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The extensive use of tetracycline antibiotics has led to the widespread presence of tetracycline-resistance genes in Gram-negative bacteria and this poses serious threats to human and animal health. In our previous study, we reported a method for rapid detection of Tet(X)-producers using MALDI-TOF MS. However, there have been multiple machineries involved in tetracycline resistance including efflux pump, and ribosomal protection protein. Our previous demonstrated the limitation in probing the non-Tet(X)-producing tetracycline-resistant strains. In this regard, we further developed a MALDI-TOF MS method to detect and differentiate Tet(X)-producers and non-Tet(X)-producing tetracycline-resistant strains. Test strains were incubated with tigecycline and oxytetracycline in separate tubes for 3 h and then analyzed spectral peaks of tigecycline, oxytetracycline, and their metabolite. Strains were distinguished using MS ratio for [metabolite/(metabolite+ tigecycline or oxytetracycline)]. Four control strains and 319 test strains were analyzed and the sensitivity was 98.90% and specificity was 98.34%. This was consistent with the results obtained from LC-MS/MS analysis. Interestingly, we also found that the reactive oxygen species (ROS) produced by tetracycline-susceptible strains were able to promote the degradation of oxytetracycline. Overall, the MALDITet(X)-plus test represents a rapid and reliable method to detect Tet(X)-producers, non-Tet(X)-producing tetracycline-resistant strains, and tetracycline-susceptible strains.

Lipopolysaccharide- (LPS-) mediated systemic inflammation plays a critical role in neurodegenerative diseases. The present study was conducted to evaluate the protective effects of epigallocatechin gallate (EGCG), the major component in green tea, on LPS-mediated inflammation and neurotoxicity. LPS treatment of macrophages induced expression of proinflammatory cytokines (TNF-α, IL-1β, and IL-6). However, EGCG pretreatment of macrophages significantly inhibited LPS-mediated induction of these cytokines. In addition, EGCG significantly diminished LPS-induced inflammatory cytokines in the peripheral mononuclear blood cells (PBMCs). Supernatant from EGCG-pretreated and LPS-activated macrophage cultures was found to be less cytotoxic to neurons than that from non-EGCG-pretreated and LPS-activated macrophage cultures. Furthermore, EGCG treatment of neurons could inhibit LPS-induced production of reactive oxygen species (ROS). Thus EGCG represents a potent and useful neuroprotective agent for inflammation-mediated neurological disorders. [ABSTRACT FROM AUTHOR]

The cytotoxic effects of terpenoid lactones are attributed to the alkylation of biological nucleophiles, especially sulfhydryl groups in proteins, by the α,β-unsaturated carbonyl moiety of lactones through Michael reaction. Therefore, the cytotoxicity could be reflected by the reactivity of the pharmacophores. In this work, the Michael reaction between 12 α,β-unsaturated-carbonyl-containing small species, i.e. 10 analogues of the alpha methylene gamma butyrolactone moiety of andrographolide, one cyclopentenone, and one methylene–pentanolide, and L-cysteine-methylester-1 were investigated by ab initio methods to mimic the alkylation of proteins by terpenoid lactones. The trend in the calculated reaction free energies of the small species is qualitatively in accordance with the reported cytotoxicity of corresponding terpenoid lactones. [ABSTRACT FROM AUTHOR]

Bowman-Birk inhibitor (BBI) is a soybean-derived protease inhibitor that has anti-inflammation and anti-HIV effect. Here, we further investigated the anti-HIV action of BBI in macrophages, focusing on its effect on viral entry. We found that BBI could significantly block HIV entry into macrophages. Investigation of the mechanism(s) of the BBI action on HIV inhibition showed that BBI down-regulated the expression of CD4 receptor (as much as 80%) and induced the production of the CC chemokines (up to 60 folds at protein level) in macrophages. This inhibitory effect of BBI on HIV entry could be blocked by the neutralization antibodies to CC chemokines. These findings indicate that BBI may have therapeutic potential as a viral entry inhibitor for the prevention and treatment of HIV infection. [ABSTRACT FROM AUTHOR]

The cytotoxic effects of terpenoid lactones are attributed to the alkylation of biological nucleophiles, especially sulfhydryl groups in proteins, by the α,β-unsaturated carbonyl moiety of lactones through Michael reaction. Therefore, the cytotoxicity could be reflected by the reactivity of the pharmacophores. In this work, the Michael reaction between 12 α,β-unsaturated-carbonyl-containing small species, i.e. 10 analogues of the alpha methylene gamma butyrolactone moiety of andrographolide, one cyclopentenone, and one methylene–pentanolide, and L-cysteine-methylester-1 were investigated by ab initio methods to mimic the alkylation of proteins by terpenoid lactones. The trend in the calculated reaction free energies of the small species is qualitatively in accordance with the reported cytotoxicity of corresponding terpenoid lactones. [ABSTRACT FROM AUTHOR]

Chronically SHIV SF162P3N -infected cynomolgus monkeys were used to determine the effects of the antibody-mediated acute CD4 + T cell depletion on viral load as well as on the immunological factors associated with disease progression. Compared with the control animals, CD4 + T cell-depleted animals with SHIV infection showed (i) little alteration in plasma viral load over the period of 22 weeks after the depletion; (ii) increased CD4 + T cell proliferation and turnover of macrophages at the early phase of the depletion, but subsequent decline to the basal levels; and (iii) little impact on the expression of the inflammatory cytokines and CC chemokines associated with disease progression. These findings indicate that the antibody-mediated acute CD4 + T cell depletion had minimal impact on plasma viral load and disease progression in chronically SHIV SF162P3N -infected cynomolgus monkeys. Future investigations are necessary to identify the key factor(s) related to the immune activation and macrophage infection during the CD4 deletion in chronic viral infection., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Human semen contains a factor that can enhance HIV infection up to 10-fold in cultures. This factor is termed semen-derived enhancer of virus infection (SEVI) and is composed of proteolytic fragments (PAP248-286) from prostatic acid phosphatase in semen. In this study, we examined whether macaque SEVI can facilitate simian immunodeficiency virus (SIV) or chimeric simian/human immunodeficiency virus (SHIV) infection. We also studied the effect of epigallocatechin gallate (EGCG) on macaque SEVI-mediated SIV or SHIV enhancement., Methods: SIV or SHIV was mixed with different concentrations of macaque SEVI in the presence or absence of EGCG. The mixture was added to cultures of TZM-bl cells or macaque PBMCs. The effect of EGCG on macaque SEVI was measured by Congo-red staining assay and thioflavin T (ThT) fluorescence assay and was visualized by a transmission electron microscope., Results: We identified that there is one amino acid difference at the site of 277 between human PAP248-286 and macaque PAP248-286. Macaque SEVI significantly enhanced SIV or SHIV infection of TZM-bl cells and macaque PBMCs. EGCG could block macaque SEVI-mediated enhancement of SIV or SHIV infection. Mechanistically, EGCG could degrade the formation of macaque SEVI amyloid fibrils that facilitates HIV attachment to the target cells., Conclusions: The finding that macaque SEVI could enhance SIV or SHIV infection indicates the possibility to use the macaque SEVI in vivo studies with the macaque models. In addition, future studies are necessary to examine whether EGCG can be used as an effective microbicide for preventing SIV or SHIV mucosal transmission.

Study Hypothesis: Is it possible to immunologically activate human cervical epithelial cells to produce antiviral factors that inhibit herpes simplex virus type 2 (HSV-2) replication?, Study Finding: Our results indicate that human cervical epithelial cells possess a functional TLR3/RIG-I signaling system, the activation of which can mount an Interferon-λ (IFN-λ)-mediated anti-HSV-2 response., What Is Known Already: There is limited information about the role of cervical epithelial cells in genital innate immunity against HSV-2 infection., Study Design, Samples/materials, Methods: We examined the expression of toll-like receptors (TLRs) and retinoic acid-inducible I (RIG-I) in End1/E6E7 cells by real-time PCR. The IFN-λ induced by TLR3 and RIG-I activation of End1/E6E7 cells was also examined by real-time PCR and ELISA. HSV-2 infection of End1/E6E7 cells was evaluated by the real-time PCR detection of HSV-2 gD expression. The antibody to IL-10Rβ was used to determine whether IFN-λ contributes to TLR3/RIG-I mediated HSV-2 inhibition. Expression of interferon regulatory factor 3 (IRF3), IRF7, IFN-stimulated gene 56 (ISG56), 2'-5'-oligoadenylate synthetase I (OAS-1) and myxovirus resistance A (MxA) were determined by the real-time PCR and western blot. End1/E6E7 cells were transfected with shRNA to knockdown the IRF3, IRF7 or RIG-I expression. Student's t-test and post Newman-Keuls test were used to analyze stabilized differences in the immunological parameters above between TLR3/RIG-I-activated cells and control cells., Main Results and the Role of Chance: Human cervical epithelial cells expressed functional TLR3 and RIG-I, which could be activated by poly I:C and 5'ppp double-strand RNAs (5'ppp dsRNA), resulting in the induction of endogenous interferon lambda (IFN-λ). The induced IFN-λ contributed to TLR3/RIG-I-mediated inhibition of HSV-2 replication in human cervical epithelial cells, as an antibody to IL-10Rβ, an IFN-λ receptor subunit, could compromise TLR3/RIG-I-mediated inhibition of HSV-2. Further studies showed that TLR3/RIG-I signaling in the cervical epithelial cells by dsRNA induced the expression of the IFN-stimulated genes (ISGs), ISG56, 2'-5'-oligoadenylate synthetase I (OAS-1) and myxovirus resistance A (MxA), the key antiviral elements in the IFN signaling pathway. In addition, we observed that the topical treatment of genital mucosa with poly I:C could protect mice from genital HSV-2 infection., Limitations, Reasons for Caution: Future prospective studies with primary cells and suitable animal models are needed in order to confirm these outcomes., Wider Implications of the Findings: The findings provide direct and compelling evidence that there is intracellular expression and regulation of IFN-λ in human cervical epithelial cells, which may have a key role in the innate genital protection against viral infections., Large Scale Data: Not applicable., Study Funding and Competing Interests: This work was supported by the National Natural Science Foundation of China (81301428 to L.Z. and 81271334 to W.-Z.H.), the Fundamental Research Funds for the Central Universities (2042015kf0188 to L.Z.), the China Postdoctoral Science Foundation (2013M531745 to L.Z.), the Development Program of China ('973', 2012CB518900 to W.-Z.H.) from the Ministry of Science and Technology of the People's Republic of China, grants (DA12815 and DA022177 to W.-Z.H.) from the National Institute on Drug Abuse (NIDA) and the open project of Hubei Key Laboratory of Wudang Local Chinese Medicine Research (WDCM005 to M.S.). The authors declare no competing financial interests., (© The Author 2015. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Crosslinked chitosan microcarries were prepared by the reaction of glutaraldehyde with fructose-modified chitosan. Various factors that influence the preparation were studied and the reaction conditions were optimized. Morphology of rat hepatocyte cultured on chitosan microcarriers was observed using phase contrast microscopy and scanning electron microscope, the metabolic activity was measured. Rat hepatocytes cultured on chitosan microcarrier retained the spherical shape as they have in vivo and had high metabolic activity. Fructose can enhance the metabolic activity of hepatocytes and fructose-modified chitosan microcarrier is a promising scaffold for hepatocytes attachment, which can be used in bioartificial liver support system.