Kinetics of Immune Cells and Neutralizing Antibody Titres Against Viral Pathogens of Bovine Respiratory Disease

Choden, Tshering

Kinetics of Immune Cells and Neutralizing Antibody Titres Against Viral Pathogens of Bovine Respiratory Disease

dc.contributor.advisor	van der Meer, Franciscus Johannes
dc.contributor.author	Choden, Tshering
dc.contributor.committeemember	Orsel, Karsina
dc.contributor.committeemember	Van Marle, Guido
dc.date	2024-05
dc.date.accessioned	2024-01-19T21:33:06Z
dc.date.available	2024-01-19T21:33:06Z
dc.date.issued	2024-01-19
dc.description.abstract	Bovine Respiratory Disease (BRD) arises from complex interactions between viral and bacterial pathogens, environmental stressors, and host factors. BRD significantly impact feedlots due to its high prevalence, economic impact, and animal welfare concerns. Therefore, implementing an effective preventive management strategy, such as preconditioning (PC) aims to reduce the incidence and health impact of BRD in feedlots compared to conventional auction-derived practice. To measure and compare the health impact and effectiveness of this strategy, we evaluated the proportion of immune cells (cell-mediated and humoral) and neutralising antibodies (NAb) using the flow cytometry technique and virus neutralisation assay, respectively. Peripheral blood mononuclear cells (n=8) and serum (n=20) samples from preconditioned (PC) and auction-derived (AD) cattle were evaluated at three different time points in the feedlot (day 0, day 20, and day 40) to determine the proportion of immune cells (CD21+ B cells, CD4+ Th cells, CD3+ CTLs, and WC1+ γδ T cells) and to determine the NAb titres (against BHV 1, BVDV, BRSV and BPIV 3). We observed a high B cell response, and high and persistent NAb titres against BRD viral pathogens in PC cattle during the first 40 days in the feedlot compared to the AD group. Furthermore, most of the lymphocytes among the CD3+ T cells were WC1+ γδ expressing cells, with a smaller proportion of CD4+ expressing T-helper and CD8+ expressing cytotoxic T-lymphocytes, however, the CD4+ Th cells showed major fluctuations in their proportions within the PBMCs. In conclusion, the result provided us with a strong understanding of the immune response in PC calves, particularly the humoral immunity, and specifically the number of NAbs induced following preconditioning. This will help with the prediction of BRD in young calves during their first 40 days in a feedlot, and to evaluate the efficacy of vaccination strategies in preconditioning programs.
dc.identifier.citation	Choden, T. (2024). Kinetics of immune cells and neutralizing antibody titres against viral pathogens of Bovine Respiratory Disease (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca.
dc.identifier.uri	https://hdl.handle.net/1880/118016
dc.identifier.uri	https://doi.org/10.11575/PRISM/42860
dc.language.iso	en
dc.publisher.faculty	Graduate Studies
dc.publisher.institution	University of Calgary
dc.rights	University of Calgary graduate students retain copyright ownership and moral rights for their thesis. You may use this material in any way that is permitted by the Copyright Act or through licensing that has been assigned to the document. For uses that are not allowable under copyright legislation or licensing, you are required to seek permission.
dc.subject	Bovine Respiratory Disease
dc.subject	Preconditioning
dc.subject	Feedlot
dc.subject	Humoral Immune Response
dc.subject	Cell-Mediated Immune Response
dc.subject	Neutralising Antibodies
dc.subject.classification	Veterinary Science
dc.title	Kinetics of Immune Cells and Neutralizing Antibody Titres Against Viral Pathogens of Bovine Respiratory Disease
dc.type	master thesis
thesis.degree.discipline	Veterinary Medical Sciences
thesis.degree.grantor	University of Calgary
thesis.degree.name	Master of Science (MSc)
ucalgary.thesis.accesssetbystudent	I do not require a thesis withhold – my thesis will have open access and can be viewed and downloaded publicly as soon as possible.