Immunoadjuvant activity of marine bacteria exopolysaccharides in normal and immunosuppressive conditions

Abstract

Aim. To assess the mechanisms of immunoadjuvant activity of marine bacteria exopolysaccharides (PS) in normal and immunosuppressive conditions in vivo. Material and methods. Experimental studies were carried out on male ВALB/c mice, immunized with compositions of PS or aluminum hydroxide and ovalbumin (OVA). Immunosuppression was induced by triple intraperitoneal administration of dexamethasone (2 mg/kg). Serum levels of specific antibodies (IgG, IgG1, and IgG2a) and cytokines (IFN-γ, IL-2, IL-10) were determined. Results. The inclusion of PS to the immune compositions led to the formation of an enhanced specific IgG, IgG1, and IgG2a to OVA, comparable to the effect of aluminum hydroxide. The studied PS also contributed to an increase in the level of both pro- and anti-inflammatory cytokines. Conclusion. PS from marine bacteria act as adjuvants in normal and immunosuppressive conditions, stimulating a mixed Th1 (IgG2a, INF-γ) and Th2 (IgG1, IL-10) immune response to OVA.