Toxoplasma gondii is an obligate intracellular protozoan parasite and is able to infect birds and mammals including humans. In order to find effective antigen-adjuvant combinations that can boost the immunogenicity and protection of antigen vaccines against toxoplasmosis， we examined the protective efficacy in mice immunized with recombinant protein HSP70 when co-administered with ginseng stem-and-leaf saponins (GSLS) isolated from Panax ginseng . All immunized mice produced significantly high levels of specific antibodies against rTgHSP70， and splenocytes from mice presented strong proliferative immune responses. Vaccinated mice displayed a significantly increased percentage of CD4 and CD8 T cells， indic... More
Toxoplasma gondii is an obligate intracellular protozoan parasite and is able to infect birds and mammals including humans. In order to find effective antigen-adjuvant combinations that can boost the immunogenicity and protection of antigen vaccines against toxoplasmosis， we examined the protective efficacy in mice immunized with recombinant protein HSP70 when co-administered with ginseng stem-and-leaf saponins (GSLS) isolated from Panax ginseng . All immunized mice produced significantly high levels of specific antibodies against rTgHSP70， and splenocytes from mice presented strong proliferative immune responses. Vaccinated mice displayed a significantly increased percentage of CD4 and CD8 T cells， indicating a strong immune response was triggered. The cellular and humoral immune responses were enhanced， which could be reflected of the increased mRNA levels of IFN-γ and IL-4， respectively. Immunization with rTgHSP70 and GSLS prolonged survival time of the treated mice compared to the controls， which died within 6 days after challenge with the virulent T. gondii RH strain. Our data demonstrate that by addition with GSLS， rTgHSP70 induced a strong immune response and provided partial protection against T. gondii ; therefore GSLS could be used as a promising vaccine adjuvant against acute toxoplasmosis.
