Studies on immunoprophylactic potential of recombinant mature surface antigen 2 (rSAG2) protein against Toxoplasma gondii infection† Singh Harkirat1,*, Tewari Anup K., Maharana Biswa R.2, Sudan Vikrant3, Mishra Ashok K., Singh Rajendra4, Raina Opinder K., Rao Jammi R. Division of Parasitology, Indian Veterinary Research Institute (IVRI), Izatnagar–243122, Uttar Pradesh 1Department of Veterinary Parasitology, College of Veterinary Science, Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Ludhiana 2Department of Parasitology, Lala Lajpat Rai University of Veterinary and Animal Sciences, Hisar 3Department of Veterinary Parasitology, College of Veterinary Science, Rampura Phul, Guru Angad Dev Veterinary and Animal Sciences 4Division of Pathology, Indian Veterinary Research Institute (IVRI), Izatnagar *Corresponding author: Email: drharkiratsingh@hotmail.com
Online Published on 15 February, 2024. Abstract The immunoprophylactic potential of recombinant mature surface antigen 2 (rSAG2) protein and the whole cell lysate antigen (TLA) of Toxoplasma gondii were assessed by cytokine profiling and assaying the humoral immune responses in mouse model. Profiles of a selected group of cytokines, viz., IL-4, IL-5, IL-10, IFN-γ and TNF-α were studied using sandwich ELISA, while the humoral response was assessed by measuring the serum IgG, IgG1 and IgG2a profiles. Following live challenge with T. gondii tachyzoites, the level of IFN- γ was found to increase significantly (1.5 to 2.0-fold) in vaccinated groups while the levels of IL-4 (4.0 to 6.0-fold), IL-5 (2.5 to 3.0-fold), IL-10 (2.5 to 45.0-fold) and TNF- α (1.5 to 1.8-fold) were significantly higher in control group. The IgG response was significantly higher (P<0.05) in immunized groups in comparison to the controls. The IgG1 and IgG2a sub-classes were also higher in the immunized group. However, decline in IgG2a response was observed in rSAG2 as well as TLA immunized mice. Immunization with recombinant protein as immunogen, while resulting in a marginal increase in the survival period of the immunized mice did not confer total protection. Top Keywords Cytokine profiling, Immunoprophylaxis, SAG2, Whole cell lysate antigen, Toxoplasma gondii. Top |