Enhancing immune responses by a novel multi-epitope ROP8 DNA vaccine plus interleukin-12 plasmid as a genetic adjuvant against acute Toxoplasma gondii infection in BALB/c mice.
BACKGROUND
Toxoplasmosis is a widespread zoonotic infection, caused by an obligate intracellular protozoan. The infection is often asymptomatic in immunocompetent individuals, although in persons with impaired immune system may lead to severe and progressive complications. Constant attempts of scientists have made valuable findings in the development of Toxoplasma gondii (T. gondii) candidate vaccines. However, an effective vaccine has not been successfully developed yet. In the current study, we tested the co-delivery of a novel multi-epitope pcROP8 DNA vaccine with a plasmid encoding IL-12 (pcIL-12) to assess the immune responses in BALB/c mice against acute T. gondii infection.


METHODS
BALB/c mice were immunized on days 0, 21, and 42. The immune responses of both vaccinated and control groups were evaluated using cytokine and antibody measurements, lymphocyte proliferation assay, and survival time.


RESULTS
The findings demonstrated that immunization with multi-epitope pcROP8 significantly enhanced the level of anti-T. gondii antibodies, TH1-type cellular immune responses, lymphocyte proliferation, and prolonged survival time, compared to control groups (P < 0.05). Furthermore, the use of pcIL-12 as a genetic adjuvant led to enhancements of the above-mentioned immune responses in BALB/c mice (P < 0.05).


CONCLUSIONS
The co-administration of pcIL-12 with multi-epitope pcROP8 vaccine, could successfully enhance the level of protection. Thus, this immunization regimen may represent an effective vaccine strategy against acute T. gondii infection.
['Foroutan|Masoud|M|', 'Barati|Mohammad|M|', 'Ghaffarifar|Fatemeh|F|']
D000818:Animals D000913:Antibodies, Protozoan D016207:Cytokines D000939:Epitopes D018664:Interleukin-12 D051379:Mice D008807:Mice, Inbred BALB C D010957:Plasmids D015800:Protozoan Proteins D016052:Protozoan Vaccines D014122:Toxoplasma D014123:Toxoplasmosis D019444:Vaccines, DNA
ROP8 Vaccine Interleukin-12 Toxoplasma gondii BALB/c