Exogenous Melatonin Enhances Dihydrochalcone Accumulation in Lithocarpus litseifolius Leaves via Regulating Hormonal Crosstalk and Transcriptional Profiling.

Dihydrochalcones (DHCs) constitute a specific class of flavonoids widely known for their various health-related advantages. Melatonin (MLT) has received attention worldwide as a master regulator in plants, but its roles in DHC accumulation remain unclear. Herein, the elicitation impacts of MLT on DHC biosynthesis were examined in Lithocarpus litseifolius, a valuable medicinal plant famous for its sweet flavor and anti-diabetes effect. Compared to the control, the foliar application of MLT significantly increased total flavonoid and DHC (phlorizin, trilobatin, and phloretin) levels in L. litseifolius leaves, especially when 100 µM MLT was utilized for 14 days. Moreover, antioxidant enzyme activities were boosted after MLT treatments, resulting in a decrease in the levels of intracellular reactive oxygen species. Remarkably, MLT triggered the biosynthesis of numerous phytohormones linked to secondary metabolism (salicylic acid, methyl jasmonic acid (MeJA), and ethylene), while reducing free JA contents in L. litseifolius. Additionally, the flavonoid biosynthetic enzyme activities were enhanced by the MLT in leaves. Multiple differentially expressed genes (DEGs) in RNA-seq might play a crucial role in MLT-elicited pathways, particularly those associated with the antioxidant system (SOD, CAT, and POD), transcription factor regulation (MYBs and bHLHs), and DHC metabolism (4CL, C4H, UGT71K1, and UGT88A1). As a result, MLT enhanced DHC accumulation in L. litseifolius leaves, primarily by modulating the antioxidant activity and co-regulating the physiological, hormonal, and transcriptional pathways of DHC metabolism.

Trailblazing in adjuvant research: succinate's uncharted territory with neutrophils.

The purpose of this study is to investigate the previously unknown connection that succinate has with neutrophils in the setting of adjuvant-mediated immunological enhancement. It has been discovered that succinates stimulate the recruitment of neutrophils in immunization sites, which in turn induces the expression of what is known as neutrophil-derived B cell-activating factor (BAFF). Further amplification of vaccine-induced antibody responses is provided via the succinate receptor 1-interferon regulatory factor 5 (SUCNR1-IRF5)-BAFF signaling pathway, which provides insights into a unique mechanism for immunological enhancement.NEW & NOTEWORTHY This study explores the role of succinate as a vaccine adjuvant, revealing its capacity to enhance neutrophil recruitment at immunization sites, which boosts B cell activation through the succinate receptor 1-interferon regulatory factor 5-B cell-activating factor (SUCNR1-IRF5-BAFF) signaling pathway. Results demonstrate succinate's potential to amplify vaccine-induced antibody responses, highlighting its significance in immunological enhancement and offering new insights into the adjuvant mechanisms of action, particularly in neutrophil-mediated immune responses.

The trogocytosis of neutrophils on initial transplanted tumor in mice.

The role of neutrophils in tumor initiation stage is rarely reported because of the lack of suitable models. We found that neutrophils recruited in early tumor nodules induced by subcutaneous inoculation of B16 melanoma cells were able to attack tumor cells by trogocytosis. The anti-tumor immunotherapy like peritoneal injection with TLR9 agonist CpG oligodeoxynucleotide combined with transforming growth factor ß2 inhibitor TIO3 could increase the trogocytic neutrophils in the nodules, as well as CD8+ T cells, natural killer (NK) cells, and their interferon-γ production. Local use of Cxcl2 small interfering RNA significantly reduced the number of neutrophils and trogocytic neutrophils in tumor nodules, as well as CD8+ T and NK cells, and also enlarged the nodules. These results suggest that neutrophils recruited early to the inoculation site of tumor cells are conducive to the establishment of anti-tumor immune microenvironment. Our findings provide a useful model system for studying the effect of neutrophils on tumors and anti-tumor immunotherapy.

Massively recruited sTLR9+ neutrophils in rapidly formed nodules at the site of tumor cell inoculation and their contribution to a pro-tumor microenvironment.

Neutrophils exert either pro- or anti-tumor activities. However, few studies have focused on neutrophils at the tumor initiation stage. In this study, we unexpectedly found a subcutaneous nodule in the groin areas of mice inoculated with tumor cells. The nodule was developed 24 h after the inoculation, filled with tumor cells and massively recruited neutrophils, being designated as tumor nodules. 22% of the neutrophils in tumor nodules are surface TLR9 (sTLR9) expressing neutrophils (sTLR9+ neutrophils). With tumor progression, sTLR9+ neutrophils were sustainably increased in tumor nodules/tumor tissues, reaching to 90.8% on day 13 after inoculation, with increased expression of IL-10 and decreased or no expression of TNFα. In vivo administration of CpG 5805 significantly reduced sTLR9 expression of the sTLR9+ neutrophils. The reduction of sTLR9 on neutrophils in tumor nodules contributed to the induction of an anti-tumor microenvironment conductive to the inhibition of tumor growth. Overall, the study provides insights for understanding the role of sTLR9+ neutrophils in the tumor development, especially in the early stage.

Prevalence and potential risk factors of PDCoV in pigs based on publications during 2015-2021 in China: Comprehensive literature review and meta-analysis.

Porcine deltacoronavirus (PDCoV), a novel coronavirus which infects pigs, spreading around the world and causing huge economic losses. In recent years, there have also been human cases of PDCoV infection, which poses a potential threat to public health. Therefore, we conducted a systematic review and meta-analysis to assess the prevalence of PDCoV in pigs in China between 2015 and 2021. The prevalence of PDCoV in China was searched from five databases (CNKI, VIP, WanFang, PubMed and ScienceDirect) and 65 articles met the inclusion criteria, with a total of 25,977 samples, including 3828 positive cases. The overall prevalence of PDCoV was 13.61% (3828/25,977), with the highest prevalence in northern China (19.18%) and the lowest prevalence in southwest China (7.19%). We also analyzed other subgroup information, such as sampling years, test methods, age and geographic factors. The results show that PDCoV is endemic in China and climate may be a potential risk factor for PDCoV infection. It is suggested that appropriate measures should be taken in different climatic areas to reduce local PDCoV infection.

Incorporation of a TGF-ß2-inhibiting oligodeoxynucleotide molecular adjuvant into a tumor cell lysate vaccine to enhance antiglioma immunity in mice.

Introduction: Transforming growth factor ß2 (TGF-ß2), also known as glioma-derived T-cell suppressor factor, is associated with the impairment of tumor immune surveillance. Therefore, blocking TGF-ß2 signaling probably be a feasible strategy to develop a novel type of adjuvant for glioma vaccines to enhance antitumor immunity. Methods: A TGF-ß2 inhibitory oligodeoxynucleotide, TIO3, was designed with sequences complementary to the 3' untranslated region of TGF-ß2 mRNA. The expression of TGF-ß2 and MHC-I was detected by qPCR, western and flow cytometry in vitro. All the percentage and activation of immune cells were detected by flow cytometry. Subsequently, TIO3 was formulated with Glioma cell lysate (TCL) and investigated for its antitumor effects in GL261 murine glioma prophylactic and therapeutic models. Results: TIO3 could efficiently downregulate the expression of TGF-ß2 while increase the MHC-I's expression in GL261 and U251 glioma cells in vitro. Meanwhile, TIO3 was detected in mice CD4+ T, CD8+ T, B and Ly6G+ cells from lymph nodes after 24 hours incubation. Moreover, TCL+TIO3 vaccination significantly prolonged the survival of primary glioma-bearing mice and protected these mice from glioma re-challenge in vivo. Mechanistically, TCL+TIO3 formulation strongly evoke the antitumor immune responses. 1) TCL+TIO3 significantly increased the composition of CD4+ and CD8+ T cells from draining lymph nodes while promoted their IFN-γ production and reduced the expression of TGF-ß2 and PD1. 2) TCL+TIO3 activated the NK cells with the elevation of CD69 or NKG2D expression and PD1 reduction. 3) TCL+TIO3 increased the glioma-specific lysis CTLs from spleen. 4) TCL+TIO3 downregulated PD-L1 expression in glioma tissues and in Ly6G+ cells among glioma-infiltrating immune cells. Conclusion: TIO3 is a promising adjuvant for enhancing TCL-based vaccines to produce a more vigorous and long-lasting antitumor response by interfering with TGF-ß2 expression.

Immunotherapy for lung cancer combining the oligodeoxynucleotides of TLR9 agonist and TGF-ß2 inhibitor.

Tumor immunotherapies have shown promising antitumor effects, especially immune checkpoint inhibitors (ICIs). However, only 12.46% of the patients benefit from the ICIs, the rest of them shows limited effects on ICIs or even accelerates the tumor progression due to the lack of the immune cell infiltration and activation in the tumor microenvironment (TME). In this study, we administrated a combination of Toll-like receptor 9 (TLR9) agonist CpG ODN and Transforming growth factor-ß2 (TGF-ß2) antisense oligodeoxynucleotide TIO3 to mice intraperitoneally once every other day for a total of four injections, and the first injection was 24 h after LLC cell inoculation. We found that the combination induced the formation of TME toward the enrichment and activation of CD8+ T cells and NK cells, accompanied with a marked decrease of TGF-ß2. The combined therapy also effectively inhibited the tumor growth and prolonged the survival of the mice, even protected the tumor-free mice from the tumor re-challenge. Both of CpG ODN and TIO3 are indispensable, because replacing CpG ODN with TLR9 inhibitor CCT ODN showed no antitumor effect, CpG ODN or TIO3 alone did not lead to ideal antitumor results. This effect was possibly initiated by the activation of dendritic cells at the tumor site. This systemic antitumor immunotherapy with a combination of the two oligonucleotides (an immune stimulant and an immunosuppressive cytokine inhibitor) before the tumor formation may provide a novel strategy for clinical prevention of the postoperative tumor recurrence.

Rational design of a ZnO nanowire laser on a surface plasmon polariton.

Plasmonic lasers, which use the strong confinement of surface plasmon polaritons, are key parts to realize ultracompact coherent light sources at deep subwavelength scales. We propose a plasmonic laser composed of a silicon substrate, ZnO nanowire, dielectric layer, metal layer, and electrode. In this structure, the superimposed coupling of the surface plasmon mode at the metal interface with the high refractive index gain nanowire mode makes the electric field in the spacer layer significantly enhanced. The ZnO nanowire is used as gain material to provide gain compensation. The optical and electrical properties are simulated with the geometric parameters and dielectric layer material. The results show that the structure has strong confinement of the optical field and can realize a deep subwavelength constraint at a lower threshold level. It provides theoretical support for realizing ultracompact coherent light sources.

Neutrophils recruited to immunization sites initiating vaccine-induced antibody responses by locally expressing BAFF.

Neutrophils played a key role in the innate immune responses. Less is known about whether and how the neutrophils recruited in the immunization sites affecting the vaccine-induced antibody responses. In the process of evaluating the efficacy of an oil-in-water emulsion-formulated vaccine in mice, we found that neutrophils were rapidly and massively recruited to immunization sites but were barely detected in the draining lymph nodes. Interestingly, B cell-activating factor (BAFF) was abundantly expressed in the recruiting neutrophils at a very early stage. The initial neutrophil-derived BAFF firstly brought about the B cell responses in the local part, then subsequently in lymphoid organs. Activated B cells produced more BAFF through TLR9-IRF5 signaling pathway, thereby amplifying the vaccine-induced antibody responses. Suppressing BAFF in the neutrophils could weaken the B cell activation and reduce the antibody production. The data indicate that vaccines endow neutrophils with the potential to orchestrate antibody responses at immunization sites.

Ag metal interconnect wires formed by pseudoplastic nanoparticles fluid imprinting lithography with microwave assistant sintering.

Nanoimprint technology has the advantages of low cost, high precision, high fidelity and high yield. The metal nanoparticle fluid is non-Newtonian fluid, which is used as the imprint transfer medium to realize high fidelity of pattern because of its shear thinning effect. In order to functionalize the metal nanoparticles microstructure, the subsequent sintering step is required to form a metal interconnect wire. Metal interconnect wire with fewer grain boundaries and fewer holes have excellent mechanical and electronic properties. In this paper, the pseudoplastic metal nanoparticle fluid was formed by Ag nanoparticle and precursor solution, and then the thermal diffusion process was completed by microwave sintering after interconnects were embossed. The influence of microwave and thermal atmosphere on the microstructure and performance of Ag Interconnect wires was analyzed and discussed, and the Ag Interconnect wires performance was determined under the influence of time and temperature parameters. In our experiments, the interconnects after microwave sintering can achieve 39% of the conductivity of bulk silver. The microwave sintering module might be integrated as the heat treatment module of the metal micro/nano pattern directly imprint lithography.

In vitro assembly of chimeric virus-like particles composed of a porcine circovirus 2b capsid protein and a B-cell epitope of infectious bursal disease virus.

OBJECTIVES: To develop a method for in vitro assembly of recombinant proteins expressed in E. coli into chimeric virus-like particles (cVLPs). RESULTS: A fusion protein (Bepi-Cap-A) between capsid protein (Cap) of PCV2b and B cell epitope (Bepi) of IBDV was expressed in E. Coli, and purified. For assembling them into cVLPs (Bepi-Cap-VLP), the Bepi-Cap-A was suspended in buffer C [0.03% ("%" stands for "v/v" unless otherwise indicated) polyethylene glycol, 0.4 M Tris, 10 mM ß-mercaptoethanol, 5% glycerol, 0.02% (w/v) gellan gum, 0.1 M glycine, 0.03% Tween 80, 500 mM NaCl], and incubated. After centrifugation, the pellet was resuspended in buffer D [50 mM Na2HPO4, 50 mM NaH2PO4, 0.01% (w/v) gellan gum, 0.05 mM EDTA, 500 mM NaCl, 0.03% Tween 80, pH 6.5], and then dialyzed against dialysis buffer (50 mM Na2HPO4, 50 mM NaH2PO4, 500 mM NaCl, 0.03% Tween 80, pH 6.5). The procedure resulted in typical and immunogenic Bepi-Cap-VLP. CONCLUSIONS: The data provide a method which is feasible for in vitro assembly of recombinant proteins into chimeric virus-like particles.

The role of probiotic intervention in regulating gut microbiota, short-chain fatty acids and depression-like behavior in lead-exposed rats.

OBJECTIVES: The aim of this study was to observe the depression-like behavior changes of rats exposed to lead with or without probiotic intervention, and to investigate changes in the gut microbiota and fecal short-chain fatty acids (SCFAs) levels after lead exposure, and the possible functions of probiotics in this process. MATERIAL AND METHODS: Adult male Sprague Dawley rats were exposed to a 300 mg/l lead acetate solution for 24 weeks, with or without probiotic (freeze-dried powder containing Lactobacillus and Bifidobacterium: 6 billion live bacteria/2 g) intervention in weeks 17-24. The sucrose preference test (SPT), the forced swim test (FST), and the tail suspension test (TST) were preformed to study the depression- like behaviors of these rats. The alteration of rat gut microbiota induced by lead exposure was analyzed by 16S rRNA sequencing, and the levels of fecal SCFAs were detected using gas chromatography. RESULTS: Neurobehavioral tests showed that lead exposure induced depression-like behavior in rats, including reduced sucrose preference in the SPT, and increased immobility times in the FST and the TST. Sequencing and gas chromatography showed that lead exposure changed the structure and the phylogenetic diversity of the gut microbiota, as well as significantly altered the levels of SCFAs. Moreover, the depression-like behaviors, and the changes in both gut microbiota and SCFAs, could be mitigated by probiotic intervention. CONCLUSIONS: Lead exposure not only changes the structure and diversity of the gut microbiome but also affects metabolic function. Probiotic intervention may be a novel initiative for the prevention and treatment of neurological damage following lead exposure. Int J Occup Med Environ Health. 2022;35(1):95-106.

Utilization of Ultrasonic Image Characteristics Combined with Endoscopic Detection on the Basis of Artificial Intelligence Algorithm in Diagnosis of Early Upper Gastrointestinal Cancer.

The aim of this study was to evaluate the diagnostic value of artificial intelligence algorithm combined with ultrasound endoscopy in early esophageal cancer and precancerous lesions by comparing the examination of conventional endoscopy and artificial intelligence algorithm combined with ultrasound endoscopy, and by comparing the real-time diagnosis of endoscopy and the ultrasonic image characteristics of artificial intelligence algorithm combined with endoscopic detection and pathological results. 120 cases were selected. According to the inclusion and exclusion criteria, 80 patients who met the criteria were selected and randomly divided into two groups: endoscopic examination combined with ultrasound imaging based on intelligent algorithm processing (cascade region-convolutional neural network (Cascade RCNN) model algorithm group) and simple use of endoscopy group (control group). This study shows that the ultrasonic image of artificial intelligence algorithm is effective, and the detection performance is better than that of endoscopic detection. The results are close to the gold standard of doctor recognition, and the detection time is greatly shortened, and the recognition time is shortened by 71 frames per second. Compared with the traditional convolutional neural network (CNN) algorithm, the accuracy and recall of image analysis and segmentation using feature pyramid network are increased. The detection rates of CNN model, Cascade RCNN model, and endoscopic detection alone in early esophageal cancer and precancerous lesions are 56.3% (45/80), 88.8% (71/80), and 44.1% (35/80), respectively. The detection rate of Cascade RCNN model and CNN model was higher than that of endoscopy alone, and the difference was statistically significant (P < 0.05). The sensitivity, specificity, positive predictive value, and negative predictive value of Cascade RCNN model were higher than those of CNN model, which was close to the gold standard for physician identification. This provided a reference basis for endoscopic ultrasound identification of early upper gastrointestinal cancer or other gastrointestinal cancers.

The adjuvanticity of manganese for microbial vaccines via activating the IRF5 signaling pathway.

Manganese (Mn2+) has been reported to activate macrophages and NK cells, and to induce the production of type-I interferons (IFNs) by activating the cGAS-STING pathway. Few studies have been conducted on its adjuvanticity to microbial vaccines, and on the involvement of the interferon regulatory factor (IRF) 5 signaling pathway in the adjuvanticity. In this study, we demonstrated that Mn2+ could facilitate various microbial vaccines to induce enhanced antibody responses, and facilitate the influenza virus vaccine to induce protective immunity against the influenza virus challenge. When formulated in vaccines, Mn2+ could activate murine CD4+ T cells, CD8+ T cells, B cells and DCs, and induce the expression and phosphorylation of TANK-binding kinase 1 (TBK1) and IRF5 in the splenocytes of the immunized mice, resulting in the increased expression of type-I IFNs, TNF-α, B cell-activating factor of the TNF family (BAFF) and B lymphocyte-induced maturation protein-1 (Blimp-1). The induced TBK1 could recruit and bind the IRF5. Furthermore, the Mn2+ induced expression of IRF5 and Blimp-1 was prohibited by a IRF5 interfering oligonucleotide. The data suggest the Mn2+ could be used as a novel type of adjuvants for microbial vaccines, and the activation of IRF5 signaling pathway might involve in the adjuvanticity.

Simple Strategy for Synthesizing LiNi0.8Co0.15Al0.05O2 Using CoAl-LDH Nanosheet-Coated Ni(OH)2 as the Precursor: Dual Effects of the Buffer Layer and Synergistic Diffusion.

Ni-rich layered oxide LiNi0.8Co0.15Al0.05O2 is a promising cathode material for high-power lithium-ion batteries due to its high energy density and low cost. However, obtaining LiNi0.8Co0.15Al0.05O2 with a large and uniform particle size and without undesired Al-related phases using some conventional synthesis methods is quite difficult. These problems seriously affect the electrochemical performance of LiNi0.8Co0.15Al0.05O2, thus impeding its wide application. Here, we propose a simple strategy to synthesize LiNi0.8Co0.15Al0.05O2 using CoAl-layered double hydroxide (CoAl-LDH) nanosheet-coated Ni(OH)2 as the precursor. Compared with LiNi0.8Co0.15Al0.05O2 synthesized from nickel-cobalt-aluminum hydroxide and Al(OH)3-coated nickel-cobalt hydroxide precursors, LiNi0.8Co0.15Al0.05O2 produced using the proposed approach showed good sphericity, a large and uniform particle size, a pure phase, and excellent electrochemical performance. The superior properties are attributed to the dual effects of the buffer layer and synergistic diffusion. Specifically, the CoAl-LDH coating layer reacts with LiOH during the lithiation-calcination process to form a Li1-x(Co0.75Al0.25)1+xO2 mesophase as the buffer layer, which increases the formation temperature of the layered structure and reduces Li+/Ni2+ cation mixing, making a well-ordered crystal structure. Moreover, spectroscopic analysis results and density functional theory calculations indicated a synergistic diffusion effect between Co and Al, and the presence of Co on the surface promotes the diffusion of Al during the lithiation-calcination process, thus avoiding the formation of undesired Al-related phases and allowing for a uniform element distribution.

CpG ODN as an adjuvant arouses the vigor of B cells by relieving the negative regulation of surface TLR9 to enhance the antibody response to vaccine.

The surface Toll-like receptor 9 (sTLR9) has been identified on the surface of the B cells and was presumed to be a negative regulator of B cell responses. CpG ODN, a TLR9 agonist, has been successfully used as an adjuvant of hepatitis B vaccine to enhance antibody responses. However, it is unknown whether the sTLR9 is involved in regulating the activation and maturation of B cells in the antibody responses induced by CpG ODN-adjuvanted vaccines. In this study, we immunized mice with hepatitis B vaccine adjuvanted by CpG ODN (CpG 5805) and found that CpG 5805 enhanced the antibody response to vaccine and meanwhile down-regulated the sTLR9 levels on B cells. With antibody feeding assay and flow cytometry analysis, we further found that CpG 5805 induced a movement of the sTLR9 in B cells, internalized first and then mobilized to endosomes. Accompanied with the movement, CD80, CD86, CD40, and MHC II molecules were significantly up-regulated on the B cells. Interestingly, the B cells with internalized sTLR9 enlarged morphologically, and the sTLR9 levels were obviously lower and CD40 levels were obviously higher on the enlarged B cells. Together, the data presented here uncover that CpG ODN can induce the mobilization and relocation of sTLR9 in B cells, thereby triggering the B cell vigor by relieving the negative regulatory effect of sTLR9 on B cells, which may be one of the mechanisms for CpG ODN acting as a vaccine adjuvant to enhance the antibody response.Key points• CpG ODN-enhanced antibody response positively associates with B cell sTLR9 reduction.• CpG ODN reduces the sTLR9 levels by relocating it from B cell surface to endosomes.• sTLR9 reduction arouses B cell vigor via promoting B cell maturation and activation. Graphical Abstract.

TGF-ß2 interfering oligonucleotides used as adjuvants for microbial vaccines.

The success of using immune checkpoint inhibitors to treat cancers implies that inhibiting an immunosuppressive cytokine, such as TGF-ß2, could be a strategy to develop novel adjuvants for microbial vaccines. To develop nucleic acid based TGF-ß2 inhibitors, we designed three antisense oligonucleotides, designated as TIO1, TIO2, and TIO3, targeting the conserve regions identical in human and mouse TGF-ß2 mRNA 3'-untranslated region. In cultured immune cells, TIO3 and TIO1 significantly reduced the TGF-ß2 mRNA expression and protein production. In mice, the TIO3 and TIO1, when formulated in various microbial vaccines, significantly enhanced the antibody response to the vaccines, and the TIO3-adjuvanted influenza virus vaccine induced effective protection against the influenza virus challenge. In the immunized mice, TIO3 formulated in microbial vaccines dramatically reduced surface-bound TGF-ß2 expression on CD4+ T cells and CD19+ B cells in the lymph node (LN) cells and spleen cells; up-regulated the expression of CD40, CD80, CD86, and MHC II molecules on CD19+ B cells and CD11c+ dendritic cells; and promoted IFN-γ production in CD4+ T cells and CD8+ T cells in the LN cells. Overall, TIO3 or TIO1 could be used as a novel type of adjuvant for facilitating the microbial vaccines to elicit more vigorous and persistent antibody response by interfering with TGF-ß2 expression.

Expression pattern of the interferon regulatory factor family members in influenza virus induced local and systemic inflammatory responses.

Type I interferon is considered to be a key cytokine in influenza virus-induced acute lung injury (ALI), in which IRF3 and IRF7 play particularly important roles. However, whether all nine members of IRF family are involved in influenza virus-induced immune response is currently unknown. In this study, we found that all members of IRF family responded to influenza virus. The IRF family expression profile seems to be related to the pathogenicity of the particular influenza virus strain. The influenza virus mainly relies on endosomal TLR signals and the positive feedback loop of IFN-I to cause either direct or indirect different expression of all IRF family members locally or systemically. Interestingly, IRF6 was somewhat different from other IRF family members during influenza virus infection. Overall, the expression profile of the IRF family may be a valuable reference for the prevention and treatment of influenza complications, which encourage further, more in-depth research.

Diversity of locally produced IFN-α subtypes in human nasopharyngeal epithelial cells and mouse lung tissues during influenza virus infection.

The excessively expressed interferon-α (IFN-α) might contribute to the uncontrolled inflammatory responses, causing pathological damage during influenza virus infection. However, the correlation of the pathological damage with the expression profile of IFN-α subtypes in the focus of infection with influenza viruses is poorly understood. To investigate this, we detected the IFN-α subtype dominance in human respiratory epithelial cells and mouse lungs, both of which were infected with influenza viruses. It was found that IFN-α1, IFN-α6, IFN-α14, and IFN-α16 were dominantly expressed in respiratory epithelial cells from the patients infected with IAV, whereas IFN-α5, IFN-α8, and IFN-α21 were dominantly expressed in respiratory epithelial cells from the patients infected with less pathogenic IBV and that IFN-α1, IFN-α9, and IFN-α15 were dominantly expressed in lungs of the mice infected with H1N1 IAV, and IFN-α2, IFN-α12, and IFN-α13 were dominantly expressed in lungs of the mice infected with less pathogenic H9N2 IAV. Compared with H9N2 IAV, H1N1 IAV induced higher mortality rates and more obvious body weight loss in the mice. In addition, IAV or H1N1 IAV induced a significantly higher level of CXCL10 mRNA in the human respiratory epithelial cells or the mouse lungs, respectively. In mice, the high level of Cxcl10 mRNA was accompanied by the abundant infiltrated neutrophils and more severe pathological changes in the lungs. Together, the data presented here indicate that the pathogenicity of influenza viruses is correlated with the IFN-α subtypes induced by influenza viruses. KEY POINTS: • Different influenza viruses induce differential inflammation responses. • Various influenza viruses induce diverse expression profiles of IFN-α subtypes. • The locally produced IFN-α subtypes correlated to the differential inflammation. Graphical abstract.

Rae1 drives NKG2D binding-dependent tumor development in mice by activating mTOR and STAT3 pathways in tumor cells.

Natural killer group 2 member D (NKG2D) ligands (NKG2DLs) on tumor cells engage NKG2D and mediate killing by NKG2D+ immune cells. However, tumor cells with high levels of NKG2DLs are still malignant and proliferate rapidly. We investigated the reason for NKG2DL-expressing cell progression. Tumor cells in mice were assessed for their NKG2DL expression, ability to attract immune cells, tumorigenicity, mTOR, and signal transducer and activator of transcription 3 (STAT3) signaling activation. Antibody blockade was used to determine the effect of NKG2DL-NKG2D interaction on signaling activation in vitro. Retinoic acid early inducible gene 1 (Rae1) was related to the expression of other NKG2DLs, the promotion of tumorigenicity, Mmp2 expression, mTOR and STAT3 phosphorylation in GL261 cells, and the recruitment of NKG2D+ cells in mice. Rae1 also induced NKG2DL expression, mTOR, and STAT3 phosphorylation in GL261 cells and LLC cells, but not in B16 and Pan02 cells, which did not express NKG2DLs, when cocultured with PBMCs; the induced phosphorylation was eliminated by Rae1-NKG2D blockade. Inhibition of mTOR and/or STAT3 decreased PBMC-induced migration and proliferation of GL261 cells in vitro. Rae1, a NKG2DL on tumor cells, plays a driving role in the expression of other NKG2DLs and in tumor development in mice by activating mTOR and STAT3 pathways, relying on its interaction with NKG2D on immune cells.