Transfection of bovine cells with synthetic mRNA to induce expression of functional antibodies against Tritrichomonas foetus surface antigen TF1.17.

Bovine trichomonosis is caused by the urogenital parasite Tritrichomonas foetus (T. foetus). In the United States, approved therapies are lacking, and management is limited to culling infected bulls. Preputial therapy with synthetic mRNA could lead to effective new treatments. We developed synthetic mRNA encoding bovine IgG1 against two epitopes of the T. foetus cell surface antigen TF1.17 and used the mRNA to transfect bovine cells in vitro. Transfected cells expressed membrane anchored or secreted versions of the antibodies with a NanoLuciferase (NanoLuc) reporter molecule fused to each light chain. Luminescence in cells and supernatants collected 24 and 48 h post-transfection confirmed the production of anti-TF1.17 and was significantly higher than in non-transfected controls (p < 0.05). Anti-TF1.17 bound to live parasites as indicated by significantly higher luminescence following treatment with 24 and 48 h post-transfection supernatants compared to transfection controls (p = 0.001). Treatment of T. foetus with concentrated anti-TF1.17 antibody decreased parasite viability. When T. foetus were added to mRNA transfected kidney cells 48 h post transfection, cytopathic effects of the parasites were reduced following 24 h of co-culture with cells producing anti-TF1.17 as compared to controls (p < 0.05). To our knowledge, this is the first use of mRNA transfection of bovine cells to induce the expression of antibodies that can bind to T. foetus, decrease their viability and their cytopathic effects on host cells. This work forms the basis for the development of novel mRNA-mediated approaches to treat or prevent bovine trichomonosis.