Biology subjects

Hetrick, B.

Publications and source records attributed to Hetrick, B..

10 recordsLinked to original sources

bioRxiv2026

Development of hybrid alphavirus-influenza A, B, and D pseudovirions for rapid quantification of neutralization antibodies and antiviral drugs

The emergence and spread of highly pathogenic avian influenza H5N1 subtypes have raised global concerns due to their ability to cross species barriers and occasional spillover to humans. The viruses primarily infect wild birds and poultry, which have caused significant, sporadic outbreaks in mammals including dairy cattle. Influenza D virus is a recently identified influenza virus that mainly affects cattle with frequent spillover to other species such as swine. Despite the availability of poultry vaccines, there are no H5N1 and Influenza D vaccines for cattle or other potentially affected livestock. Given a history of frequent influenza pandemics originating from avian and mammalian hosts, there is an urgent need for enhanced surveillance, biosecurity, and the development of antivirals and vaccines. Here we describe the development of a novel hybrid alphavirus-influenza pseudovirion (Ha-IV), which is a non-replicating influenza virus-like particle composed of viral structural proteins and an RNA genome derived from a fast-expressing alphaviral vector. As a proof-of-concept, we assembled Ha-IV pseudoviruses based on influenza D and influenza A and B subtypes, and demonstrated their infectivity. In addition, we validated an influenza A pseudovirus based on the H5N1 clade 2.3.4.4b strain, A/Texas/37/2024, for rapid quantification of neutralization antibodies within 4 to 18 hours. Furthermore, we used the pseudovirus to quantify infected cow sera and performed a correlation study with the classic hemagglutinin inhibition assay (HIA). We demonstrate that the Ha-IAV pseudovirus-based assay is consistent with HIA in identifying protective antibody responses. Our results demonstrate that this new Ha-IV pseudovirus provides a rapid tool for quantifying the infectivity of emerging HA mutants and for assessing neutralizing antibody responses.

microbiology↗

bioRxiv2025

Versatile HIV Rev-dependent reporter cell system for stringent and sensitive quantification of viral reservoirs, neutralizing antibodies, and restriction factors

Detecting and measuring HIV reservoirs, neutralizing antibodies, and restriction factors are important for HIV cure research and the development of new therapeutics and vaccines. Here we describe the development and validation of several HIV Rev-dependent indicator cell lines for these purposes. These reporter cells come from different T-lymphoblast cell lines, including MOLT-4-R5, SupT1-R5, CEM-SS, A3R5, and from the adherent TZM cell platform based on HeLa clone JC53. These cells express CD4, CXCR4, and various levels of CCR5. We compared these cell lines for responsiveness to both X4 and R5-tropic viruses, and confirmed that reporter expression in these cells is not affected by stimulation from mitogens but is responsive to HIV Tat and Rev, reducing non-specific reporter induction from the leaky LTR promoter. To validate the sensitivity of the Rev-dependent reporter cell systems, we conducted a viral dilution assay with three primary HIV-1 clade C swarms from an adult in Malawi. We also validated the systems for quantifying antibody neutralization and screening restriction factors; these systems are also sensitive for viral outgrowth assays for quantifying viral reservoirs in clinical and basic research settings. Given that the systems can measure HIV accurately in complex environments with mitogens or other substances, they can be used for versatile applications, such as quantifying latent reservoirs, testing inhibitory compounds, conducting neutralizing antibody assays, and identifying new restriction factors.

microbiology↗

bioRxiv2025

CD34 serves as an intrinsic innate immune guardrail protecting stem cells from replicating retroviruses

Stem cells are highly resistant to viral infection compared to their differentiated progeny, and this resistance is associated with stem cell-specific restriction factors and intrinsic interferon stimulated genes (ISGs). In HIV infection, proviral DNA has been detected in certain bone marrow hematopoietic stem cells, yet widespread stem cell infection in vivo is restricted. Intriguingly, exposing bone marrow stem cells to HIV in vitro led to viral replication selectively only in the CD34- population, but not in the CD34+ cells. The mechanism dictating this CD34-based HIV restriction remained a mystery, especially since HIV has a capacity to antagonize restriction factors and ISGs. CD34 is a common marker of hematopoietic stem and progenitor cells. Here, we report the intrinsic antiviral properties of CD34. Expression of CD34 in HIV-1 producer cells results in the loss of progeny virion infectivity. Conversely, removal of CD34 using CRISPR/Cas9 knockout or stem cell differentiation cytokines promotes HIV-1 replication in stem cells. These results suggest that in addition to restriction factors and intrinsic ISGs, CD34 serves as a host innate protection preventing retrovirus replication in stem cells. Mechanistically, CD34 does not block viral entry, integration, and release. Instead, it becomes incorporated onto progeny virions, which inactivates virus infectivity. These findings offer new insights into innate immunity in stem cells, and highlight intriguing retrovirus-host interactions in evolution.

immunology↗

bioRxiv2025

Development of a novel hybrid alphavirus-Nipah virus pseudovirion for rapid quantification of neutralization antibodies

Nipah virus (NiV) is an emergent paramyxovirus that causes serious disease in humans and animals. Accurate quantification of neutralizing antibodies (nAB) against NiV is essential for vaccine development. The current standard, the plaque reduction neutralization test (PRNT), requires authentic infectious NiV and BSL-4 containment, taking 4-7 days to complete. In this study, we developed a hybrid alphavirus-Nipah virus pseudovirion (Ha-NiV) composed of a non-replicating Nipah virus virus-like particle (VLP) that encapsulates an RNA genome from a fast-expressing SFV (Semliki Forest Virus) alphaviral vector. Ha-NiV can infect NiV target cells but is replication incompetent, enabling rapid quantification of nAB (6-18 hours) in BSL-2 conditions. We validated Ha-NiV using sera from Nipah virus-infected African green monkeys and established a good correlation (R2 = 0.86) with PRNT, demonstrating comparable specificity and sensitivity. These results demonstrate that the Ha-NiV assay can serve as a novel platform for convenient and rapid quantification of nAB in BSL-2 settings.

microbiology↗

bioRxiv2024

Maternal Western-style diet programs skeletal muscle gene expression in lean adolescent Japanese macaque offspring

Early-life exposure to maternal obesity or a maternal calorically dense Western-style diet (WSD) is strongly associated with a greater risk of metabolic diseases in offspring, most notably insulin resistance and metabolic dysfunction-associated steatotic liver disease (MASLD). Prior studies in our well-characterized Japanese macaque model demonstrated that offspring of dams fed a WSD, even when weaned onto a control (CTR) diet, had reductions in skeletal muscle mitochondrial metabolism and increased skeletal muscle insulin resistance compared to offspring of dams on CTR diet. In the current study, we employed a nested design to test for differences in gene expression in skeletal muscle from lean 3-year-old adolescent offspring from dams fed a maternal WSD in both the presence and absence of maternal obesity or lean dams fed a CTR diet. We included offspring weaned to both a WSD or CTR diet to further account for differences in response to post-weaning diet and interaction effects between diets. Overall, we found that a maternal WSD fed to dams during pregnancy and lactation was the principal driver of differential gene expression (DEG) in offspring muscle at this time point. We identified key gene pathways important in insulin signaling including PI3K-Akt and MAP-kinase, regulation of muscle regeneration, and transcription-translation feedback loops, in both male and female offspring. Muscle DEG showed no measurable difference between offspring of obese dams on WSD compared to those of lean dams fed WSD. A post-weaning WSD effected offspring transcription only in individuals from the maternal CTR diet group but not in maternal WSD group. Collectively, we identify that maternal diet composition has a significant and lasting impact on offspring muscle transcriptome and influences later transcriptional response to WSD in muscle, which may underlie the increased metabolic disease risk in offspring.

physiology↗

bioRxiv2021

Identification of the SHREK family of proteins as broad-spectrum host antiviral factors

Mucins and mucin-like molecules are highly glycosylated, high-molecular-weight cell surface proteins that possess a semi-rigid and highly extended extracellular domain. P-selectin glycoprotein ligand-1 (PSGL-1), a mucin-like glycoprotein, has recently been found to restrict HIV-1 infectivity through virion incorporation that sterically hinders virus particle attachment to target cells. Here, we report the identification of a family of antiviral cellular proteins, named the Surface-Hinged, Rigidly-Extended Killer (SHREK) family of virion inactivators (PSGL-1, CD43, TIM-1, CD34, PODXL1, PODXL2, CD164, MUC1, MUC4, and TMEM123), that share similar structural characteristics with PSGL-1. We demonstrate that SHREK proteins block HIV-1 infectivity by inhibiting virus particle attachment to target cells. In addition, we demonstrate that SHREK proteins are broad-spectrum host antiviral factors that block the infection of diverse viruses such as influenza A. Furthermore, we demonstrate that a subset of SHREKs also blocks the infectivity of a hybrid alphavirus-SARS-CoV-2 virus-like particle. These results suggest that SHREK proteins may be a part of host innate immunity against enveloped viruses.

microbiology↗

bioRxiv2020

Development of a novel hybrid alphavirus-SARS-CoV-2 particle for rapid in vitro screening and quantification of neutralization antibodies, antiviral drugs, and viral mutations

Timely development of vaccines and antiviral drugs is critical to control the COVID-19 pandemic 1-6. Current methods for quantifying vaccine-induced neutralizing antibodies involve the use of pseudoviruses, such as the SARS-CoV-2 spike protein (S) pseudotyped lentivirus7-14. However, these pseudoviruses contain structural proteins foreign to SARS-CoV-2, and require days to infect and express reporter genes15. Here we describe the development of a new hybrid alphavirus-SARS-CoV-2 (Ha-CoV-2) particle for rapid and accurate quantification of neutralization antibodies and viral variants. Ha-CoV-2 is a non-replicating SARS-CoV-2 virus-like particle, composed of SARS-CoV-2 structural proteins (S, M, N, and E) and a RNA genome derived from a fast expressing alphavirus vector 16. We demonstrated that Ha-CoV-2 can rapidly and robustly express reporter genes in target cells within 3-6 hours. We further validated Ha-CoV-2 for rapid quantification of neutralization antibodies, viral variants, and antiviral drugs. In addition, as a proof-of-concept, we assembled and compared the relative infectivity of a panel of 10 Ha-CoV-2 variant isolates (D614G, P.1, B.1.1.207, B.1.351, B.1.1.7, B.1.429, B.1.258, B.1.494, B.1.2, B.1.1298), and demonstrated that these variants in general are 2-10 fold more infectious. Furthermore, we quantified the anti-serum from an infected and vaccinated individual; the one dose vaccination with Moderna mRNA-1273 has greatly increased the anti-serum titer for approximately 6 fold. The post-vaccination serum has also demonstrated various neutralizing activities against all 9 variants tested. These results demonstrated that Ha-CoV-2 can be used as a robust platform for rapid quantification of neutralizing antibodies against SARS-CoV-2 and its variants.

microbiology↗

bioRxiv2020

A traditional Chinese medicine, Respiratory Detox Shot (RDS), inhibits the infection of SARS-CoV, SARS-CoV-2, and the Influenza A virus in vitro

The ongoing global pandemic of coronavirus disease 2019 (COVID-19) has resulted in the infection of over 60 million people and has caused over 1.4 million deaths as of December 2020 in more than 220 countries and territories. Currently, there is no effective treatment for COVID-19 to reduce mortality. We investigated the potential anti-coronavirus activities from an oral liquid of traditional medicine, Respiratory Detox Shot (RDS), which contains mostly herbal ingredients traditionally used to manage lung diseases. Here we report that RDS inhibited the infection of target cells by SARS-CoV and SARS-CoV-2 pseudoviruses, and by infectious wild-type SARS-CoV-2. We further demonstrated that RDS inhibits viral early infection steps. In addition, we found that RDS can also block the infection of target cells by Influenza A virus. These results suggest that RDS may broadly inhibit the infection of respiratory viruses.

microbiology↗

bioRxiv2020

PSGL-1 blocks SARS-CoV-2 S protein-mediated virus attachment and infection of target cells

P-selectin glycoprotein ligand-1 (PSGL-1) is a cell surface glycoprotein that binds to P-, E-, and L-selectins to mediate the tethering and rolling of immune cells on the surface of the endothelium for cell migration into inflamed tissues. PSGL-1 has been identified as an interferon-γ (INF-γ)-regulated factor that restricts HIV-1 infectivity, and has recently been found to possess broad-spectrum antiviral activities. Here we report that the expression of PSGL-1 in virus-producing cells impairs the incorporation of SARS-CoV and SARS-CoV-2 spike (S) glycoproteins into pseudovirions and blocks virus attachment and infection of target cells. These findings suggest that PSGL-1 may potentially inhibit coronavirus replication in PSGL-1+ cells.Competing Interest StatementThe authors have declared no competing interest.View Full Text

microbiology↗

bioRxiv2019

Maternal Obesity and Western-style Diet Impair Fetal and Juvenile Offspring Skeletal Muscle Insulin-Stimulated Glucose Transport in Nonhuman Primates

Infants born to mothers with obesity have a greater risk for childhood obesity and metabolic diseases; however, the underlying biological mechanisms remain poorly understood. We used a nonhuman primate model to investigate whether maternal obesity combined with a western-style diet (WSD) impairs offspring muscle insulin action. Briefly, adult females were fed a control (CON) or WSD prior to and during pregnancy and lactation. Offspring were weaned to a CON or WSD. Muscle glucose uptake and insulin signaling were measured ex vivo in fetal and juvenile offspring. In vivo signaling was evaluated before and after an intravenous insulin bolus just prior to weaning. We find that fetal muscle exposed to maternal WSD had reduced insulin-stimulated glucose uptake and impaired insulin signaling. In juvenile offspring, insulin-stimulated glucose uptake was similarly reduced by both maternal and post-weaning WSD. Analysis of insulin signaling activation revealed distinct changes between fetal and post-weaning WSD exposure. We conclude that maternal WSD leads to a persistent decrease in insulin-stimulated glucose uptake in juvenile offspring even in the absence of increased offspring adiposity or markers of systemic insulin resistance. Switching offspring to a healthy diet did not ameliorate the effects of maternal WSD suggesting earlier interventions may be necessary.

physiology↗