cutting edge adjuvants. the age arriving soon

Cytokines, as immune activators, have been investigated in mammalian systems as natural adjuvants and therapeutics. In particular, interleukin-2 (IL-2) has been studied widely as a vaccine adjuvant and immuno-enhancer because of its role in activating T cell proliferation. We show here that the first nonmammalian IL-2 gene cloned, chicken IL-2 (ChIL-2), exhibits similar biologic activities to those of mammalian IL-2. To assess the activities of ChIL-2 in vivo, we injected birds with recombinant ChIL-2 (rChIL-2) protein. rChIL-2 treatment induced peripheral blood lymphocytes to express cell surface IL-2 receptors (IL-2R) within 48 h and resulted in an increase in the proportion of peripheral blood CD4+ and CD8+ T cells. Using bromodeoxyuridine (BrdU) incorporation as a measurement of cell proliferation, we showed the increase in T cell populations to be due to cell proliferation. The ability of ChIL-2 to cause both activation and proliferation of T cells in vivo indicates that it has the potential to be used as an immune activator.


In the face of reducing reliance on in-feed antibiotics, a greater emphasis has been placed on the development of vaccines, as well as making currently available vaccines more efficient by developing better adjuvants that can provide prolonged effective immunity. Efforts are underway to enhance vaccine efficacy with the use of adjuvants, particularly cytokines. The use of cytokines in vaccine formulation has been given serious consideration due to the ability of driving an appropriate immune response and ensuring a protective outcome. Many chicken cytokines and TLR are currently being characterized to gain more insight into how these molecules act to enhance the immune response to vaccination. Cytokines such as IFN-, IFN-, ChIL-1 and cMGF have been shown to possess adjuvant activities, and have the potential to be used in vaccine formulations to provide improved protection against disease.