Differential Expression of Bovine Leucocyte Antigen Class I Chain-Related Genes 2 in preganant Dairy Cows and Neonatal Calves

摘要

Major histocompatibility complex takes the capital contribution to maternal immune responses to the semiallogenic fetus. As the member of BoLA-Ib, the machenism of class I chain-related genes 2 (MIC2) on pregnant setup and delivery, till remains to be elucidated. To evaluate the possible effect of MIC2 on pregnant establishment and delivery, neonatal ear tissues, fetal placenta, peripheral blood Polymorphonuclear Neutrophils (PMN) of dairy cow in different pregnant stages were collected to analyze MIC2 expression by quantitative RT-PCR. MIC2 on PMN in dairy cows was down regulated expressed in 1st and 2nd trimesters and recoveried back to normal level in peripartum. Moreover, MIC2 was novel upregulated expressed in neonatal ear tissues and downregulated expressed in fetal placenta. These results suggested that MIC2 lowly expressed in the 1st and 2nd trimester of pregnant cows could suppress NKG2D binding MIC2 on PMN and therefore, let embryo escape from maternal immune response. Anabiotic MIC2 expression in peripartum suggested that maternal immune to full grown foetus recover back to normal level which be in favour of delivery. In foetus, novel upregulated expression of MIC2 in tissues was favourible for foetus to escape its autoimmunity. Whereas, downregulated expression in fetal placenta let placenta decoherenced from maternal placentome which was beneficial to delivery.