Ethnopharmacological relevance: Influenza virus vaccines (IVV) with balanced TH1/TH2 responses are critical for controlling seasonal influenza. Emerging evidences suggest that herbal polysaccharides can induce potent TH1 or mixed TH1/TH2 responses.
Aim of study: The study aims to determine the efficacy and safety of crude polysaccharides from cultivated Artemisia rupestris L. (CPCAR) as an adjuvant for IVV.
Materials and methods: CPCAR was prepared with hot extraction and ethanol precipitation method and primary physico-chemical characters were tested. Mice were vaccinated by subcutaneous route with IVV formulated with different dose of CPCAR to detecting the elicited TH1/TH2 responses and long-term immune responses with dose-sparing sparing effect.
Results: IVV formulated with CPCAR without LPS contamination could augment balanced TH1/TH2 responses, as indicated by early IgG response, hemagglutination inhibition (HAI) antibodies, effector T-cells, and cytotoxic T lymphocytes (CTL). Moreover, CPCAR elicited long-term IgG, HAI antibodies, memory T cells, and balanced CD4/CD8 responses within 168 days after vaccination. Compared with IVV alone, a low or high dose of IVV formulated with CPCAR improved the levels of IgG, IgG1, and IgG2a and enhanced memory T cells and balanced CD4/CD8 responses, displaying a 10-fold dose-sparing effect. As determined by IgE response and monitoring results of weekly body weight and daily symptoms after vaccination, anaphylaxis or adverse effect was not observed.
Conclusions: Collectively, the study demonstrated the potential of CPCAR as an aqueous polysaccharide adjuvant for IVV to induce rapid and balanced TH1/TH2 responses and long-lasting immunity with dose-sparing effect.
Keywords: Adjuvant; Cultivated artemisia. rupestris L.; Influenza vaccine; Polysaccharides; Vaccines.
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