Particle bombardment-mediated DNA vaccination with rotavirus VP6 induces high levels of serum rotavirus IgG but fails to protect mice against challenge.
Particle bombardment-mediated DNA vaccination with rotavirus VP6 induces high levels of serum rotavirus IgG but fails to protect mice against challenge.
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粒子轰击介导的轮状病毒 VP6 DNA 疫苗接种可诱导高水平的血清轮状病毒 IgG，但无法保护小鼠免受攻击。
作者：
Choi,AH;Knowlton,DR;McNeal,MM;Ward,RL
轮状病毒内衣壳蛋白VP 6含有保守的表位，这些表位是引发针对同一组轮状病毒内不同血清型的保护性免疫的潜在靶标。为探讨轮状病毒EDIM株VP 6单独免疫能否诱导保护性免疫，构建了含轮状病毒EDIM株VP 6基因的真核表达载体pcDNA 1/EDIM 6。克隆的基因6全长1356个核苷酸，5′端非编码区23个核苷酸，3′端非编码区139个核苷酸，编码框1194个核苷酸，编码397个氨基酸。重组VP 6在兔网织红细胞裂解物中表达，热变性的重组VP 6在SDS-凝胶中迁移，表观分子量约为43 kDa。当表达产物未热变性时，观察到对应于重组VP 6的寡聚体的另外五条多肽带。为了确定重组VP 6的免疫原性，用pcDNA 1/EDIM 6肌内或皮内注射雌性BALB/c小鼠，或使用Geniva Accell颗粒递送装置用质粒包被的金珠表皮接种。仅皮内注射和颗粒递送引起可测量的血清抗轮状病毒IgG应答，但颗粒递送后产生的应答显著更大（P< 0.001）。然而，没有一种递送方法诱导血清或粪便抗轮状病毒伊加应答，并且当用EDIM攻击时，在免疫小鼠中没有观察到针对感染的保护。因此，在该模型中，单独用VP 6进行肠胃外免疫引起大的抗轮状病毒IgG应答，但不引起针对鼠轮状病毒感染的保护。
The rotavirus inner capsid protein VP6 contains conserved epitopes that are potential targets for eliciting protective immunity against different serotypes within the same group of rotavirus. In order to determine whether VP6 alone can induce protective immunity, an expression vector pcDNA1/EDIM6 containing gene 6 of rotavirus EDIM strain was constructed and used as a vaccine in an adult mouse model. Cloned gene 6 was determined to be 1356 nucleotides long and contained a 5′ noncoding region of 23 nucleotides, a 3′ noncoding region of 139 nucleotides, and a coding frame of 1194 nucleotides for a polypeptide of 397 amino acid residues. Recombinant VP6 was expressed in rabbit reticulocyte lysate and the heat-denatured recombinant VP6 migrated in SDS-gels with an apparent molecular weight of approximately 43 kDa. Five additional polypeptide bands corresponding to oligomers of recombinant VP6 were observed when the expressed product was not heat denatured. To determine the immunogenicity of recombinant VP6, female BALB/c mice were injected intramuscularly or intradermally with pcDNA1/EDIM6, or were inoculated epidermally with plasmid-coated gold beads using the Geniva Accell particle delivery device. Only intradermal injection and particle delivery elicited measurable serum anti-rotavirus IgG responses, but responses developed following particle delivery were significantly (P< 0.001) greater. However, none of the delivery methods induced serum or stool anti-rotavirus IgA responses and, when challenged with EDIM no protection against infection was observed in the immunized mice. Therefore, parenteral immunization with VP6 alone elicited large anti-rotavirus IgG responses but did not elicit protection against murine rotavirus infection in this model.