In-silico identification of B-cell epitopes from PorB, NsPA and opA60 proteins to design a chimeric protein against Neisseria Gonorrhoeae

Abstract

Neisseria gonorrhoeae, the causative agent of gonorrhoea, remains a significant global public health challenge due to increasing antimicrobial resistance to first line treatment plan and lack of effective vaccine with an annual global incidence of approximately 87 million. Neisseria gonorrhoeae infection causes significant morbidity and can pose significant long-term impacts on reproductive and neonatal health. Global rates and resurgence of the infection have increased over the past two decades associated with antimicrobial resistance to key antimicrobials as stated by the Center for Disease Control and Prevention pointing out the drug-resistant N. gonorrhoeae as an urgent threat to public health. Neisseria gonorrhoeae is a human-restricted Gram-negative bacterium responsible for the infections of the genital tract as well as the rectum, the pharynx and the eyes. Collectively these infections are known as gonorrhoea and are primarily caused by sexual contact. Infection of the lower genital tract can range from asymptomatic to more invasive ascending infection. In women, this can be particularly severe and can result into pelvic inflammatory disease (PID), ectopic pregnancy and infertility. Severe outcomes of the gonorrhoea infection are particularly problematic in low development and middle-income countries. This study aimed at designing a novel chimeric vaccine candidate using an in-silico approach to identify B-cell epitopes from three surface-exposed proteins of the Neisseria gonorrhoeae bacteria: Opacity associated protein 60 (Opa60), Porin B (PorB) and Neisseria surface protein (NsPA). Subsequently, the vaccine chimera was designed by mapping nine shortlisted epitopes from these proteins and incorporating a suitable adjuvant and linkers. The Beta defensing adjuvant was used for the construction.