Inhibition of Rotavirus Infectivity by a Neoglycolipid Receptor Mimetic

Abstract

Group A rotaviruses are a major cause of diarrhea in the young of many mammalian species. In rotavirus infected piglets mortality can be as high as 60%. Previous research in this laboratory has identified a porcine intestinal GM3 ganglioside receptor that is required for sialic acid-dependent rotavirus recognition of host cells. In addition, we previously demonstrated exogenously added GM3 can competitively inhibit porcine rotavirus binding and infectivity of host cells in vitro. Sialyllactose, the carbohydrate moiety of GM3, is approximately 3 orders of magnitude less effective than GM3 at inhibiting rotavirus binding to cells. Furthermore, production of therapeutic quantities of GM3 ganglioside for use as an oral carbomimetic in swine is cost prohibitive. In an effort to circumvent these problems, a sialyllactose-containing neoglycolipid was synthesized and evaluated for its ability to inhibit rotavirus binding and infectivity of host cells. Sialyllactose was coupled to dipalmitoylphosphatidylethanolamine (PE) by reductive amination and the product (SLPE) purified by HPLC. Characterization of the product showed a single primulin (lipid) and resorcinol (sialic acid) positive band by thin layer chromatography and quantification of phosphate and sialic acid yielded a 1:1 molar ratio. Mass spectroscopy confirmed a molecular weight coinciding with SLPE. Concentration-dependent binding of rotavirus to SLPE was demonstrated using a thin-layer overlay assay. Using concentrations comparable to GM3, SLPE was also shown to inhibit rotavirus binding to host cells by 80%. Furthermore, SLPE was shown to decrease rotavirus infection of host cells by over 90%. Finally, preliminary results of in vivo animal challenge studies using newborn piglets in their natural environment, demonstrated SLPE afforded complete protection from rotavirus disease. The efficacy of SLPE in inhibiting rotavirus binding and infection in vitro and in vivo, coupled with its relatively low-cost, large-scale production capabilities make SLPE a promising candidate for further exploration as a possible prophylactic or therapeutic nutriceutical for combating rotavirus disease in animals. Most importantly, the results presented here provide proof of concept that the nutriceutical approach of providing natural or synthetic dietary receptor mimetics for protection against gastrointestinal virus infectious disease in all species is plausible.

Human milk oligosaccharides inhibit rotavirus infectivityin vitroand in acutely infected piglets

“…These results are in agreement with previous studies showing that the infectivity of SA-dependent strains of RV was reduced in the presence of SA-containing compounds ( 31 , 32 ) . Bergner et al ( 33 ) reported that a sialyllactose-containing neoglycolipid reduced RV OSU strain binding to MA-104 cells and in newborn piglets. Similarly, sialyloligosaccharides isolated from egg yolk hindered the infectivity of a SA-dependent strain of RV isolated from simians (SA-11), both in vitro and in vivo ( 34 ) .…”

Microbial composition and in vitro fermentation patterns of human milk oligosaccharides and prebiotics differ between formula‐fed and sow‐reared piglets

“…HMO are resistant to host hydrolases, and .90% of HMO are undigested and arrive intact in the large intestine (5). HMO have been shown to modulate proliferation, differentiation, and apoptosis of intestinal cells in vitro (6,7) and act as decoys to prevent adherence of pathogens to host epithelial cells (8,9). Another contribution of HMO to intestinal health is in its prebiotic effect on infant gut microbiota.…”

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 .…”

“…17,35-41 Some milk OS have been shown to bind to bacterial exotoxins and pathogens including Campylobacter jejuni, pathogenic E. coli, and rotavirus. 39,[42][43][44][45][46] Oligosaccharides from bovine milk have been shown to have strong affinity for several enteropathogenic strains of Escherichia coli isolated from dairy calves. 43 These findings have led some to hypothesize that mammarysecreted OS are a component of lactogenic immunity and function to help protect the neonate from pathogens and bacterial translocation while the gut is open.…”