Effect of different adjuvants on various immune cells and cytokines in allergic asthma mouse model

Abstract

Abstract Allergic asthma is a complex chronic disease which displays combined traits referred to as Th2 mediated eosinophilic allergy, ILC2 mediated allergy, and Th17 cell mediated neutrophilic allergy. In our current study of allergic asthma model, the populations of immune cells related to as well as outside of the Th2 immune response were analyzed for the ratio of cytokines in IL-4, IL5, IL17A and IFN-γ expressing CD4+ T cells utilizing of BALB/c mice sensitized with ovalbumin and a different adjuvant such as Alhydrogel (alum), papain, lipopolysaccharide (LPS), and CpG. In lung and bronchoalveolar lavage fluid, the percentage of eosinophils was lower in groups injected with LPS and papain than those with no adjuvant. In contrast, the injection of LPS and papain increased the percentage of neutrophils when compared to the no adjuvant group. The number of B cells in alum-injected group was higher than those of other groups. Although the percentage of innate lymphoid cells (ILCs) increased slightly for ILC1 and ILC2 in the group injected with papain, the other adjuvants did not cause any differences. After PMA/ionomycin stimulation, the ratio of IL-4 expressing CD4+ T cells in the papain-injected group increased significantly while the other adjuvant groups showed little or no changes. The production of IL-17A in CD4+ T cells increased in LPS-injected group and that of IFN-gamma also increased in CpG-injected group. Our results suggest that many distinct allergic asthma mouse models can be established by specific sensitization protocols exploiting different adjuvants, thus representing the complexity of clinical symptoms.