含两种不同肽段的血吸虫多抗原肽疫苗的合成与生物活性

目的:合成由曼氏血吸虫28 Ku GST抗原肽段26-43(P26)、141-153(P₁₄₁)和日本血吸虫26 Ku GST 抗原肽段187-202(J₁₈₇)中的两种不同肽段组成的血吸虫多抗原肽疫苗,通过活性试验考察其抗原性、免疫原性及对实验动物的保护性免疫效果。方法:用Boc 化学和Fmoc 化学相结合的策略合成含两种不同抗原肽的多抗原肽疫苗,产物经斑点酶联免疫吸附试验测定抗原性,在无免疫佐剂存在下接种小鼠,ELISA 试验检测血清抗体,并用日本血吸虫尾蚴攻击感染,6 周后剖杀小鼠进行体内成虫和肝内虫卵计数。结果:合成多抗原肽能不同程度地与感染日本血吸虫的病人或病兔血清结合,并能诱导昆明小鼠产生对日本血吸虫天然抗原特异的抗体应答。接种(P26)2(J187)2 MAP、(P26)2(P141)2 MAP和(P26)4(P141)4 MAP的昆明小鼠,与对照组比较成虫检获数分别减少40-1 % ,61-1 % 和34-4% ; 每克肝脏虫卵数分别减少48-4% ,67-1 % 和47-4% 。结论:含两种不同抗原肽的合成血吸虫多抗原肽疫苗能够诱导昆明小鼠产生显著的抗日本血吸虫感染的保护性免疫力,选择更好的肽段结合在一起将有可能获得免疫保护作用更强的多抗原肽疫苗分子。

SYNTHESIS AND BIOACTIVITIES OF MULTIPLE ANTIGENIC PEPTIDE VACCINES CONTAINING TWO DIFFERENT SCHISTOSOMAL ANTIGENIC PEPTIDES

AIM: To synthesize the multiple antigenic peptide (MAP) vaccines consisting of two different schistosomal antigenic peptides, 26 43(AAGVDYEDERISFQDWPK,P 26 ) and 141 153(ESLKGSTGKLAVG,P 141 ) derived from Sm28GST and 187 202(PQIDKYLKSSKYIAWP, J 187 ) derived from Sj26GST, and to examine their antigenicities, immunogenicities and protective effects on experimental animals. METHODS: The multiple antigenic peptide vaccines consisting of two different antigenic peptides have been synthesized using both Boc and Fmoc chemistry and their antigenicities have been tested with dot ELISA. Mice were bled to test antibody responses after vaccination with the synthetic MAPs, and were infected with Schistosoma japonicum cercariae. Six weeks after infection, the mice were killed to recover the adult worms and the eggs in liver. RESULTS: The synthetic MAPs could be bound to a certain extent by both patient and infected rabbit sera, and were able to elicit antibody responses specific to natural antigen of Schistosoma japonicum . Furthermore, immunization with (P 26 ) 2(J 187 ) 2 MAP, (P 26 ) 2(P 141 ) 2 MAP and (P 26 ) 4(P 141 ) 4 MAP in Kunming mice reduced, respectively, the worm burden by 40 1%, 61 1% and 34 4%, and reduced the liver eggs by 48 4%, 67 1% and 47 4%. CONCLUSION: More effective vaccines against schistosomiasis may be obtained by combination of suitable antigenic peptides into a MAP molecule.