Search Results (624)

Human leukocyte antigen class I (HLA-I) molecules present intracellular peptides on the cell surface to enable CD8+ T cells to effectively control viral infections. Many viruses disrupt this antigen presentation pathway to evade immune detection. In this study, we demonstrate that SARS-CoV-2 Nsp1 impairs both the constitutive and interferon-γ (IFN-γ)-induced upregulation of HLA-I. Moreover, Nsp1 also blocks IFN-γ-induced expression of HLA-II. We found that, contrary to previously published work, the early SARS-CoV-2 B 1.1.7 Alpha variant lacking the accessory protein ORF8 retained full capacity to downregulate HLA-I, comparable to an ORF8-expressing wild-type isolate. While ectopic overexpression of ORF8 could reduce HLA-I surface levels, this effect was only observed at high expression levels. In contrast, moderate expression of the viral protein Nsp1 was sufficient to potently suppress both basal and IFN-γ-induced HLA-I, as well as HLA-II expression. To probe the underlying mechanism, we analyzed HLA-I-associated genes in previously published RNA-sequencing datasets and confirmed that Nsp1 reduces expression of components required for HLA-I biosynthesis and antigen processing. These findings identify Nsp1 as a key factor that impairs antigen presentation pathways, potentially contributing to the ability of SARS-CoV-2 to modulate immune recognition. Full article

Avian influenza A viruses (IAVs) pose a persistent threat to the poultry industry, causing substantial economic losses. Although traditional vaccines have helped reduce the disease burden, they typically rely on multivalent antigens, emphasize humoral immunity, and require intensive production. This study aimed to establish a genetically matched host–cell system to evaluate antigen-specific immune responses and identify conserved CD8+ T cell epitopes in avian influenza viruses. To this end, we developed an MHC class I genotype (B21)-matched host (Lohmann VALO SPF chicken) and cell vector (DF-1 cell line) model. DF-1 cells were engineered to express the hemagglutinin (HA) gene of clade 2.3.4.4b H5N1 either transiently or stably, and to stably express the matrix 1 (M1) and nucleoprotein (NP) genes of A/chicken/South Korea/SL20/2020 (H9N2, Y280-lineage). Following prime-boost immunization with HA-expressing DF-1 cells, only live cells induced strong hemagglutination inhibition (HI) and virus-neutralizing (VN) antibody titers in haplotype-matched chickens. Importantly, immunization with DF-1 cells transiently expressing NP induced stronger IFN-γ production than those expressing M1, demonstrating the platform’s potential for differentiating antigen-specific cellular responses. CD8+ T cell epitope mapping by mass spectrometry identified one distinct MHC class I-bound peptide from each of the HA-, M1-, and NP-expressing DF-1 cell lines. Notably, the identified HA epitope was conserved in 97.6% of H5-subtype IAVs, and the NP epitope in 98.5% of pan-subtype IAVs. These findings highlight the platform’s utility for antigen dissection and rational vaccine design. While limited by MHC compatibility, this approach enables identification of naturally presented epitopes and provides insight into conserved, functionally constrained viral targets. Full article

Recent preclinical and clinical studies have confirmed the essential role of interferons in the host’s immune response against malignant cells. Merkel cell carcinoma (MCC) is a rare, aggressive skin cancer strongly associated with Merkel cell polyomavirus (MCPyV). Despite progress in understanding MCC pathogenesis, the role of innate immune signaling, particularly interferon-γ (IFN γ) and its downstream pathways, remains underexplored. This review summarizes recent findings on IFN-γ in MCC, highlighting its dual role in promoting both antitumor immunity and immune evasion. IFN-γ enhances cytotoxic T cell responses, upregulates MHC class I/II expression, and induces tumor cell apoptosis. Transcriptomic studies have shown that IFN-γ treatment upregulates immune-regulatory genes including PD-L1, HLA-A/B/C, and IDO1 by over threefold; it also activates APOBEC3B and 3G, contributing to antiviral defense and tumor editing. Clinically, immune checkpoint inhibitors (ICIs) such as pembrolizumab and avelumab yield objective response rates of 30–56% and two-year overall survival rates exceeding 60% in advanced MCC. However, approximately 50% of patients do not respond, in part due to IFN-γ signaling deficiencies. This review further discusses IFN-γ’s crosstalk with the STAT1/3/5 pathways and emerging combination strategies aimed at restoring immune sensitivity. Understanding these mechanisms may inform personalized immunotherapeutic approaches and guide the development of IFN-γ–based interventions in MCC. Full article

Fecal microbiota transplantation (FMT) promotes growth performance and intestinal development in yellow-feathered broilers, but whether the virome and metabolites contribute to its growth-promoting effect remains unclear. This study removed the microbiota from FMT filtrate using a 0.45 μm filter membrane, retaining the virome and metabolites to perform fecal virome transplantation (FVT), aiming to investigate its regulatory role in broiler growth. Healthy yellow-feathered broilers with high body weights (top 10% of the population) were used as FVT donors. Ninety-six 8-day-old healthy male yellow-feathered broilers (95.67 ± 3.31 g) served as FVT recipients. Recipient chickens were randomly assigned to a control group and an FVT group. The control group was gavaged with 0.5 mL of normal saline daily, while the FVT group was gavaged with 0.5 mL of FVT solution daily. Growth performance, immune and antioxidant capacity, intestinal development and related gene expression, and microbial diversity were measured. The results showed that FVT improved the feed utilization rate of broilers (the feed conversion ratio decreased by 3%; p < 0.05), significantly increased jejunal length (21%), villus height (69%), and crypt depth (84%) (p < 0.05), and regulated the jejunal barrier: insulin-like growth factor-1 (IGF-1) (2.5 times) and Mucin 2 (MUC2) (63 times) were significantly upregulated (p < 0.05). FVT increased the abundance of beneficial bacteria Lactobacillales. However, negative effects were also observed: Immunoglobulin A (IgA), Immunoglobulin G (IgG), Immunoglobulin M (IgM), Interleukin-1 beta (IL-1β), Interleukin-6 (IL-6), Tumor Necrosis Factor-alpha (TNF-α), and Interferon-gamma (IFN-γ) in broilers were significantly upregulated (p < 0.05), indicating immune system overactivation. Duodenal barrier-related genes Mucin 2 (MUC2), Occludin (OCLN), Claudin (CLDN1), and metabolism-related genes solute carrier family 5 member 1 (SLC5A1) and solute carrier family 7 member 9 (SLC7A9) were significantly downregulated (p < 0.05). The results of this trial demonstrate that, besides the microbiota, the gut virome and metabolites are also functional components contributing to the growth-promoting effect of FMT. The differential responses in the duodenum and jejunum reveal spatial heterogeneity and dual effects of FVT on the intestine. The negative effects limit the application of FMT/FVT. Identifying the primary functional components of FMT/FVT to develop safe and targeted microbial preparations is one potential solution. Full article

Type-I Interferon (IFN) is essential for antiviral immunity in both mice and humans; thus, we investigated whether LAT affects HSV-1 infectivity in the absence of IFN by infecting IFNαβR^−/− and wild-type control mice with HSV-1 McKrae (LAT-plus) and dLAT2903 (LAT-minus) viruses. IFNαβR^−/− mice survived ocular infection with the LAT-plus virus, while no infected mice survived infection with the LAT-minus virus. Increased death in infected mice correlated with a higher expression in the neurovirulence γ34.5 gene but not with gB expression. To determine the region of LAT that contributed to higher mortality, IFNαβR^−/− mice were infected with recombinant viruses expressing the first 1.5 kb or the first 811bp region of 1.5 kb LAT. Similar to LAT-plus infected mice, IFNαβR^−/− mice infected with LAT1.5kb were protected from death, while infection with the LAT811bp virus was similar to that of LAT-minus, suggesting that increased pathogenicity in the absence of LAT depends on the second half of 1.5 kb LAT. To confirm the in vivo upregulation of γ34.5 expression in the absence of LAT, rabbit skin and Neuro2A cells were infected with LAT-plus, LAT-minus, LAT1.5kb, or LAT811bp viruses. γ34.5 expression was significantly higher in LAT-minus- and LAT811bp-infected rabbit skin cells and Neuro2A cells than in LAT-plus- and LAT1.5kb-infected cells, suggesting that sequences after the 811bp of LAT contribute to γ34.5 upregulation. However, except for γ34.5 expression, ICP0, ICP4, and gB expression were not affected by the absence of LAT or truncated forms of LAT. To confirm that higher γ34.5 expression contributes to higher mortality in the absence of LAT, we infected IFNαβR^−/− mice with a recombinant virus lacking LAT and γ34.5 expression, and, in contrast to LAT-minus, all infected mice survived. Our results suggest that LAT controls γ34.5 expression and that higher γ34.5 expression and mortality in infected mice are associated with the second half of 1.5 kb LAT. Full article

Background: Cerebral aneurysm (CA) is a focal or diffuse pathological dilation of the cerebral arterial wall that arises due to various etiological factors. It represents a serious vascular condition, particularly affecting the elderly, and carries a high risk of rupture and neurological morbidity. Clonidine (CL), an α2-adrenergic receptor agonist, has been reported to suppress aneurysm progression; however, its underlying molecular mechanisms, especially in relation to cerebral endothelial dysfunction, remain unclear. This study aimed to investigate the potential of CL to mitigate CA development by modulating apoptosis, inflammation, and oxidative stress in an Angiotensin II (Ang II)-induced endothelial injury model. Methods: Human brain microvascular endothelial cells (HBMECs) were used to establish an in vitro model of endothelial dysfunction by treating cells with 1 µM Ang II for 48 h. CL was administered 2 h prior to Ang II exposure at concentrations of 0.1, 1, and 10 µM. Cell viability was assessed using the MTT assay. Oxidative stress markers, including reactive oxygen species (ROS) and Nitric Oxide (NO), were measured using 2′,7′–dichlorofluorescin diacetate (DCFDA). Gene expression levels of vascular endothelial growth factor (VEGF), matrix metalloproteinases (MMP-2 and MMP-9), high mobility group box 1 (HMGB1), and nuclear factor kappa B (NF-κB) were quantified using RT-qPCR. Levels of proinflammatory cytokines; tumor necrosis factor-alpha (TNF-α), Interleukin-6 (IL-6), and interferon-gamma (IFN-γ); were measured using commercial ELISA kits. Results: Ang II significantly increased ROS production and reduced NO levels, accompanied by heightened proinflammatory cytokine release and endothelial dysfunction. MTT assay revealed a marked decrease in cell viability following Ang II treatment (34.18%), whereas CL preserved cell viability in a concentration-dependent manner: 44.24% at 0.1 µM, 66.56% at 1 µM, and 81.74% at 10 µM. CL treatment also significantly attenuated ROS generation and inflammatory cytokine levels (p < 0.05). Furthermore, the expression of VEGF, HMGB1, NF-κB, MMP-2, and MMP-9 was significantly downregulated in response to CL. Conclusions: CL exerts a protective effect on endothelial cells by reducing oxidative stress and suppressing proinflammatory signaling pathways in Ang II-induced injury. These results support the potential of CL to mitigate endothelial injury in vitro, though further in vivo studies are required to confirm its translational relevance. Full article

Military personnel deployed to Iraq and Afghanistan were exposed to emissions from open-air burn pits, where plastics, metals, and medical waste were incinerated. These exposures have been linked to deployment-related respiratory diseases (DRRD) and may also impact neurological health via the lung–brain axis. To investigate molecular mechanisms, adult male rats were exposed to filtered air, naphthalene (a representative volatile organic compound), or a combination of naphthalene and carbon black (surrogate for particulate matter; CBN) via whole-body inhalation (six hours/day, three consecutive days). Lung, brain, and plasma samples were collected 24 h after the final exposure. Pro-inflammatory biomarkers were assessed using multiplex electrochemiluminescence and western blot. Differentially expressed genes (DEGs) were identified by RNA sequencing, and elastic net modeling was used to define exposure-predictive gene signatures. CBN exposure altered inflammatory biomarkers across tissues, with activation of nuclear factor kappa B (NF-κB) signaling. In the lung, gene set enrichment revealed activated pathways related to proliferation and inflammation, while epithelial–mesenchymal transition (EMT) and oxidative phosphorylation were suppressed. In the brain, EMT, inflammation, and senescence pathways were activated, while ribosomal function and oxidative metabolism were downregulated. Elastic net modeling identified a lung gene signature predictive of CBN exposure, including Kcnq3, Tgfbr1, and Tm4sf19. These findings demonstrate that inhalation of a surrogate burn pit mixture induces inflammatory and metabolic gene expression changes in both lung and brain tissues, supporting the utility of this animal model for understanding systemic effects of airborne military toxicants and for identifying potential biomarkers relevant to DRRD and Veteran health. Full article

Human leukocyte extract (HLE), a non-immunogenic dialyzable leukocyte preparation (<10 kDa), may serve as a safe adjuvant in immunotherapy. We investigated the effects of albendazole (ABZ), HLE, and their combination in Mesocestoides vogae infected mice, focusing on lymphoid cells in the peritoneal cavity, the site of larval proliferation and parasite-induced immunosuppression. Peritoneal lymphoid cells were analysed by flow cytometry and qPCR. Cells proliferative responses to ConA, LPS, and parasite excretory/secretory (E/S) antigens, cytokine production (ELISA), IgM and IgG isotypes in exudates and parasite antigen recognition (Western blot) were assessed. Efficacy was measured by larval burden and 14-3-3 gene expression in larvae. HLE combined with ABZ enhanced larval clearance and suppressed 14-3-3 gene expression in larvae. HLE and combination therapy increased CD3⁺ T cell frequencies, especially CD3^+high, reduced regulatory CD3+/IL-10 Tregs and expression of Foxp3⁺. All treatments diminished CD19⁺/IL-10⁺ Bregs, correlating with lower CD9 and Atf3 mRNA levels compared to infected mice. Transcription factors T-bet expression was strongly upregulated, while GATA3 was moderately elevated. IFN-γ production and T/B cell proliferation were restored after HLE and combination therapy, partially, even in the presence of E/S antigens. IgM and total IgG levels against parasite antigens declined, while Th1-associated IgG2a increased in ABZ+HLE and HLE-treated groups. Albendazole failed to reverse the immunosuppressive Treg-type immunity but was more effective in reducing Breg populations and their functions. HLE enhanced ABZ efficacy by restoring Th1 responsiveness, reducing Treg/Breg activity, and modulating antibody profiles. It represents a promising immunomodulatory adjuvant in the treatment of the infections associated with Th2/Treg-driven immunosuppression. Full article

Background: Previous studies have shown Radix Hedysari (RH)’s gastroprotective potential, but its active components and mechanisms remain uncharacterized. This study aimed to identify RH’s bioactive fractions, elucidate protection mechanisms, establish flavonoid dose-effect relationships, and determine the pharmacodynamic basis. Methods: Chemical profiling quantified eight flavonoids via HPLC. Network pharmacology screened targets/pathways using TCMSP, GeneCards databases. In vivo validation employed cisplatin–induced injury models in Wistar rats (n = 10/group). Assessments included: behavioral monitoring; organ indices; ELISA (MTL, VIP, IFN–γ, IgG, IL–6, TNF–α etc.); H&E; and Western blot:(SCF, c–Kit, p65). Dose–effect correlations were analyzed by PLS–DA. Results: Content determination indicated that Calycosin–7–glucoside and Ononin were notably enriched on both the n–BuOH part and the EtOAc part. Network pharmacology identified 5 core flavonoids and 8 targets enriched in IL–17/TNF signaling pathways. n–BuOH treatment minimized weight loss vs. MCG, increased spleen/thymus indices. n–BuOH and HPS normalized gastrointestinal, immune, inflammatory biomarkers (p < 0.01 vs. MCG). Histopathology confirmed superior mucosal protection in n–BuOH group vs. MCG. Western blot revealed n–BuOH significantly downregulated SCF, c–kit, and p65 expressions in both gastric and intestinal tissues (p < 0.001 vs. MCG). PLS–DA demonstrated Calycosin–7–glucoside had the strongest dose–effect correlation (VIP > 1) with protective outcomes. Conclusions: The n–BuOH fraction of RH is the primary bioactive component against chemotherapy–induced gastrointestinal injury, with Calycosin–7–glucoside as its key effector. Protection is mediated through SCF/c–Kit/NF–κB pathway inhibition, demonstrating significant dose–dependent efficacy. These findings support RH’s potential as a complementary therapy during chemotherapy. Full article

Background/Objectives: Contagious agalactia (CA) is a disease typically caused by Mycoplasma agalactiae, affecting small ruminants worldwide and being endemic in certain countries. CA causes severe economic losses due to mastitis, agalactia, and arthritis. As an alternative to existing immunoprophylactic measures, this study aimed to develop a recombinant subunit vaccine against M. agalactiae and evaluate its specific immune response in goats. Methods: Goats were divided into three groups: group 1 received recombinant proteins (P40 and MAG_1560), group 2 received formalin-inactivated M. agalactiae, and group 3 received Tris-buffered saline (negative control). All solutions were emulsified in Freund’s adjuvant. Animals were monitored for 181 days. IgG antibody production was assessed by ELISA, and peripheral blood mononuclear cells (PBMCs) were analyzed by real-time PCR for the expression of IL-1β, IFN-γ, IL-12, and MHC class II genes. Results: M. agalactiae-specific antibody response was observed for six months in the sera of animals from group 1. Analysis of cytokine gene expression revealed increased IL-1β mRNA levels over time in both experimental groups. In group 1, IFN-γ mRNA levels increased with P40 stimulation and decreased with MAG_1560. IL-12 mRNA expression decreased over time in group 1 with P40 stimulation, whereas group 2 showed increased IL-12 expression for both proteins. MHC-II expression was stimulated in both groups. Conclusions: The recombinant proteins induced antibody production and cytokine expression, demonstrating immunogenic potential and supporting their promise as vaccine candidates capable of eliciting both humoral and cellular immune responses against M. agalactiae. Full article

The active form of vitamin D₃, 1,25(OH)₂D₃, exerts hierarchical control over gene expression, initially targeting transcription factors (TFs) that drive downstream responses. Here, we profile the transcriptional landscape of primary keratinocytes (HPEKp) and squamous cell carcinoma (SCC) cells in response to 1,25(OH)₂D₃, revealing a distinct shift in regulatory targets. While TFs accounted for 9.23% of differentially expressed genes (DEGs) in keratinocytes, this proportion dropped to 4.9% with prolonged exposure. In contrast, SCC cells displayed a five-fold reduction in TFs deregulation and a concurrent enrichment of long non-coding RNAs (lncRNAs), which comprised 22.25% of DEGs after 24 h treatment, with 81% upregulated. Integrative transcriptomic and in silico analyses showed that lncRNA induction was predominantly VDR-dependent, partially RXRA-dependent, and PDIA3-independent. Notably, 90% of deregulated lncRNAs were atypical for head and neck SCC. Several of these lncRNAs exhibit potential antitumor properties and may modulate SCC cell responsiveness to interferon-gamma (IFN-γ). In conclusion, these findings suggest that in SCC cells, the regulation of lncRNA expression—rather than transcription factor modulation—may represent a mechanism of the cellular response to 1,25(OH)₂D₃. Full article

Oxytetracycline (OTC) has served as an antibiotic to treat various bacterial infections in fish raised in aquaculture. Nonetheless, administering OTC in overly high doses can lead to adverse side effects in fish and also negatively impact on their surroundings. The objective of this work was to evaluate the expression levels of immune markers such as TLR-1, TLR-2, IκB-α, MyD88, NF-κB, IFN-γ, and IL-6 in intestinal cell primary culture (foregut, midgut, and hindgut) using qRT-PCR, and in addition, to assess the in vivo response to different doses of OTC in coho salmon at different times. The expression levels of all genes increased significantly after 1 h on day 1 with high doses of OTC compared with control conditions in all tissues under both approaches (in vivo and in vitro). However, the transcriptional responses decreased to 3, 6, and 12 h in vitro and day 3 in vivo. In conclusion, the transcriptional responses were differentially modulated by OTC in the three intestinal portions under both experimental conditions. These results demonstrate for the first time in primary cell culture fish that the expression of immune biomarkers in all tissues induces a differential response of these genes, depending on the concentration of OTC and the kinetics of time. This study offers valuable insights that can be applied to enhance aquaculture, determine optimal drug doses, and improve fish health. Full article

The objective of this study was to formulate a compound suspension comprising paeoniflorin and curcumin, assess its quality characteristics, and investigate its protective efficacy against acute liver injury in mice. The prescriptions were screened using a single-factor test, and nine groups of suspensions were prepared using the dispersion method. Fifty KM mice (four weeks old) were selected and randomly divided into five groups: the CON, LD, PF, CUR, and PC groups. The doses of both paeoniflorin and curcumin were 100 mg/kg BW, and different suspensions were given to different groups by gavage for 14 days. All the groups except the CON group were injected intraperitoneally with 20 μg/kg LPS and 700 mg/kg D-GalN on the last day. According to the results, the suspension prepared using the optimal prescriptions was orange-yellow in color, with homogeneous turbidity and good re-dispersibility. The combination treatment could reduce the severity of pathological injuries of liver, improve the ultrastructure of hepatocytes, increase the activities of T-SOD, GSH-Px, and CAT, decrease the levels of IFN-γ, TNF-α, and IL-1, and down-regulate the expression of genes such as TLR4, MyD88, IκBα, and NLRP3. The underlying mechanism might be associated with the enhancement of antioxidant enzyme activities, inhibition of the TLR4/NF-κB/NLRP3 signaling pathway, and suppression of inflammasome assembly and release in hepatic tissues. Full article

Background/Objectives: Esophageal squamous cell carcinoma (ESCC) is a common form of esophageal cancer with a poor prognosis and limited treatment options. Epidermal growth factor receptor (EGFR), an overexpressed oncogenic gene in all ESCC patients, is an attractive target for developing therapies against ESCC. There is an extremely urgent need to develop immunotherapy tools targeting EGFR for the treatment of ESCC. Methods: In this study, we developed human Interleukin-21 (hIL-21)-armed, chimeric-antigen-receptor-modified T (CAR-T) cells targeting EGFR as a new therapeutic approach. The CAR contains a variable domain of the llama heavy chain of heavy-chain antibodies (VHHs), also known as nanobodies (Nbs), as a promising substitute for the commonly used single-chain variable fragment (ScFv) for CAR-T development. Results: We show that nanobody-derived, EGFR-targeting CAR-T cells specifically kill EGFR-positive esophageal cancer cells in vitro and in animal models. Human IL-21 expression in CAR-T cells further improved their expansion and antitumor ability and were observed to secrete more interferon-gamma (IFN-γ), tumor necrosis factor alpha (TNF-α), and Interleukin-2 (IL-2) when co-cultured with ESCC cell lines in vitro. More CD8⁺ CAR-T cells and CD3⁺CD8⁺CD45RO⁺CD62L⁺ central memory T cells were detected in CAR-T cells expressing hIL-21 cells. Notably, hIL-21-expressing CAR-T cells showed superior antitumor activity in vivo in a KYSE-150 xenograft mouse model. Conclusions: Our results show that hIL-21-armed, nanobody-derived, EGFR-specific CAR-T cell therapy is a highly promising option for treating ESCC patients. Full article

Background: Rabbit hemorrhagic disease (RHD) is an acute, hemorrhagic and highly lethal infectious disease caused by rabbit hemorrhagic disease virus (RHDV), which causes huge economic losses to the rabbit breeding industry. Moreover, there is limited cross-protection between the two different serotypes of classic RHDV (GI.1) and RHDV2 (GI.2). The shortcomings of traditional inactivated vaccines have led to the development of novel subunit vaccines that can protect against both strains, and the VP60 capsid protein is the ideal antigenic protein. This study focused on developing a bivalent RHDV vaccine that can prevent infection with both GI.1 and GI.2 strains. Methodology: Baculovirus vectors containing classic RHDV and RHDV2 VP60 were co-transfected with linearized baculovirus into sf9 cells and transferred to baculovirus via homologous recombination of the VP60 gene. Infected sf9 cells were lysed, and after purification via Ni-NTA chromatography, VLPs were observed using transmission electron microscopy (TEM). In order to evaluate the immunogenicity of the chimeric RHDV VLP vaccine in rabbits, the RHDV VP60-specific antibody, IL-4, IFN-γ and neutralizing antibody titers were analyzed in serum using ELISA and HI. Results: The recombinant baculovirus system successfully expressed chimeric RHDV VLPs with a diameter of 32–40 nm. After immunization, it could produce specific antibodies, IL-4 and IFN-γ. Following the second immunization, neutralizing antibodies, determined using hemagglutination inhibition (HI) assays, were elicited. Conclusions: These data show that the chimeric RHDV VLP bivalent vaccine for immunized New Zealand rabbits can induce humoral immunity and cellular immunity in vivo, and the immunization effect of the high-dose group is similar to that of the current commercial vaccine. Full article