Antigens for detecting toxoplasma infection by monitoring cellular immunity
Antigens of Toxoplasma gondii that provide specific and strong delayed type hypersensitivity (DTH) immune response, or which stimulate IFN-γ secretion, are used for testing subjects for infection. Any skin testing format may be adapted for testing for the delayed type hypersensitivity, including a patch, a needle, or a prong. Presence of DTH indicates infection. Alternate methods of detecting a T cell response including monitoring IFN-γ secretion may be used.
1. An in vitro method of monitoring a T cell response in a T cell from a subject, wherein the subject has not been immunized against Toxoplasma gondii , the method comprising: contacting the T cell of the subject with a composition comprising
a truncated MIC4 comprising the amino acids 58-231 of the amino acid sequence as set forth in SEQ ID NO: 55, or a sequence at least 90% identical thereto; and
detecting or quantifying release of a cytokine.
2. The method of claim 1 wherein the response is a delayed-type hypersensitivity response.
3. The method of claim 1 wherein the response is release of a cytokine.
4. The method of claim 1 wherein the response is release of interferon-γ.
5. The method of claim 1 wherein the T cells are in peripheral blood mononuclear cells.
6. The method of claim 1 wherein the T cells are in a blood sample.
7. The method of claim 1 further comprising the step of detecting or quantifying release of interferon-γ.