Intradermal but Not Intramuscular Modified Vaccinia Ankara Immunizations Protect Against Intravaginal Tier2 Simian–Human Immunodeficiency Virus Challenges in Female Macaques
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Researchers have been exploring multiple strategies to develop an HIV vaccine. In this study, the investigators determined the immunogenicity and efficacy of intradermal and intramuscular routes of modified vaccinia Ankara (MVA) vaccination in female rhesus macaques. They found that both routes of MVA vaccination enabled control of viral replication, but only the intradermal vaccination was effective in protection against viral acquisition. Their findings suggest that the intradermal MVA vaccinations provide protection by modulating the innate and T helper responses.
Very-Long-Chain Fatty Acids Induce Glial-Derived Sphingosine-1-Phosphate Synthesis, Secretion, and Neuroinflammation
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Very-long-chain fatty acids (VLCFAs) are the most abundant fatty acids in myelin. During age‑associated degeneration of myelin, glia are exposed to increased levels of VLCFAs. Investigators previously described a novel phenotype in patients that harbors a novel variant in the peroxisomal enzyme ACOX1. Here, they report that that glial loss of ACOX1 leads to an increase of VLCFAs, which results in a concomitant increase in sphingosine-1-phosphate (S1P). They found that suppressing S1P function attenuates the pathological phenotypes caused by excess VLCFAs.
Investigation of Monoclonal Antibody CSX-1004 for Fentanyl Overdose
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The opioid crisis in the United States is primarily driven by the highly potent synthetic opioid fentanyl and has led to more than 70,000 overdose deaths annually; thus, new therapies for fentanyl overdose are urgently needed. Here, the authors present the first clinic-ready, fully human monoclonal antibody CSX-1004 with picomolar affinity for fentanyl and related analogs. In mice, CSX-1004 reverses fentanyl antinociception and the intractable respiratory depression caused by the ultrapotent opioid carfentanil.
Host Immunity Associated With Spontaneous Suppression of Viremia in Therapy-Naïve Young Rhesus Macaques Following Neonatal SHIV Infection
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Previously, investigators developed a pediatric rhesus macaque model for simian–human immunodeficiency virus infection that can be exploited to identify host immunity associated with viremia suppression. In the present study, they used the model (with male and female animals) to characterize humoral and cellular immunity and plasma biomarkers associated with spontaneous viremia suppression. They identified CD8-expressing cells and varied T-cell subsets that were associated with viremia suppression.
Conjugation of HIV-1 Envelope to Hepatitis B Surface Antigen Alters Vaccine Responses in Rhesus Macaques
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Researchers are interested in developing an HIV-1 vaccine that improves upon the regimen used in the RV144 clinical trial. The authors tested the hypothesis that a conjugate vaccine based on the learned response to immunization with hepatitis B virus could be utilized to expand T-cell help and improve antibody production against HIV-1. Using juvenile rhesus macaques of both sexes, they evaluated the immunogenicity of their conjugate regimen.
Intravenous Bacille Calmette–Guérin Vaccination Protects Simian Immunodeficiency Virus–Infected Macaques From Tuberculosis
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People with HIV are susceptible to developing tuberculosis and experiencing associated complications. Researchers assessed the safety, immunogenicity, and efficacy of intravenous Bacille Calmette–Guérin vaccination in male and female cynomolgus macaques coinfected with simian immunodeficiency virus (SIV) and Mycobacterium tuberculosis. The vaccine conferred protection in all vaccinated SIV-naive animals and in 9 of 12 vaccinated SIV-infected animals. These data suggest that the vaccine is immunogenic and efficacious in SIV-infected animals.
Broad Receptor Tropism and Immunogenicity of a Clade 3 Sarbecovirus
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Investigators showed that the S glycoprotein of the clade 3 sarbecovirus PRD-0038 in the African Rhinolophus bat has a broad angiotensin-converting enzyme 2 (ACE2) usage and that receptor-binding domain (RBD) mutations further expand receptor promiscuity and enable human ACE2 utilization. They generated a cryogenic electron microscopy structure of the RBD bound to ACE2, explaining receptor tropism and highlighting differences between SARS-CoV-1 and SARS-CoV-2.
HIV-1 Remission: Accelerating the Path to Permanent HIV-1 Silencing
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Current HIV treatment strategies are focused on forced proviral reactivation and elimination of reactivated cells with immunological or toxin-based technologies. Researchers have proposed the use of a novel “block-lock-stop” approach, which entails the long-term durable silencing of viral expression and permanent transcriptional deactivation of the latent provirus. In the present study, the authors present this approach and its rationale.
High Throughput Analysis of B Cell Dynamics and Neutralizing Antibody Development During Immunization With a Novel Clade C HIV-1 Envelope
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Broadly neutralizing antibodies from chronic infection are an area of interest for HIV-1 vaccine development. Using male and female rhesus macaques, a team of researchers conducted a high-throughput longitudinal study to determine how B cells respond to vaccines expressing different HIV-1 Env immunogens. In most animals, the B cells failed to achieve neutralizing activity. One animal, however, developed neutralizing antibodies against the vaccine strain. These data suggest that early elicitation might favor the induction of neutralizing antibodies against HIV-1 Env.
Timing of Initiation of Anti-Retroviral Therapy Predicts Post-Treatment Control of SIV Replication
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Researchers are interested in approaches to reducing viral rebound following interruption of antiretroviral therapy, but more work is needed to understand major factors that determine the viral “setpoint” level. Researchers previously assessed how timing of treatment can affect the frequency of rebound from latency. In the current study, the authors analyzed data from multiple studies of simian immunodeficiency virus (SIV) infection in rhesus macaques to further explore the dynamics and predictors of post-treatment viral control.