Preliminary study on expression and functions of Toxoplasma gondii SRS67 and SRS20A proteins.
6 affiliations
- 1Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Beijing University of Agriculture, No. 7 Beinong Road, Changping, Beijing, 102206, People's Republic of China.
- 2Coccidia Laboratory, College of Animal Science and Technology/College of Veterinary Medicine, Beijing University of Agriculture, Changping, Beijing, 102206, People's Republic of China.
- 3Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Beijing University of Agriculture, No. 7 Beinong Road, Changping, Beijing, 102206, People's Republic of China. [email protected].
- 4Coccidia Laboratory, College of Animal Science and Technology/College of Veterinary Medicine, Beijing University of Agriculture, Changping, Beijing, 102206, People's Republic of China. [email protected].
- 5Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Beijing University of Agriculture, No. 7 Beinong Road, Changping, Beijing, 102206, People's Republic of China. [email protected].
- 6Coccidia Laboratory, College of Animal Science and Technology/College of Veterinary Medicine, Beijing University of Agriculture, Changping, Beijing, 102206, People's Republic of China. [email protected].
Abstract
Background
Toxoplasma gondii surface proteins play critical roles in parasite invasion, proliferation, and host immune modulation, and represent promising targets for anti-toxoplasmosis intervention. SRS67 and SRS20A are poorly characterized surface proteins of T. gondii, and their biological functions and host regulatory effects remain largely unclear.Methods
In the present study, we prepared recombinant SRS67 and SRS20A proteins and generated corresponding polyclonal antibodies to explore their functional characteristics and protective potentials.Results
Immunofluorescence analysis localized both proteins as punctate signals surrounding the parasite membrane, indicating their involvement in surface-associated biological processes. In vitro phenotypic assays demonstrated that the prepared polyclonal antibodies significantly inhibited host cell invasion and intracellular proliferation of T. gondii. In vivo animal experiments further showed that antibody treatment effectively alleviated T. gondii-caused pathological injuries in mice. In the acute RH infection model, single or combined protein immunization increased the survival rate of mice by approximately 60%, and combined immunization delayed mortality by 1-2 days. In chronic PRU infection, antibody intervention reduced brain cyst burden by over 85% and markedly attenuated meningeal thickening and neuronal necrosis. Mechanistically, SRS67 upregulated the expression of Th1 cytokines (TNF-α, IL-18) during acute infection, while both proteins downregulated IFN-γ to limit excessive immune-mediated tissue damage. The elevated glutathione (GSH) level suggested the participation of these proteins in antioxidant regulation. During chronic infection, combined immunization synergistically enhanced superoxide dismutase (SOD) activity to resist oxidative stress, and decreased IFN-γ expression contributed to the maintenance of immune homeostasis.Conclusions
Collectively, this study systematically characterizes the biological functions of SRS67 and SRS20A, and demonstrates that their polyclonal antibodies exert potent inhibitory effects against T. gondii infection by directly blocking parasite biological behaviors and indirectly regulating host immune responses and antioxidant status. Our findings provide novel insights into the functional mechanisms of SRS family proteins and support the development of SRS-targeted anti-Toxoplasma strategies.
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BibTeX
@article{chen2026preliminary,
title = {{Preliminary study on expression and functions of Toxoplasma gondii SRS67 and SRS20A proteins.}},
author = {Xiaoxiao Chen and Tingting Yi and Wenyu Ma and Xuefei Liang and Shuaijing Niu and Mengze Du and Shuanghai Zhou and Qiuming Li and Deqi Yin},
journal = {Parasites \& vectors},
year = {2026},
month = oct,
doi = {10.1186/s13071-026-07629-1},
url = {https://europepmc.org/article/MED/42907993},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Preliminary study on expression and functions of Toxoplasma gondii SRS67 and SRS20A proteins.
AU - Xiaoxiao Chen
AU - Tingting Yi
AU - Wenyu Ma
AU - Xuefei Liang
AU - Shuaijing Niu
AU - Mengze Du
AU - Shuanghai Zhou
AU - Qiuming Li
AU - Deqi Yin
PY - 2026
DA - 2026/10/20
JO - Parasites & vectors
DO - 10.1186/s13071-026-07629-1
UR - https://europepmc.org/article/MED/42907993
AB - Background Toxoplasma gondii surface proteins play critical roles in parasite invasion, proliferation, and host immune modulation, and represent promising targets for anti-toxoplasmosis intervention. SRS67 and SRS20A are poorly characterized surface proteins of T. gondii, and their biological functions and host regulatory effects remain largely unclear.Methods In the present study, we prepared recombinant SRS67 and SRS20A proteins and generated corresponding polyclonal antibodies to explore their functional characteristics and protective potentials.Results Immunofluorescence analysis localized both proteins as punctate signals surrounding the parasite membrane, indicating their involvement in surface-associated biological processes. In vitro phenotypic assays demonstrated that the prepared polyclonal antibodies significantly inhibited host cell invasion and intracellular proliferation of T. gondii. In vivo animal experiments further showed that antibody treatment effectively alleviated T. gondii-caused pathological injuries in mice. In the acute RH infection model, single or combined protein immunization increased the survival rate of mice by approximately 60%, and combined immunization delayed mortality by 1-2 days. In chronic PRU infection, antibody intervention reduced brain cyst burden by over 85% and markedly attenuated meningeal thickening and neuronal necrosis. Mechanistically, SRS67 upregulated the expression of Th1 cytokines (TNF-α, IL-18) during acute infection, while both proteins downregulated IFN-γ to limit excessive immune-mediated tissue damage. The elevated glutathione (GSH) level suggested the participation of these proteins in antioxidant regulation. During chronic infection, combined immunization synergistically enhanced superoxide dismutase (SOD) activity to resist oxidative stress, and decreased IFN-γ expression contributed to the maintenance of immune homeostasis.Conclusions Collectively, this study systematically characterizes the biological functions of SRS67 and SRS20A, and demonstrates that their polyclonal antibodies exert potent inhibitory effects against T. gondii infection by directly blocking parasite biological behaviors and indirectly regulating host immune responses and antioxidant status. Our findings provide novel insights into the functional mechanisms of SRS family proteins and support the development of SRS-targeted anti-Toxoplasma strategies.
SN - 1756-3305
ER -