Bovine CD4(+) T-cell lines reactive with soluble and membrane antigens of Cowdria ruminantium

Cowdria-specific CD4(+) T-cell lines generated from immunised cattle respon d to both soluble and membrane proteins of the agent, Furthermore, the line s produced the Cowdria-inhibitory cytokine IFN-gamma in response to soluble antigens fractionated by gel filtration and FPLC. Activity eluted as a sin gle peak around fraction 15 for all T-cell lines tested. This fraction indu ced the highest production of IFN-gamma by the lines and was shown by SDS-p olyacrylamide gel electrophoresis and silver staining analysis to contain l ess than 10 different bands ranging from 22 to 32 kDa. Given their high sen sitivity and specificity, these short-term CD4(+) T-cell Lines will be valu able tools for the identification of Cowdria antigens for incorporation in a subunit vaccine. (C) 1999 Elsevier Science B,V, All rights reserved.