Selected Grantee Publications
Long-Term Evolutionary Adaptation of SIVcpz toward HIV-1 Using a Humanized Mouse Model
Schmitt et al., Journal of Medical Primatology. 2022.
https://www.doi.org/10.1111/jmp.12616
Chimpanzee-derived simian immunodeficiency viruses (SIVcpz) are thought to have evolved into the highly pathogenic HIV-1 Group M, but the genetic adaptations required for SIV progenitor viruses to become pathogenic and established as HIVs in the human population have remained unclear. Using humanized mice of both sexes, researchers mimicked the evolution of SIVcpz into HIV-1 Group M through serial passaging. After four generations, the researchers observed increased initial viral load, increased CD4+ T cell decline, and nonsynonymous substitutions. Overall, these data indicate increased viral fitness and pathogenicity. This work also demonstrates the utility of humanized mice in recreating the adaptive pressures necessary for the evolution of SIVcpz into HIV-1. Supported by ORIP (P51OD011104, P51OD011106), NCATS, and NIAID.
Early Treatment Regimens Achieve Sustained Virologic Remission in Infant Macaques Infected with SIV at Birth
Wang et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-32554-z
About 150,000 children are infected postnatally with HIV each year. Early antiretroviral therapy (ART) in infants with HIV can reduce viral reservoir size, but ART-free virologic remission has not been achieved. The researchers hypothesized that proviral reservoir seeding in infants exposed to HIV might differ from that in adults. They characterized viral reservoirs in neonatal rhesus macaques of both sexes inoculated with simian immunodeficiency virus (SIV) at birth and given combination ART. The researchers reported that 9 months of treatment initiated at day 3 resulted in a sustained virologic remission, suggesting that early intervention with proper treatment regimens could be an effective strategy. Supported by ORIP (P51OD011104), NIAID, NICHD, and NIDCR.
Recreating the Heart’s Helical Structure–Function Relationship With Focused Rotary Jet Spinning
Chang et al., Science. 2022.
https://www.doi.org/10.1126/science.abl6395
The investigators developed a tissue engineering approach that enables rapid deposition of cardiomyocyte microfibers with programmable alignments in 3D geometries. Using this focused rotary jet spinning (FRJS) method, they reproduced tissue scaffolds with contractile cells' helical alignments, resembling complex structures of the musculature and properties of a natural heart. This work represents an important advance towards biofabrication of tissue models for healthy and diseased hearts by manipulating orientation of specific fibers. With the technological advancement over other competing methods, FRJS might provide a pathway towards fabricating other tissues and organs with diverse cell populations. Supported by ORIP (S10OD023519) and NCATS.
A Clade C HIV-1 Vaccine Protects Against Heterologous SHIV Infection by Modulating IgG Glycosylation and T Helper Response in Macaques
Sahoo et al., Science Immunology. 2022.
https://www.doi.org/10.1126/sciimmunol.abl4102
Vaccines for HIV-1 capable of generating a broadly cross-reactive neutralizing antibody response are needed urgently. The researchers tested the protective efficacy of a clade C HIV-1 vaccination regimen in male rhesus macaques. The vaccine was administered either orally using a needle-free injector or via parenteral injection. Significant protection was observed for both vaccination routes following the simian–human immunodeficiency virus (SHIV) challenge, with an estimated efficacy of 68% per exposure. The glycosylation profile of IgG and HIV-resistant helper T cell response contributes to the protection. Supported by ORIP (P51OD011132), NIAID, and NIDCR.
Innate Immune Regulation in HIV Latency Models
Olson et al., Retrovirology. 2022.
https://www.doi.org/10.1186/s12977-022-00599-z
Researchers are interested in developing therapeutic approaches to target latent HIV reservoirs, which are unaffected by antiretroviral therapy. Previous studies suggest that HIV latency might be related to viral RNA sensing, interferon (IFN) signaling, and IFN-stimulated gene (ISG) activation. In this study, the researchers evaluated responses to stimulation by retinoic acid–inducible gene I agonists and IFN in multiple CD4+ T cell line models for HIV latency. The models represented various aspects of latent infection and viral control. Several of the cell lines demonstrated reduced ISG induction, suggesting that long-term latency might be related to dysregulation of the downstream IFN response. These effects likely reflect transcriptional changes occurring within a core set of ISGs and altering IFN responses. Additional studies could provide insight into the functions of these ISGs in HIV latency. Supported by ORIP (P51OD010425), NCATS, and NIAID.
Safety and Antiviral Activity of Triple Combination Broadly Neutralizing Monoclonal Antibody Therapy Against HIV-1: A Phase 1 Clinical Trial
Julg et al., Nature Medicine. 2022.
https://www.doi.org/10.1038/s41591-022-01815-1
Previous evidence suggests that at least three broadly neutralizing antibodies (bNAbs) targeting different epitope regions are needed for robust treatment and control of HIV. The investigators evaluated the safety, tolerability, and pharmacokinetics of PGDM1400, an HIV-1 V2-glycan–specific antibody, in a first-in-human trial. The primary endpoints were safety, tolerability, pharmacokinetics, and antiviral activity. The trial met the prespecified endpoints in male and female adults. These data will help advance understanding of the capabilities, limitations, and future role of bNAb combinations in HIV prevention and care. Supported by ORIP (R01OD024917), NIAID, and NCATS.
Early Post-Vaccination Gene Signatures Correlate With the Magnitude and Function of Vaccine-Induced HIV Envelope–Specific Plasma Antibodies in Infant Rhesus Macaques
Vijayan et al., Frontiers in Immunology. 2022.
https://www.doi.org/10.3389/fimmu.2022.840976
An effective vaccine is needed to reduce HIV infections, particularly among younger people. The initiation of an HIV vaccine regimen in early life could allow the development of mature HIV‑specific antibody responses that protect against infection. The investigators compared the effects of two vaccine regimens in infant rhesus macaques (sex not specified). Both vaccines induced a rapid innate response, indicated by elevated inflammatory plasma cytokines and altered gene expression. By performing a network analysis, the investigators identified differentially expressed genes associated with B cell activation. These findings suggest that vaccine-induced immunity can be optimized by modulating specific antibody and T cell responses. Supported by ORIP (P51OD011107), NCI, NIAID, and NIDCR.
The Early Life Microbiota Mediates Maternal Effects on Offspring Growth in a Nonhuman Primate
Petrullo et al., iScience. 2022.
https://www.doi.org/10.1016/j.isci.2022.103948
Mammalian mothers influence offspring development by providing nutrients and other bioactive compounds through the placenta or milk. A relatively unexplored mechanism for maternal effects is vertical transmission of bacteria through milk to the infant gut. Infants that receive more glycan-utilizing bacteria from milk might better exploit oligosaccharides, which could improve nutrition and accelerate growth. Researchers found that first-time vervet mothers harbored a milk bacterial community that was less diverse due to the dominance of Bacteroides fragilis, a glycan-utilizing bacteria. These low-parity females had infants that grew faster, suggesting that vertical transmission of bacteria via milk can mediate maternal effects on growth. These results indicate non-nutritive milk constituents play important roles in development. Commercial milk formula might need to be improved or supplemented to better support infant health. Supported by ORIP (P40OD010965) and NCATS.
Vaccine-Induced, High-Magnitude HIV Env-Specific Antibodies with Fc-Mediated Effector Functions Are Insufficient to Protect Infant Rhesus Macaques against Oral SHIV Infection
Curtis et al., mSphere. 2022.
https://www.doi.org/10.1128/msphere.00839-21
A tailored, effective HIV vaccine is needed to prevent mother-to-child viral transmission. In nonhuman primate models, infection with simian–human immunodeficiency virus (SHIV) can be prevented by administering broadly neutralizing HIV envelope (Env)–specific antibodies. Investigators tested the efficacy of an intramuscular vaccine regimen against SHIV infection in male and female infant rhesus macaques. The vaccine induced Env-specific antibodies in plasma, with antibody-dependent cellular cytotoxicity and phagocytic function. These antibodies, however, were insufficient for protection against infection. Future studies could focus on improving the breadth of antibody response and improving cell-mediated immunity. Supported by ORIP (P51OD011107), NCI, NIAID, and NIDCR.