Leveraging core proteome data of <i>Kingella kingae</i> for multi-epitope vaccine design against TonB dependent receptor (TDR): an <i>in silico</i> approach

<i>Kingella kingae</i> is a Gram-negative bacterium that causes invasive infections in children and older or immunocompromised individuals, making it a significant public health concern. In this study, a pan-proteomic mediated vaccine target mining was attempted to identify potential vaccine targets in <i>K. kingae</i>. Currently, there is no vaccine available against this pathobiont. Therefore, we designed and validated an <i>in silico</i> vaccine construct by targeting the lactoferrin/transferrin-binding TonB-dependent receptor. Antigenic regions of the TonB receptor were mapped, and the predicted epitopes were anticipated to be effective in a broad range of the world population. Using their combinations with linkers and various adjuvants, 12 vaccine constructs were prepared. The best construct (C7) with no allergenicity and high antigenicity was subjected to molecular modeling, docking with important immune receptors of humans, and then molecular dynamics (MD) simulation. After binding validation and stability assessment, it was cloned into a pet-28a + plasmid vector. Immune response was also simulated, and the vaccine was observed to invoke B- and T-cell induction. These findings can help accelerate the development of a new vaccine against <i>K. kingae</i> or other pathogens targeting the homolog of TonB. Nevertheless, we propose additional testing of C7 construct for efficacy and safety <i>in vitro</i> and <i>in vivo.</i>