Sero-epidemiological study of the rotavirus VP8* protein from different P genotypes in Valencia, Spain

Abstract

The aims of the present work were to determine the prevalence and titer of serum antibodies against several rotavirus VP8* proteins from different P genotypes in children and adults in Valencia, Spain; and to determine the role of the secretor status (FUT2 G428A polymorphism) in the antibody response. The VP8* protein from the P[4], P[6], P[8], P[9], P[11], P[14] and P[25] genotypes were produced in E. coli. These proteins were tested with 88 serum samples from children (n = 41, 3.5 years old in average) and from adults (n = 47, 58 years old in average) by ELISA. A subset of 55 samples were genotyped for the FUT2 G428A polymorphism and the antibody titers compared. The same subset of samples was also analysed by ELISA using whole rotavirus Wa particles (G1P[8]) as antigen. Ninety-three per cent of the samples were positive for at least one of the VP8* antigens. Differences in the IgG seroprevalence were found between children and adults for the P[4], P[8] and P[11] genotypes. Similarly, significant differences were found between adults and children in their antibody titers against the P[4], P[8], and P[11] VP8* genotypes, having the children higher antibody titers than adults. Interestingly, positive samples against rare genotypes such as P[11] (only in children), P[14] and P[25]were found. While no statistical differences in the antibody titers between secretors and non-secretors were found for any of the tested P genotypes studied, a higher statistic significant prevalence for the P[25] genotype was found in secretors compared to non-secretors. Significant differences in the antibody titers between secretors and non-secretors were found when the whole viral particles from the Wa rotavirus strain (G1P[8]) were used as the antigen.Rotaviruses are the leading etiologic agent of viral gastroenteritis in infants and young children worldwide 1 . Rotavirus contains segmented, double stranded RNA genome. The rotavirus protein VP7 makes up the outer capsid protein shell and VP4 forms the spikes that emanate through the outer capsid. VP7 is a glycoprotein that determines the G-type antigen while VP4 is a protease-sensitive protein that determines the P-type antigen 2 . The common rotavirus classification involves their genome composition and their serological reactivity, so the scientific community uses the VP7, VP4 and VP6 proteins to classify them. Rotaviruses are classified into 7 groups (A to G) based in the immunological reactivity of the VP6 (middle layer viral protein). Rotaviruses from the groups A to C have been isolated from humans but the most prevalent is the group A.The two outer capsid protein, VP7 and VP4, are used to classify rotavirus in G and P types (genotypes and/or serotypes). Nowadays we can count more than 36 different G-genotypes and 51 P-genotypes (https://rega.kuleuven.be/cev/viralmetagenomics/virus-classification/rcwg). The most prevalent genotypes in humans infections are G1P[8], G2P[4], G3P[8] and G4P [8]. More recently a classification using the eleven segments of the genome has been settled...

The Rotavirus Vaccine Landscape, an Update

“…In RV, resistance to infection appears to be genotype-dependent, is mediated mainly by histo-blood group antigens (HBGAs) [ 38 , 39 ] and could be conditioned by microbiota composition [ 40 ]. For over 30 years, sialic acid was considered the glycoside receptor of animal RVs, yet human strains were considered independent from sialic acid [ 41 ]. The recently discovered role of HBGAs as potential receptors has significantly advanced understanding of RV diversity, evolution and epidemiology.…”

“…The precursor consists of a galactose molecule (Gal) bound to an N-acetylglucosamine molecule (GlcNAc) that form a disaccharide. Depending on the bond that joins both sugars, the precursors are classified into two different groups: type I (link β-1,3) or type II (link β-1,4) [ 41 ]. Secretor status is determined by the FUT 2 gene, which encodes for galactosidase 2 alpha-fucosyltransferase (adds a fucose residue in the α-1,2 position of the Gal residue), where non-secretors lack functionality in that enzyme and are consequently unable to express the H antigen [ 41 ].…”

“…Depending on the bond that joins both sugars, the precursors are classified into two different groups: type I (link β-1,3) or type II (link β-1,4) [ 41 ]. Secretor status is determined by the FUT 2 gene, which encodes for galactosidase 2 alpha-fucosyltransferase (adds a fucose residue in the α-1,2 position of the Gal residue), where non-secretors lack functionality in that enzyme and are consequently unable to express the H antigen [ 41 ]. The other gene that is part of this system codes for FUT3 (Lewis gene), which adds another fucose residue in position α-1,3 or α-1,4 to the GlcNAc motif of the initial precursors or H (secretory state) of type I or type II [ 42 ].…”

The Role of Host Glycobiology and Gut Microbiota in Rotavirus and Norovirus Infection, an Update

“…Although some discrepancies have been found, most reports have shown that positive secretor status was strongly associated with susceptibility to P [8] and P [4] genotypes [36,41,42]. As for serological studies, higher RV-specific immunoglobulin G (IgG) titres in serum and IgA titres in saliva have been reported in secretors compared to non-secretors [43][44][45][46]. Higher anti-RV antibody titres reflects a larger number of previous infections, making it an indirect marker of susceptibility.…”

Effect of Infant and Maternal Secretor Status on Rotavirus Vaccine Take—An Overview

“…Several studies have investigated rotavirus-specific antibody titers in adults in association with secretor status [9,[35][36][37][38]. All of these studies have shown that secretors have higher serum rotavirus IgG titers, as well as higher neutralization antibody titers against the predominant strains in the study population (mostly P [8]).…”