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Abstract：
UNASSIGNED: Non-typhoidal Salmonella (NTS) generally causes self-limiting gastroenteritis. However, older adults (≥65 years) can experience more severe outcomes from NTS infection. We have previously shown that a live attenuated S. Typhimurium vaccine, CVD 1926 (I77 ΔguaBA ΔclpP ΔpipA ΔhtrA), was immunogenic in adult but not aged mice. Here we describe modification of CVD 1926 through deletion of steD, a Salmonella effector responsible for host immune escape, which we hypothesized would increase immunogenicity in aged mice.
UNASSIGNED: Mel Juso and/or mutuDC cells were infected with S. Typhimurium I77, CVD 1926, and their respective steD mutants, and the MHC-II levels were evaluated. Aged (18-month-old) C57BL/6 mice received two doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and the number of FliC-specific CD4+ T cells were determined. Lastly, aged C57BL/6 mice received three doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and then were challenged perorally with wild-type S. Typhimurium SL1344 (108 CFU). These animals were also evaluated for antibody responses.
UNASSIGNED: MHC-II induction was higher in cells treated with steD mutants, compared to their respective parental strains. Compared to PBS-vaccinated mice, CVD 1926 ΔsteD elicited significantly more FliC-specific CD4+ T cells in the Peyer\'s Patches. There were no significant differences in FliC-specific CD4+ T cells in the Peyer\'s patches or spleen of CVD 1926- versus PBS-immunized mice. CVD 1926 and CVD 1926 ΔsteD induced similar serum and fecal anti-core and O polysaccharide antibody titers after three doses. After two immunizations, the proportion of seroconverters for CVD 1926 ΔsteD was 83% (10/12) compared to 42% (5/12) for CVD 1926. Compared to PBS-immunized mice, mice immunized with CVD 1926 ΔsteD had significantly lower S. Typhimurium counts in the spleen, cecum, and small intestine upon challenge. In contrast, there were no differences in bacterial loads in the tissues of PBS-vaccinated and CVD 1926-immunized animals.
UNASSIGNED: These data suggest that the steD deletion enhanced the immunogenicity of our live attenuated S. Typhimurium vaccine. Deletion of immune evasion genes could be a potential strategy to improve the immunogenicity of live attenuated vaccines in older adults.
UNASSIGNED: Mel Juso and/or mutuDC cells were infected with S. Typhimurium I77, CVD 1926, and their respective steD mutants, and the MHC-II levels were evaluated. Aged (18-month-old) C57BL/6 mice received two doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and the number of FliC-specific CD4+ T cells were determined. Lastly, aged C57BL/6 mice received three doses of PBS, CVD 1926, or CVD 1926 ΔsteD perorally (109 CFU) and then were challenged perorally with wild-type S. Typhimurium SL1344 (108 CFU). These animals were also evaluated for antibody responses.
UNASSIGNED: MHC-II induction was higher in cells treated with steD mutants, compared to their respective parental strains. Compared to PBS-vaccinated mice, CVD 1926 ΔsteD elicited significantly more FliC-specific CD4+ T cells in the Peyer\'s Patches. There were no significant differences in FliC-specific CD4+ T cells in the Peyer\'s patches or spleen of CVD 1926- versus PBS-immunized mice. CVD 1926 and CVD 1926 ΔsteD induced similar serum and fecal anti-core and O polysaccharide antibody titers after three doses. After two immunizations, the proportion of seroconverters for CVD 1926 ΔsteD was 83% (10/12) compared to 42% (5/12) for CVD 1926. Compared to PBS-immunized mice, mice immunized with CVD 1926 ΔsteD had significantly lower S. Typhimurium counts in the spleen, cecum, and small intestine upon challenge. In contrast, there were no differences in bacterial loads in the tissues of PBS-vaccinated and CVD 1926-immunized animals.
UNASSIGNED: These data suggest that the steD deletion enhanced the immunogenicity of our live attenuated S. Typhimurium vaccine. Deletion of immune evasion genes could be a potential strategy to improve the immunogenicity of live attenuated vaccines in older adults.
摘要：
■非伤寒沙门氏菌（NTS）通常会导致自限性胃肠炎。然而,老年人(≥65岁)可经历NTS感染更严重的结局.我们以前已经证明减毒鼠伤寒沙门氏菌活疫苗，CVD1926(I77ΔguaBAΔclpPΔpipAΔhtrA)，在成年但不是老年小鼠中具有免疫原性。在这里，我们描述了通过删除steD对CVD1926的修改，一种负责宿主免疫逃逸的沙门氏菌效应，我们假设这会增加老年小鼠的免疫原性。
■MelJuso和/或mutuDC细胞感染了鼠伤寒沙门氏菌I77，CVD1926及其各自的steD突变体，并评估MHC-II水平。老年（18月龄）C57BL/6小鼠接受两剂PBS，测定经口CVD1926或CVD1926ΔsteD(109CFU)和FliC特异性CD4+T细胞的数量。最后,老年C57BL/6小鼠接受三剂PBS，经口CVD1926或CVD1926ΔsteD(109CFU),然后用野生型鼠伤寒沙门氏菌SL1344(108CFU)经口攻击。还评估了这些动物的抗体应答。
■MHC-II诱导在用steD突变体处理的细胞中更高，与它们各自的亲本菌株相比。与PBS接种的小鼠相比，CVD1926ΔsteD在Peyer's斑块中引起明显更多的FliC特异性CD4+T细胞。与PBS免疫的小鼠相比，CVD1926的Peyer斑块或脾脏中的FliC特异性CD4T细胞没有显着差异。CVD1926和CVD1926ΔsteD在三个剂量后诱导了相似的血清和粪便抗核心和O多糖抗体滴度。两次免疫后,CVD1926的血清转化器的比例ΔsteD为83%(10/12)，而CVD1926为42%(5/12)。与PBS免疫的小鼠相比，用CVD1926ΔsteD免疫的小鼠脾脏中鼠伤寒沙门氏菌计数显着降低，盲肠,和小肠在挑战。相比之下,PBS疫苗接种和CVD1926免疫动物的组织中细菌负荷没有差异.
这些数据表明steD缺失增强了我们的减毒鼠伤寒沙门氏菌活疫苗的免疫原性。删除免疫逃避基因可能是改善老年人减毒活疫苗免疫原性的潜在策略。
■MelJuso和/或mutuDC细胞感染了鼠伤寒沙门氏菌I77，CVD1926及其各自的steD突变体，并评估MHC-II水平。老年（18月龄）C57BL/6小鼠接受两剂PBS，测定经口CVD1926或CVD1926ΔsteD(109CFU)和FliC特异性CD4+T细胞的数量。最后,老年C57BL/6小鼠接受三剂PBS，经口CVD1926或CVD1926ΔsteD(109CFU),然后用野生型鼠伤寒沙门氏菌SL1344(108CFU)经口攻击。还评估了这些动物的抗体应答。
■MHC-II诱导在用steD突变体处理的细胞中更高，与它们各自的亲本菌株相比。与PBS接种的小鼠相比，CVD1926ΔsteD在Peyer's斑块中引起明显更多的FliC特异性CD4+T细胞。与PBS免疫的小鼠相比，CVD1926的Peyer斑块或脾脏中的FliC特异性CD4T细胞没有显着差异。CVD1926和CVD1926ΔsteD在三个剂量后诱导了相似的血清和粪便抗核心和O多糖抗体滴度。两次免疫后,CVD1926的血清转化器的比例ΔsteD为83%(10/12)，而CVD1926为42%(5/12)。与PBS免疫的小鼠相比，用CVD1926ΔsteD免疫的小鼠脾脏中鼠伤寒沙门氏菌计数显着降低，盲肠,和小肠在挑战。相比之下,PBS疫苗接种和CVD1926免疫动物的组织中细菌负荷没有差异.
这些数据表明steD缺失增强了我们的减毒鼠伤寒沙门氏菌活疫苗的免疫原性。删除免疫逃避基因可能是改善老年人减毒活疫苗免疫原性的潜在策略。
