C-X-C chemokine receptor type 4 and cytokine expressions in cows of a dairy herd with high prevalence of calves persistently infected with bovine viral diarrhea virus.

Animals persistently infected (PI) with bovine viral diarrhea virus (BVDV) play an important role in the spread of BVDV. Alteration of maternal C-X-C chemokine receptor type 4 (CXCR4) expression has been suspected as closely concerned with the production of PI calves. It is not clear what the influence of CXCR4 response to the prevalence of PI calves. We have previously reported a dairy herd with high prevalence of PI calves within a short period having a single origin of infection. CXCR4 and cytokine expressions in cows of this herd were investigated. There were no significant differences in CXCR4 and cytokine expressions between the dams of PI calves and the dams of non PI calves in the herd. In the comparison among the herds, CXCR4 expressions in the PI producing herds were significantly lower than the BVDV-free herd. Moreover, CXCR4 expressions in the high prevalence herd and the low prevalence herd were similar. These findings among herds corresponded with the previously reported experimental production of persistent infection with BVDV in cows. Based on the cytokine profile of these herds, IL-10 was significantly higher in the high prevalence herd and the BVDV-free herd. The combination of low expression of CXCR4 and high expression of IL-10 might be closely concerned with some bias for the production of PI calves.