Abstract: The present application provides methods of stimulating an immune response, such as a protective immune response against Treponema pallidum infection. Such methods utilize fragments of the Tp0751 protein (such as any of SEQ ID NOs: 3-10, those N-terminally truncated from amino acids 1 through 77, 1 through 114, or anywhere in between, e.g., those that start at any amino acid from 78 to 115). In some examples, a Tp0751 protein fragment has a mutated HEXXH site (HEXXH is the wild-type sequence). Also provided are the isolated soluble Tp0751 protein fragments that include a wild-type or mutated HEXXH site, as well as nucleic acids encoding such proteins and kits that include such proteins.

Abstract: The present application provides methods of stimulating an immune response, such as a protective immune response against Treponema pallidum infection. Such methods utilize fragments of the Tp0751 protein (such as any of SEQ ID NOs: 3-10, those N-terminally truncated from amino acids 1 through 77, 1 through 114, or anywhere in between, e.g., those that start at any amino acid from 78 to 115). In some examples, a Tp0751 protein fragment has a mutated HEXXH site (HEXXH is the wild-type sequence). Also provided are the isolated soluble Tp0751 protein fragments that include a wild-type or mutated HEXXH site, as well as nucleic acids encoding such proteins and kits that include such proteins.

Abstract: The present application provides methods of producing soluble Treponema pallidum protein Tp0453 (such as the fragment shown in SEQ ID NO: 3). For example, the protein can be expressed from the pET28a vector in a cell and the resulting soluble Tp0453 protein isolated from the cell. Also provided are the isolated soluble Tp0453 protein, as well as Tp0453-Tp0326 chimeric proteins (e.g., SEQ ID NO: 11), and methods of using the proteins to detect antibodies specific for T. pallidum subsp. pallidum, for example to diagnose syphilis. Devices and kits that incorporate Tp0453 protein and Tp0453-Tp0326 chimeric proteins, such as lateral flow devices, are also disclosed. Kits that include the soluble Tp0453 protein and kits that include solid substrates containing the soluble Tp0453 protein are also provided.