The human papillomavirus (HPV) vaccine, HPV related diseases and cervical cancer in the post-reproductive years

Cervical Cancer: Early Detection and Prevention in Reproductive Age Group

Cancer has been one of the major illnesses faced by people over many generations. Despite the advancements made in medicine, there are still many problems faced by humankind. Every year a large number of people are diagnosed with cervical cancer. It is the most common type of cancerous condition prevalent among females, especially females over thirty years of age. Like any other cancer, cervical cancer also occurs because of the rapid uncontrolled division of the body cells. A primary reason for its development is the longstanding infection of certain types of human papillomavirus (HPV). A screening test is done to confirm the presence of the virus in the cervix. Many screening tests are available today for accurate diagnosis or confirmation of the condition being suffered from. The main goal of screening is early detection and making certain lifestyle changes to deduce the potential harm of the disease and start the treatment as soon as possible. A thorough study of the already published articles by scholars, professors, and doctors is carried out to conclude the necessity of cervical cancer screening and early detection.

Human Papillomavirus Oncogene Manipulation Using Clustered Regularly Interspersed Short Palindromic Repeats/Cas9 Delivered by pH-Sensitive Cationic Liposomes

Clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated protein 9 (Cas9) technology enables targeted gene editing, but cancer gene therapy with this approach requires improvements to enable safe and efficient delivery of CRISPR/Cas9 to tumors. We developed and evaluated a self-assembled liposome to selectively deliver CRISPR/Cas9 to cancer tissues. Our CRISPR/Cas9 system effectively inhibited proliferation of human papillomavirus (HPV) 16-positive cervical cancer cells and induced apoptosis by inactivating the HR-HPV16E6/E7 oncogene. Based on this system, we prepared a long-circulating pH-sensitive cationic nano-liposome complex with a high cell targeting and gene knockout rate. Intratumoral injection of cationic liposomes targeted to splicing HPV16 E6/E7 in nude mice significantly inhibited tumor growth without significant toxicity in vivo. Liposomes that targeted HPV16 E6/E7 splicing were established as a basis for treatment of HPV16-positive cervical cancer drug candidates. Our study demonstrates that this liposome offers an efficient delivery system for nonviral gene editing, adding to the armamentarium of gene editing tools to advance safe and effective precision medicine-based cancer therapeutics.

Prediction and identification of human leukocyte antigen-A2-restricted cytotoxic T lymphocyte epitope peptides from the human papillomavirus 58 E7 protein

Persistent infection with high-risk human papilloma virus (HPV) is the primary cause of cervical intraepithelial neoplasia (CIN) and cervical carcinoma. HPV58 is the third most common HPV genotype in China after HPV16 and HPV18. HPV E6 and E7 are oncoproteins and are constitutively expressed in HPV-associated cancer cells, therefore they are considered to be ideal target antigens for immunotherapy, including HPV therapeutic vaccine. In the present study, human leukocyte antigen (HLA)-A2-restricted cytotoxic T lymphocyte (CTL) epitope peptides were predicted and screened from HPV58 E7 antigen and their immunogenicity was subsequently determined. A total of 6 HLA-A2-binding peptides derived from HPV58 E7 were predicted and selected using 3 different prediction programs. A negative control peptide and PBS were used as two negative controls. Peripheral blood mononuclear cells (PBMCs) with HLA-A2(+) allele were used to detect the specific cellular immune response among the 6 predicted peptides by enzyme-linked immunospot assay (ELISOPT). Following preliminary screening for the predicted peptides, the antigenicity of the peptide HPV58 E7_72-80 was further assessed by an immunoassay to a vaccine contained HPV58 E7 antigen. Specific humoral and cellular immunity were detected using the peptide HPV58 E7_72-80 as the specific antigen. A total of 6 peptides from HPV58 E7 protein were predicted and subsequently named P1 (E7_7-15: TLREYILDL), P2 (E7_14-22: DLHPEPTDL), P3 (E7_69-77: CINSTTTDV), and P4 (E7_72-80: STTTDVRTL), P5 (E7_79-87: TLQQLLMGT) and P6 (E7_83-91: LLMGTCTIV). In the ELISPOT assay on HLA-A2 (+) human PBMCs, interferon (IFN)-γ-production was evident in the P2 and P4 groups. The average numbers of IFN-γ associated spots in the P2 and P4 groups was 50.61±5.37 spot-forming cells (SFC)/1×10⁵ and 266±34.42 SFC/1×10⁵, respectively. The numbers of spots in the two peptides were significantly increased compared with the other 4 peptides and the control groups (P<0.05). In the further antigenicity verification of P4 (HPV58 E7_72-80), the peptide only stimulated the humoral immune response of the AD-HPV16/18/58 mE6E7 vaccine containing HPV58 E7 antigen. Compared with the 2 negative control groups (1:400), the antibody titers of the vaccine group (1:25,600) were significantly increased (P<0.05). In cellular immunoassays the average number of IFN-γ associated spots was 143.3±32.13 SFC/1×10⁵ in the vaccine group, which was significantly enhanced compared with the PBS group (8±5.29 SFC/1×10⁵; P<0.01) and the AD-NC group (28±5.13 SFC/1×10⁵; P<0.01). The peptide HPV58 E7_72-80 (STTTDVRTL) displayed sufficient antigenicity to a vaccine contained HPV58 E7 antigen. Therefore, HPV58 E7_72-80 peptide may be considered as a candidate epitope peptide for the construction of HPV58 peptide vaccines.

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

BACKGROUND AND AIM

Human papillomavirus (HPV) is an oncogenic agent that causes over 90% of cases of cervical cancer in the world. Currently available prophylactic vaccines are type specific and have less therapeutic efficiency. Therefore, we aimed to predict the potential species-specific and therapeutic epitopes from the protein sequences of HPV45 by using different immunoinformatics tools.

METHODS

Initially, we determined the antigenic potential of late (L1 and L2) and early (E1, E2, E4, E5, E6, and E7) proteins. Then, major histocompatibility complex class I-restricted CD8⁺ T-cell epitopes were selected based on their immunogenicity. In addition, epitope conservancy, population coverage (PC), and target receptor-binding affinity of the immunogenic epitopes were determined. Moreover, we predicted the possible CD8⁺, nested interferon gamma (IFN-γ)-producing CD4⁺, and linear B-cell epitopes. Further, antigenicity, allergenicity, immunogenicity, and system biology-based virtual pathway associated with cervical cancer were predicted to confirm the therapeutic efficiency of overlapped epitopes.

RESULTS

Twenty-seven immunogenic epitopes were found to exhibit cross-protection (≥55%) against the 15 high-risk HPV strains (16, 18, 31, 33, 35, 39, 51, 52, 56, 58, 59, 68, 69, 73, and 82). The highest PC was observed in Europe (96.30%), North America (93.98%), West Indies (90.34%), North Africa (90.14%), and East Asia (89.47%). Binding affinities of 79 docked complexes observed as global energy ranged from -10.80 to -86.71 kcal/mol. In addition, CD8⁺ epitope-overlapped segments in CD4⁺ and B-cell epitopes demonstrated that immunogenicity and IFN-γ-producing efficiency ranged from 0.0483 to 0.5941 and 0.046 to 18, respectively. Further, time core simulation revealed the overlapped epitopes involved in pRb, p53, COX-2, NF-X1, and HPV45 infection signaling pathways.

CONCLUSION

Even though the results of this study need to be confirmed by further experimental peptide sensitization studies, the findings on immunogenic and IFN-γ-producing CD8⁺ and overlapped epitopes provide new insights into HPV vaccine development.

Sequence-based approach for rapid identification of cross-clade CD8+ T-cell vaccine candidates from all high-risk HPV strains

Human papilloma virus (HPV) is the primary etiological agent responsible for cervical cancer in women. Although in total 16 high-risk HPV strains have been identified so far. Currently available commercial vaccines are designed by targeting mainly HPV16 and HPV18 viral strains as these are the most common strains associated with cervical cancer. Because of the high level of antigenic specificity of HPV capsid antigens, the currently available vaccines are not suitable to provide cross-protection from all other high-risk HPV strains. Due to increasing reports of cervical cancer cases from other HPV high-risk strains other than HPV16 and 18, it is crucial to design vaccine that generate reasonable CD8+ T-cell responses for possibly all the high-risk strains. With this aim, we have developed a computational workflow to identify conserved cross-clade CD8+ T-cell HPV vaccine candidates by considering E1, E2, E6 and E7 proteins from all the high-risk HPV strains. We have identified a set of 14 immunogenic conserved peptide fragments that are supposed to provide protection against infection from any of the high-risk HPV strains across globe.

The acceptability of human papillomavirus (HPV) vaccination among women with physical disabilities

The present paper aims to explore awareness and acceptability of human papillomavirus (HPV) vaccination and to identify factors influencing HPV acceptability among women with physical disabilities in Taiwan. The study participants were 438 adult women with physical disabilities, aged 18-69 years. The participants were all officially registered as having physical disabilities in Taipei County, Taiwan, in March 2009. The major findings were that 54.5% of the participants had previously heard about the HPV vaccine and that vaccine acceptability was very low (3.2%) if the participants would have had to pay for the vaccine but would increase to 60% if the government were to provide the vaccine for free. We found that those participants who had had a Pap smear test within the past 1 year or 3 years were significantly more likely to be aware of and willing to receive the HPV vaccine than those who had not. To increase the HPV vaccination rate among women with physical disabilities, the study suggests that the current health care system in Taiwan should consider implementing free immunization for this group of women.