Production and Preliminary In Vivo Evaluations of a Novel in silico-designed L2-based Potential HPV Vaccine

Abstract

Background: L2-based Human Papillomavirus (HPV) prophylactic vaccines, containing epitopes from HPV minor capsid proteins, are under investigation as second-generation HPV vaccines. No such vaccine has passed clinical trials yet, mainly due to the low immunogenicity of peptide vaccines; so efforts are being continued. A candidate vaccine composed of two HPV16 L2 epitopes, flagellin and a Toll-Like Receptor (TLR) 4 agonist (RS09) as adjuvants, and two universal T-helper epitopes was designed in silico in our previous researches. Methods: The designed vaccine construct was expressed in E. coli BL21 (DE3) and purified through metal affinity chromatography. Following mice vaccination, blood samples underwent ELISA and flow cytometry analyses for the detection of IgG and seven Th1 and Th2 cytokines. Results: Following immunization, Th1 (IFN-γ, IL-2) and Th2 (IL-4, IL-5, IL-10) type cytokines, as well as IgG, were induced significantly compared with the PBS group. Significant increases in IFN-γ, IL-2, and IL-5 levels were observed in the vaccinated group versus Freund’s adjuvant group. Conclusion: The obtained cytokine induction profile implied both cellular and humoral responses, with a more Th-1 favored trend. However, an analysis of specific antibodies against L2 is required to confirm humoral responses. No significant elevation in inflammatory cytokines, (IL-6 and TNF-α), suggested a lack of unwanted inflammatory side effects despite using a combination of two TLR agonists. The designed construct might be capable of inducing adaptive and innate immunity; nevertheless, comprehensive immune tests were not conducted at this stage and will be a matter of future work.

Alum and a TLR7 agonist combined with built-in TLR4 and 5 agonists synergistically enhance immune responses against HPV RG1 epitope

“…More recently, immunization of mice by two epitopic domains (10–36 and 65–89) of HPVL2 fused to flagellin, RS09 and two universal T-helper epitopes was studied. Although preliminary results of this study indicated overall induction of humoral and cellular responses but no specific immune tests were addressed 20 . There are accumulating evidences that the proper combination of several built-in adjuvants (especially TLR agonists) alone or in formulation with external adjuvants might synergistically boost the immune responses against the targeted antigenic peptide 21 , 22 .…”

Identification of hub pathways and drug candidates in gastric cancer through systems biology

“…HPV is one of the most important carcinogenic viruses in humans. Different HPV serotypes have been discovered, among which HPV-16 and HPV-18 are the most prevalent mucosal high-risk serotypes, associated with nearly 90% of human cervical cancers and 20% of oral cancers 58 – 60 . The E6 and E7 genes of HPV play a causative role in cancer progression; the former promotes degradation of p53 through its interaction with E6AP , an E3 ubiquitin ligase, while the latter binds to the retinoblastoma protein ( prb ) and disrupts its complex formation with E2F transcription factors so that p53 is suppressed and rb is promoted causing a higher rate of cell division 61 .…”

Physical Activity of ≥7.5 MET-h/Week Is Significantly Associated with a Decreased Risk of Cervical Neoplasia

“…The 5-year disease-free and overall survival rates were significantly higher among cervical cancer patients with a high M1/M2 ratio in tumor tissues compared to cases with a low M1/M2 ratio [ 24 ]. In addition, it was reported that elevation of the Th1/Th2 cytokine ratio could increase cellular immunity and prevent the progression of CIN and invasive cervical cancer [ 25 ]. Therefore, it was suggested to develop strategies that promote cellular immune responses, including increasing the Th1/Th2 cytokine ratio, preventing monocyte recruitment to the TME and shifting macrophage phenotypes to M1 macrophages, to prevent the progression of cervical cancer [ 7 ].…”