Potentiation of humoral immune responses to vaccine antigens by recombinant chicken IL-18 (rChIL-18).
Mammalian interleukin-18 (IL-18) is one of the pro-inflammatory cytokines involved in innate immune responses to microbial infection preceding the induction of both cellular and humoral immune responses. We assessed the potential of Escherichia coli-expressed His-tag purified recombinant chicken IL-18 (rHis-ChIL-18) as a potentiator of vaccine-induced immune responses in 3 week-old SPF chickens and compared it with several commonly used traditional immunostimulating adjuvants. We found that rHis-ChIL-18 significantly enhanced antibody responses to Clostridium perfringens alpha-toxoid and Newcastle disease virus (NDV) antigens, comparable to the Al(OH)3-gel, Miglyol and chitosan adjuvant. However, antibody responses were lower than water-in-oil (w/o) emulsions and combinations of rHis-ChIL-18 with Al(OH)3-gel, Miglyol or chitosan. Improved HI-titers for infectious bronchitis virus (IBV) were not noted. We conclude that rHis-ChIL-18, when delivered in the proper context, is a novel and safe immunostimulator in chickens.
Degen
Winfried G J
WG
Intervet International BV, Department of Vaccine Technology and Immunology R&D, P.O. Box 31, 5830 AA Boxmeer, The Netherlands. winfried.degen@intervet.com
van Zuilekom
Hanneke I
HI
Scholtes
Nicolette C
NC
van Daal
Nancy
N
Schijns
Virgil E J C
VE
D000276:Adjuvants, Immunologic; D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D002645:Chickens / Q000276:immunology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D007109:Immunity / Q000187:drug effects*; D020382:Interleukin-18 / Q000008:administration & dosage* / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D014611:Vaccination
D000276:Adjuvants, Immunologic; D000907:Antibodies, Bacterial; D020382:Interleukin-18; D011994:Recombinant Proteins