T- and B-cell response analysis following calf immunisation with experimental Mycoplasma bovis vaccine containing saponin and lysozyme dimer

Abstract

Abstract Introduction: Mycoplasma bovis is a well-known cause of various disorders in cattle, such as pneumonia, arthritis, mastitis kerato-conjunctivitis, pharyngitis, laryngitis, otitis media, meningitis, and reproductive disorders. There are no commercial vaccines against M. bovis in Europe, therefore, experimental ones are still under investigation. The aim of this study was to evaluate the effect of experimental M. bovis vaccine, containing the Polish field M. bovis strain as well as saponin and lysozyme dimer adjuvants, on the T- and B-cell response in calves. Material and Methods: The study was carried out on 12 calves divided into two equal groups: experimental and control. The experimental group was subcutaneously injected with the vaccine composed of the field M. bovis strain as well as saponin and lysozyme dimer as adjuvants, whereas the control one received phosphate buffered saline (PBS). The blood samples were collected prior to the study (day 0), then in 24 h intervals up to day 7 and then each 7 days until day 84 post immunisation. The T- and B-cell response as CD2+ (T-cells), CD4+ (T-helper cells), CD8+ (T-cytotoxic cells), and WC4+ (B-cells) markers was analysed using flow cytometry. Results: In response to the immunisation, the general stimulation of T-cell was observed, the most seen in an increase in CD8+ subpopulation. Similarly, a visible rise in the percentage of WC4+ cells was registered in the vaccinated calves when compared to the control animals. Conclusion: This study demonstrated that the novel experimental M. bovis vaccine containing saponin and lysozyme dimer effectively stimulated the cell-mediated immunity in the calves.