Interaction of species A rotavirus VP4 with the cellular proteins vimentin and actin related protein 2 discovered by a proximity interactome assay.

IMPORTANCE: Rotavirus (RV) is an important zoonosis virus, which can cause severe diarrhea and extra-intestinal infection. To date, some proteins or carbohydrates have been shown to participate in the attachment or internalization of RV, including HGBAs, Hsc70, and integrins. This study attempted to indicate whether there were other proteins that would participate in the entry of RV; thus, the RV VP4-interacting proteins were identified by proximity labeling. After analysis and verification, it was found that VIM and ACTR2 could significantly promote the proliferation of RV in intestinal cells. Through further viral binding assays after knockdown, antibody blocking, and recombinant protein overexpression, it was revealed that both VIM and ACTR2 could promote RV replication.

Identification of a Novel Interferon Lambda Splice Variant in Chickens.

Type III interferons (IFNLs) have critical roles in the host's innate immune system, also serving as the first line against pathogenic infections of mucosal surfaces. In mammals, several IFNLs have been reported; however, only limited data on the repertoire of IFNLs in avian species is available. Previous studies showed only one member in chicken (chIFNL3). Herein, we identified a novel chicken IFNL for the first time, termed chIFNL3a, which contains 354 bp, and encodes 118 amino acids. The predicted protein is 57.1% amino acid identity with chIFNL. Genetic, evolutionary, and sequence analyses indicated that the new open reading frame (ORF) groups with type III chicken IFNs represent a novel splice variant. Compared to IFNs from different species, the new ORF is clustered within the type III IFNs group. Further study showed that chIFNL3a could activate a panel of IFN-regulated genes and function mediated by the IFNL receptor, and chIFNL3a markedly inhibited the replication of Newcastle disease virus (NDV) and influenza virus in vitro. These data collectively shed light on the repertoire of IFNs in avian species and provide useful information that further elucidate the interaction of the chIFNLs and viral infection of poultry. IMPORTANCE Interferons (IFNs) are critical soluble factors in the immune system, and are composed of 3 types (I, II, and III) that utilize different receptor complexes (IFN-αR1/IFN-αR2, IFN-γR1/IFN-γR2, and IFN-λR1/IL-10R2, respectively). Herein, we identified IFNL from the genomic sequences of chicken and termed it chIFNL3a, located on chromosome 7 of chicken. Phylogenetically clustered with all known types of chicken IFNs, the finding of this IFN is considered a type III IFN. To further evaluate the biological properties of chIFNL3a, the target protein was prepared by the baculovirus expression system (BES), which could markedly inhibit the replication of NDV and influenza viruses. In this study, we uncovered a new interferon lambda splice variant of chicken, termed chIFNL3a, which could inhibit viral replication in cells. Importantly, these novel findings may extend to other viruses, offering a new direction for therapeutic interventions.

Interferon-Inducible Transmembrane Protein 3 (IFITM3) Restricts Rotavirus Infection.

Rotavirus (RV) is a non-enveloped icosahedral virus with an 11-segment double-stranded RNA genome, belonging to the family of rotaviruses. RV is one of the pathogens causing diarrhea in infants and young animals, and it induces the production of type I interferons (IFNs), which can trigger antiviral function by inducing the production of interferon-stimulated genes (ISGs). Although IFITM3, an ISG localizing to late endosomes, can limit many viral infections, whether or not it restricts the infection of RV is still unknown. Therefore, we attempted to determine whether IFITM3 also restricts RV infection by using over-expression and knockout cell strains. It was found that IFITM3-expressing cell strains were less susceptible to RV infection, as the replication of RV in over-expressing cells was significantly less than in control group cells. Correspondingly, IFITM3-knockout cells were significantly susceptible compared to the normal cells. Furthermore, the IFN-induced antiviral effect was significantly attenuated in the absence of IFITM3, and IFITM3 delayed RV escape from endosomes in the presence of IFITM3, suggesting that endogenous IFITM3 is of great importance in type I IFN-mediated antiviral responses and may restrict infection by affecting the function of the late endosomal compartment. In conclusion, these data provide the first evidence that IFITM3 limits RV infection in vitro and delays RV escape from late endosomes into the cytoplasm.

A Vaccine of SARS-CoV-2 S Protein RBD Induces Protective Immunity.

The pandemic of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has posed great threat to the world in many aspects. There is an urgent requirement for an effective preventive vaccine. The receptor binding domain (RBD), located on the spike (S) gene, is responsible for binding to the angiotensin-converting enzyme 2 (ACE2) receptor of host cells. The RBD protein is an effective and safe antigen candidate. The six-helix bundle (6HB) "molecular clamp" is a novel thermally-stable trimerization domain derived from a human immunodeficiency virus (HIV) gp41 protein segment. We selected the baculovirus system to fuse and express the RBD protein and 6HB for imitating the natural trimeric structure of RBD, named RBD-6HB. Recombinant RBD-6HB was successfully obtained from the cell culture supernatant and purified to high homogeneity. The purity of the final protein preparation was more than 97%. The results showed that the protein was identified as a homogeneous polymer. Further studies showed that the RBD-6HB protein combined with AL/CpG adjuvant could stimulate animals to produce sustained high-level antibodies and establish an effective protective barrier to protect mice from challenges. Our findings highlight the importance of trimerized SARS-CoV-2 S protein RBD in designing SARS-CoV-2 vaccines and provide a rationale for developing a protective vaccine through the induction of antibodies against the RBD domain.

Antibody dependent enhancement: Unavoidable problems in vaccine development.

In some cases, antibodies can enhance virus entry and replication in cells. This phenomenon is called antibody-dependent infection enhancement (ADE). ADE not only promotes the virus to be recognized by the target cell and enters the target cell, but also affects the signal transmission in the target cell. Early formalin-inactivated virus vaccines such as aluminum adjuvants (RSV and measles) have been shown to induce ADE. Although there is no direct evidence that there is ADE in COVID-19, this potential risk is a huge challenge for prevention and vaccine development. This article focuses on the virus-induced ADE phenomenon and its molecular mechanism. It also summarizes various attempts in vaccine research and development to eliminate the ADE phenomenon, and proposes to avoid ADE in vaccine development from the perspective of antigens and adjuvants.

A novel spin-valley-coupled nodal-ring semimetal in single-layer Ta2C3.

Nodal-ring semimetals with band crossing are the new type of quantum materials that have attracted considerable interest from scholars for research. In general, the spin-orbit coupling (SOC) effect opens a band gap at the Dirac point. Therefore, finding 2D nodal-ring semimetals with resistance to SOC has more challenges. Based on first-principles calculations, we propose here that the two-dimensional (2D) Ta2C3 monolayer is a novel nodal-ring semimetal. In particular, Ta2C3 forms six closed rings in the Brillouin zone (BZ) with SOC, which originates from the dxy,x2-y2 orbitals of Ta and the pz orbitals of C. The nodal-ring bands at the K point in Ta2C3 exhibits characteristics of valley splitting and spin polarization due to the breaking of inversion symmetry and SOC. The masximal spin-splitting at the K point is as large as 268.87 meV and 61.90 meV for the conduction band minimum (CBM) and valence band maximum (VBM), respectively. The massless Dirac fermions in the non-equivalent valley have the opposite Berry curvature and spin moment. Therefore, 2D Ta2C3 is novel spin-valley-coupled nodal-ring semimetal. In addition, we found interesting negative differential resistance effects when calculating its transport properties. Our results not only provide an ideal platform for studying the combination of new physical properties, spintronics and valleytronics, but also open the way for designing low-power and fast-transport electronic devices.

Bisphenol A attenuates testosterone production in Leydig cells via the inhibition of NR1D1 signaling.

Bisphenol A (BPA) is an endocrine-disrupting compound that impairs testosterone synthesis in male mammals. A circadian clock gene deficiency leads to diminished fertility and even infertility in male mice. However, whether circadian clock signaling pathways mediate the suppressive effect of BPA on testosterone synthesis in Leydig cells (LCs) remains unknown. The present study aims to detect the effect of BPA on cellular circadian clock and testosterone synthesis in mouse LCs, and examine the mechanisms underlying NR1D1 signaling. BPA treatment significantly attenuated the transcription levels of Nr1d1 and steroidogenic genes (Hsd3b2 and Hsd17b3) in TM3 cells, but increased other circadian clock gene levels (Per2 and Dbp). BPA treatment also significantly downregulated NR1D1 and StAR protein expression, but upregulated BMAL1 protein expression in TM3 cells. Furthermore, there was a marked decline in testosterone production in BPA-treated TM3 cells. Intraperitoneal injection of BPA profoundly reduced NR1D1 and StAR protein levels and steroidogenic gene transcription levels (Cyp11a1, Hsd3b2, and Hsd17b3), while enhancing BMAL1 protein and other circadian clock gene (Per2 and Dbp) levels in mouse testes. Notably, serum testosterone levels were also drastically reduced in BPA-treated mice. Moreover, SR9009, an NR1D1 agonist, augmented testosterone production in TM3 cells via elevated expression of steroidogenic genes (StAR, Cyp11a1 and Hsd17b3). Conversely, Nr1d1 knockdown inhibited testosterone accumulation and attenuated steroidogenic gene expression. Moreover, treatment with SR9009 partially reversed the BPA effect on the circadian clock and testosterone production. Taken together, our study demonstrates that BPA perturbs testosterone production, at least partially, via inhibiting NR1D1 signaling in LCs.

Two-dimensional topological insulators of Pb/Sb honeycombs on a Ge(111) semiconductor surface.

Based on first-principles hybrid functional calculations, we demonstrate the formation of two-dimensional (2D) topological insulators (TIs) of Pb/Sb honeycombs on Ge(111) semiconductor surface. We show that 1/3 Cl-covered Ge(111) surface offers an ideal template for metal deposition. When Pb and Sb atoms are deposited on Cl-Ge(111) surface, they spontaneously form a hexagonal lattice (Pb/Sb@Cl-Ge(111)). The Pb/Sb@Cl-Ge(111) exhibits a 2D TI state with large bulk gap of 0.27 eV for Pb@Cl-Ge(111) and 0.81 eV for Sb@Cl-Ge(111). The mechanism of 2D TI state is the substrate orbital-filtering effect that effectively removes the p z bands of Pb(Sb) away from the Fermi level, leaving behind only the p x and p y orbitals at the Fermi level. Our findings pave another way for future design of 2D topological insulators on conventional semiconductor surface, which promotes the application of 2D TIs in spintronics and quantum computing devices at room-temperature.

Efficacy of oral cryotherapy on oral mucositis prevention in patients with hematological malignancies undergoing hematopoietic stem cell transplantation: a meta-analysis of randomized controlled trials.

OBJECTIVES: Controversy exists regarding whether oral cryotherapy can prevent oral mucositis (OM) in patients with hematological malignancies undergoing hematopoietic stem cell transplantation (HSCT). The aim of the present meta-analysis was to evaluate the efficacy of oral cryotherapy for OM prevention in patients with hematological malignancies undergoing HSCT. METHODS: PubMed and the Cochrane Library were searched through October 2014. Randomized controlled trials (RCTs) comparing the effect of oral cryotherapy with no treatment or with other interventions for OM in patients undergoing HSCT were included. The primary outcomes were the incidence, severity, and duration of OM. The secondary outcomes included length of analgesic use, total parenteral nutrition (TPN) use, and length of hospital stay. RESULTS: Seven RCTs involving eight articles analyzing 458 patients were included. Oral cryotherapy significantly decreased the incidence of severe OM (RR = 0.52, 95% CI = 0.27 to 0.99) and OM severity (SMD = -2.07, 95% CI = -3.90 to -0.25). In addition, the duration of TPN use and the length of hospitalization were markedly reduced (SMD = -0.56, 95% CI = -0.92 to -0.19; SMD = -0.44, 95% CI = -0.76 to -0.13; respectively). However, the pooled results were uncertain for the duration of OM and analgesic use (SMD = -0.13, 95% CI = -0.41 to 0.15; SMD = -1.15, 95% CI = -2.57 to 0.27; respectively). CONCLUSIONS: Oral cryotherapy is a readily applicable and cost-effective prophylaxis for OM in patients undergoing HSCT.

The efficacy and safety of sirolimus-based graft-versus-host disease prophylaxis in patients undergoing allogeneic hematopoietic stem cell transplantation: a meta-analysis of randomized controlled trials.

BACKGROUND: The efficacy and safety of sirolimus (SIR)-based graft-versus-host disease (GVHD) prophylaxis in patients who were subjected to allogeneic hematopoietic stem cell transplantation (allo-HSCT) remain to be clarified; this meta-analysis was conducted to evaluate these factors. STUDY DESIGN AND METHODS: Data from original research were obtained from PubMed, Embase, and Cochrane central register of controlled trials databases. Randomized controlled trials (RCTs) evaluating the efficacy of SIR-based prophylaxis in allo-HSCT were included. The risk ratio (RR), with a 95% confidence interval (CI), was used to pool data. The random effects model was used, irrespective of the presence or absence of heterogeneity. RESULTS: Five RCTs were included in the meta-analysis. SIR was observed to significantly decrease the incidence of Grade II to IV acute GVHD (aGVHD; RR, 0.65; 95% CI, 0.47-0.89). However, the incidence of Grade III to IV aGVHD and chronic GVHD was not decreased (RR, 0.91; 95% CI, 0.59-1.40; RR, 1.04; 95% CI, 0.88-1.23, respectively). An analysis of the toxic effects of SIR revealed that SIR effected a significant increase in the incidence of sinusoidal obstructive syndrome (RR, 2.24; 95% CI, 1.26-4.01), while that of thrombotic microangiopathy was not significantly increased (RR, 2.48; 95% CI, 0.87-7.06). Moreover, SIR did not improve event-free survival and overall survival (RR, 0.97; 95% CI, 0.85-1.10; and RR, 0.92; 95% CI, 0.82-1.02, respectively). CONCLUSION: This meta-analysis indicated that the SIR-based regimen is an effective and safe alternative prophylaxis strategy for GVHD.

[Radioprotective effect of rmIL-12 on mice irradiated by γ-ray].

The aim of this study was to investigate the radioprotective effect of recombinant murine interleukin 12 (rmIL-12) on mice irradiated by γ-ray. Fifty- six BALB/c mice were totally irradiated by 6.0 Gy of (60)Co γ-ray and randomly divided into irradiation control group,rmIL-12 treated group and recombinant murine thrombopoietin (rmTPO) treated group.The 5 and 20 µg/kg of rmIL-12 were administrated intraperitoneally at 24 h before irradiation respectively (low and high dose rmIL-12 treated group), 15 µg/kg of rmTPO was administrated subcutaneously at 30 min and 24 h following irradiation in rmTPO treated group. The general conditions of mice were observed twice a day, the changes in body weight and peripheral blood cell counts were examined once every three days, bone marrow cells were collected to perform colony cultivation at day 14 and 28 after irradiation. The results showed that the general conditions of mice in rmIL-12 treated group were better than those in irradiation control group. Compared with the irradiation control group,5 and 20 µg/kg rmIL-12 treatment significantly promoted platelet recovery, resulting in less profound nadirs (15.9% vs 8.1%,18.2% vs 8.1%,P < 0.01) and rapid recovery to normal levels (11 days vs 14 days). WBC count recovery rate in rmIL-12 treated group was faster than that in the irradiation control group. The WBC and platelet count recovery rate in 5 µg/kg rmIL-12 treated group were as fast as that in the rmTPO treated group, both of which were slower than that in 20 µg/kg rmIL-12 treated group (P > 0.05). Semi-solid bone marrow cell culture also demonstrated that rmIL-12 could stimulate bone marrow cells to form more CFU-Mix than those in the irradiation control group in vitro at day 14 and 28 after irradiation(P < 0.01).There was no significant difference between rmIL-12 and rmTPO treated groups (P > 0.05), CFU-GM counts in 5 µg/kg rmIL-12 treated group and rmTPO treated group at day 28 after irradiation were higher than those in irradiation control group(P < 0.05), but less than those in 20 µg/kg rmIL-12 treated group (P < 0.05). It is concluded that rmIL-12 has a significant radioprotective effect on mice irradiated by γ-ray.

[Therapeutic effect of rmIL-12 combined with G-CSF on acute radiation sickness produced by γ-ray irradiation in mice].

The aim of this study is to observe the therapeutic effect of recombinant murine interleukin 12 (rmIL-12) combining with granulocyte colony stimulating factor (G-CSF) on mice irradiated by γ-rays. 56 BALB/c mice were totally irradiated by 6.0 Gy of (60)Co γ-ray and randomly divided into irradiation control group, rmIL-12 treatment group, G-CSF treatment group and combination therapy (rmIL-12 plus G-CSF) group. rmIL-12 20 µg/kg was administrated intraperitoneally at 1 h following irradiation, and was administrated every 3 days after irradiation for 4 times in rmIL-12 treatment group. G-CSF 100 µg/kg was administrated subcutaneously the 2 h following irradiation for 14 d in G-CSF treatment group. The dose and method of rmIL-12 and G-CSF in combination therapy group were same as in rmIL-12 group and G-CSF group. The general status of mice were observed twice a day, the changes in body weight, peripheral blood cell (WBC and Plt) counts were examined once every three days, bone marrow cells were collected to perform colony cultivation on day 14 and 28 after irradiation. The results showed that WBC count recovery time in combination therapy group was significantly earlier than that of the control group (7 d vs 11 d), WBC count recovery velocity in the combination therapy group was no significant different from that of the G-CSF treatment group. Combined therapy significantly promoted Plt count recovery, resulting in less profound nadirs (16.5% vs 8.1%, P < 0.01) and rapid recovery to normal levels (11 d vs 14 d), Plt count recovery velocity in the combination therapy group was no significant different from that of the rmIL-12 treatment group. Culture of bone marrow cells in semi-solid medium also demonstrated that combination of rmIL-12 and G-CSF could stimulate bone marrow cells to form more CFU-GM and CFU-Mix than those of the irradiation control group in vitro on day 14 and 28 after irradiation (P < 0.05). It is concluded that the combination of rmIL-12 and G-CSF can significantly accelerate the recovery of hematopoietic function in mice with acute radiation sickness.