Prevention of childhood rotavirus disease through the use of Rotarix™and RotaTeq™vaccines

Valeriana jatamansi Jones Inhibits Rotavirus-Induced Diarrhea via Phosphatidylinositol 3-Kinase/Protein Kinase B Signaling Pathway

Rotavirus (RV), as the main cause of diarrhea in children under 5 years, contributes to various childhood diseases. Valeriana jatamansi Jones is a traditional Chinese herb and possesses antiviral effects. In this study we investigated the potential mechanisms of V. jatamansi Jones in RV-induced diarrhea. MTT assay was performed to evaluate cell proliferation and the diarrhea mice model was constructed using SA11 infection. Mice were administered V. jatamansi Jones and ribavirin. Diarrhea score was used to evaluate the treatment effect. The enzyme-linked immunosorbent assay was performed to detect the level of cytokines. Western blot and quantitative reverse transcription-PCR were used to determine protein and mRNA levels, respectively. Hematoxylin-eosin staining was applied to detect the pathological change of the small intestine. TdT-mediated dUTP nick-end labeling was conducted to determine the apoptosis rate. The results showed V. jatamansi Jones promoted MA104 proliferation. V. jatamansi Jones downregulated phosphatidylinositol 3-kinase (PI3K) and protein kinase B (AKT) in protein level, which was consistent with the immunohistochemistry results. Moreover, V. jatamansi Jones combined with ribavirin regulated interleukin-1β (IL-1β), interferon γ, IL-6, tumor necrosis factor α, and IL-10, and suppressed secretory immunoglobulin A secretion to remove viruses and inhibit dehydration. V. jatamansi Jones + ribavirin facilitated the apoptosis of small intestine cells. In conclusion, V. jatamansi Jones may inhibit RV-induced diarrhea through PI3K/AKT signaling pathway, and could therefore be a potential therapy for diarrhea.

Macleaya cordata extracts exert antiviral effects in newborn mice with rotavirus-induced diarrhea via inhibiting the JAK2/STAT3 signaling pathway

Accumulating evidence demonstrates that Macleaya cordata extract exerts antiviral and anti-inflammatory effects in various diseases. The present study aimed to investigate the potential effects of M. cordata on rotavirus SA11-induced diarrhea in mice. Diarrhea severity, levels of inflammatory cytokines, histological changes in the small intestine and the underlying mechanisms were evaluated in rotavirus-stimulated mice treated with 1, 2 and 4 mg/kg/day M. cordata or 4 mg/kg/day ribavirin (positive control). M. cordata treatment effectively ameliorated rotavirus-induced diarrhea in a dose-dependent manner by decreasing viral RNA levels. In addition, M. cordata reduced the release of pro-inflammatory cytokines including migration inhibitory factor, interleukin (IL)-8, IL-β, interferon-γ and tumor necrosis factor-α, and elevated the secretion of the anti-inflammatory cytokine IL-10 following rotavirus infection. M. cordata inhibited intestinal epithelial cell apoptosis and improved intestinal inflammation after rotavirus infection. The study also revealed that M. cordata exerted antiviral and anti-inflammatory effects on rotavirus-induced diarrhea by suppressing the Janus kinase 2 (JAK2)/STAT3 pathway, as reflected by decreased protein expression of phosphorylated (p)-JAK2 and p-STAT3. Overall, M. cordata effectively inhibited the inflammation caused by rotavirus, which was closely associated with the suppression of JAK2/STAT3 phosphorylation. These data suggested that M. cordata may be applied as a treatment for rotavirus-induced diarrhea.

MiR-525-3p mediates antiviral defense to rotavirus infection by targeting nonstructural protein 1

MicroRNAs (miRNAs) are short RNAs of approximately 22 nucleotides that post-transcriptionally regulate gene expression by controlling mRNA stability or translation. They play critical roles in intricate networks of host-pathogen interactions and innate immunity. Rotaviruses (RVs) are the leading cause of severe diarrhea among infants and young children worldwide. This study was undertaken to demonstrate the importance of cellular miRNAs during RV (human Wa RV or Rhesus RV) strains infection. Twenty-nine differentially regulated miRNAs were identified during RV infection, and miR-525-3p was downregulated and validated by quantitative real-time polymerase chain reaction (qRT-PCR). MiR-525-3p mimic inhibited RV replication in dose-dependent manner. Correspondingly, the miR-525-3p inhibitors enhanced RV replication. We confirmed that miR-525-3p was complementary to the 3' untranslated region (UTR) of nonstructural protein 1(NSP1) of RV (Wa or Rhesus) strains. Interestingly, miR-525-3p induced type I interferon (IFN) expression and proinflammatory cytokines during RV infection through IFN regulatory factor (IRF) 3/IRF7 and NF-κB activation, which can induce an antiviral state to further suppress RV infection. In addition, RV suppressed miR-525-3p expression to evade host innate immunity through the action of the RV protein NSP1. These results suggest that miR-525-3p has the potential to be used as an antiviral therapeutic against RV infection.

Antiviral effects of cyclosporine A in neonatal mice with rotavirus-induced diarrhea

OBJECTIVES

Because rotavirus gastroenteritis is associated with high morbidity and mortality especially in developing countries, it is necessary to develop antirotavirus drugs for the treatment of rotavirus infection. Previous studies have demonstrated that cyclosporin A (CsA) has antiviral properties against rotavirus. Its effect has not yet been evaluated against rotavirus diarrheal disease. The aim of this study was to assess the anti-rotavirus efficacy of CsA in neonatal mice after induction of rotavirus diarrhea.

METHODS

Suckling mice were inoculated with murine rotavirus. On the onset of diarrhea, mice were given different concentrations of CsA. To evaluate the effects of CsA on reduction of rotavirus diarrhea, diarrhea score, fecal virus shedding, and pathological lesion change in the small intestine, messenger RNA (mRNA) expression levels in the small intestine and spleen of mice were measured for type I interferon (IFN-α and IFN-β), inflammation-related cytokines (interleukin [IL]-8, IL-10, IFN-γ, and tumor necrosis factor-α), and inflammatory signaling pathways (p38, c-Jun N-terminal kinase, activator protein-1, and nuclear factor-kappa B).

RESULTS

Among virus-inoculated and CsA-treated groups, a dose of 5 mg · kg⁻¹ · day⁻¹ of CsA inhibited diarrhea and improved fecal virus shedding and intestinal lesion changes. IFN-β mRNA expression was significantly increased in rotavirus-induced diarrhea mice treated with 5 mg · kg⁻¹ · day⁻¹ of CsA, whereas the mRNA expression levels of inflammation-related cytokines (IL-8, IL-10, IFN-γ, and tumor necrosis factor-α) and inflammatory signaling pathways (p38, c-Jun N-terminal kinase, activator protein-1, and nuclear factor-kappa B) were markedly decreased. Antiviral effects of CsA were dose dependent.

CONCLUSIONS

CsA can inhibit rotavirus infection in neonatal mice through its antiviral properties. The mechanism for this may be through CsA suppression of inflammation by viral inhibition in animal models.

Neonatal protection by an innate immune system of human milk consisting of oligosaccharides and glycans

This review discusses the role of human milk glycans in protecting infants, but the conclusion that the human milk glycans constitute an innate immune system whereby the mother protects her offspring may have general applicability in all mammals, including species of commercial importance. Infants that are not breastfed have a greater incidence of severe diarrhea and respiratory diseases than those who are breastfed. In the past, this had been attributed primarily to human milk secretory antibodies. However, the oligosaccharides are major components of human milk, and milk is also rich in other glycans, including glycoproteins, mucins, glycosaminoglycans, and glycolipids. These milk glycans, especially the oligosaccharides, are composed of thousands of components. The milk factor that promotes gut colonization by Bifidobacterium bifidum was found to be a glycan, and such prebiotic characteristics may contribute to protection against infectious agents. However, the ability of human milk glycans to protect the neonate seems primarily to be due to their inhibition of pathogen binding to their host cell target ligands. Many such examples include specific fucosylated oligosaccharides and glycans that inhibit specific pathogens. Most human milk oligosaccharides are fucosylated, and their production depends on fucosyltransferase enzymes; mutations in these fucosyltransferase genes are common and underlie the various Lewis blood types in humans. Variable expression of specific fucosylated oligosaccharides in milk, also a function of these genes (and maternal Lewis blood type), is significantly associated with the risk of infectious disease in breastfed infants. Human milk also contains major quantities and large numbers of sialylated oligosaccharides, many of which are also present in bovine colostrum. These could similarly inhibit several common viral pathogens. Moreover, human milk oligosaccharides strongly attenuate inflammatory processes in the intestinal mucosa. These results support the hypothesis that oligosaccharides and other glycans are the major constituents of an innate immune system of human milk whereby the mother protects her infant from enteric and other pathogens through breastfeeding. These protective glycans may prove useful as a basis for the development of novel prophylactic and therapeutic agents that inhibit disease by mucosal pathogens in many species.