Development and characterization of an antibody that recognizes influenza virus N1 neuraminidases.

Influenza A viruses (IAVs) continue to pose a huge threat to public health, and their prevention and treatment remain major international issues. Neuraminidase (NA) is the second most abundant surface glycoprotein on influenza viruses, and antibodies to NA have been shown to be effective against influenza infection. In this study, we generated a monoclonal antibody (mAb), named FNA1, directed toward N1 NAs. FNA1 reacted with H1N1 and H5N1 NA, but failed to react with the NA proteins of H3N2 and H7N9. In vitro, FNA1 displayed potent antiviral activity that mediated both NA inhibition (NI) and blocking of pseudovirus release. Moreover, residues 219, 254, 358, and 388 in the NA protein were critical for FNA1 binding to H1N1 NA. However, further validation is necessary to confirm whether FNA1 mAb is indeed a good inhibitor against NA for application against H1N1 and H5N1 viruses.

DUSP22 suppresses tumor progression by directly dephosphorylating AKT in non-small cell lung cancer.

Protein kinase B (AKT) plays a pivotal in regulating cell migration, proliferation, apoptosis, and survival, making it a prominent target for anticancer therapy. While the kinase activity of AKT has been extensively explored, its dephosphorylation have largely remained uncharted. Herein, we aimed to unravel the molecular mechanisms governing AKT dephosphorylation, with a specific emphasis on dual-specificity phosphatases DUSP22. Our investigation sought to shed light on the potential of DUSP22 as a potential therapeutic target for non-small cell lung cancer (NSCLC). To determine the expression level of DUSP22 in NSCLC cell lines, the gene expression profiling interactive analysis (GEPIA) and Oncomine database were searched. Additionally, the effect of DUSP22 on patient survival was analyzed with Kaplan-Meier database. Antitumor effects of DUSP22 were tested in A549 and H1299 cell lines. Experiments are based on: (1) cell viability determined by the cell counting kit-8 assay and colony-formation assay; (2) cell migratory ability assessed through the scratch assay and the transwell migration assay; (3) the mechanism behind the antitumor effects of DUSP22 dissected with co-immunoprecipitation (Co-IP) and in vitro kinase assays. Our study revealed a significant downregulation of DUSP22 in both NSCLC cell lines and tissues. Meanwhile, survival rate analysis results demonstrated that reduced DUSP22 expression was correlated with poorer overall survival in lung cancer patients. Moreover, DUSP22 exhibited an inhibitory effect on the cell viability and migratory capacity of A549 and H1299 cells. This inhibition was accompanied by the decrease in the phosphorylation of AKT and p38. Mechanistically, the phosphatase domain of DUSP22 interacted with AKT, resulting in the inhibition of AKT phosphorylation. This inhibitory effect was contingent upon the phosphatase activity of DUSP22. These findings provide compelling evidence that DUSP22 directly interacted with AKT, leading to the dephosphorylation of AKT at S473 and T308 residues, ultimately curbing the proliferation and migration of lung cancer cells. Additionally, our results also highlight a preclinical rationale for utilizing DUSP22 as a prognostic marker in NSCLC.

Mouse Ocilrp2/Clec2i negatively regulates LPS-mediated IL-6 production by blocking Dap12-Syk interaction in macrophage.

C-type lectin Ocilrp2/Clec2i is widely expressed in dendritic cells, lymphokine-activated killer cells and activated T cells. Previous studies have shown that Ocilrp2 is an important regulator in the activation of T cells and NK cells. However, the role of Ocilrp2 in the inflammatory responses by activated macrophages is currently unknown. This study investigated the expression of inflammatory cytokines in LPS-induced macrophages from primary peritoneal macrophages silenced by specific siRNA target Ocilrp2. Ocilrp2 was significantly downregulated in macrophages via NF-κB and pathways upon LPS stimuli or VSV infection. Silencing Ocilrp2 resulted in the increased expression of IL-6 in LPS-stimulated peritoneal macrophages and mice. Moreover, IL-6 expression was reduced in LPS-induced Ocilrp2 over-expressing iBMDM cells. Furthermore, we found that Ocilrp2-related Syk activation is responsible for expressing inflammatory cytokines in LPS-stimulated macrophages. Silencing Ocilrp2 significantly promotes the binding of Syk to Dap12. Altogether, we identified the Ocilrp2 as a critical role in the TLR4 signaling pathway and inflammatory macrophages' immune regulation, and added mechanistic insights into the crosstalk between TLR and Syk signaling.

A Novel Humanized Anti-Abrin A Chain Antibody Inhibits Abrin Toxicity In Vitro and In Vivo.

Abrin, a type-II ribosome inactivating protein from the seed of Abrus precatorius, is classified as a Category B bioterrorism warfare agent. Due to its high toxicity, ingestion by animals or humans will lead to death from multiple organ failure. Currently, no effective agents have been reported to treat abrin poisoning. In this study, a novel anti-abrin neutralizing antibody (S008) was humanized using computer-aided design, which possessed lower immunogenicity. Similar to the parent antibody, a mouse anti-abrin monoclonal antibody, S008 possessed high affinity and showed a protective effect against abrin both in vitro and in vivo, and protected mice that S008 was administered 6 hours after abrin. S008 was found that it did not inhibit entry of abrin into cells, suggesting an intracellular blockade capacity against the toxin. In conclusion, this work demonstrates that S008 is a high affinity anti-abrin antibody with both a neutralizing and protective effect and may be an excellent candidate for clinical treatment of abrin poisoning.

Blocking the death checkpoint protein TRAIL improves cardiac function after myocardial infarction in monkeys, pigs, and rats.

Myocardial infarction (MI) is a leading cause of death worldwide for which there is no cure. Although cardiac cell death is a well-recognized pathological mechanism of MI, therapeutic blockade of cell death to treat MI is not straightforward. Death receptor 5 (DR5) and its ligand TRAIL [tumor necrosis factor (TNF)-related apoptosis-inducing ligand] are up-regulated in MI, but their roles in pathological remodeling are unknown. Here, we report that blocking TRAIL with a soluble DR5 immunoglobulin fusion protein diminished MI by preventing cardiac cell death and inflammation in rats, pigs, and monkeys. Mechanistically, TRAIL induced the death of cardiomyocytes and recruited and activated leukocytes, directly and indirectly causing cardiac injury. Transcriptome profiling revealed increased expression of inflammatory cytokines in infarcted heart tissue, which was markedly reduced by TRAIL blockade. Together, our findings indicate that TRAIL mediates MI directly by targeting cardiomyocytes and indirectly by affecting myeloid cells, supporting TRAIL blockade as a potential therapeutic strategy for treating MI.

TNFAIP8 promotes cisplatin resistance in cervical carcinoma cells by inhibiting cellular apoptosis.

Cervical cancer is the second most prevalent malignant tumor in women worldwide. Failure of successful treatment is most prevalent in patients with the metastatic disease and the chemotherapy refractory disease. Tumor necrosis factor α-induced protein 8 (TNFAIP8) serves as an anti-apoptotic and pro-oncogenic protein, and is associated with cancer progression and poor prognosis in a number of different cancer types. However, the physiological and pathophysiological roles of TNFAIP8 in cervical carcinogenesis and development remain poorly understood. In the present study, it was demonstrated that TNFAIP8 protein expression levels were significantly increased in cervical cancer tissues compared with the non-tumor adjacent tissues using immunohistochemistry. Additionally, it was demonstrated that TNFAIP8 overexpression is associated with cisplatin resistance. Furthermore, depletion of TNFAIP8 impaired HeLa cell proliferation and viability in vitro, improved cisplatin sensitivity, and promoted cisplatin-induced cellular apoptosis and death. Subsequent mechanistic analysis demonstrated that TNFAIP8 silencing promoted caspase-8/-3 activation and p38 phosphorylation in HeLa cells treated with cisplatin, whereas apoptosis regulator B-cell lymphoma-2 expression was inhibited with TNFAIP8-silenced HeLa cells following treatment with cisplatin. These data suggested that TNFAIP8 serves as an anti-apoptotic protein against cisplatin-induced cell death, which eventually leads to chemotherapeutic drug-treatment failure. Therefore, the present data suggested that TNFAIP8 may be a promising therapeutic target for the treatment of cervical cancer.

Ablation of Venusian oxygen ions by unshocked solar wind.

As an Earth-like planet Venus probably had a primordial dipole field for several million years after formation of the planet. Since this dipole field eventually vanished the ionosphere of Venus has been exposed to the solar wind. The solar wind is shocked near Venus, and then scavenges the ionospheric particles through the magnetosheath and the magnetotail. The escape rate of oxygen ions (O+) estimated from spacecraft observations over the past several decades has manifested its importance for the evolution of planetary habitability, considering the accumulated effect over the history of Venus. However, all the previous observations were made in the shocked solar wind and/or inside the wake, though some simulations showed that unshocked solar wind can also ablate O+ ions. Here we report Venus Express observations of O+ ions in the unshocked solar wind during the solar minimum. The observations suggest that these O+ ions are accelerated by the unshocked solar wind through pickup processes. The estimated O+ escape rate, 2.1 × 1024 ions/s, is comparable to those measured in the shocked solar wind and the wake. This escape rate could result in about 2 cm global water loss over 4.5 billion years. Our results suggest that the atmospheric loss at unmagnetized planets is significantly underestimated by previous observations, and thus we can emphasize the importance of an Earth-like dipole for planetary habitability.

OCILRP2 signaling synergizes with LPS to induce the maturation and differentiation of murine dendritic cells.

Osteoclast Inhibitory Lectin-related Protein 2 (OCILRP2) is a typical type II transmembrane protein and belongs to C-type lectin-related protein family. It is preferentially expressed in dendritic cells (DC), B lymphocytes, and activated T lymphocytes. Upon binding to its ligand, OCILRP2 can promote CD28-mediated co-stimulation and enhance T cell activation. However, the role of OCILRP2 in DC development and activation is unclear. In this report, we present evidence that recombinant protein OCILRP2-Fc inhibits the generation and LPS-induced maturation of murine bone marrow-derived dendritic cells (BMDCs) by downregulating the expression of CD11c, MHC-II, and co-stimulators CD80 and CD86. OCILRP2-Fc also reduces the capacity of BMDCs to take up antigens, activates T cells, and secret inflammatory cytokines such as IL-6, IL-12, and TNF-α. Additionally, we show that OCILRP2-Fc may cause the aforementioned effects through inhibiting NF-κB activation. Therefore, OCILRP2 is a new regulator of DC maturation and differentiation following TLR4 activation.

TIPE2 controls innate immunity to RNA by targeting the phosphatidylinositol 3-kinase-Rac pathway.

RNA receptors such as TLR3 and retinoid acid-inducible gene I/melanoma differentiation-associated gene 5 play essential roles in innate immunity to RNA viruses. However, how innate immunity to RNAs is controlled at the molecular level is not well understood. We describe in this study a new regulatory pathway of anti-RNA immunity that is composed of PI3K, its target GTPase Rac, and the newly described immune regulator TNF-α-induced protein 8 like-2 (TIPE2, or TNFAIP8L2). Polyinosinic-polycytidylic acid [Poly (I:C)], a dsRNA receptor ligand, activates Rac via its guanine nucleotide exchange factor Tiam; this leads to the activation of cytokine genes and, paradoxically, downregulation of the Tipe2 gene. TIPE2 is a negative regulator of immunity; its deficiency leads to hyperactivation of the PI3K-Rac pathway as exemplified by enhanced AKT, Rac, P21-activated kinase, and IFN regulatory factor 3 activities. As a consequence, TIPE2 knockout myeloid cells are hyperreactive to Poly (I:C) stimulation, and TIPE2 knockout mice are hypersensitive to Poly (I:C)-induced lethality. These results indicate that TIPE2 controls innate immunity to RNA by targeting the PI3K-Rac pathway. Therefore, manipulating TIPE2 or Rac functions can be effective for controlling RNA viral infections.

[Human bone marrow mesenchymal stem cells differentiated into dopaminergenic neurons in vitro].

Midbrain dopamine (DA) neurons play an essential role in modulating motor control. Defects in central DA neurons affect a wide range of neurological disorders including Parkinson's disease (PD). The greatest motivation in the field has been the potential use of DA neurons for cell transplantation therapy in Parkinsonian patients. Recent studies indicated that BMSCs could differentiate into DA neurons in vitro as neural stem cells (NSC) and embryonic stem cells (ESC) could. However, there are no direct evidences about functional DA neurons derived from BMSCs. According to the protocols which had been applicated in inducing neuronal stem cells and embryonic stem cells differentiate into DA neurons in vitro, the present study provides a protocol by using 50 micromol/L brain derived neurotrophy factor (BDNF), 10 micromol/L forskolin (FSK) and 10 micromol/L dopamine (DA) to induce BMSCs differentiate into DA neurons. After 2 weeks of differentiation, the cells expressed the character of neurons in ultrastructure. RT-PCR discovered mRNA of NSE (neuron specific enolase), Nurr1, Ptx3, Lmx1b and Tyrosine hydroxylase (TH) were positive. Immunocytochemistry staining indicated the ratio of TH-positive neural cells was significantly increased after induced 2 weeks (24.80 +/- 3.36) % compared to that of induction of 3 days (3.77 +/- 1.77) %. And the DA release was also different between differentiated and undifferentiated cells detected by high performance liquid chromatography (HPLC). That is to say BDNF and FSK and DA can induce BMSCs differentiate into DA neurons in vitro, and the transdifferentiated cells express mature neurons characters. BMSCs might be a suitable and available source for the in vitro derivation of DA neurons and cell transplantation therapy in some central neural system diseases such as PD.