Plasma levels of TNF-α, IFN-γ, IL-4 and IL-10 during a course of experimental contagious bovine pleuropneumonia

Plasma cytokine concentrations varied between animals in each group. Depletion of CD4+ T cells did not induce significant changes in plasma levels of TNF-α, IL-4, and IL-10, suggesting a minor role of CD4+ T cells in regulation or production of the three cytokines during the time window of depletion (1-2 weeks post depletion). Unexpectedly, the IFN-γ concentrations were slightly, but statistically significantly higher in the depleted group (p < 0.05) between week three and four post infection. Three CD4+ T cell-depleted animals that experienced severe disease, had high levels of TNF-α and IFN-γ. Only one severely diseased non-depleted animal showed a high serum concentration of IL-4 post infection.Comparison of most severely diseased animals, which had to be euthanized prior to the expected date, versus less severe diseased animals, irrespective of the depletion status, suggested that high TNF-α levels are correlated with more severe pathology in concomitance with high IFN-γ levels.Contagious bovine pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides, is characterized by a severe fibrinous exudative pleuropneumonia. CBPP causes decreased productivity and direct losses of cattle, and on CBPP affected countries rigorous limitation to international trade are imposed in accordance with World Organization of Animal Health (OIE) regulation. The disease has been eradicated in Europe, Asia and America through the application of restrictions to the movement of cattle, as well as test and slaughter policies combined with compensation for livestock keepers. Such policies are difficult to apply in most African countries because of pastoralism, lack of economical resources, and fragmented veterinary services.The current live vaccine, based on the attenuated strain T1/44, confers limited efficacy although it has been reported to have a degree of pathogenicity [1,2]. Annual revaccinations are necessary to confer a sufficient level of protection for the cattle pop