Antigens for detecting toxoplasma infection by monitoring cellular immunity

Abstract

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 . A  Toxoplasma gondii -derived antigen composition, wherein the composition comprises a  Toxoplasma gondii -derived antigen selected from the group consisting of:
 a. isolated and purified MIC1, MIC3, MIC4, or MIC6,   b. truncated MIC1, MIC3, MIC4, or MIC6,   c. extended MIC1, MIC3, MIC4, or MIC6,   d. a fusion protein comprising any two or more of MIC1, MIC3, MIC4, or MIC6,   e. a fusion protein of any of MIC1, MIC3, MIC4, or MICE with a moiety that enhances or facilitates purification, recombinant production, or immune cell stimulation, and   f. combinations thereof.   
     
     
         2 . The antigen composition of  claim 1  which is produced in bacteria and comprises less than 0.1 EU/ml lipopolysaccharide. 
     
     
         3 . A kit comprising (a) a  Toxoplasma gondii -derived antigen composition of  claim 1  and (b) an applicator device for administration of the  Toxoplasma gondii -derived antigen to a subject. 
     
     
         4 . The kit of  claim 3  wherein the  Toxoplasma gondii -derived antigen composition is separately packaged within the kit. 
     
     
         5 . The kit of  claim 3  wherein the applicator device is separately packaged within the kit. 
     
     
         6 . The kit of  claim 3  wherein the applicator device comprises a patch. 
     
     
         7 . The kit of  claim 3  wherein the applicator device comprises a needle. 
     
     
         8 . The kit of  claim 3  wherein the applicator device comprises a prong. 
     
     
         9 . The kit of  claim 8  wherein the applicator device delivers the composition percutaneously. 
     
     
         10 . A method of delivering  Toxoplasma gondii -derived antigen to a subject comprising:
 contacting an applicator device which is loaded with the  Toxoplasma gondii -derived antigen composition of  claim 1  with skin of the subject, whereby the  Toxoplasma gondii -derived antigen composition is delivered to the skin of the subject.   
     
     
         11 . The method of  claim 10  wherein the applicator device comprises a patch. 
     
     
         12 . The method of  claim 10  wherein the applicator device comprises a needle. 
     
     
         13 . The method of  claim 10  wherein the applicator device comprises a prong. 
     
     
         14 . The method of  claim 13  wherein the applicator device delivers the composition percutaneously. 
     
     
         15 . An applicator device for administering one or more  Toxoplasma gondii -derived antigens to a mammal, comprising one or more  Toxoplasma gondii -derived antigens, wherein the  Toxoplasma gondii -derived antigens are selected from the group consisting of:
 a. isolated and purified MIC1, MIC3, MIC4, or MIC6,   b. truncated MIC1, MIC3, MIC4, or MIC6,   c. extended MIC1, MIC3, MIC4, or MIC6,   d. a fusion protein comprising any two or more of MIC1, MIC3, MIC4, or MIC6,   e. a fusion protein of any of MIC1, MIC3, MIC4, or MICE with a moiety that enhances or facilitates purification, recombinant production, or immune cell stimulation, and   f. combinations thereof.   
     
     
         16 . The applicator device of  claim 15  which comprises a plurality of prongs to which a plurality of  Toxoplasma gondii -derived antigens has been applied. 
     
     
         17 . The applicator device of  claim 15  wherein the applicator comprises one or more prongs which are configured to receive a liquid comprising  Toxoplasma gondii -derived antigen and to puncture skin to deliver the  Toxoplasma gondii -derived antigen percutaneously. 
     
     
         18 . The applicator device of  claim 15  wherein the  Toxoplasma gondii -derived antigens are devoid of GRA7. 
     
     
         19 . The applicator device of  claim 15  which comprises a patch for transdermal administration. 
     
     
         20 . The applicator device of  claim 15  which comprises a needle. 
     
     
         21 . A method of eliciting a T cell response in a subject comprising:
 contacting a  Toxoplasma gondii -derived antigen composition of  claim 1  with T cells of the subject, whereby the  Toxoplasma gondii -derived antigen composition induces a T cell response.   
     
     
         22 . The method of  claim 21  wherein the response is a delayed type hypersensitivity response. 
     
     
         23 . The method of  claim 21  wherein the response is release of a cytokine. 
     
     
         24 . The method of  claim 21  wherein the response is release of interferon-γ. 
     
     
         25 . The method of  claim 21  wherein the T cells are in peripheral blood mononuclear cells. 
     
     
         26 . The method of  claim 21  wherein the T cells are in a blood sample. 
     
     
         27 . The method of  claim 21  wherein the contacting is performed in vitro. 
     
     
         28 . The method of  claim 21  further comprising the step of detecting or quantifying release of a cytokine. 
     
     
         29 . The method of  claim 21  further comprising the step of detecting or quantifying release of interferon-γ.