Quantitation of transforming growth factor-β in plasma and pulmonary epithelial lining fluid of sheep experimentally infected with maedi-visna virus

A model of experimental infection with EV1, a lytic British isolate of maed-visna virus (MVV), was developed. Ten Texel sheep were allocated to two groups and inoculated by the respiratory route with different inocula. Six of the animals received 107.2 TCID50 (tissue culture infective dose) of EV1 strain, while four sheep were sham-inoculated with identically prepared virus-free buffer solution. Experimental infection was followed for 8 weeks post-inoculation (PI), with development of precipitating antibodies to MVV developed in the MVV-inoculated animals during the first 4 weeks PI. Transforming growth factor-β (TGF-β) levels, in both bronchoalveolar lavage fluid supernatant and plasma samples, were measured. Concentrations of pulmonary epithelial lining fluid (PELF) TGF-β were calculated. TGF-β concentrations in PELF were approximately 165-fold higher than in plasma. No significant differences in the concentrations of plasma or PELF TGF-β, either within or between groups, were observed.