Design, Immune Responses and Anti-Tumor Potential of an HPV16 E6E7 Multi-Epitope Vaccine

Abstract

Cervical cancer is a common type of cancer among women worldwide and infection with high-risk human papillomavirus (HPVs) types represents the major risk factor for the etiopathogenesis of the disease. HPV-16 is the most frequently identified HPV type in cervical lesions and expression of E6 and E7 oncoproteins is required for the uncontrolled cellular proliferation. In the present study we report the design and experimental testing of a recombinant multi-epitope protein containing immunogenic epitopes of HPV-16 E6 and E7. Tumor preventive assays, based on the engraftment of TC-1 cells in mice, showed that the E6E7 multi-epitope protein induced a full preventive anti-tumor protection in wild-type mice, as well as in mice deficient in expression of CD4+ T cells and TLR4 receptor. Nonetheless, no anti-tumor protection was observed in mice deficient in CD8+ T cells. Also, the vaccine promoted high activation of E6/E7-specific T cells and in a therapeutic-approach, E6E7 protein conferred full anti-tumor protection in mice. These results show a potential use of this E6E7 multi-epitope antigen as a new and promising antigen for the development of a therapeutic vaccine against tumors induced by HPV.

In silico/In vivo analysis of high-risk papillomavirus L1 and L2 conserved sequences for development of cross-subtype prophylactic vaccine

“…In addition, above-mentioned epitopes had the highest T-cell epitope prediction scores which were obtained from proteasomal cleavage and tap transport analysis. High degree of conservancy was observed between subtypes for these epitopes ( [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] (EATVYLPPVPVSKVV-type16), L1 416-430 (DT YRFV TSQAIACQK-type16), L1 417-431 (DT YRFVQSVAITCQK-type18), L2 281-297 (PDFLDIVALHRPALTSR-type16), L2 274-290 (SDFMDIIRLHRPALTSR-type18) and L2 [54][55][56][57][58][59][60][61][62][63][64][65][66][67][68][69] (FFGGLGIGTGSGTGGR-type16) epitopes had the highest binding affinity scores. Among them, L2 54-69 had the greatest degree of conservancy (high similarity with all of the high-risk HPV types).…”

“…CABS-Dock server performs Global docking procedure which at first explicit fully flexible docking simulation and then clustering-based scoring. Receptor flexibility was limited by default to small backbone fluctuation but could be increased to include selected receptor fragments 56,57 . This study presented an example of MHC-peptide docking performed by each individual epitope and available PDB file (Table 13) of HLA alleles, separately.…”

“…In L1 protein, L1 [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] (EATVYLPPVPVSKVV-type16), L1 408-421 (PPPGGTLEDTYRFV-type16) and L1 404-417 (NFGVPPPPTTSLVD-type 18) epitopes had the best B cell epitope identification scores. For L2 protein, L2 [22][23][24][25][26][27][28][29][30][31][32][33][34][35] (KQSGTCPPDVVPKV-type18), L2 100-113 (PSDPSIVSLVEETS-type16), L2 94-107 (EPVGPTDPSIVTLI-type18) and L2 [57][58][59][60][61][62][63][64][65][66][67][68][69][70] (GLGIGTGSGTGGRT-type16) epitopes showed the highest epitope identification score between their own protein sequences.…”

Designing of CD8⁺ and CD8⁺-overlapped CD4⁺ epitope vaccine by targeting late and early proteins of human papillomavirus

“…Among the five epitopes of E6 protein, RTEVYQFAF [41][42][43][44][45][46][47][48][49] and YSRIRE-LRY [72][73][74][75][76][77][78][79][80] were predicted to have binding affinity for HLA-A*(32:01, 29:02) and HLA-B*58: 01 MHC class I alleles (Table 1D). Out of 13 MHC-binding E7 peptides (Table 1E), STLSFVCPW [93][94][95][96][97][98][99][100][101] (HLA-A*32:01, HLA-B*58:01, HLA-B*57:01), LQQLFLSTL [87][88][89][90][91][92][93][94][95] (HLA-A*02:06), and QLFLSTLSF [89][90][91][92][93][94][95][96][97] (HLA-B*15:02, HLA-B*15:01, HLA-A*32:01) were predicted to have a binding affinity of IC 50 <200 nm. Furthermore, three out of seven epitopes of L1 protein, such as HVEEYDLQF…”

Synergistic antitumor effect of a human papillomavirus DNA vaccine harboring E6E7 fusion gene and vascular endothelial growth factor receptor 2 gene

“…The E6 and E7 oncoproteins of HP drive cervical cancer development and are critical for the maintenance of the transformed state . In addition to cervical cancer, HPV infection underlies 40% or more of the cases of oropharyngeal, anal, penile, vaginal, and vulvar cancers . The immunologically foreign nature of the HPV E6 and E7 proteins, coupled with their critical role in maintaining the cancerous state, makes them ideal target antigens for therapeutic cancer vaccination .…”