Résumé
By means of genetic cloning and recombinant techniques, full genome cDNA sequences of rotavirus strain TB-Chen were isolated from an infantile hospitalized with acute gastroenteritis. Nucleotide sequences analyses showed that the full genome of strain TB-Chen contains 18613 nucleotides, encoding 5791 amino acids. Genotyping results showed that the strain TB-Chen belongs to genotype G2P[4]/NSp4[A]. This is the first report on a full genome of Group A rotavirus in China, and has important significance for deep understanding structure and functions of rotaviruses and developing rotavirus vaccines.
Résumé
<p><b>OBJECTIVE</b>To evaluate in vivo immunological protective efficacy and safety of expressed recombinant rotavirus epitopes in mice.</p><p><b>METHODS</b>Using the Flock House virus capsid protein as a vector, three epitopes derived from rotavirus Vp4 amino acid 223-242 [rotavirus epitope A, (REA)], 243-262 [rotavirus epitope B, (REB)], and 234-251 [rotavirus epitope C, (REC)] were genetically engineered on the surface of the vector protein and expressed in pET-3 (E. coli BL21 [DE3]) system into multiple epitopes, REABC, which comprises REA, REB, and REC. Kunming strain mice were inoculated with the recombinant epitopes REABC, and then challenged perorally by cell culture-adapted rotavirus Wa (type G1P1A) and SA11 (type G3P2). Infection syndrome was observed, and virus antigen in stools of mice and serum neutralizing antibody activities were determined and analyzed.</p><p><b>RESULTS</b>The recombinant epitopes REABC significantly induced rotavirus specific neutralyzing antibodies against WA and SA11, reduced virus reproduction, elicitted immune memory in inoculated mice, and protected inoculated mice from challenge by WA or SA11 (P<0.001).</p><p><b>CONCLUSION</b>The recombinant epitopes have high immunological protective efficacy and mild side effects in mice. It may be used as an epitope-based vaccine candidate in human.</p>