The use of recombinant ovine IL‐1β and TNF‐α as natural adjuvants and their physiological effects in vivo

Abstract

In the present study we have investigated the use of recombinant ovine IL-1beta and TNF-alpha both alone and in combination, as natural adjuvants in vaccination trials in sheep. Initial experiments were conducted to investigate the physiological effects of the cytokines in vivo and determine what dose could be administered without adverse pyrogenic effects. Even at the maximum dose tested (100 microg) the only significant physiological effect was a transient increase in body temperature of approximately 2 degrees C in sheep injected with TNF-alpha. Administration of either cytokine had profound effects on the levels of circulating leucocytes for up to 5 days postinjection. The incorporation of either IL-1beta or TNF-alpha in aqueous or Al(OH)3 vaccine formulations enhanced antibody responses to a recombinant antigen from the cestode parasite Taenia ovis. The addition of IL-1beta to aqueous vaccine formulations increased antibody responses 15-20-fold and in Al(OH)3 formulations by three to six fold. TNF-alpha stimulated 1.5 to six-fold and 2.5 to seven-fold increases in antibody levels in aqueous and Al(OH)3-based formulations, respectively, in a dose-dependent manner. The addition of either cytokine to Quil A or IFA vaccines did not enhance the antibody levels elicited. When 10 microg of both IL-1beta and TNF-alpha were incorporated in the aqueous or Al(OH)3 vaccine formulations, increases of 21-fold and 25-fold, respectively, were observed in antibody levels. The adjuvant activity of IL-1beta and TNF-alpha in combination in the Al(OH)3-based vaccine resulted in antibody levels commensurate with those obtained using Quil A or IFA.

Physiological effects and adjuvanticity of recombinant brushtail possum TNF‐α

“…16 In sheep, low doses of ovine TNF-α given intramuscularly caused only minor increases in temperatures, while a larger dose of 100 µg caused a transient temperature increase of 2.0°C and the animals became lethargic. 7 In our study the highest dose of 150 µg TNF-α administered by an intravenous route caused a transient 2.7°C increase in body temperature. Several of the animals became lethargic after administration of TNF-α but this effect was not related to the dose.…”

“…18 In sheep, administration of recombinant TNF-α enhanced the antibody levels to the recombinant cestode parasite Taenia ovis fusion protein, 45W-GST, between 1.5-and six-fold for an aqueous and between 2.5-and seven-fold for an Al(OH) 3based formulation. 7 In the present study the inclusion of TNF-α in the vaccine stimulated antibody levels two-and four-fold for aqueous and Al(OH) 3 -based formulations, respectively. However, the only significant increase in antibody titres as a result of the inclusion of TNF-α was for the Al(OH) 3 formulation, where TNF-α appeared to induce a stronger antibody response.…”

“…Rothel et al reported fluctuations in numbers of circulating white blood cells in sheep after intramuscular injection of 100 µg of recombinant ovine TNF-α. 7 The cytokine caused an increase in total leucocyte numbers at 24 h after injection, primarily due to a two-four-fold increase in neutrophil counts, but did not significantly affect lymphocyte numbers. In a different study, Johnson et al found that infusion of ovine TNF-α into sheep caused a decrease in numbers of circulating neutrophils and lymphocytes for up to 4 h after injection.…”

“…Our results also show a number of similarities to those reported by Rothel et al for the effect of ovine IL-1β in sheep. 7 In these animals administration of cytokine caused a drop in total leucocyte numbers within 30 min, primarily due to a loss of neutrophils, lymphocytes, monocytes and eosinophils from the peripheral blood. This was followed by a marked elevation in white blood cell numbers which peaked at 24 h after injection, predominantly due to a four-fold increase in neutrophil numbers.…”

“…Recently, Rothel et al demonstrated that incorporation of recombinant ovine TNF-α in aqueous or Al(OH) 3 vaccine formulation enhanced antibody responses to a cestode antigen. 7 We have previously cloned TNF-α from possums, 8 and now have produced bioactive recombinant possum TNF-α in the yeast Pichia pastoris. The present paper studies some of the properties of P. pastoris-expressed TNF-α, including the physiological effects on possums and the adjuvant effect of TNF-α on antibody responses to the model antigen, keyhole limpet haemocyanin (KLH).…”