SAG1

As a specific protein in the tachycardia stage of toxoplasma, the surface antigen of toxoplasma P30(SAG1) can be identified by serum antibody of toxoplasma infection stage or convalescence stage, though it only accounts for 3% ~ 5% of the total amount of the parasite. P30 has strong immunogenicity, and the main effect mechanism for inducing immunoprotection of body cells may be achieved by CD4+, CD8+ and other lymphocytes under the regulation and coordination of cytokine ifn-type and il-2. When CD8+ is increased, it can acquire the ability to fight against acute toxoplasma infection. It plays a very important role in the protection of host against toxoplasma. In the aspect of humoral immunity, toxoplasma antigen mainly induces the body to produce IgM, IgA and IgG antibodies to resist re-infection. Therefore, it is generally believed that P30 is one of the main candidate antigens for immune diagnosis and subunit vaccine of toxoplasma infection, but the isolation is difficult.