Animal Reproduction and Biotechnology Laboratory, Department of Biomedical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO 80523, USA.
Am J Reprod Immunol. 2010 Oct;64(4):295-306. doi: 10.1111/j.1600-0897.2010.00904.x. Epub 2010 Jul 29.
Infection of naïve pregnant cows with non-cytopathic (ncp) bovine viral diarrhea virus (BVDV) results in transplacental infection of the fetus. Infection of the pregnant cow with ncp BVDV late in gestation (after day 150) results in transient infection (TI), as both the dam and fetus can mount an immune response to the virus. In contrast, if the fetus is infected with ncp BVDV early in gestation (before day 150), the fetal immune system is undeveloped and unable to recognize the virus as foreign. This results in induction of immune tolerance to the infecting BVDV strain and persistent infection (PI).
Infection of naïve pregnant heifers with ncp BVDV2 on day 75 was hypothesized to induce differential gene expression in white blood cells of the dams and their fetuses, adversely affecting development and antiviral immune responses in PI fetuses.
Gene expression differed in maternal blood cells in the presence of PI versus uninfected fetuses. PI adversely affected fetal development and antiviral responses, despite protective immune responses in the dam.
Fetal PI with BVDV alters maternal immune function, compromises fetal growth and immune responses, and results in expression of maternal blood biomarkers that can be used to identify cows carrying PI fetuses.
未感染过的怀孕奶牛感染非致细胞病变（ncp）牛病毒性腹泻病毒（BVDV）会导致胎儿经胎盘感染。妊娠晚期（150 日龄后）感染 ncp BVDV 的怀孕奶牛会发生短暂感染（TI），因为母体和胎儿都可以对病毒产生免疫反应。相比之下，如果胎儿在妊娠早期（150 日龄前）感染 ncp BVDV，胎儿的免疫系统尚未发育，无法将病毒识别为外来物。这会导致对感染的 BVDV 株产生免疫耐受和持续性感染（PI）。
假设在第 75 天用 ncp BVDV2 感染未感染的怀孕小母牛会导致母体白细胞和胎儿中的差异基因表达，从而对 PI 胎儿的发育和抗病毒免疫反应产生不利影响。
PI 组与未感染组相比，母血细胞中的基因表达存在差异。尽管母体存在保护性免疫反应，但 PI 仍会对胎儿的发育和抗病毒反应产生不利影响。
BVDV 的胎儿 PI 会改变母体的免疫功能，损害胎儿的生长和免疫反应，并导致可用于识别携带 PI 胎儿的母体血液生物标志物的表达。
