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Liposome-based vaccine delivery systems are known to enhance immune responses. Ganoderma lucidum polysaccharides (GLP) have been widely studied as immunomodulator and it could be as inducers of strong immune responses. In the research, GLP and ovalbumin (OVA) were encapsulated into liposome as vaccine and inoculated to mice. The magnitude and kinetics of the humoral and cellular immune responses were investigated. The results showed that GLP-OVA-loaded liposomes (GLPL/OVA) could induce more powerful antigen-specific immune responses than each single-component formulation. Mice immunized with GLPL/OVA displayed higher antigen-specific IgG antibodies, better splenocytes proliferation, higher cytokine secretion by splenocytes and significant activation of CD3+CD4+ and CD3+CD8+ T cells. Thus the GLPL/OVA formulation produced a heightened humoral and cellular immune response, with an overall Th1 bias. Enhanced immune responses elicited by the GLPL/OVA formulation might be attributed to effective activation and mature of DC in draining lymph nodes. Overall, these findings indicate that GLPL have the potential to enhance immune responses as vaccine delivery systems.

Adjuvants improve vaccine potency by enhancing immunogenicity and sustaining long-term immune responses. Lentinan (LNT), a β-1,3-glucohexaose with β-1,6-branches, is extracted from the mushroom Lentinus edodes and functions as an effective immunostimulatory drug. Previous studies have demonstrated the adjuvant activity of calcium carbonate (CaCO3) microspheres as well as their use as antigen delivery systems. In this study, we successfully loaded CaCO3 microspheres with LNT and evaluated their physicochemical characteristics prior to the adsorption of ovalbumin. Our experimental results demonstrated that LNT-CaCO3 significantly enhanced lymphocyte proliferation, and boosted the frequency of CD69 + B cells and the ratio of CD4+ to CD8 + T cells in spleen lymphocytes. Moreover, LNT-CaCO3 unexpectedly induced the secretion of IgG and Th-associated cytokines (IL-2, IL-4, IFN-γ, and TNF-α) in immunized mice. Therefore, LNT-CaCO3 microspheres induce robust cellular and humoral immune responses and have potential utility as vaccine delivery systems.

Dendritic cells (DCs) are professional antigen-presenting cells (APC) that play a central role in the initiation and regulation of immune responses. We have previously demonstrated that Lycium barbarum polysaccharides liposomes (LBPL) as immune adjuvant elicits strong antigen-specific Th1 immune responses. The purpose of this study was to investigate underlying mechanism of liposomes promoting effect of Lycium barbarum polysaccharides (LBP) on activating DCs. LBP were loaded with high entrapment efficiency (86%) into liposomes using reverse phase evaporation. LBPL activation of phenotypic and functional maturation of DCs was explored through mechanistic studies of the TLR4-MyD88-NF-κB signaling pathway and amount of proinflammatory cytokines released. We found that LBPL indeed activated immature DCs and induced DCs maturation characterized by up-regulation of co-stimulatory molecules (MHCII, CD80, CD86), production of cytokines (IL-12p40, TNF-α), and enhancement of antigen uptake. Additionally, we demonstrated that liposomes could promote LBP up-regulation of TLR4, MyD88, TRAF6, NF-κB gene and protein expression.

The purpose of this study was to optimize the preparation conditions of Lycium barbarum polysaccharides liposome (LBPL) by response surface methodology (RSM) and to investigate the effect of LBPL activating function of peritoneal macrophages. LBPL was prepared using the reverse-phase evaporation method. The optimal preparation conditions of LBPL by RSM were as follows: the ratio of lipid to drug (w/w) of 25:1, the ultrasound time of 14 min and the ratio of soybean phospholipids to cholesterol (w/w) of 2.4:1. Under these conditions, the experimental encapsulation efficiency of LBPL was 86.37±0.63%, which was close to the predicted value. These indicated that LBPL with high entrapping efficiency and small particle size could be prepared by the reverse-phase evaporation method, which is applied easily. Furthermore, macrophages are the key players in the innate immune system. LBPL could effectively enhance peritoneal macrophages phagocytosis and resulted in inducing NO (nitric oxide) production in mouse peritoneal macrophages.

The aim of this study was to investigate the optimizing preparation conditions of Ganoderma lucidum polysaccharide liposome (GLPL) with response surface methodology (RSM) and the immunological enhancement activity of GLPL. The immunological enhancement activity of GLPL on splenocyte proliferation was measured. The optimum formulation of GLPL, in which the ratio of soybean phospholipid to cholesterol(w/w) of 11:1, the ratio of soybean phospholipid to tween-80 (w/w) of 10.5:1 and ultrasonic time(min) of 11, had higher entrapment efficiency (EE) of 71.43±0.49% with spherical shape and uniform sizes. In addition, GLPL could significantly promote splenocyte proliferation singly or synergistically with PHA and LPS. That indicated that the immunological enhancement of Ganoderma lucidum polysaccharide (GLP) was significantly enhanced after encapsulation with the liposome.