Bovine neonatal pancytopenia - Comparative proteomic characterization of two BVD vaccines and the producer cell surface proteome (MDBK)

Abstract

BackgroundBovine neonatal pancytopenia (BNP) is a disease syndrome in newborn calves of up to four weeks of age, first observed in southern Germany in 2006. By now, cases have been reported in several countries around the globe. Many affected calves die within days due to multiple haemorrhages, thrombocytopenia, leukocytopenia and bone marrow depletion. A certain vaccine directed against Bovine Virus Diarrhoea Virus (BVDV) was recently shown to be associated with BNP pathogenesis. Immunized cows develop alloantibodies that are transferred to newborn calves via colostrum intake. In order to further elucidate BNP pathogenesis, the purpose of this study was to characterize and compare the protein composition of the associated vaccine to another vaccine directed against BVDV not related to BNP and the cell surface proteome of MDBK (Madin-Darby Bovine Kidney) cells, the cell line used for production of the associated vaccine.ResultsBy SDS-PAGE and mass spectrometry, we were able to detect several coagulation-related and immune modulatory proteins, as well as cellular and serum derived molecules being shared between the associated vaccine and MDBK cells. Furthermore, the number of proteins identified in the BNP related vaccine was almost as high as the number of surface proteins detected on MDBK cells and exceeded the amount of proteins identified in the non-BNP related vaccine over 3.5 fold. The great amount of shared cellular and serum derived proteins confirm that the BNP associated vaccine contained many molecules originating from MDBK cells and vaccine production.ConclusionsThe respective vaccine was not purified enough to prevent the development of alloantibodies. To narrow down possible candidate proteins, those most likely to represent a trigger for BNP pathogenesis are presented in this study, giving a fundament for further analysis in future research.

Calf-Level Factors Associated with Bovine Neonatal Pancytopenia – A Multi-Country Case-Control Study

“…Bridger et al [24] showed that maternal alloantibodies to surface antigens of neonatal leucocytes are transferred via colostrum from BNP dams to neonatal calves, and higher antibody titres in the dam led to more severe clinical signs in the calf. Various proteins found in both PregSure vaccine and the cell line used to produce the vaccine have been implicated as possible alloantigen candidates [21][22][23]25]. Bell et al [26] suggest that feeding BNP colostrum from multiple cows increases the likelihood that the colostrum will contain antibodies that will react with most calf allotypes, which fits with our finding that calves from unvaccinated dams were at increased risk of BNP if they were fed colostrum from other cows.…”

“…We did not identify any other important calf or management-related risk factors. Research into BNP pathogenesis is on-going with a prevailing hypothesis that it is a neonate-maternal incompatibility phenomenon related to PregSure-induced maternal alloantibodies against bovine cell surface molecules due to bioprocess-related impurities from the cell line used for virus propagation [20][21][22]. Bastian et al [20] showed that sera of dams that had previously had a BNP calf contained alloantibodies that bound to bovine leucocytes, and Foucras et al [23] reproduced BNP in healthy calves by transferring serum antibodies from PregSure-vaccinated dams.…”

The risks of using allogeneic cell lines for vaccine production: the example of Bovine Neonatal Pancytopenia

“…To manufacture this vaccine, BVD virus is cultured in Madin-Darby bovine kidney (MDBK) cells [30] and, following purification, combined with a novel proprietary adjuvant (Procison-A TM ; a micro-fluidized oil-in-water adjuvant composed of Quil-A, Cholesterol, mineral oil [31]). High levels of residual bovine proteins have been detected in Pregsure© [8,9,32] and alloantibodies from BNP cows have been shown to recognize MDBK cells [8,9,12,19]. Furthermore, experimental immunization of calves with Pregsure© confirmed that vaccination induces alloantibodies that bind MDBK cells and leukocytes [10,19].…”

Impact of three inactivated bovine viral diarrhoea virus vaccines on bulk milk p80 (NS3) ELISA test results in dairy herds

“…The elevated antibody reactivity against whole BVDV observed with the PregSure BVD vaccine is possibly due to increased immunogenicity associated with the specific adjuvant used in this vaccine (Demasius et al, 2013). The PregSure BVD vaccine has recently been withdrawn, due to links with neonatal pancytopenia in calves (Deutskens et al, 2011;Euler et al, 2013).…”