Human Papillomavirus L1 Research Articles

Characterization of an Escherichia coli-derived human papillomavirus type 16 and 18 bivalent vaccine.

Human papillomavirus (HPV) types 16 and 18 account for approximately 70% of cervical cancer worldwide. Neutralizing HPV prophylactic vaccines offer significant benefit, as they block HPV infection and prevent subsequent disease. However, the three licensed HPV vaccines that cover these two genotypes were produced in eukaryotic cells, which is expensive, particularly for low-income countries where HPV is highest. Here, we report a new HPV16 and -18 bivalent candidate vaccine produced from Escherichia coli. We used two strategies of N-terminal truncation of HPV L1 proteins and soluble non-fusion expression to generate HPV16 and HPV18 L1-only virus-like particles (VLPs) in a scalable process. Through comprehensive characterization of the bivalent candidate vaccine, we confirm lot consistency in a pilot scale-up of 30L, 100L and 500L. Using cryo-EM 3D reconstruction, we found that HPV16 and -18VLPs present in a T=7 icosahedral arrangement, similar in shape and size to that of the native virions. This HPV16/18 bivalent vaccine shares comparable immunogenicity with the licensed vaccines. Overall, we show that the production of a HPV16/18 bivalent vaccine from an E. coli expression system is robust and scalable, with potentially good accessibility worldwide as a population-based immunization strategy.

Beta Human Papillomavirus Infection Is Prevalent in Elephantiasis and Exhibits a Productive Phenotype: A Case-Control Study.

Elephantiasis is considered a cutaneous region of immune deficiency with cobblestone-like surface caused by a wart-like eruption. Verrucosis is a diffuse human papillomavirus (HPV) infection linked to immunodeficiency disorders. The objective of this study was to examine the prevalence of HPV infection in lymphedema and its pathogenic role in elephantiasis. A retrospective case-control study was performed examining lymphedematous skin and controls of peritumoral normal skin. HPV infection was evaluated at the DNA, protein, and histopathologic levels by polymerase chain reaction, immunohistochemistry, and light microscopy, respectively. Overall, 540 HPV DNAs were detected in 120 of 122 cutaneous samples (median 4 HPV DNAs per sample, range 0-9). Compared with controls, no differences existed in type or number of HPVs identified. Instead, a diverse spectrum of HPV-related histopathologies were evident, likely reflecting the multiplicity of HPV genotypes detected. Most notably, increasing histopathologic lymphedema stage significantly correlated with markers of productive HPV infection such as altered keratohyaline granules and HPV L1 capsid expression. Limitations of this study are the absence of normal skin controls not associated with neoplasia or subclinical lymphedema, and lack of assessment of HPV copy number per keratinocyte infected. In conclusion, productive HPV infection, not HPV type or numbers detected, distinguished lymphedematous skin from controls. These findings support the theory that lymphedema creates a region of depressed immunity that permits productive HPV infection, manifested clinically by diffuse papillomatosis, characteristic of elephantiasis.

Recurrent respiratory papillomatosis (RRP)-time for a reckoning?

ObjectivesRecurrent respiratory papillomatosis (RRP) is a rare disease, but one with severe morbidity and occasional mortality. The aetiological agent is human papillomavirus (HPV), and HPV types 6 and 11 account for over 90% of all cases. In the active phase of the disease, patients require multiple hospital admissions for surgical removal or ablation of these benign tumors, which are likely to obstruct the airways if left unchecked. Long‐term sequelae include scarring of the vocal cords, change in voice timbre, or even muteness if a tracheostomy is required. The aim of this study was to determine if adjuvant vaccination with the quadrivalent HPV L1 vaccine (Gardasil™) would decrease numbers of surgical treatments post‐vaccination.MethodsA prospective pilot study following a cohort of 12 RRP patients, all of whom gave fully informed consent to participate. All patients had their papillomas typed and if they were found to have types 6 or 11, were vaccinated at the time of first surgical treatment in the hospital, according to the manufacturer's protocols. Patients were followed up closely with 3 or 6 month follow‐up visits. Standard surgical treatments were given and were not affected by whether they participated in the study.ResultsWe found a >7‐fold decrease in the incidence rates of papillomatosis requiring surgical intervention from the pre‐vaccination period (47.44/1000 patient‐months) compared to the post‐vaccination period (6.71/1000 patient‐months).DiscussionSurgical treatments for RRP are robust markers for papillomata which require treatment because of the dangers of obstruction of the airway. Despite the small size of this cohort (due to the rarity of this disease), the data suggests that adjuvant use of quadrivalent HPV L1 vaccine imparts significant benefit to this group of patients. A large multi‐center randomized placebo controlled trial is required to definitively establish whether this hypothesis is true and can become the new standard of therapy.Level of Evidence3b

Clinical significance of CK7, HPV-L1, and koilocytosis for patients with cervical low-grade squamous intraepithelial lesions: a retrospective analysis

Most cervical low-grade squamous intraepithelial lesions (LSILs) do not progress to high-grade squamous intraepithelial lesions (HSILs); however, reliable biomarkers that predict LSIL progression are lacking. We investigated the association of cytokeratin 7 (CK7), human papillomavirus-L1 capsid protein (HPV-L1), and koilocytosis with clinical outcomes of patients with LSIL. CK7, HPV-L1, Ki67, and p16-INK4A expression was determined in 72 cervical LSIL and 28 HSIL biopsy samples; koilocytosis was evaluated by reviewing biopsy slides. Fifty patients with LSIL received follow-up. CK7, HPV-L1, and koilocytosis were detected in 48.6%, 44.4%, and 52.0% of LSIL tissues and in 78.6%, 10.7%, and 64.3% of HSIL tissues, respectively. Lesion grade was correlated directly with CK7 expression (P=.007) and inversely with HPV-L1 expression (P=.004). CK7 expression in LSILs was correlated inversely with HPV-L1 expression and directly with p16-INK4A and Ki67 status. Furthermore, koilocytosis was significantly associated with HPV-L1 and p16-INK4A expression. Progression to cervical intraepithelial lesions of grades ≥2 occurred in 34% of cases. CK7 negativity and HPV-L1 positivity were significantly associated with lower HSIL progression rates. HPV-L1-positive and CK7-negative LSILs showed significantly lower progression rates compared with HPV-L1-negative and CK7-positive LSILs (6.3% v-positive cases showed a significantly lower progression rate (17.6%) compared with nonkoilocytic and HPV-L1-negative cases (50%). CK7-negative, HPV-L1-positive, and koilocytic LSILs showed a progression rate of 7.7%. Koilocytosis and p16-INK4A were not significantly associated with clinical outcomes. Hence, evaluating HPV-L1, CK7, and koilocytosis profiles combined may be more reliable for LSIL prognostication.

HPV L1 and P16 Expression in CIN1 to Predict Future CIN2.

The goal of this study was to use the biomarkers human papillomavirus (HPV) L1 and p16 to develop an algorithm that could triage the individual patient with CIN1 at risk for progression. A total of 82 patients initially diagnosed with CIN1 at Peking University Shenzhen Hospital in China had their initial and follow-up paraffin-embedded tissue blocks immune-stained for HPV L1 capsid protein and p16. For CIN1, any staining of abnormal epithelium was considered positive. All patients were followed until they developed CIN2+ or for ≥3 years. About 38 patients regressed (HPV-, Cytology-), 17 persisted (CIN1), and 27 progressed (≥CIN2+). At initial diagnosis, HPV L1 capsid protein was expressed in 42.7% of the CIN1 cases. There was no difference in L1 expression among the 3 groups. However, p16-positive staining in the progression group was significantly higher than in the regression group (P<0.05). In the regression group, the proportion of HPV L1-/p16- category was significantly higher than that in the progression group. In the progression group, when CIN1 lesions progressed to CIN2+, the L1-positive rate was significantly decreased from 51.9% to 18.5%, the p16+/HPV L1+ rate decreased from the initial (44.4%) to the final diagnosis (14.8%), and the p16+/HPV L1- rate increased from the initial (25.9%) to the final diagnosis (66.7%). P16 expression is a clear risk factor for the progression of CIN1. The p16-/HPV L1- pattern was significantly associated with the regression of CIN1. Moving from CIN1 to CIN2+ over time, p16+/HPV L1+ decreased, and p16+/HPV L1- increased. Unfortunately, our objective of finding a sensitive and specific triage algorithm for the individual patient with CIN1 was not achieved.

Characterizing the spatio-temporal role of sorting nexin 17 in human papillomavirus trafficking.

The human papillomavirus (HPV) L2 capsid protein plays an essential role during the early stages of viral infection. Previous studies have shown that the interaction between HPV L2 and endosomal sorting nexin 17 (SNX17) is conserved across multiple PV types where it plays an essential role in infectious entry, suggesting an evolutionarily conserved pathway of PV trafficking. Here we show that the peak time of interaction between HPV-16 L2 and SNX17 is rather early, at 2 h post-infection. Interestingly, the L2-SNX17 interaction appears to be important for facilitating capsid disassembly and L1 dissociation, suggesting that L2 recruitment of SNX17 occurs prior to capsid disassembly. Furthermore, we also found evidence of L2-SNX17 association at the later stages of infectious entry, suggesting that the SNX17-mediated sorting machinery is either involved at different stages of HPV trafficking or that L2-SNX17 interaction is a long-lasting event in HPV trafficking.

Epitope design of L1 protein for vaccine production against Human Papilloma Virus types 16 and 18.

Cervical cancer accounts for about two-thirds of all cancer cases linked etiologically to Human Papilloma Virus (HPV). 15 oncogenic HPV types can cause cervical cancer, of which HPV16 and HPV18 combinedly account for about 70% of it. So, effective epitope design for the clinically relevant HPV types 16 and 18 would be of major medical benefit. Here, a comprehensive analysis is carried out to predict the epitopes against HPV types 16 and 18 through “reverse vaccinology” approach. We attempted to identify the evolutionarily conserved regions of major capsid protein (L1) as well as minor capsid protein (L2) of HPV and designed epitopes within these regions. In this study, we analyzed about 49 and 27 sequences of HPV L2 and L1 proteins respectively. Since we found that the intertype variability of L2 is higher than for L1 proteins, our analysis was emphasized on epitopes of L1 of HPV types 16 and 18. We had selected HLA-A*0201, DRB1*1501, DQB1*0602, DRB1*0401 and DQB1*0301 alleles for the prediction of T cell epitopes of L1 of HPV 16 and 18. Finally, we reported that predicted epitope sequences EEYDLQFIFQLCKITLTA, and RHGEEYDLQFIFQLCKITLTA of L1 protein of HPV 16, and LPDPNKF, PETQRLVWAC, PVPGQYDA, YNPETQRLVWAC, DTGYGAMD, PVPGQYDATK, KQDIPKVSAYQYRVFRV, RDNVSVDYKQTQLCI and YSRHVEEYDLQFIF of L1 protein of HPV 18 could be therapeutic tools for vaccine design against HPV.

Stop codon mutagenesis for homogenous expression of human papillomavirus L1 protein in Escherichia coli

Human papillomavirus (HPV) is widely accepted to be the major causative pathogen of cervical cancer, warts, and other epithelial tumors. Virus infection and subsequent disease development can be prevented by vaccination with HPV vaccines derived from eukaryotic expression systems. Here, we report the soluble expression of the major capsid protein L1 of HPV31, a dominant carcinogenic HPV genotype, in Escherichia coli. HPV31 L1 protein and its elongated form (L1+) were observed in SDS-PAGE and CE-SDS analysis, generated by the native HPV31 L1 gene with a TAA stop codon. Replacing the TAA with TAG but not TGA could completely terminate protein translation. Mass spectrometry sequencing showed that L1+ comprised L1 with a C-terminal extension of 38 amino acids (aa). RNA folding analysis revealed that the unfaithful L1+ expression may result from translational read-through, as TAG is more stable and accessible than the other stop codons. The 38-aa elongated fragment perturbs self-assembly of HPV31 L1+, as shown in size and morphology analyses. By 3D cryo-electron microscopy structure determination, we show self-assembly of purified HPV31 L1 (TAG) VLPs into T = 7 icosahedral symmetry particles, resembling the native HPV virion. Finally, through additional characterization and antigenicity/immunogenicity assays, we verified that the E.coli-derived HPV31 VLPs are an ideal immunogen for HPV vaccine development. Our findings outline a codon optimization stratagem for protein expression and provide a method for the in-depth investigation of prokaryotic translation regulation.

Increased HPV L1 gene methylation and multiple infection status lead to the difference of cervical epithelial cell lesion in different ethnic women of Xinjiang, China.

Human papillomavirus (HPV) L1 gene methylation deeply involved in the progression and heterogeneity of cervical cell epithelial lesions. The DNA ploidy also represented the early lesions of cervical cell, and it was associated with different HPV infection status in different ethnic women. So, the research was to explore whether it was possible that HPV L1 gene methylation and HPV infection status as the risk factors to lead to the differences of cervical epithelial cells’ lesions in different ethnics women.The flow-through hybridization and gene chip for HPV genotypes test, general characteristics, and cervical exfoliated cell samples were collected from 94 Uygur and 79 Han women with HPV-16 infection. The cases were divided into the single HPV-16 (sHPV-16) infection group and multiple HPV-16 (mHPV-16) infection group in each ethnic women. The DNA ploidy was analyzed by flow cytometry, and the methylation-sensitive high resolution melting (MS-HRM) was used to test the HPV-16 L1 gene methylation, the results of methylation was segmented into mild methylation, moderate methylation, and severe methylation groups. Multifactor logistic analysis explored the relation between DNA heteroploid and HPV-16 infection status, HPV-16 L1 gene methylation in different ethnic women.The higher proportion of mHPV-16 infection in Uygur than Han women (61.7% vs 38.0%). L1 gene methylation had statistic difference between single and mHPV-16 infection under the same ethnic women. The proportion of DNA heteroploid had statistic difference between different HPV-16 infection status or different L1 gene methylation grades in Han or Uygur women. Both L1 gene methylation and HPV infection status were the risk factors of DNA heteroploid. Compared to the sHPV-16 infection, the odds ratio (OR) of mHPV-16 infection were 4.409 (CI: 1.398–13.910) and 3.279 (CI: 1.069–10.060) in Han and Uygur women. Compared the mild L1 gene methylation, the OR of moderate L1 gene methylation were 3.313 (CI: 1.002–10.952) and 5.075 (CI: 1.385–18.603) in Han and Uygur women, the OR of severe L1 gene methylation were 20.592 (CI: 3.691–114.880) and 63.634 (CI: 10.400–389.368) in Han and Uygur women.The study first reported that HPV L1 gene methylation and HPV infection status were the risk factors to the DNA heteroploid of cervical cell in different ethnics women, HPV L1 gene methylation and infection status should be recommended to the existing system of cervical lesion screening in order to provide better serves for the HPV infected women, especially for the ethnic women with high proportion of severe L1 gene methylation and multiple infection status.

Genital Human Papillomavirus Infection in Indian HIV-Seropositive Men Who Have Sex With Men.

The incidence of penile cancer in Indian men is high. Little is known about genital human papillomavirus (HPV) infection in Indian HIV-seropositive men who have sex with men (MSM), a population that may be at particularly high risk for genital HPV infection and, potentially, penile cancer. In this study, we assessed the prevalence and risk factors for genital HPV infection in this population. Three hundred HIV-seropositive MSM were recruited from 2 clinical sites in India. They were tested for genital HPV infection using L1 HPV DNA polymerase chain reaction with probes specific for 29 types and a mixture of 10 additional types. Participants received an interviewer-administered questionnaire that included questions on demographics and behaviors. Human papillomavirus data were available from 299 participants. The prevalence of any HPV type in the penis and scrotum was 55% and 54%, respectively. Human papillomavirus type 35 was the most common oncogenic HPV type followed by HPV-16. In multivariate analysis, being the insertive partner with 100+ male partners increased the odds of any penile HPV infection compared with not being insertive with any partners (odds ratio, 2.5; 95% confidence interval, 1.3-5.1). Circumcision was protective against penile HPV infection (odds ratio, 0.39; 95% confidence interval, 0.19-0.76). The prevalence of penile and scrotal HPV infection was high among Indian HIV-seropositive MSM. The most common oncogenic HPV type in this population, HPV-35, is not included in any currently available HPV vaccines. Insertive anal sex with men and lack of circumcision were the primary risk factors for penile HPV infection in this population.

Comparison of FFPE histological versus LBP cytological samples for HPV detection and typing in cervical cancer

Human papillomavirus (HPV) infection is closely associated with cervical cancer. This study analyzed HPV genotype prevalence in 75 cases of formalin-fixed paraffin embedded (FFPE) tissue samples from patients diagnosed with cervical cancer. Genotype prevalence was assessed using Reverse Blot Assay (REBA) and quantitative polymerase chain reaction (qPCR), which target the HPV L1 and HPV E6/E7 genes, respectively. HPV DNA chip tests were also performed using liquid based preparation (LBP) cytological samples from the same patients who provided the FFPE histological samples. We observed a slight difference in HPV genotype distribution as assessed by DNA chip versus REBA. One possible explanation for this difference is that normal regions could be mixed with lesion regions when cytological samples are extracted from each patient with cancer. For the detection of moderate dysplasia, the main target of diagnosis, this difference is anticipated to be greater. We also made several unexpected observations. For example, HPV multi-infection was not detected. Moreover, the rate of HPV positivity varied radically depending on the cancer origin, e.g. squamous cell carcinoma versus adenocarcinoma.Our results imply that it is important to determine whether cytological specimens are suitable for HPV genotyping analysis and cervical cancer diagnosis. Future research on the mechanisms underlying cervical cancer pathogenesis is also necessary.

Enhancement of humoral and cell mediated immune response to HPV16 L1-derived peptides subsequent to vaccination with prophylactic bivalent HPV L1 virus-like particle vaccine in healthy females

Currently prophylactic HPV16/18 L1 virus-like particle (VLP) vaccines are employed with great success for the prevention of HPV infection. However, limited information is available regarding the immune responses against human papillomavirus (HPV) 16/18 L1 subsequent to HPV16/18 L1 VLP vaccination, primarily due to the lack of widely used assays for immune monitoring. The aim of the present study was to identify HPV16 L1-derived B and T cell epitopes for monitoring the immune responses after HPV16/18 L1 VLP vaccination in healthy females. The levels of immunoglobulin G (IgG), IgE, IgA and IgM reactive to HPV16 L1-derived peptides were measured by multiplex bead suspension assay. Following detailed B cell epitope mapping, T cell responses specific to HPV16 L1-derived peptides were evaluated by an IFN-γ ELISPOT assay. The levels of IgG, IgM and IgA reactive to 20-mer peptides (PTPSGSMVTSDAQIFNKPYW) at positions 293-312 and 300-319 of HPV16 L1 were significantly increased in the plasma after 2, 7, and 12 months after first vaccination. Detailed epitope mapping identified the amino acid sequence (TSDAQIFNKP) at position 301-310 of HPV16 L1 as an immunogenic B cell epitope. In addition, T cell responses to an HLA-A2- and HLA-A24-restricted epitope (QIFNKPYWL) at position 305-313 of HPV16 L1 were increased following immunization, suggesting that the HPV16/18 L1-VLP vaccination as able to induce specific immune responses in T and B cells simultaneously. The identified B and T cell epitopes may be useful as a biomarker for monitoring the immune responses subsequent to HPV16/18 L1 VLP vaccination. Thus, the present study may provide novel information to improve the understanding of the immune responses to HPV16 L1.

Quantitative Measurement of L1 Human Papillomavirus Type 16 Methylation for the Prediction of Preinvasive and Invasive Cervical Disease.

Methylation of the human papillomavirus (HPV) DNA has been proposed as a novel biomarker. Here, we correlated the mean methylation level of 12 CpG sites within the L1 gene, to the histological grade of cervical precancer and cancer. We assessed whether HPV L1 gene methylation can predict the presence of high-grade disease at histology in women testing positive for HPV16 genotype. Pyrosequencing was used for DNA methylation quantification and 145 women were recruited. We found that the L1 HPV16 mean methylation (±SD) significantly increased with disease severity (cervical intraepithelial neoplasia [CIN] 3, 17.9% [±7.2] vs CIN2, 11.6% [±6.5], P < .001 or vs CIN1, 9.0% [±3.5], P < .001). Mean methylation was a good predictor of CIN3+ cases; the area under the curve was higher for sites 5611 in the prediction of CIN2+ and higher for position 7145 for CIN3+. The evaluation of different methylation thresholds for the prediction of CIN3+ showed that the optimal balance of sensitivity and specificity (75.7% and 77.5%, respectively) and positive and negative predictive values (74.7% and 78.5%, respectively) was achieved for a methylation of 14.0% with overall accuracy of 76.7%. Elevated methylation level is associated with increased disease severity and has good ability to discriminate HPV16-positive women that have high-grade disease or worse.

HPV and systemic lupus erythematosus: a mosaic of potential crossreactions.

Etiology, pathogenesis, and immunology of systemic lupus erythematosus (SLE) form a complex, still undeciphered picture that recently has been further made complicated by a new factor of morbidity: human papillomaviruses (HPVs). Indeed, a prevalence of HPV infections has been reported among SLE patients. Searching for molecular mechanisms that might underlie and explain the relationship between HPV infection and SLE, we explored the hypothesis that immune responses following HPV infection may crossreact with proteins that, when altered, associate with SLE. Analyzing HPV L1 proteins and using Epstein-Barr virus (EBV) and human retrovirus (HERV) as controls, we found a vast peptide overlap with human proteins comprehending lupus Ku autoantigen proteins p86 and p70, lupus brain antigen 1 homolog, lupus antigen expressed in neurons and muscles, natural killer cell IgG-like receptors, complement proteins C4-A and C4-B, complement receptor CD19, and others. The multitude and heterogeneity of peptide overlaps not only further support the hypothesis that crossreactivity can represent a primum movens in SLE onset, but also provide a molecular framework to the concept of SLE as "an autoimmune mosaic syndrome." Finally, once more, it emerges the need of using the principle of peptide uniqueness as a new paradigm for safe and efficacious vaccinology.

HUMAN PAPILLOMA VIRUS IMMUNOGEN CREATION ON THE BASE OF CHIMERIC RECOMBINANT PROTEIN L2E7

The cervical cancer is one of the most common diseases in world. This malignancy is the seventh highest prevalence oncological disease worldwide and the second highest prevalence oncological disease of women in the world. Meanwhile women need to be infected by human papilloma virus (HPV) is absolutely necessary for it further evolution, HPV DNA was found in 99.97% cases of disease. Except cervical cancer, HPV cause 85% of rectal cancer, 50% of the vulva, vagina and penis cancers, 20% of oropharyngeal cancer and 10% of larynx and esophagus cancers. In 2009, 14 000 women were diagnosed with cervical cancer in Russia. The growth in morbidity was 19% (in comparison with 1999). The most effective recognised measure for almost each infection prophylaxis is a vaccination. Two human papilloma virus vaccines are available in Russia nowadays Gardasil and Cervarix, produced in Belgium and the Netherlands respectively. Cervarix is a bivalent vaccine based on virus-like particles (VLP) of two types. Recombinant major capsid proteins L1 HPV 16 and HPV 18 express in baculovirus expression system and self-assembled into virus-like particles (about 70 percent of cervical cancers are caused by HPV 16 and HPV 18). VLP of each strain produced in different baculovirus vectors and then combined in single drug. Gardasil is like Cervarix with few exceptions. Producing organisms are fungi S. cerevisiae in this case, and this vaccine contains low-risk HPV 6 and HPV 11 VLP. Thus, Gardasil is quadrivalent HPV-6/11/16/18 vaccine. These vaccines are very effective in averting infection of disease and dont have significant side-effects, however they have some disadvantages. Firstly, they have a high price because of necessity of their expression in eukaryotic cells. Secondly, they are strain-specific, so vaccines are completely effective only for viruss strains which are represented in the vaccine. Thirdly, it`s the absence of therapeutic (treatment of established infection) value of stated vaccines. According to information from literature, N-terminus of the L2 protein can induce non strain-specific neutralizing antibody that protects organism from papillomavirus challenge. E7 protein is a virus oncogene, its function is unlimited proliferation of infected cells that cause malignization in chronic course of disease. This protein is a very attractive target for therapeutic vaccines because of its necessity both for virus life cycle and sustenance of malignant phenotype in cancer cells. So, in this research the design of immunogen on the base of proteins HPV L2 and E7 is selected, vaccine on the base of which will avoid the disadvantages of Gardasil and Cervarix listed above. The stain-producer of protein on the base of cells E. coli was created. The protein was purified in denaturing reducing conditions by metal-affine chromatography and refold by sequential remove of urea and 2-mercaptoethanol.

Colorimetric Detection of 23 Human Papillomavirus Genotypes by Loop-Mediated Isothermal Amplification.

Human papillomavirus (HPV) infection is linked to cervical cancer. With the technological development of molecular biology and epidemiology, detection and treatment of HPV has become an important mean to prevent cervical cancer. A simple, rapid, and sensitive colorimetric loop-mediated isothermal amplification (LAMP) method was established herein to detect 23 HPV genotypes. The sequences of the primers for the LAMP reaction were located in the L1 gene of the HPV genome. As it is a fluorescent dye, calcein was added before the reaction. The reaction was run under isothermal conditions at 65°C for 40 minutes. A positive reaction was indicated by a color change from yellow to fluorescent green. The fluorescence curve diagram represents the monitoring of real time quantitative instrument. 450 cervical swab samples from patients with single infections of 23 different HPV genotypes were examined to evaluate the specificity. The results revealed no cross-reaction with other HPV genotypes. A serial dilution of a cloned plasmid containing 23 HPV L1 gene sequences was employed to evaluate the sensitivity. Different HPV subtypes have different detection capability. The sensitivity of different HPV subtypes tested by LAMP assay was in the range from 1.0 x10 to 4.0 x 103 copies per reaction. The LAMP assay and the RDB (reverse dot blot) were compared for detecting and genotyping HPV among the 450 clinical samples. There were 385 (85.6%) and 375 (83.3%) HPV positive specimens detected by LAMP and RDB, respectively, as well as 306 (68.0%) and 296 (65.8%) for HR-HPV positive specimens. The agreement between the LAMP and RDB assays was 93.3% (κ = 0.75) for HPV positivity and 94.7% (κ = 0.88) for HR-HPV positivity. It was concluded that this colorimetric LAMP assay had potential application for the rapid screening of the HPV infection in resource-limited hospitals or rural clinics.

Efficacy of Human Papillomavirus L1 Protein Vaccines (Cervarix and Gardasil) in Reducing the Risk of Cervical Intraepithelial Neoplasia: A Meta-analysis.

Human papillomavirus (HPV) can induce cervical intraepithelial neoplasia (CIN). Vaccination against HPV can play an important role in CIN prevention. This study aims to estimate the efficacy of L1 protein vaccines (Cervarix and Gardasil) in CIN 1, 2, 3 risk reduction using meta-analysis. Relevant articles were identified by two independent researchers searching international databanks. After application of inclusion/exclusion criteria and quality assessment, eligible articles were entered into the final meta-analysis. Inverse variance method and fixed effect model were used to combine the results of the primary studies. The heterogeneity between the results was assessed using Cochrane and I2 indices. Of 11,530 evidence identified during the primary search, three papers were found eligible for meta-analysis, including 7213 participants in the intervention groups and 7170 healthy controls. The efficacy (95% confidence interval) of HPV 6, 11, 16, 18 monovalent and quadrivalent vaccines against CIN 1, CIN 2, and CIN 3 were estimated as of 95% (88–98), 97% (85–99), and 95% (78–99), respectively. This study showed that L1 protein vaccines Cervarix and Gardasil are highly protective vaccines playing an effective role in the prevention of HPV 6, 11, 16, 18 which are responsible for CIN 1, CIN 2, and CIN 3.

Immunization of mice by a multimeric L2-based linear epitope (17-36) from HPV type 16/18 induced cross reactive neutralizing antibodies.

Current licensed and commercially available prophylactic human papillomavirus (HPV) vaccines (Cervarix and quadrivalent/nine valents Gardasil) are based on major capsid protein L1 virus-like particles (VLPs) production which are expensive and type specific. Minor capsid L2-RG1 linear epitope (17-36) is a known candidate for induction of cross-neutralizing antibodies to develop low-cost pan-HPV vaccines. Herein, we report construction and expression of a three tandem repeats of L2-RG1 derived from HPV16 and 18 fused with the same head to tail pattern (HPV16:17-36×3+ HPV18:17-36×3; hereafter termed dual-type fusion L2 peptide) in E. coli and provide the results of its immunogenicity in mice. SDS-PAGE and western blot analyses indicated proper expression of the peptide that could be further purified by Ni-NTA affinity chromatography via the located C-terminal 6xHis-tag. Mice immunized by formulation of the purified peptide and Freund adjuvant raised neutralizing antibodies which showed proper cross reactivity to HPV L2 (11-200) of types: 18, 16, 31 and 45 (which totally are responsible for 90% of cervical cancers) and efficiently neutralized HPV18/16 pseudoviruses in vitro. Our results imply the possibility of development of a simple, low-cost preventive HPV vaccine based on this dual-type fusion L2 peptide in bacterial expression system with broad spectrum.

Enantioselective Inhibition of Human Papillomavirus L1 Pentamer Formation by Chiral‐Proline Modified Calix[4]arenes: Targeting the Protein Interface

AbstractAlthough current human papillomavirus (HPV) vaccines can protect well against infection, they are effective only for a limited number of subtypes. Coupled with the dilemma that no efficient prescription is currently clinically available for therapy, there is an urgent need to develop new anti‐HPV agents. In the present study l‐ and d‐Proline modified calix[4]arenes (Pro‐C4 A) were investigated to determine any differences in their effect on the assembly of HPV 16 L1 pentamer (L1‐p). The mechanism of action using model peptides was investigated by Matrix‐Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI‐TOF‐MS) and Nuclear Magnetic Resonance (NMR) and revealed that the binding was targeting the basic residues at L1 interface. This was also well supported by the trypsin digestion experiments and molecular simulations performed on the full‐length L1. The large energy and morphology differences revealed by molecular simulations explain the binding disparity of l‐ and d‐Pro‐C4 A to L1, and consequently the selective inhibition of them on L1‐p formation. The present study opens a way to develop enantioselective and cost‐effective inhibitors for L1‐p formation, which might be used as a new kind of anti‐HPV agent and could be extended to other viruses based on similar mechanisms.

Prevalencia de tipos de virus del papiloma humano en hombres que tienen sexo con hombres, en Chihuahua, México

The aim of this work was to determine human papilloma virus (HPV) high and low risk (HR and LR) genotypes prevalence, and other HPV infection associated risk factors, in men who have sex with men (MSM). A cross-sectional study was conducted, to this end, 104 MSM responded a social demographic and sexual behavior questionnaire and consented sampling of anal epithelium for molecular analysis by polymerase chain reaction (PCR), with β -globin primers as internal control, and HPV L1 region primers. Subsequently, typing was performed by sequencing. Prevalence of HPV in MSM was 34%: 10% HR and 24% LR. The most frequent oncogenic HPV types were 16 (20%), 73 (20%) and 45 (20%), and non-oncogenic VPH 11 (36%), 62 (28%) and 6 (12%). MSM less than 30 years old had greater HPV prevalence. Presence of human immunodeficiency virus (HIV) was not significantly associated to HPV infection in the studied population.