Flow cytometry follow-up analysis of peripheral blood leukocyte subpopulations in calves experimentally infected with field isolates of Mycoplasma bovis

Abstract

Changes in peripheral blood leukocyte subpopulations were investigated in calves challenged intratracheally with three different Mycoplasma bovis isolates in Groups E1, E2, and E3. The controls received a placebo. Blood samples were collected before challenge and then at days 1 to 7, 14, 21 and 28. White blood cells (WBC), polymorphonuclear leukocytes (PMNLs), lymphocytes (LYMs), monocytes, eosinophils and basophils (mid-size cells, MID), as well as CD2+ lymphocyte subsets with CD4:CD8 ratio were also analysed. A transient increase of WBC and PMNLs in all challenged calves was observed on day 1. Increased LYM counts were observed in E1 throughout the study, whereas in E2 the LYM counts were higher only between days 14 and 28, and consistently lower in E3. The MID count had broadly comparable values for all groups. Stimulation of the CD2 + response was observed in E2 and E3 in contrast with E1 which had a lower CD2 + throughout. The CD4 + response was dominant in E1 and E2, whereas in E3 a parallel CD4 + and CD8 + stimulation was observed. The B-cell response (WC4 + ) and an increased CD4:CD8 ratio was most apparent in E1. The main host responses to M. bovis infections are a stimulation of CD4 + cells and an enhancement of the WC4 + response. Key words: Calf, Mycoplasma bovis, leukocytes, flow cytometryThe disease caused by Mycoplasma bovis in cattle is responsible for substantial economic losses to the farming industry around the world. Infection by M. bovis can cause bronchopneumonia, mastitis, arthritis, keratoconjunctivitis, otitis, meningitis, and reproductive disorders (Nicholas and Ayling, 2003). In Poland, 64.3 per cent of calves affected with bovine respiratory disease (BRD) were

Prevalence of pathogens from Mollicutes class in cattle affected by respiratory diseases and molecular characteristics of Mycoplasma bovis field strains

“…However, MLST results published by Dudek et al (7) revealed that a Polish strain (not included in this study) did not cluster with any previously described clonal complexes. Therefore, in the future, other genotyping methods should be included in order to compare genetic diversity of Polish M. bovis strains with isolates from other countries.…”

“…Due to the difficulty of effective isolation of mycoplasmas under laboratory conditions, molecular methods are considered to be the most suitable and have recently been generally recommended for diagnosis of mycoplasmal infection (28). The survey of M. bovis spread and studies on its genetic diversity were performed in different parts of the world because M. bovis is well-equipped to generate diversity, and new clones may appear (2,7,23,29).…”

Analysis of the immune response of calves to various saponin-based adjuvants for an experimental Mycoplasma bovis vaccine

“…The percentages of peripheral blood lymphocytes such as T-cell (CD2 + ), T-helper cell (CD4 + , Th), T-cytotoxic suppressor cell (CD8 + , Tc/s) and B-cell (WC4 + ) antigens were determined using a flow cytometer (Coulter Epics XL 4C, Beckman Coulter Company, USA). The expression of the CD markers was determined using primary mouse anti-bovine monoclonal antibodies and for WC4 + expression additionally by the use of rabbit anti-mouse secondary polyclonal antibody (AbD Serotec, a Bio-Rad Company) as described by Dudek et al (2015).…”

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

“…In contrast, the T-cytotoxic and B-cells were generally stimulated in the vaccinated calves throughout the study. In our previous study the same Polish M. bovis strain was used for calf challenge ( 7 ). The results of this study showed general T-cell suppression in the affected calves, especially concerning the CD8 + cell subpopulation.…”

“…The CD2 + (T-cells), CD4 + (T-helper cells), CD8 + (T-cytotoxic cells), and WC4 + (B-cells) antigens were detected by specific mono- and polyclonal antibodies (Bio-Rad Laboratories Inc.) and analysed using a flow cytometer (Coulter Epics XL 4C, Beckman Coulter Company, USA) according to the procedure described by Dudek et al . ( 7 ).…”