Immunization with Tp0954, an adhesin of Treponema pallidum, provides protective efficacy in the rabbit model of experimental syphilis

Abstract

Syphilis, a chronic multisystemic disease caused by spirochete Treponema pallidum subspecies pallidum infection, continues to be a serious global health problem and congenital syphilis remains a major cause of adverse outcomes in pregnancy in developing countries. The development of an effective vaccine is the most cost-effective way to eliminate syphilis, but so far has been elusive. Here, we evaluated the immunogenicity and protective efficacy of Tp0954, a T. pallidum placental adhesin, as a potential vaccine candidate in a New Zealand White rabbit model of experimental syphilis. Animals immunized with recombinant Tp0954 (rTp0954) produced high titers of Tp0954-specific serum IgG, high levels of IFN-γ from splenocytes and specific splenocyte proliferation response when compared to control animals immunized with PBS and Freund’s adjuvant (FA). Furthermore, rTp0954 immunization significantly delayed the development of cutaneous lesions, promoted inflammatory cellular infiltration at the primary lesion sites, as well as inhibited T. pallidum dissemination to distal tissues or organs when compared with that of the control animals. In addition, the naïve rabbits receiving popliteal lymph nodes from Tp0954-immunized, T. pallidum-challenged animals were not infected by T. pallidum, confirming sterile immunity. These findings suggest that Tp0954 is a potential vaccine candidate against syphilis.

Neurosyphilis: insights into its pathogenesis, susceptibility, diagnosis, treatment, and prevention

“…The latest field of molecular biology and bioinformatics provides unprecedented opportunities for the identification of new vaccine targets. Several adhesins, such as TP0136 ( 142 ), TP0751 ( 143 ), and TP0954 ( 144 ), have been identified as major vaccine candidates, highlighting their role in invasion and dissemination of T. pallidum . Current limitations of these candidates include the requirement of extremely high doses, lack of cross-protection and potential side effects of adjuvants ( 142 , 144 ).…”

“…Several adhesins, such as TP0136 ( 142 ), TP0751 ( 143 ), and TP0954 ( 144 ), have been identified as major vaccine candidates, highlighting their role in invasion and dissemination of T. pallidum . Current limitations of these candidates include the requirement of extremely high doses, lack of cross-protection and potential side effects of adjuvants ( 142 , 144 ). Although some scientists have attempted multicomponent vaccines, complete protection against infection has not yet been achieved ( 137 ).…”

A Mannose-Modified Lipid Calcium Phosphate Nanoparticle Vaccine Increased the Anti-Tumor Immune Response by Modulating the Tumor Microenvironment

“…Mannose-modified lipid calcium phosphate nanoparticle vaccine is a novel tumor immunotherapy method that can enhance the immune response to tumors by regulating the tumor microenvironment [213]. Studies [214][215][216][217][218][219][220] have shown that the vaccine can activate the body's immune system, promote the expression and recognition of tumor-associated antigens, and trigger a specific immune response against tumor cells.…”