Abstract

Pertussis Toxin (PT) is a critical virulence factor of *Bordetella pertussis*, whose S1 subunit possesses ADP-ribosyltransferase activity that disrupts G-protein signaling, a fundamental process in cell membrane biology and signal transduction. This study investigates the immunogenicity of a genetically detoxified S1 subunit (PT-S1-detox) as a safer, next-generation vaccine component. The research objective was to evaluate the capacity of PT-S1-detox to elicit robust humoral and cellular immune responses in a murine model. Mice were immunized with the PT-S1-detox antigen, and the resulting immune response was characterized. Key findings indicate that PT-S1-detox successfully induced high titers of antigen-specific IgG antibodies, demonstrating a strong humoral response. Furthermore, the antigen stimulated a significant cellular response, evidenced by the proliferation of T-lymphocytes and the production of Th1- and Th2-associated cytokines, which are crucial for long-term protective immunity. These results confirm that the genetic detoxification process preserves the necessary epitopes for comprehensive immune recognition. The study's significance lies in validating PT-S1-detox as a highly promising candidate for inclusion in acellular pertussis vaccines, offering a pathway to improved vaccine efficacy and reduced reactogenicity by targeting a key membrane-interacting toxin component.