Human milk oligosaccharides inhibit rotavirus infectivityin vitroand in acutely infected piglets

Abstract

Human milk (HM) is rich in oligosaccharides (HMO) that exert prebiotic and anti-infective activities. HM feeding reduces the incidence of rotavirus (RV) infection in infants. Herein, the anti-RV activity of oligosaccharides was tested in an established in vitro system for assessing cellular binding and viral infectivity/replication, and also tested in a newly developed, acute RV infection, in situ piglet model. For the in vitro work, crude HMO isolated from pooled HM, neutral HMO (lacto-N-neotetraose, LNnT; 2 0 -fucosyllactose) and acidic HMO (aHMO, 3 0 -sialyllactose, 3 0 -SL; 6 0 -sialyllactose, 6 0 -SL) were tested against the porcine OSU strain and human RV Wa strain. The RV Wa strain was not inhibited by any oligosaccharides. However, the RV OSU strain infectivity was dose-dependently inhibited by sialic acid (SA)-containing HMO. 3 0 -SL and 6 0 -SL concordantly inhibited 125 I-radiolabelled RV cellular binding and infectivity/replication. For the in situ study, a midline laparotomy was performed on 21-d-old formula-fed piglets and six 10 cm loops of ileum were isolated in situ. Briefly, 2 mg/ml of LNnT, aHMO mixture (40 % 6 0 -SL/10 % 3 0 -SL/50 % SA) or media with or without the RV OSU strain (1 £ 10 7 focus-forming units)were injected into the loops and maintained for 6 h. The loops treated with HMO treatments þ RV had lower RV replication, as assessed by non-structural protein-4 (NSP4) mRNA expression, than RV-treated loops alone. In conclusion, SA-containing HMO inhibited RV infectivity in vitro; however, both neutral HMO and SA with aHMO decreased NSP4 replication during acute RV infection in situ.Key words: Human milk oligosaccharides: Rotavirus: Piglets: Infection Rotaviruses (RV) are double-stranded RNA viruses of the family Reoviridae, which are the most common viral agents causing viral gastroenteritis and diarrhoea in infants and young children worldwide. Each year, approximately 1·4 billion episodes of RV gastroenteritis (RVGE) occur in children under 5 years of age in developing countries, and half a million children die (1,2) .Vaccination is the main public health intervention to prevent RV infection. Systematic reviews of vaccine effectiveness and vaccination-impact studies in industrialised countries (USA, Europe and Australia) have demonstrated an effectiveness of 85 -100 % associated with decreased hospitalisations for RVGE (3) . Vaccination-impact studies have demonstrated that the burden of RVGE has been reduced significantly since the introduction of RV vaccination (3) . However, efficacy trials in developing countries in Africa and Asia showed that vaccine efficacy was lower than that observed in other countries, typically 40 -70 % (4) . Although the efficacy of RV vaccines correlates closely with the national per capita income (5) , it is unclear why vaccination is less efficacious in developing countries (6) . This reduced vaccine efficacy coupled with the high cost and barriers to a widespread distribution of RV vaccines (7) suggest that other means for preventing RV should...

Norovirus GII.4 Antibodies in Breast Milk and Serum Samples

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A Randomized Clinical Trial Evaluating the Effects of Oligosaccharides on Transfer of Passive Immunity in Neonatal Dairy Calves

“…Colostrum and milk from cattle and other species naturally contain a variety of OS, but the biological functions of these have yet to be completely determined . Some milk OS have been shown to bind to bacterial exotoxins and pathogens including Campylobacter jejuni , pathogenic E. coli , and rotavirus . Oligosaccharides from bovine milk have been shown to have strong affinity for several enteropathogenic strains of Escherichia coli isolated from dairy calves .…”

Human Milk Oligosaccharides as Promising Antivirals

“…A number of neutral and acidic HMOs was tested against the sialic‐acid‐dependent porcine OSU strain . The synthetically produced individual HMOs, 3‐sialyllactose (3′SL) and 6‐sialyllactose (6′SL), and the complex mixture of isolated HMOs dose‐dependently inhibited the porcine rotavirus binding to the MA‐104 cells as well as they reduced overall infectivity of the strain .…”