Selected Grantee Publications
Alterations in Abundance and Compartmentalization of miRNAs in Blood Plasma Extracellular Vesicles and Extracellular Condensates during HIV/SIV Infection and its Modulation by Antiretroviral Therapy (ART) and Delta-9-Tetrahydrocannabinol (Δ9-THC)
Kopcho et al., Viruses. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10053514/
MicroRNAs (miRNAs) have been shown to regulate host response to HIV infection. Previously, investigators proposed that the assortment of extracellular miRNAs into distinct carriers could provide a new dimension to miRNA-based biomarkers. In this follow-up study, the investigators used particle purification liquid chromatography to determine the abundance and compartmentalization of blood plasma extracellular miRNAs into extracellular vesicles and extracellular condensates during simian immunodeficiency virus (SIV) infection in male rhesus macaques. They reported that different treatments—combination ART and Δ9‑THC—impart distinct effects on the enrichment and compartmentalization of extracellular miRNAs. These data suggest that the extracellular miRNA profile in blood plasma is altered following SIV infection. Supported by ORIP (P51OD011104, P51OD011133), NIAID, and NIDA.
CD8+ Lymphocytes Do Not Impact SIV Reservoir Establishment under ART
Statzu et al., Nature Microbiology. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9894752/
The HIV-1 latent reservoir has been shown to persist following antiretroviral therapy (ART), but the mechanisms underlying the establishment and maintenance of the reservoir are not fully understood. Using rhesus macaques of both sexes, investigators examined the effects of CD8+ T cells on formation of the latent reservoir with simian immunodeficiency virus (SIV) infection. They found that CD8+ T cell depletion resulted in slower decline of viremia but did not change the frequency of infected CD4+ T cells in the blood or lymph nodes. Additionally, the size of the persistent reservoir was unchanged. These findings suggest that the viral reservoir is established largely independent of SIV-specific cytotoxic T lymphocyte control. Supported by ORIP (P51OD011132), NIAID, NCI, NIDDK, NIDA, NHLBI, and NINDS.
Multimodal Single-Cell and Whole-Genome Sequencing of Small, Frozen Clinical Specimens
Wang et al., Nature Genetics. 2023.
https://www.nature.com/articles/s41588-022-01268-9
Single-cell RNA sequencing has led to improved understanding of tumor heterogeneity to drug response, but the broad application of those methods remains challenging due to practical requirements that are incompatible with clinical care workflow, such as the need for large and fresh tissues. The researchers demonstrated that several single-cell genomics techniques are feasible from small, frozen tissues and provide biological data outputs similar to those collected from fresh tissue while reducing artifactual signals and compositional biases introduced by fresh-tissue processing. These results provide a new perspective for translating these methods to clinical studies. Supported by ORIP (S10OD020056), NIAID, and NCI.
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.
Elevated Transferrin Receptor Impairs T Cell Metabolism and Function in Systemic Lupus Erythematosus
Voss et al., Science Immunol. 2023.
https://www.science.org/doi/10.1126/sciimmunol.abq0178
Systemic lupus erythematosus (SLE) is an autoimmune disease in which dysfunctional T cells exhibit abnormalities in metabolism. Investigators performed a CRISPR screen to examine mechanisms associated with the role of excess iron in dysfunctional T cells. The transferrin receptor (CD71) was identified as differentially critical for Type 1 T helper cells and inhibitory for induced regulatory T cells. Activated T cells induced CD71 and iron uptake, which was exaggerated in SLE-prone T cells. Disease severity correlated with CD71 expression in cells from male and female patients with SLE, and blocking CD71 in vitro enhanced interleukin 10 secretion. These findings suggest that T cell iron uptake via CD71 contributes to T cell dysfunction and can be targeted to limit SLE-associated pathology. Supported by ORIP (S10OD030264), NIAID, NCI, and NIDDK.
Surrogate Biomarkers of Disease Progression in Human Pegivirus Seropositive Human Immunodeficiency Virus–Infected Individuals
Vimali et al., Viral Immunology. 2023.
Researchers have previously observed that human pegivirus (HPgV) infection is associated with reduced progression of HIV. Investigators examined markers of HIV progression in male and female individuals with HIV and HPgV infection. They reported that HIV plasma viral load was lower in HPgV-seropositive individuals with HIV than in HPgV‑seronegative individuals with HIV. They also found that clinical markers of hepatic damage were significantly lower in HPgV-seropositive individuals with HIV. Future work could examine pathways through which HPgV influences HIV control, which might inform the development of new therapeutics. Supported by ORIP (P51OD011132) and NIAID.
The Ras GTPase‐Activating‐Like Protein IQGAP1 Bridges Gasdermin D to the ESCRT System to Promote IL‐1β Release via Exosomes
Liao et al., The EMBO Journal. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9811620/
The investigators identified IQGAP1, a scaffold protein, as a gasdermin D (GSDMD)–interacting protein through a nonbiased proteomic analysis. Functional investigation indicated that the interaction is required for lipopolysaccharide (LPS)- and ATP-induced exosome release. Further analysis revealed that IQGAP1 serves as an adaptor that bridges GSDMD and the associated IL‐1β complex to Tsg101 and enables the packaging of GSDMD and IL‐1β into exosomes. This process is dependent on an LPS‐induced increase in GTP‐bound CDC42, a small GTPase known to activate IQGAP1. This study reveals IQGAP1 as a link between inflammasome activation and exosomal release of IL‐1β. Supported by ORIP (S10OD023436) and NIAID.
Duration of Antiretroviral Therapy Impacts the Degree of Residual SIV Infection in the Gut in Long‐Term Non‐Progressing Chinese Rhesus Macaques
Solis-Leal et al., Journal of Medical Virology. 2023.
https://onlinelibrary.wiley.com/doi/abs/10.1002/jmv.28185
HIV and simian immunodeficiency virus (SIV) reservoirs have been shown to persist with antiretroviral therapy (ART), particularly in the gut‐associated lymphoid tissues in the intestine. The effects of ART on the reservoir size, however, had not been explored fully. In this study, researchers used male Chinese‐origin rhesus macaques to assess the effects of long- and short-term ART on gut infection—across segments of the small and large intestines—in long‐term non‐progressors (LTNPs). They reported that although ART does not eliminate SIV in LTNPs, a longer ART period dramatically reduces SIV infection and diversity in the gut. Further studies are needed to better understand the reduction of HIV gut reservoirs in this context. Supported by ORIP (P51OD011133, P51OD011104), NIAID, NIMH, and NINDS.
De Novo Protein Fold Design Through Sequence-Independent Fragment Assembly Simulations
Pearce et al., PNAS. 2023.
https://doi.org/10.1073/pnas.2208275120
Researchers developed an automated open-source program, FoldDesign, to create high-fidelity stable folds. Through sequence-independent replica-exchange Monte Carlo simulations and energy force field optimalization of secondary structure, FoldDesign can render novel areas of protein structure and function space that natural proteins have not reached through evolution. These completely different yet stable structures replicate natural proteins’ characteristics with closely matching buried residues and solvent-exposed areas. This work demonstrates a strong potential of creating desired protein structures with potential clinical and industrial applications. Supported by ORIP (S10OD026825), NIAID, NCI, NIEHS, and NIGMS.