Background: Rotaviruses are a major cause of pediatric gastroenteritis. The rotavirus P[6] genotype is the most prevalent genotype isolated from Korean neonates but has rarely been reported in other countries. Histo-blood group antigen (HBGA) is known to play an important role in rotavirus infection. We investigated the relationship between rotavirus genotype and HBGA-Lewis blood type in Korean children and explored the reasons for the predominance of rotavirus P[6] strain in Korean neonates.
Methods: Blood and stool samples were collected from 16 rotavirus-infected patients. Rotavirus G (VP7) and P (VP4) genotyping was performed using reverse transcription-PCR and sequencing. Lewis antigen phenotypes (Lea/Leb) were tested, and HBGA-Lewis genotype was determined by sequencing the secretor (FUT2) and Lewis (FUT3) genes. Deduced amino acid sequences and three-dimensional structures of the VP8* portion of the rotavirus VP4 protein were analyzed.
Results: All P[6] rotaviruses were isolated from neonates under one month of age, who were negative or weakly positive for the Leb antigen. However, 10 of the 11 non-P[6] rotaviruses were isolated from older children who were Leb antigen-positive. The VP8* amino acid sequences differed among P[6], P[4], and P[8] genotypes. Korean P[6] strains showed a unique VP8* sequence with amino acid substitutions, including Y169>L169, which differed from the sequences of P[6] strains from other countries.
Conclusions: The predominance of the rotavirus P[6] genotype in Korean neonates may be related to the interaction between HBGA-Lewis antigen and the VP8* portion of the VP4 protein, and this information will be helpful in future neonatal vaccine development.
Keywords: Genotype; Histo-blood group antigen; Korean; Lewis; Neonate; Rotavirus; VP4 protein.