermore, patterns of transmission of each virus from a neotropical monkey suggest that ZIKV has greater potential than DENV-2 to establish a sylvatic transmission cycle in the Americas. Supported by ORIP (P40OD010938) and NIAID.
TGF-β Blockade Drives a Transitional Effector Phenotype in T Cells Reversing SIV Latency and Decreasing SIV Reservoirs In Vivo
Kim et al., Nature Communications. 2024.
https://pubmed.ncbi.nlm.nih.gov/38355731/
Interruption of antiretroviral therapy leads to rapid rebound of viremia due to the establishment of a persistent viral reservoir early after infection. Using a treatment regimen similar to the one tested in clinical trials, the authors show how galunisertib affects immune cell function, increases simian immunodeficiency virus (SIV) reactivation, and reduces the viral reservoir in female rhesus macaques. Their findings reveal a galunisertib-driven shift toward an effector phenotype in T and natural killer cells. Taken together, this work demonstrates that galunisertib, a clinical-stage TGF-β inhibitor, reverses SIV latency and decreases SIV reservoirs by driving T cells toward an effector phenotype, enhancing immune responses in vivo in the absence of toxicity. Supported by ORIP (R24OD010947), NIAID, and NCI.
Pigs in Transplantation Research and Their Potential as Sources of Organs in Clinical Xenotransplantation
Raza et al., Comparative Medicine. 2024.
https://pubmed.ncbi.nlm.nih.gov/38359908/
The pig has now gained importance as a potential source of organs for clinical xenotransplantation. When an organ from a wild-type (i.e., genetically unmodified) pig is transplanted into an immunosuppressed nonhuman primate, a vigorous host immune response causes hyperacute rejection (within minutes or hours). This response has been largely overcome by (1) extensive gene editing of the organ-source pig and (2) administration to the recipient of novel immunosuppressive therapy based on blockade of the CD40/CD154 T-cell costimulation pathway. The combination of gene editing and novel immunosuppressive therapy has extended life-supporting pig kidney graft survival to greater than 1 year and of pig heart survival to up to 9 months. This review briefly describes the techniques of gene editing, the potential risks of transfer of porcine endogenous retroviruses with the organ, and the need for breeding and housing of donor pigs under biosecure conditions. Supported by ORIP (P40OD024628) and NIAID.
Pathogenesis and Virulence of Coronavirus Disease: Comparative Pathology of Animal Models for COVID-19
Kirk et al., Virulence. 2024.
https://pubmed.ncbi.nlm.nih.gov/38362881
Researchers have used animal models that can replicate clinical and pathologic features of severe human coronavirus infections to develop novel vaccines and therapeutics in humans. The purpose of this review is to describe important animal models for COVID-19, with an emphasis on comparative pathology. The highlighted species included mice, ferrets, hamsters, and nonhuman primates. Knowledge gained from studying these animal models can help inform appropriate model selection for disease modeling, as well as for vaccine and therapeutic developments. Supported by ORIP (T32OD010993) 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.
Targeting Pancreatic Cancer Metabolic Dependencies Through Glutamine Antagonism
Encarnación-Rosado et al., Nature Cancer. 2024.
https://pubmed.ncbi.nlm.nih.gov/37814010/
Pancreatic ductal adenocarcinoma (PDAC) cells thrive in the austere, complex tumor microenvironment by reprogramming their metabolism and relying on scavenging pathways, but more work is needed to translate this knowledge into clinically relevant therapeutic interventions. Investigators demonstrated that treating PDAC cells with a Gln antagonist, 6‑diazo-5-oxo-l-norleucine (DON), caused a metabolic crisis by globally impairing Gln metabolism, resulting in a significant decrease in proliferation. They observed a profound decrease in tumor growth in several in vivo models using sirpiglenastat (DRP-104), a pro-drug version of DON that was designed to circumvent DON-associated toxicity. These proof-of-concept studies suggested that broadly targeting Gln metabolism could provide a therapeutic avenue for PDAC. Combining this therapeutic with an extracellular-signal-regulated kinase (or ERK) signaling pathway inhibitor could further improve it. Supported by ORIP (S10OD021747), NCI, and NIAID.
Cytomegalovirus Infection Facilitates the Costimulation of CD57+CD28- CD8 T Cells in HIV Infection and Atherosclerosis via the CD2–LFA-3 Axis
Winchester et al., Journal of Immunology. 2024.
https://pubmed.ncbi.nlm.nih.gov/38047900/
People with HIV are at increased risk of developing atherosclerosis and other cardiovascular diseases, and HIV coinfection with cytomegalovirus (CMV) is associated with immune activation and inflammation. In this study, researchers explored the role of the CD2–LFA-3 axis in driving activation and proliferation of CD57+CD28- CD8 T cells using clinical samples from patients with or without HIV. They propose a model in which CMV infection is linked to enhanced CD2 expression on the T cells, enabling the activation via LFA-3 signals and potentially leading to cardiopathogenic interactions with vascular endothelial cells that express LFA-3. This work provides a potential therapeutic target in atherosclerosis development and progression, especially for people with HIV. Supported by ORIP (P51OD011132, U24OD011023) and NIAID.