Evidence is presented that immunologic mechanisms can influence the development of Toxoplasma cysts. The RH strain of Toxoplasma gondii produced cysts in tissue cultures (monolayers of rabbit corneal endothelial cells) when antitoxoplasma rabbit serum and fresh dyetest-negative guinea-pig serum were added to the medium. Immune rabbit serum alone also mediated a minimal amount of cyst formation by the organism, but fresh guinea-pig serum alone did not. The possible modes of action of the various immune components are presented, and their theoretical relationship to Toxoplasma cyst formation in infected eye tissues is discussed.
Shimada K, O'Connor GR, Yoneda C. Cyst Formation by Toxoplasma gondii (RH Strain) in VitroThe Role of Immunologic Mechanisms. Arch Ophthalmol. 1974;92(6):496-500. doi:10.1001/archopht.1974.01010010510010