鼠伤寒沙门氏菌hilD基因缺失株的免疫效果评价

Evaluation of Immunogenicity of the hilD Gene Deletion Strain of Salmonella typhimurium

为探究鼠伤寒沙门氏菌(Salmonella typhimurium)hilD基因缺失株的免疫效果,本研究利用鼠伤寒沙门氏菌亲本株S.T(pcDNA3.1)、hilD基因缺失株S.T(ΔhilD+pcDNA3.1)和回补株S.T(ΔhilD+pcDNA3.1-hilD)免疫小鼠,通过比较小鼠的血清Ig G抗体效价、血清抑菌能力、白细胞吞噬细菌能力、CD4^(+)/CD3^(+)与CD8^(+)/CD3^(+)比率、相关细胞因子(IL-4,IL-10,IFN-γ,TNF-β,MCP-1)水平、脾淋巴细胞增殖指数SI和肠粘膜s Ig A抗体水平等指标,以评价S.T(ΔhilD+pcDNA3.1)的免疫效果。结果显示,与S.T(pcDNA3.1)和S.T(ΔhilD+pcDNA3.1-hilD)相比,S.T(ΔhilD+pcDNA3.1)免疫小鼠后,除白细胞吞噬细菌能力、CD4^(+)/CD3^(+)与CD8^(+)/CD3^(+)比率优于S.T(pcDNA3.1)与S.T(ΔhilD+pcDNA3.1-hilD)外,血清IgG抗体效价、血清抑菌能力、相关细胞因子水平(IL-4,IL-10,IFN-γ,TNF-β,MCP-1)、脾淋巴细胞增殖指数SI及肠粘膜s Ig A抗体水平均显著优于S.T(pcDNA3.1)与S.T(ΔhilD+pcDNA3.1-hilD);小鼠经二次免疫后攻毒,S.T(ΔhilD+pcDNA3.1)对鼠伤寒沙门氏菌提供的免疫保护率可达100%,且小鼠各脏器损伤程度最低;对肠炎沙门氏菌提供的交叉免疫保护率也达到60%。结果表明S.T(ΔhilD+pcDNA3.1)免疫小鼠后能诱导产生良好的体液免疫、细胞免疫和黏膜免疫,在攻毒后能提供良好的免疫保护力及交叉免疫保护力。

In order to explore the immunogenicity of hilD gene deletion strain of Salmonella typhimurium,in this study,the parental strain S.T(pcDNA3.1),the hilD gene deletion strain S.T(ΔhilD+pcDNA3.1)and the supplement strain S.T(ΔhilD+pcDNA3.1-hilD)were used to immunize Kunming mice,through comparing mouse serum Ig G antibody titer,serum antibacterial ability,leukocyte phagocytic ability,CD4^(+)/CD3^(+)and CD8^(+)/CD3^(+)ratio,related cytokines(IL-4,IL-10,IFN-γ,TNF-β,MCP-1)level,splenic lymphocyte proliferation index SI and intestinal mucosal s Ig A antibody level,etc.,to evaluate the immunogenicity of S.T(ΔhilD+pcDNA3.1).The results showed that compared with ST(pcDNA3.1)and ST(ΔhilD+pcDNA3.1-hilD),in addition to leukocyte phagocytic ability,CD4^(+)/CD3^(+)and CD8^(+)/CD3^(+)ratio was better than that of ST(pcDNA3.1)and ST(ΔhilD+pcDNA3.1-hilD)after ST(ΔhilD+pcDNA3.1)immunized mice,serum Ig G antibody titer,serum antibacterial ability,related cytokine levels(IL-4,IL-10,IFN-γ,TNF-β,MCP-1),splenic lymphocyte proliferation index SI and intestinal mucosal s Ig A antibody levels were significantly better than that of ST(pcDNA3.1)and ST(ΔhilD+pcDNA3.1-hilD)after the mice were challenged after the second immunization,the immune protection rate of S.T(ΔhilD+pcDNA3.1)against Salmonella typhimurium was up to 100%,and the degree of organ damage was the lowest,and the cross-immune protection rate against Salmonella enteritis was also up to 60%.The results indicated that S.T(ΔhilD+pcDNA3.1)could induce good humoral immunity,cellular immunity and mucosal immunity,and provide good immune protection and cross immune protection after challenge.