摘要
目的鉴定三种LPS模拟位合成肽的抗原性、诱导抗LPS抗体的产生及对细菌攻击的保护性。方法三种LPS模拟位合成肽与载体BSA交联后,ELISA测定其与多种抗LPS单、多克隆抗体的结合活性;合成肽与蓝载体交联物免疫Balb/c小鼠,观察其诱发小鼠体内抗LPS抗体产生的规律及血清抗LPS抗体效价;鉴定针对细菌感染的保护性效应。结果三种合成肽均能与抗鼠伤寒和大肠杆菌LPS抗体结合;用合成肽-蓝载体交联物免疫动物可诱发小鼠体内针对两种LPS的抗体反应,并对细菌攻击的免疫动物具不同程度的保护性作用,以合成肽13a,13b及12W与蓝载体交联物免疫的小鼠在鼠伤寒沙门氏菌攻击后存活时间分别为(6.5±0.77),(9.5±1.38)及(9.3±0.75)d,而PBS/蓝载体对照组存活时间为5d。结论本研究所采用的3种LPS表位模拟肽作为疫苗免疫小鼠能够产生针对细菌攻击的保护性效应,提示此3种表位模拟肽作为LPS交叉保护性疫苗候选的可行性与可靠性。
Objective To characterize three poptide mimics of lipopolysaccharide （LPS） epitopes which induce the humoral immune response to LPS and the protective immunity against S. typhi bacterium. Methods The three poptide mimics of LPS epitopes were synthesized according to sequences of phage clones screened from phage display poptide library using anti-LPS antibody as target. Peptide mimics was conjugated to Blue Carrier （BC） as vaccine. Balb/c mice were immunized with the poptide-BC, and then challenged with Gram-negative bacteria. Anti-LPS antibodies in poptide-BC-immunized mice were detected by ELISA using poptide-BSA as coating antigen. Survival days of mice were observed. Results Spocific antibodies against S. typhi-LPS7261 and E. coli-LPS 2630 were elicited in mice immunized with poptide 13a-, poptide 13b-, and 12w-BC conjugations, and could be boosted by inactive or live bacteria. After challenge with S. typhi, the survival time of mice immunized with poptide 13a-, poptide 13b- and 12w-BC conjugations were （6.5 ± 0.77）, （9.5 ± 1.38）, and （9.3 ± 0.75） days, respectively. While the survival time of mice immunized with BC was 5 days. Conclusion These results suggest that these three poptides can mimic the antigenicity of LPS epitopes and can induce secondary antibody response, like thymus-dependent antigens. These poptide mimics could be a new vaccine candidate of LPS.
出处
《免疫学杂志》
CAS
CSCD
北大核心
2007年第2期117-120,共4页
Immunological Journal
基金
国家自然科学基金资助项目(30471550)
关键词
脂多糖
表位模拟肽
保护性免疫
Lipopolysaccharide
Peptide mimics
Protective immunity
