RECOMBINANT CYTOKINES AS IMMUNOLOGICAL ADJUVANTS

This paper describes the bacterial expression and purification of bioactive recombinant ovine interleukin-2 (rovIL-2), interleukin-1alpha (rovIL-1alpha) and tumour necrosis factor alpha. These purified proteins had specific activities in appropriate bioassays of 1 x 10(7), 1 x 10(7) and 1 x 10(-5) U/mg, respectively. Recombinant ovIL-1alpha was assessed as an immunological adjuvant for the sheep response to the model protein avidin. When delivered either intradermally or intramuscularly in conjunction with avidin in aluminium hydroxide the rovIL-1alpha significantly enhanced the secondary humoral response. Doses of 1, 10 or 100 mug per sheep enhanced the humoral response to a similar extent. Recombinant ovIL-1beta had similar adjuvant activity in that it was demonstrated to significantly enhance the sheep humoral response to an experimental H. contortus antigen. This increase in specific antibody, however, did not correlate with enhanced protection against infection with third stage H. contortus larvae. In addition incorporation of rovIL-1beta into the formulation was shown not to alter the isotype profile of H. contortus antigen specific antibody.