Submitted to: Journal of Animal Science Supplement
Publication Type: Proceedings
Publication Acceptance Date: 3/1/2013
Publication Date: 7/8/2013
Citation: Falkenberg, S.M., Ridpath, J.F., Bauermann, F.V. 2013. Circulating immune cell subpopulations in pestivirus persistently infected calves and non-infected calves varying in immune status [Abstract]. Journal of Animal Science Supplement. American Society of Animal Science Meeting, July 8-12, 2013,Indianapolis, Indiana. 91:649. Interpretive Summary:
Technical Abstract: The circulating immune cell subpopulations in cattle representing varying stages of immune status categorized as; colostrum deprived (CD), receiving colostrum (COL), colostrum plus vaccination (VAC) and persistently infected with a pestivirus (PI) were compared. The PI calves were infected with a HoBi-like virus, which is a member of the Pestivirus genus and similar to bovine viral diarrhea virus. All calves in the PI group tested positive for viral protein using a commercial ELISA test, all other calves tested negative. Calves in the CD and COL group averaged 60 days of age (DOA), VAC averaged 150 DOA and PI 24 DOA. Blood samples were collected and analyzed by flow cytometry within 2 h after collection. The leukocyte (LEUK) and granulocyte populations were identified using forward and side scatter plots. Primary antibodies were used for identification of the cell markers CD4, CD8, B cell, Gamma-delta (GDTCR) and CD14. Comparisons between immune status groups for total circulating cell populations (cell/mL) revealed differences (p<0.0001) for total LEUK, CD8, B cell, GDTCR and CD14 with the PI group having the lowest total numbers of cells in circulation. While no differences were observed for the absolute number of circulating CD4 among the groups, the proportion of CD4 within total LEUK populations was significantly different (p<0.0001). Significant differences (p<0.002) were also observed in the CD8, B cell, GDTCR and CD14 populations. The PI group had a greater proportion of CD4 cells and the VAC group had the greatest proportion of CD8, while the COL group had the greatest B cell, GDTCR and CD14. No differences (p>0.05) in the absolute number or proportion of circulating cells identified as granulocytes. These results suggest immune cell populations vary between immune status groups with the greatest differences observed for the PI calves. Defining differences associated with different immune statuses could provide insight into immune function.