• Vaccine Name: PLG-rROP38-rROP18
• Target Pathogen: Toxoplasma gondii
• Target Disease: Toxoplasmosis
• Type: Subunit vaccine
• Status: Research
• Host Species for Licensed Use: Human
• Antigen: ROP18(Xu et al., 2015); ROP38 (Xu et al., 2015)
• ROP18 gene engineering:
  • Type: Recombinant protein preparation
  • Description: TgROP18 complete open reading frame was amplified from the PRU strain RNA by RT-PCR with primers introducing BamHI and SalI sites.The gene was inserted into pET-30a(+) vectors.The recombinant plasmids were transformed into E. coli BL21-codon plus (DE3)-RIL competent cells (Stratagene). The cells were selected, grown, and harvested, releasing the TgROP18 protein. The protein was made into PLG microparticles by water-in-oil-in-water double emulsion solvent evaporation technique. (Xu et al., 2015)
  • Detailed Gene Information: Click Here.
• ROP38 gene engineering:
  • Type: Recombinant protein preparation
  • Description: TgROP38 complete open reading frame was amplified from the PRU strain genomic DNA with primers introducing BsmBI and BamHI sites. The gene was inserted into pSMK vectors. The recombinant plasmids were transformed into E. coli BL21-codon plus (DE3)-RIL competent cells (Stratagene). The cells were selected, grown, and harvested, releasing the TgROP38 protein.The protein was made into PLG microparticles by water-in-oil-in-water double emulsion solvent evaporation technique. (Xu et al., 2015)
  • Detailed Gene Information: Click Here.
• Immunization Route: subcutaneous injection
• Description: T. gondii subunit vaccine of ROP18 and ROP38 encapsulated in PLG (Xu et al., 2015)

Mouse Response

• Host Strain: Kunming mice (Xu et al., 2015)
• Host age: 6 to 8 weeks old (Xu et al., 2015)
• Host gender: female (Xu et al., 2015)
• Vaccination Protocol: Mice were randomly divided into nine groups (19 mice each) and were injected subcutaneously at five different points at a 2-week interval. Each group were injected of different vaccines (with 10μg proteins): 1) 100μg PBS, 2) 100μg PLG, 3) 100μg rTgROP38, 4) 100μg rTgROP18, 5) 50μg rTgROP38 + 50μg rTgROP18, 6) 100μg PLG-rROP38, 7) 100μg PLG-rROP18, 8) 100μg PLG-rROP38-rROP18 (50μg rROP38 + 50μg rROP18), and 9) blank controls which were not treated until challenged. (Xu et al., 2015)
• Challenge Protocol: Eight weeks after the second immunization, 10 mice in all groups were challenged orally with 10 cysts of the PRU strain and were used to calculate the mean number of cysts per brain 1 month later. (Xu et al., 2015)
• Efficacy: Immunization with various protein vaccines significantly decreased the brain cyst formation in mice (P < 0.01), compared with all the control groups. The brain cyst number in the mice immunized with PLG-rROP38-rROP18 was the lowest, with a cyst reduction of 81.3 %. (Xu et al., 2015)