@article{oai:iwate-u.repo.nii.ac.jp:00009362,
 author = {青木, 美樹子 and 丹羽, 友一郎 and 小松, 司 and 岡田, 啓司 and 安田, 準 and 板垣, 匡},
 issue = {1},
 journal = {産業動物臨床医学雑誌},
 month = {Jun},
 note = {Cryptosporidium parvumは生後間もない子牛に感染し下痢を引き起こす消化管内寄生原虫である．本研究ではC. parvumの感染制御において，あらかじめ大腸菌ワクチンを接種した母牛の初乳を介した新生子牛への免疫賦与が効果を持つか否かを検討した．まず，C. parvumが常在する農家の妊娠牛に，免疫を賦活する目的で大腸菌ワクチンを投与したところ，末梢血中のCD4+T細胞およびCD8+T細胞の増加がみられ，さらに分娩後の初乳ではCD4+T細胞，CD8+T細胞あるいはγδT細胞の割合が増加した．その初乳を給与された子牛では末梢血中のそれらのT細胞サブセットが増加する傾向がみられたが，これらの新生子牛の糞便からは対照群と同様にC. parvumオーシストが検出され，その排出数や下痢の程度，下痢の発現時期にもほとんど差異がみとめられなかった．牛におけるC. parvum感染防御においてCD4+T細胞およびCD8+T細胞がいずれも重要であるとされているが，今回の研究で大腸菌ワクチン投与によって誘導される各リンパ球サブセットをはじめとする種々の免疫賦活物質を初乳を介して新生子牛に賦与してもC. parvum感染防御効果は得られなかった．今後さらにC. parvum特異的免疫の移入を含むその他の免疫賦活法を検討していく必要がある．, Cryptosporidium parvum is an enteric protozoan that infects neonatal calves and causes severe diarrhea. We examined whether colostrum from E. coli vaccinated dams would provide better protection against C. parvum in neonatal calves. Pregnant Holstein cows kept at a C. parvumpositive
farm were vaccinated against E. coli during the dry period. The number of CD4+ cells and CD8+ cells in the peripheral blood was higher in the vaccinated cows after parturition compared to
those in non-vaccinated cows. The colostrum from these vaccinated cows contained higher percentages
of CD4+, CD8+, and γδT cells compared to that from non-vaccinated cows. The calves fed the colostrum from vaccinated dams showed increased numbers of T cell subsets in the peripheral blood compared to calves fed the colostrum from non-vaccinated dams. However, the number of C. parvum oocyst detected in the feces, the severity of diarrhea and the timing of onset of diarrhea were similar for both groups of calves. Although CD4+ and CD8+ T cells are very important immune cells to protect calves from C. parvum infection, the colostrum from the E. coli vaccinated dams containing higher numbers of these T cells did not improve protection against C. parvum in calves. Further studies, including those focusing on C. parvum-specific immune protection, are needed to provide better immunity to calves.},
 pages = {7--13},
 title = {大腸菌ワクチン投与後のホルスタイン母牛の初乳を給与された新生子牛におけるリンパ球動態とクリプトスポリジウム感染防御効果},
 volume = {2},
 year = {2011}
}