Toxoplasma P22

One of the key surface antigens of T. gondii is Surface Antigen 2 (SAG2), also known as P22. SAG2 is a member of the SAG1-related sequence (SRS) superfamily, which plays a crucial role in the parasite’s ability to invade host cells and evade the host immune response. The SAG2 protein is expressed on the surface of the tachyzoite stage of T. gondii and is involved in host cell attachment and invasion.

Recombinant SAG2 (P22) is produced through genetic engineering techniques, where the SAG2 gene is cloned and expressed in a suitable host system, such as Escherichia coli or Pichia pastoris. This recombinant protein is used extensively in serological assays to detect antibodies against T. gondii in infected individuals. The recombinant form of SAG2 retains its immunogenic properties, making it an effective tool for diagnosing toxoplasmosis.

Recombinant SAG2 is particularly valuable in serological assays, such as enzyme-linked immunosorbent assays (ELISA) and western blotting, for the detection of IgG antibodies against T. gondii. These assays are crucial for diagnosing acute and chronic toxoplasmosis, as well as for monitoring the immune response in infected individuals. The high sensitivity and specificity of recombinant SAG2-based assays make them reliable tools for large-scale seroepidemiological studies .

Recent advancements in multiplex serology have further enhanced the utility of recombinant SAG2. Multiplex assays allow for the simultaneous detection of antibodies against multiple antigens, increasing the efficiency and throughput of serological testing. For instance, the inclusion of recombinant SAG2 in bead-based multiplex assays has shown high sensitivity and specificity, even at high sample dilutions .