2'-Fucosyllactose Inhibits Coxsackievirus Class A Type 9 Infection by Blocking Virus Attachment and Internalisation

Rapid and highly sensitive colorimetric LAMP assay and integrated device for visual detection of monkeypox virus

BACKGROUND

The monkeypox virus (MPXV) is a linear double-stranded DNA virus with a large genome that causes tens of thousands of infections and hundreds of deaths in at least 40 countries and regions worldwide. Therefore, timely and accurate diagnostic testing could be an important measure to prevent the ongoing spread of MPXV and widespread epidemics.

RESULTS

Here, we designed multiple sets of primers for the target region of MPXV for loop-mediated isothermal amplification (LAMP) detection and identified the optimal primer set. Then, the specificity in fluorescent LAMP detection was verified using the plasmids containing the target gene, pseudovirus and other DNA/RNA viruses. We also evaluated the sensitivity of the colorimetric LAMP detection system using the plasmid and pseudovirus samples, respectively. Besides, we used monkeypox pseudovirus to simulate real samples for detection. Subsequent to the establishment and introduction of a magnetic beads (MBs)-based nucleic acid extraction technique, an integrated device was developed, characterized by rapidity, high sensitivity, and remarkable specificity. This portable system demonstrated a visual detection limit of 137 copies/mL, achieving sample-to-answer detection within 1 h.

SIGNIFICANCE

The device has the advantages of integration, simplicity, miniaturization, and visualization, which help promote the realization of accurate, rapid, portable, and low-cost testing. Meanwhile, this platform could facilitate efficient, cost-effective and easy-operable point-of-care testing (POCT) in diverse resource-limited settings in addition to the laboratory.

2'-Fucosyllactose Inhibits Human Norovirus Replication in Human Intestinal Enteroids

Human noroviruses (HuNoVs) are the leading cause of acute gastroenteritis worldwide. Currently, there are no targeted antivirals for the treatment of HuNoV infection. Histo-blood group antigens (HBGAs) on the intestinal epithelium are cellular attachment factors for HuNoVs; molecules that block the binding of HuNoVs to HBGAs thus have the potential to be developed as antivirals. Human milk oligosaccharides (HMOs) are glycans in human milk with structures analogous to HBGAs. HMOs have been shown to act as decoy receptors to prevent the attachment of multiple enteric pathogens to host cells. Previous X-ray crystallography studies have demonstrated the binding of HMO 2'-fucosyllactose (2'FL) in the same pocket as HBGAs for some HuNoV strains. We evaluated the effect of 2'FL on the replication of a globally dominant GII.4 Sydney [P16] HuNoV strain using human intestinal enteroids (HIEs) from adults and children. A significant reduction in GII.4 Sydney [P16] replication was seen in duodenal and jejunal HIEs from multiple adult donors, all segments of the small intestine from an adult organ donor and in two pediatric duodenal HIEs. However, 2'FL did not inhibit HuNoV replication in two infant jejunal HIEs that had significantly lower expression of α1-2-fucosylated glycans. 2'FL can be synthesized in large scale, and safety and tolerance have been assessed previously. Our data suggest that 2'FL has the potential to be developed as a therapeutic for HuNoV gastroenteritis.

2'-Fucosyllactose restores the intestinal mucosal barrier in ulcerative colitis by inhibiting STAT3 palmitoylation and phosphorylation

BACKGROUND & AIMS

2'-Fucosyllactose (2'-FL), the primary constituent of human milk oligosaccharides, has been identified as a potential regulator of inflammation in inflammatory bowel disease. Despite this recognition, the specific mechanisms through which 2'-FL alleviates ulcerative colitis (UC) remain ambiguous. This study seeks to investigate the potential anti-inflammatory properties of 2'-FL concerning intestinal inflammation and uncover the associated mechanisms.

METHODS

C57BL/6J mice were orally administered a daily dose of 500 mg/kg 2'-FL for 11 consecutive days, followed by the induction of colitis using 3 % (wt/vol) dextran sulfate sodium (DSS) for the final 6 days. Subsequently, a comprehensive range of techniques, including an Acyl-biotin exchange assay, fluorescein-isothiocyanate-labeled dextran assay, histopathology, ELISA, quantitative real-time PCR, Western blot, immunofluorescence staining, immunohistochemistry staining, Alcian blue-periodic acid schiff staining, TdT-mediated dUTP nick end labeling, transmission electron microscopy, iTRAQ quantitative proteomics, bioinformatics analysis, and the generation of signal transducer and activator of transcription 3 (STAT3) knockout mice, were employed to explore the relevant molecular mechanisms.

RESULTS

Administration of 2'-FL significantly ameliorated DSS-induced colitis in mice and enhanced the integrity of the intestinal mucosal barrier. 2'-FL downregulated the phosphorylation of STAT3 and inhibited STAT3-related signaling pathways in colon tissues, which, in turn, reduced inflammatory responses. Interestingly, knockdown of STAT3 attenuated the protective effects of 2'-FL, highlighting that 2'-FL-mediated inflammatory attenuation is dependent on STAT3 expression. Additionally, 2'-FL could influence STAT3 activation by modulating the palmitoylation and depalmitoylation of STAT3.

CONCLUSIONS

2'-FL promotes the recovery of the intestinal mucosal barrier and suppresses inflammation in ulcerative colitis by inhibiting the palmitoylation and phosphorylation of STAT3.

Antivirals and Vaccines

New antivirals are urgently needed to treat respiratory diseases caused by RNA viruses [...].