Preventing cervical cancer and genital warts - How much protection is enough for HPV vaccines?

Topical Application of Temperature-Sensitive Gel Containing Caerin 1.1 and 1.9 Peptides on TC-1 Tumour-Bearing Mice Induced High-Level Immune Response in the Tumour Microenvironment

The development of topical cream drugs that increase the immune activation of tumour-infiltrating lymphocytes against tumour and chronic viral infection-associated lesions is of great immunotherapeutic significance. This study demonstrates that the topical application of a temperature-sensitive gel containing caerin 1.1 and 1.9 peptides reduces nearly 50% of the tumour weight of HPV16 E6/E7-transformed TC-1 tumour-bearing mice via improving the tumour microenvironment. Confocal microscopy confirms the time-dependent penetration of caerin 1.9 through the epidermal layer of the ear skin structure of mice. Single-cell transcriptomic analysis shows that the caerin 1.1/1.9 gel expands the populations with high immune activation level and largely stimulates the pro-inflammatory activity of NK and dendritic cells. Closely associated with INFα response, Cebpb seems to play a key role in altering the function of all Arg1^hi macrophages in the caerin group. In addition, the caerin gel treatment recruits almost two-fold more activated CD8⁺ T cells to the TME, relative to the untreated tumour, which shows a synergistic effect derived from the regulation of S1pr1, Ccr7, Ms4a4b and Gimap family expression. The TMT10plex-labelling proteomic quantification further demonstrates the activation of interferon-alpha/beta secretion and response to cytokine stimulus by the caerin gel, while the protein contents of several key regulators were elevated by more than 30%, such as Cd5l, Gzma, Ifit1, Irf9 and Stat1. Computational integration of the proteome with the single-cell transcriptome consistently suggested greater activation of NK and T cells with the topical application of caerin peptide gel.

Is one dose of human papillomavirus vaccine as effective as three?: A national cohort analysis

AIM

Prophylactic human papillomavirus (HPV) vaccines are highly effective at preventing pre-cancerous cervical lesions when given in a three-dose schedule. Some post-hoc trial data suggest that one dose prevents HPV infection. If one dose could prevent pre-cancerous cervical lesions, then global cervical cancer prevention would be greatly facilitated. We assessed the effectiveness of quadrivalent HPV vaccine by number of doses against cervical intraepithelial neoplasia (CIN) 2 or 3/adenocarcinoma-in-situ (AIS)/cancer in Australia up to seven years post vaccination.

METHODS

We linked registry data from all 8 jurisdictional cervical screening registers, with the national HPV vaccination register, death index and cancer registers for all Australian women aged 15 or under when eligible for vaccine who screened between April 2007 (when vaccination commenced) and 31 December 2014. We performed Cox proportional hazard regression, adjusted a priori for age, socioeconomic status, and area of residence, to estimate hazard ratios of histologically confirmed CIN2/CIN3/AIS/cancer.

RESULTS

We included 250,648 women: 48,845 (19·5%) unvaccinated, 174,995 (69·8%) had received three doses, 18,190 (7·3%) two doses and 8,618 (3·4%) one dose. The adjusted hazard ratio was significantly lower for all dose groups compared to unvaccinated women (1 dose 0·65 (95%CI 0·52-0·81), 2 doses 0·61 (0·52-0·72) and 3 doses 0·59 (0·54-0·65).) With adjustment for age at vaccination amongst the vaccinated group, the adjusted hazard ratios for one dose and two dose recipients were comparable to three dose recipients (one dose 1.01 (95%CI 0.81-1.26), two doses 1.00 (0.85-1.17).) Multiple sensitivity analyses, including use of different dose assignment methods, produced consistent findings. Comparison with a historical cohort of age matched women showed that the result was not due to herd protection alone.

CONCLUSIONS

One dose had comparable effectiveness as two or three doses in preventing high-grade disease in a high coverage setting. These findings support the hypothesis that one dose vaccination may be a viable strategy when working towards the global elimination of cervical cancer.

Incidence of cervical high-grade squamous intraepithelial lesions in HIV-1-infected women with no history of cervical pathology: up to 17 years of follow-up

Currently, Papanicolaou smears are proposed at three-year intervals for cervical screening to all women living with HIV. The aim of this retrospective cohort study was to provide data on the incidence of cervical high-grade squamous intraepithelial lesions (HSIL) in cervical smear confirmed by histology in HIV-1-infected women (two consecutive normal Papanicolaou smears at baseline) after a long-term follow-up. Sixty-seven women (recruited between March 1999 and January 2003) were analyzed. The median period of follow-up was 13.2 years (range: 7.4-17.1 years) with a total of 583 Papanicolaou smears. Twenty-seven percent of these HIV-1-infected women had poorly-controlled HIV. Cumulative incidence of HSIL was 18% (12/67; 95%CI: 11-29%) of which one was an invasive squamous cell carcinoma and two were carcinoma in situ. These women had not been well-engaged with the annual Papanicolaou smear screening program and had poor adherence to antiretroviral therapy. Development of HSIL was associated with high-risk-HPV infection (OR: 14.9; 95%CI: 3.0, 75.1). At last Papanicolaou smear, prevalence of high-risk-HPV infection was 30% (20/66, 95%CI: 21-42%). In conclusion, the incidence of cervical HSIL in HIV-1-infected women with poor antiretroviral therapy adherence or poor immunological status reinforces the need to identify those HIV-1-infected women at risk of developing cervical cancer.

Early use of the HPV 2-dose vaccination schedule: Leveraging evidence to support policy for accelerated impact

Although human papillomavirus (HPV) vaccines were initially licensed based on efficacy after three-dose regimens in women aged 15-26 years, it was recognized early in clinical development that comparable immunogenicity could be obtained after just two doses when administered to younger girls. In both Canada and Mexico, public health authorities made the decision to administer two doses 6 months apart with a planned additional dose at 60 months, while simultaneously doing further study to determine if the third dose would confer meaningful additional benefit. This delayed third dose approach permitted a more cost-effective program with opportunities for improved compliance while minimizing injections and leaving open the opportunity to provide a full three-dose vaccination series. It required close cooperation across many governmental and civil society leadership bodies and real-time access to emerging data on HPV vaccine effectiveness. Although still limited, there is increasing evidence that even one-dose vaccination is sufficient to provide prolonged protection against HPV infection and associated diseases. Ongoing clinical trials and ecological studies are expected to consolidate existing data regarding one dose schedule use. However, to accelerate the preventive effect of HPV vaccination some jurisdictions, in particular those with limited resources may already consider the initiation of a one dose vaccination with the possibility of giving the second dose later in life if judged necessary. Such an approach would facilitate vaccination implementation and might permit larger catch-up vaccination programs in older girls (or as appropriate, girls and boys), thereby accelerating the impact on cervical cancer and other HPV-associated diseases.

The Prevalence of Genus Alpha Human Papillomavirus in Women with Uterine Cervical Infection and/or Inflammation in Western Iran

Introduction:

Human papillomavirus (HPV) infection is strongly associated with risk of cervical cancer and genital warts.

Aim:

The study aimed to report the prevalence of genus alpha human papillomavirus (HPV) types in women with cervical infection and/or inflammatory in Western Iran.

Materials and Methods:

In a cross-sectional study, 435 women were clinically diagnosed with cervical infections. The method of HPVs detection was polymerase chain reaction (PCR). The majority of patients (304 patients) did Pap smear based on liquid-based specimens.

Results:

Out of 435 patients, 150 patients (34.5%) had HPV positivity that the prevalence of high-risk HPVs was 52.7%. Out of 76 patients with Pap smear positivity, 68.4% had atypical squamous cells of undetermined significance cytology class and 31.6% had low-grade squamous intraepithelial lesion cytology class. The most prevalence rate of HPV was in age ≤30 years. HPV 16 and HPV 56 were the most prevalence rate among high-risk HPVs. Overall HPV alpha-10 (59%) and HPV alpha-9 (32.2%) had the most prevalence rate.

Conclusions:

Among high-risk HPVs, HPV 16 was the most common HPV detected in our population with a very low prevalence of HPV 18. In addition, HPV 6 and then HPV 11 had the most prevalence rate in the women with uterine cervix (cervical) infection among low-risk HPVs.

Explanations for the high potency of HPV prophylactic vaccines

HPV L1 virus-like particle (VLP) vaccines administered in a prime/boost series of three injections over six months have demonstrated remarkable prophylactic efficacy in clinical trials and effectiveness in national immunization programs with high rates of coverage. There is mounting evidence that the vaccines have similar efficacy and effectiveness even when administered in a single dose. The unexpected potency of one dose of these VLP vaccines may largely be attributed to structural features of the particles, which lead to the efficient generation of long-lived antigen-specific antibody-producing cells and unique features of the virus life cycle that make the HPV virions highly susceptible to antibody-mediated inhibition of infection.

A Genetically Modified attenuated Listeria Vaccine Expressing HPV16 E7 Kill Tumor Cells in Direct and Antigen-Specific Manner

Attenuated Listeria monocytogenes (L. monocytogenes, LM) induces specific CD8⁺ and CD4⁺ T cell responses, and has been identified as a promising cancer vaccine vector. Cervical cancer is the third most common cancer in women worldwide, with human papillomavirus (HPV), particularly type 16, being the main etiological factor. The therapeutic HPV vaccines are urgently needed. The E7 protein of HPV is necessary for maintaining malignancy in tumor cells. Here, a genetically modified attenuated LM expressing HPV16 E7 protein was constructed. Intraperitoneal vaccination of LM4Δhly::E7 significantly reduced tumor size and even resulted in complete regression of established tumors in a murine model of cervical cancer. We provided evidence that recombinant LM strains could enter the tumor tissue and induce non-specific tumor cell death, probably via activation of reactive oxygen species and increased intracellular Ca²⁺ levels. LM4Δhly::E7 effectively triggered a strong antigen-specific cellular immunity in tumor-bearing mice, and elicited significant infiltration of T cells in the intratumoral milieu. In summary, these data showed LM4Δhly::E7 to be effective in a cervical cancer model and LM4Δhly::E7 induced an antitumor effect by antigen-specific cellular immune responses and direct killing of tumor cells, indicating a potential application against cervical cancer.

Controlled Hybrid-Assembly of HPV16/18 L1 Bi VLPs in Vitro

Based on the helix4-exchanged HPV16 L1 and HPV18 L1, HPV16 L1 Bi and HPV18 L1 Bi, we have successfully realized the controlled hybrid-assembly of HPV16/18 L1 Bi VLPs (bihybrid-VLPs) in vitro. The bihybrid-VLPs were further confirmed by fluorescence resonance energy transfer (FRET) and complex-immunoprecipitation (Co-IP) assays. The ratio of 16 L1 Bi and 18 L1 Bi in bihybrid-VLPs was verified to be 3:5 based on a modified magnetic Co-IP procedure, when mixing 1 equiv pentamer in assembly buffer solution, but it changed with conditions. In addition, the bihybrid-VLPs showed identical thermal stability as that of normal VLPs, suggesting high potential in practical applications. The present study is significant because it modified one of the vital steps of virus life cycle at the stage of virus assembly, supplying a new approach not only to deepen structural insights but also a possibility to prepare stable, low-cost, bivalent antivirus vaccine. Furthermore, the controlled hybrid-assembly of bihybrid-VLPs in vitro provides suggestions for the design of effective multivalent hybrid-VLPs, being a potential to develop broad-spectrum vaccines for the prevention of infection with multiple types of HPV.