Search Results (155)

Adenoviral vectors are widely used for gene therapy and vaccine development. To circumvent pre-existing immunity against commonly used human adenovirus type 5, vectors based on rare human serotype or animal adenoviruses have attracted increasing interest. Previously, we constructed vectors based on fowl adenovirus 4 (FAdV-4) and replaced the knob of FAdV-4 fiber2 with that of FAdV-1 fiber1 to generate FAdV4-CF1K vectors with enhanced transduction efficiency in human cells. In this study, we aimed to modify the packaging system to efficiently produce FAdV-4 vectors carrying transgenes toxic to viral replication. Chicken LMH cells failed to form colonies at low seeding densities. We collected used medium from LMH cell cultures and used it as a supplement to adapt LMH cells, generating the colony-competent subclone LMH-C3532. A lentiviral vector encoding a codon-optimized tetracycline repressor (tetR) was transduced into LMH-C3532 to establish a tetR-integrated cell line, LMH-tetR24. An adenoviral plasmid, pKFAV4-CF1K-CtG, was constructed in which a tetracycline operator (tetO)-bearing CMV promoter controlled GFP expression. The SwaI-flanked GFP in this plasmid was replaced with the HA gene from an H5N1 influenza virus to generate pKFAV4-CF1K-CtHA. Linearized adenoviral plasmids were transfected into LMH-tetR24 cells, and recombinant FAdV4-CF1K-CtG and FAdV4-CF1K-CtHA viruses were successfully rescued, amplified, and purified. When infected with FAdV4-CF1K-CtG at various multiplicities of infection (MOI), the progeny virus yield from LMH-tetR24 cells was 4–10 times higher than that from LMH-C3532 cells. For FAdV4-CF1K-CtHA, the yield difference between the two cell lines was even more pronounced, reaching 3–4 orders of magnitude. Overexpression of HA in LMH-C3532 cells negatively affected FAdV4-CF1K-CtHA replication, resulting in smaller and fewer plaques. In conclusion, by separately integrating tetR into packaging cells and TetO into the adenoviral plasmid, we established a system that can be routinely used to package FAdV-4 vectors. Notably, this system facilitates the propagation of FAdV-4 vectors carrying toxic transgenes. Full article

Junmu No.1 is a commercially important Chinese pig breed, yet stable in vitro models for investigating its muscle development mechanisms and genetic regulation remain lacking; this study aimed to establish an immortalized porcine satellite cell line from Junmu No.1 pigs to address this gap. Primary porcine satellite cells (PSCs) were isolated from a 2-day-old Junmu No.1 piglet and immortalized via lentiviral transduction using the pHAGE-EF1α-eGFP-SV40LT-BleoR vector. The resulting cell line (imPSC-JM) was characterized for morphology, satellite cell marker expression, karyotype stability, myogenic differentiation capacity, and long-term proliferative potential, and RNA sequencing combined with Gene Set Enrichment Analysis (GSEA) was performed to assess transcriptomic fidelity relative to primary PSCs. The imPSC-JM line retained characteristic spindle-shaped satellite cell morphology, consistently expressed PAX7, maintained a normal diploid karyotype (2n = 38, XY), and showed stable SV40 large T antigen expression, enabling sustained proliferation exceeding 100 cumulative population doublings while preserving myogenic differentiation and the formation of multinucleated myotubes expressing Desmin, MYHC, and DMD. Transcriptomic profiles were highly concordant with primary PSCs (Pearson r ≥ 0.95; R² = 0.9188; 83.8% of expressed genes unchanged), with key satellite-cell and myogenic regulator genes (PAX7, MYOD1, MYF5, MYOG, MYF6) unaltered, while GSEA revealed upregulation of autophagy and inflammatory signaling and downregulation of ribosome biogenesis. The imPSC-JM line thus provides a reliable experimental platform with high transcriptomic fidelity for studying muscle development and genetic regulation in Junmu No.1 pigs. Full article

Background/Objectives: Adoptive transfer of allogeneic natural killer (NK) cells represents a promising off-the-shelf immunotherapy for cancer, offering advantages in safety and availability over autologous T cell therapies. However, generating therapeutically sufficient NK cell numbers remains challenging due to their low frequency in blood sources. Engineered feeder cell co-cultures have enabled substantial expansions of NK cells to clinically relevant doses. Methods: We evaluated the plasma cell leukemia-derived ARH-77 cell line as a feeder for ex vivo NK cell expansion from healthy donor peripheral blood mononuclear cells (PBMCs). Unmodified ARH-77 was compared to K562, followed by engineering both lines to co-express B7-H6 (NKp30 ligand), CD137L (4-1BBL), IL-15, and IL-15Rα via sequential lentiviral transduction. PBMCs were co-cultured with irradiated feeders in cytokine-supplemented (IL-2, IL-21, and later IL-15) RPMI-1640 or DMEM/F-12 medium for up to 28 days. Expansion (fold change in CD3⁻CD56⁺ cells), purity, surface receptor expression, and cytotoxicity (against K562 targets) were quantified. Results: Unmodified ARH-77 supported significantly greater NK cell expansion than K562 (model-estimated 681-fold vs. 155-fold at week 4 in RPMI; p = 0.0018), with higher purity but comparable cytotoxicity and receptor profiles. Engineered ARH-77 cells achieved robust expansion in RPMI, comparable to that of engineered K562 cells. In optimized DMEM/F-12 medium, engineered ARH-77 drove superior expansion (up to model-estimated 101,241-fold; 95% CI 46,771–219,146 at week 4), significantly outperforming engineered K562 (4.4-fold greater; 95% CI 1.01 to 18.54; p = 0.0479) while maintaining high purity and equivalent cytotoxicity. Substantial inter-donor variability influenced expansion magnitude, though relative feeder performance remained consistent across donors. Conclusions: Genetically modified ARH-77 feeder cells provide a potent platform for large-scale ex vivo expansion of functional NK cells. Full article

Objectives: Membrane-enveloped virus-like particles (VLPs) constitute a versatile vaccine platform allowing for the display of heterologous viral surface antigens. The density of displayed antigens is paramount for the efficient elicitation of a strong cellular and humoral immune response. SARS-CoV-2 spike protein variants with engineered cytoplasmic tails (CTs) were generated to enhance decoration efficiency on the surface of VLPs formed by the HIV core protein Gag. These HIV (SARS-CoV-2) chimeric particles serve as a vaccine component prototype. Methods: Spike variants were first analyzed for cellular and surface expression as well as incorporation into extracellular vesicles (EVs) and VLPs using flow cytometric analysis and Western blot analysis. Receptor binding, fusogenicity, i.e., mediating the fusion of spike-positive with receptor-containing membranes, and the proteins’ potential to mediate lentiviral vector gene transduction into susceptible target cells was examined by employing syncytia-formation assays and vector titration experiments. The display of a neutralization-sensitive epitope was examined utilizing immuno-precipitation using a neutralizing antibody. Results: All four variants were shown to be cell-surface expressed, to recruit the cognate receptor, to mediate membrane fusion and cell entry of lentiviral pseudotype vector particles and to decorate VLPs and EVs. However, the spike variant encompassing a truncated CT derived from the gibbon ape leukemia virus (GaLV) transmembrane (TM) envelope protein was most efficiently incorporated into HIV Gag-formed VLPs. All variants exposed a neutralization-sensitive epitope in the receptor binding domain. Conclusions: Engineering of the CTs of viral surface antigens can enhance VLP decoration, while required functionality of the ecto-domain such as receptor recognition, fusogenicity and neutralization-sensitive epitope presentation are not abrogated. This indicates the preservation of the structural integrity of the antigen required to elicit a neutralizing humoral immunity upon vaccination. The identified truncated CT of GaLV TM may be of utility to improve the incorporation of other viral surface antigens into a variety of membrane-enveloped VLPs derived from a range of different parental viruses. Full article

The innate immune signaling pathway cGAS–STING plays an important role in the recognition of cytosolic nucleic acids and the induction of the interferon-dependent antiviral response. Despite the significant research interest in this cascade in the context of immune system function, the mechanisms regulating cGAS–STING signaling and the switch between its pro-inflammatory and pro-apoptotic effects remain largely underexplored. According to publicly available RNA-seq data and microarray analyses, SETD7 lysine methyltransferase participates in interferon signaling in cancer cells. This study aims to elucidate the role of SETD7 in the regulation of the STING-dependent immune response in human lung adenocarcinoma (LUAD) cells. For this purpose, we developed a reproducible and cost-effective method for inducing the STING cascade by transfecting cells with salmon sperm DNA (sspDNA). We demonstrated that sspDNA efficiently induces phosphorylation of the key components of the STING–TBK1–IRF3 signaling pathway and activates the expression of interferons and pro-inflammatory cytokines. Using this approach, we further demonstrated that SETD7 is involved in the regulation of the IRF3-dependent transcriptional program. Suppression of SETD7 was associated with changes in the expression of genes related to innate immune response and apoptosis, including increased levels of IFNA1, IL1B, BAK1, BBC3 (PUMA), and BCL2. Furthermore, attenuation of SETD7 expression reduced the lentiviral transduction efficacy in H1299 cells. These results suggest that SETD7 may play a role in regulating the switch in STING signaling between pro-inflammatory and pro-apoptotic responses in LUAD cells. Full article

Background/Objectives: Src homology 2 domain-containing protein tyrosine phosphatase 1 (SHP-1), also known as protein tyrosine phosphatase non-receptor type 6, functions as a tumor suppressor in breast, hepatocellular, and prostate cancers and an oncogene in glioblastoma and cervical cancer. A previous analysis of The Cancer Genome Atlas (TCGA) dataset revealed that lower SHP-1 transcript levels in bladder tumors were associated with poorer overall survival. Methods: This study aimed to evaluate the role of SHP-1 in bladder cancer and to assess the functional impact of its forced expression and knockdown in bladder carcinoma cell lines. SHP-1 expression was assessed in 19 bladder cancer cell lines and 26 bladder tissues. Lentiviral transduction was used to knock down or overexpress SHP-1 in four cell lines, followed by Western blot analysis of SHP-1 and pAkt/Akt protein expression. Results: SHP-1 protein levels were significantly lower in highly invasive cell lines (p < 0.001) and muscle-invasive tumors (p < 0.05). Functional studies demonstrated that SHP-1 modulation influenced the epithelial–mesenchymal transition (EMT) phenotype. SHP-1 expression was positively correlated with E-cadherin expression (p < 0.001) and negatively correlated with N-cadherin (p < 0.01) and Vimentin (p < 0.05) expression. Alteration of SHP-1 expression in bladder cancer cell lines affected proliferation, invasion, and migration (p < 0.05). RNA-seq analysis of the transduced cell lines revealed enrichment of gene sets related to EMT and signaling pathways involving MYC, PI3K, Akt, and mTOR. Furthermore, SHP-1 alteration impacted pAkt/Akt ratios (p < 0.05). Conclusions: Collectively, lower SHP-1 protein expression correlated with more aggressive phenotypes in bladder cancer cell lines and bladder tumors. In our limited dataset, reduced SHP-1 expression correlated with muscle-invasive disease, suggesting a potential link to more advanced tumor biology, consistent with TCGA associating reduced SHP-1 transcript expression to poorer survival rates. Our data provide preliminary functional evidence that SHP-1 may modulate Akt signaling in bladder cancer. Together, these results support further investigation of SHP-1 as a possible tumor suppressor, candidate prognostic biomarker, and potential therapeutic target in bladder cancer. Full article

Prion diseases are fatal neurodegenerative disorders that affect humans and animals, caused by the conformational conversion of the normal cellular prion protein (PrP^C) into its misfolded, infectious isoform PrP^Sc. Recently, camel prion disease (CPrD) was identified in dromedary camels (Camelus dromedarius) in Algeria. Due to the potential implications for animal and human health, as well as the possible socio-economic impact in Mediterranean regions where camels play a pivotal role as a source of food, in-depth characterization of camel prions is important to increase our understanding of camel prion disease. We developed a neuronal cell line model for studying the molecular features of camel prion infection. We genetically edited mouse neuronal CAD5 cells to generate CAD5 PrP knockout (KO) cells. We then used lentiviral transduction to generate CAD5 cells expressing camel PrP (CAD5-camel-PrP). Following infection of these cells with a CPrD-positive camel brain homogenate, we observed PrP^Sc signals at various passages, as indicated by immunoblotting analysis. RT-QuIC (Real-Time Quaking-Induced Conversion) assays further supported these findings, demonstrating transient prion conversion activity in the CPrD-infected CAD5-camel-PrP cells. Taken together, our data describe the first neuronal cell line permissive to camel prion infection, a novel in vitro tool for mechanistic studies of camel prion disease. Full article

Insulin-like growth factor 2 (IGF2) plays a pivotal role in regulating growth and development; however, its functional involvement in skeletal muscle satellite cells (SMSCs) remains incompletely understood. To elucidate the regulatory role of IGF2, goose SMSCs were engineered to overexpress IGF2 via lentiviral transduction, followed by comprehensive transcriptomic profiling. Comparative analysis revealed 2802 differentially expressed genes (DEGs) in IGF2-overexpressing cells relative to controls, comprising 1202 upregulated and 1600 downregulated genes. IGF2 overexpression markedly activated fibrogenic programs, as evidenced by the upregulation of AP-1 complex components (FOS, JUN), extracellular matrix-related genes (COL1A1, COL5A3), and Wnt signaling receptors (FZD1, FZD7). In contrast, genes involved in myogenic differentiation and contractile function were broadly suppressed, including key myogenic transcription factors (MEF2C, MEF2D), sarcomeric structural proteins (MYBPC1, ACTN2, MYOM3), and metabolic enzymes. Through the construction of protein–protein interaction networks coupled with functional enrichment analysis, we observed a concerted suppression of myogenic regulatory networks critical for myofiber formation. Quantitative real-time PCR validation further confirmed the reliability of the transcriptomic data. Collectively, these findings suggest that overexpression of IGF2 induces a phenotypic shift from myoblasts toward a fibroblast-like state, uncoupling proliferation from differentiation while enhancing fibrogenic identity. This study provides novel insights into IGF2-mediated regulatory mechanisms underlying skeletal muscle development and fibrotic processes. Full article

Diabetic cognitive impairment (DCI) is a serious and growing public health concern. The role of N6-methyladenosine (m⁶A), the predominant mRNA modification in the mammalian brain, in DCI pathogenesis remains not fully elucidated. Here, GEO-derived diabetes datasets were combined with in vivo and in vitro models to reveal aberrant expression of m⁶A-related genes. The results showed that the overall level of m⁶A RNA methylation in both the diabetic group and the high-glucose group was significantly decreased compared to the normal group. In addition, the expression of methyltransferase METTL3, which is involved in the regulation of m⁶A RNA methylation, was downregulated in both diabetic and hyperglycemic groups, and was positively correlated with the downregulation of the overall m⁶A level. Neuronal models with stable METTL3 knockdown were generated using lentiviral transduction. Subsequent ¹H-NMR metabolomic and MeRIP-qPCR analyses demonstrated that METTL3 deficiency disrupts key metabolic pathways, including phosphatidylethanolamine and phosphatidylcholine biosynthesis and glucose–alanine metabolism, and identified Fgf15 (the mouse ortholog of human FGF19) and H6PD as candidate downstream targets. Collectively, these data suggest that METTL3-dependent m⁶A RNA methylation alterations may contribute to DCI through metabolic dysregulation, positioning METTL3 as a promising therapeutic target for DCI. Full article

Background/Objectives: Human epidermal growth factor receptor 2 (HER2)-positive breast cancer is linked to poorer overall survival and a higher risk of brain metastases compared to HER2-negative breast cancer. Current preclinical studies lack robust HER2+ metastatic syngeneic mouse models for investigating targeted and immunomodulatory therapies. This study aims to develop effective HER2+ mouse models to investigate response dynamics to HER2-targeted therapy and immunotherapy. Methods: The human HER2 gene (WT or mutant p.A775_G776insYVMA, GFP-tagged at the C-terminus) was introduced into triple-negative breast cancer (TNBC) mouse mammary carcinoma cells with known metastatic potential (4T1 and EO771) via lentiviral transduction. HER2 expression and phosphorylation were analyzed using Western blotting and immunohistochemistry. Tumors were treated with HER2-targeted therapy (trastuzumab and tucatinib), immune checkpoint blockade (anti-PD-1 and anti-CTLA-4), and anti-HER2 antibody–drug conjugate (ADC) to evaluate treatment efficacy. Metastatic potential was assessed with brain fluorescence imaging. Statistical analysis included ANOVA and Kaplan–Meier tests. Results: Newly established lines demonstrated expression of HER2+, with HER2^YVMA lines showing higher phosphorylation than HER2^WT lines. Cells were tumorigenic, demonstrating in vivo tumor take rates at 100% for 4T1-HER2 and 15–30% for EO771-HER2. HER2 overexpression led to a 30% increase in spontaneous brain metastasis in the 4T1-HER2 models. Trastuzumab alone did not reduce primary tumor size but significantly reduced brain GFP signal by 17% ± 8% and 26% ± 7% in the 4T1-HER2^WT and 4T1-HER2^YVMA models, respectively. Combinational therapies with anti-HER2 therapy and immune checkpoint blockade effectively suppressed primary tumor growth and prolonged survival in EO771-HER2^YVMA model. T-Dxd, but not T-DM1, demonstrated partial treatment response in the EO771-HER2^WT model. Conclusions: HER2+ syngeneic tumor models were developed that spontaneously metastasize to the brain and demonstrate variable responses to immunotherapies and ADCs. These models are valuable for advancing molecular imaging modalities for HER2+ brain metastasis, studying blood–brain barrier penetration of HER2-targeted drugs, and exploring the combination of therapies, including immunotherapy. Full article

The Asian black bear (Ursus thibetanus, UT), a Class II protected species in China, presents significant challenges for dermatological research due to limited availability of skin specimens and technical difficulties in fibroblast isolation. To address this, this study developed an immortalized fibroblast cell line through lentiviral-mediated introduction of human telomerase reverse transcriptase (hTERT). The hTERT gene fragment was amplified via PCR and cloned into a eukaryotic expression plasmid using homologous recombination. The recombinant plasmid was packaged into lentiviral particles using a three-plasmid system (psPAX2, pMD2.G) for stable transduction of primary Ursus thibetanus skin fibroblasts (UTSF). Puromycin selection enabled isolation of positive clones, which were subsequently expanded to establish an immortalized cell line. Comprehensive validation through Western blotting, PCR and immunofluorescence confirmed successful genomic integration and sustained expression of hTERT. This study successfully immortalized the skin fibroblasts of black bears and established a fibroblast cell line of Asian black bears. This immortalized UTSF cell line provides a critical in vitro model system for investigating cutaneous physiology and pathogen interactions in this protected species. Full article

Background: Lentiviral vectors (LVs) show promise as gene therapy tools for brain tumors, but optimal envelope protein choices for different tumor types have not been determined. Methodology: This study evaluated three pseudotyped LV variants—VSV-GP, FuG-B2, and LCMV-GP—across diverse brain tumor cell lines including glioblastoma (GBM), diffuse intrinsic pontine glioma (DIPG), medulloblastoma, and metastatic brain cancers. Results: VSV-GP and FuG-B2 pseudotypes significantly outperformed LCMV-GP across most tumor types. Both VSV-GP and FuG-B2 demonstrated high transduction efficiency in GBM and DIPG cells, though some cell lines displayed selective preferences for one pseudotype over the other. Medulloblastoma cells were challenging to transduce, with only VSV-GP achieving substantial efficacy. Metastatic brain cancers showed distinct tropism patterns: melanoma metastases were preferentially transduced by the FuG-B2 pseudotype, while lung metastases showed preference for the VSV-GP pseudotype. Conclusions: These findings suggest envelope protein selection should be tailored to specific brain tumor types. VSV-GP appears most suitable for medulloblastoma and lung metastases, FuG-B2 for melanoma metastases, and both for GBM and DIPG gene therapy applications. The study provides crucial guidance for translating lentiviral gene therapy to clinical applications, supporting personalized treatment strategies based on tumor-specific vector tropism profiles. Full article

Diabetic nephropathy (DN) is the most common cause of kidney failure worldwide. Mesenchymal stromal cells (MSCs) have demonstrated promise for treating DN by promoting kidney repair and regulating inflammation. Allogeneic (Allo)-MSCs may have similar or superior anti-inflammatory effects to autologous (Auto)-MSCs but also have potential to elicit adverse immune responses due to major histocompatibility complex (MHC) mismatches. To better understand how MSC-delivered allo-antigens influence therapeutic effects of Allo-MSCs compared to Auto-MSCs in DN, lentiviral transduction was used to generate adipose-derived MSCs (ADSCs) from DBA/2J (H-2^d) mice which expressed an allogeneic class I MHC protein (H-2K^b). H-2K^b-ADSCs were injected intravenously into male DBA/2J mice at 11 and 13 weeks after initiation of diabetes, and their effects on renal functional and structural indices were compared at week 15 with those of diabetic DBA/2J recipients of vehicle alone or of empty vector-transduced DBA/2J ADSCs (EV-ADSCs). Both EV-ADSCs and H-2K^b-ADSCs resulted in reduced kidney/total body weight ratio, blood urea nitrogen (BUN), urine albumin creatinine ratio (uACR), mesangial matrix expansion (MME) and renal fibrosis compared to vehicle alone, without influencing glycemia or survival. However, H-2K^b-ADSCs recipients had greater reductions in BUN and uACR, reduced intra-renal myeloid cell infiltration, increased splenic regulatory T cell (Treg) proportions and increased intra-renal Treg infiltration and FOXP3 and IL-10 mRNA. Nonetheless, recipients of H-2K^b-ADSCs also had decreased splenic CD4/CD8 T cell ratios, increased circulating anti-H-2K^b IgG antibodies and histological and biochemical evidence of inflammatory liver injury. These novel findings demonstrated that ADSCs expressing an MHC-I allo-antigen had superior beneficial effects on DN than fully autologous ADSCs. Improved DN severity was associated with immune modulation, including Treg enhancement, but also had potentially detrimental immunological effects in mice with established diabetes. The results highlight the need for further investigation of the immune modulatory effects of Allo-MSCs in diabetes and its organ-specific complications. Full article

Lentiviral transduction remains the gold standard in adoptive modified cellular therapy, such as CAR-T; however, genome integration is not always desirable, such as when treating non-fatal autoimmune disease or for additional editing steps using CRISPR to produce allogeneic CAR-modified cells. Delivering in vitro-transcribed (IVT) mRNA represents an alternative solution but the labile nature of mRNA has led to efforts to improve half-life and translation efficiencies using a range of approaches including chemical and structural modifications. In this study, we explore the role of N⁶–methyladenosine (m6A) in a CD19-CAR sequence when delivered to T cells as an IVT mRNA. In silico analysis predicted the presence of four m6A consensus (DRACH) motifs in the CAR coding sequence and treating T cells with an inhibitor of the m6A methyltransferase (METTL3) resulted in a significant reduction in CAR protein expression. RNA analysis confirmed m6A bases at three of the predicted sites, indicating that the modification occurs independently of nuclear transcription. Synonymous mutation of the DRACH sites reduced the levels of CAR protein from 15 to >50% depending on the T cell donor. We also tested a panel of CAR transcripts with different UTRs, some containing m6A consensus motifs, and identified those which further improved protein expression. Furthermore, we found that the methylation of consensus m6A sites seems to be somewhat sequence-context-dependent. These findings demonstrate the importance of the m6A modification in stabilising and enhancing expression from IVT-derived mRNA and that this occurs within the cell, meaning targeted in vitro chemical modification during mRNA manufacturing may not be necessary. Full article

Background/Objectives: Lentiviral vectors (LVs) are most commonly pseudotyped with the vesicular stomatitis virus glycoprotein (VSV-G), which lends LVs a wide tropism as it uses the low-density lipoprotein receptor (LDLR) as the main receptor for cell entry. In some gene therapy and research applications, however, alternative pseudotypes can be useful. In this work, we characterized LVs pseudotyped with lymphocytic choriomeningitis virus (LCMV) glycoprotein, particularly in gene transfer to an LDLR-deficient mouse strain used to model cardiovascular disease, Ldlr^−/−ApoB^100/100. Methods: LCMV-LVs were used in vitro to test their transduction efficiency across a variety of cell types. In vivo, the gene transfer efficiency, LV-specific immune responses and biodistribution of VSV-G-LVs and LCMV-LVs were compared after systemic gene transfer. Results: In vitro, LCMV-LVs transduced all tested cell types at high efficiency without the use of transduction enhancers. In vivo, VSV-G-LVs showed a higher gene transfer efficiency at the same LV dose, but increasing the LCMV-LV dose enhanced the measured vector copy numbers. With both pseudotypes, most of the vector accrued in the liver, but with LCMV-LVs, a larger portion of the measured vector copies were found in the lungs. VSV-G-LVs also generated a higher titer of LV-specific IgG antibodies. The gene transfer efficiency of LCMV-LVs was affected by the mouse diet, with a high-fat diet decreasing the transduction. Conclusions: LCMV-LVs can be used as a substitute for VSV-G-LVs if an alternative pseudotype is required; however, they may require the use of a higher LV dose. Full article