A型口蹄疫合成肽疫苗的免疫效力评价

Evaluation of synthetic peptide vaccines againstfoot-andmouth disease type A

摘要:

摘要:【目的】研制A 型口蹄疫(foot-and-mouth disease，FMD)新型合成肽疫苗，为畜牧业减少经济损失。【方法】应用两种含有口蹄疫病毒(foot-and-mouth disease virus，FMDV)AF/72株VP1［131-159］、VP4［20-35］、3A［21-35］和3B［29-42］4个抗原表位的合成肽联合CpG寡聚脱氧核苷酸(5'-TCGCGAACGTTCGCCCG ATCGTCGGTA-3')在豚鼠上进行了免疫效力评价。【结果】2. 5μg/只的合成肽364 能保护4/5的豚鼠免受FMDV AF/72株的攻击，灭活苗组获得完全保护，其他组的保护效力仅为3/5;保护效力最高的两组的外周血CD4 + T淋巴细胞含量高达33.7%和36.6%，而其他组不超过27.7%，PBS组仅为18.1%。【结论】本研究筛选出一组免疫效力较好的口蹄疫A型合成肽疫苗，可以作为候选疫苗进行进一步评价。

Abstract:

Abstract:［Objective］We developed a synthetic vaccine against foot-and-mouth disease type A．［Methods］We studied two peptide-based vaccines containing residues 131 to 159 of VP1，20 to 35 of VP4，21 to 35 of 3A and 29 to 42 of 3B of the AF/72 strain of foot-and-mouth disease virus ( FMDV) coupled with a CpG oligodeoxynucleotide (5'-TCGCGAACGTTCGCCCGATCGTCGGTA-3') in guinea pigs． We assayed the FMDV-specific IgG level， serum neutralizing antibody titer，splenic lymphocytes proliferative capacity and peripheral blood T lymphocyte CD4-CD8 subsets distribution． ［Results］The data show that high dose did not ensure a good immunity． In our study，8% (4/5) of peptide 364-2. 5-inoculated guinea pigs (2.5 μg of peptide 364 per animal) were protected against AF/72 strain challenge，while the protection ratio from other peptide-immunized groups was lower except the inactivated vaccineinoculated group which showed a full protection．Our results also indicated that the stimulatory ability of CD4 + T lymphocyte response played a key role in evaluating effective FMDV vaccine．The highest percentage of CD4 + T lymphocyte was 36.6% appeared in inactivated vaccine-immunized guinea pigs，the second was 33. 7% in peptide 364-2. 5-vaccinated group，whereas the remaining ranged from 18.1% to 27.7%．There was no obvious relation between CD8 + T cells and anti-FMDV infection; our data showed that the CD4/CD8 ratio was not always appropriate for assessing the immune system status．［Conclusion］In general，we not only designed an effective vaccine against FMDV type A，but also discovered some useful information of humoral and cellular responses induced by foot-and-mouth disease vaccines．