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1.  Prior Human Polyomavirus and Papillomavirus Infection and Incident Lung Cancer: A Nested Case-Control Study 
Cancer causes & control : CCC  2015;26(12):1835-1844.
To test whether infection with select human polyomaviruses (HPyV) and human papillomaviruses (HPV) is associated with incident lung cancer.
We performed a nested case-control study, testing serum from the Carotene and Retinol Efficacy Trial (CARET), conducted 1985–2005, for antibodies to Merkel cell (MCV), KI (KIV), and WU (WUV) HPyVs as well as to six high-risk and two low-risk HPV types. Incident lung cancer cases (n=200) were frequency-matched with controls (n=200) on age, enrollment and blood draw dates, intervention arm assignment, and the number of serum freeze / thaw cycles. Sera were tested using multiplex liquid bead microarray antibody assays. We used logistic regression to assess the association between HPyV and HPV antibodies and lung cancer.
There was no evidence of a positive association between levels of MCV, KIV, or WUV antibodies and incident lung cancer (P-corrected>0.10 for all trend tests; odds ratio (OR) range 0.72 to 1.09, P-corrected>0.10 for all). There was also no evidence for a positive association between HPV 16 or 18 infection and incident lung cancer (P-corrected≥0.10 for all trend tests; OR range 0.25 to 2.54, P>0.05 for all OR>1), but the number of persons with serologic evidence of these infections was small.
Prior infection with any of several types of HPyV or HPV was not associated with subsequent diagnosis of lung cancer. Infection with these viruses likely does not influence a person’s risk of lung cancer in Western smoking populations.
PMCID: PMC4628600  PMID: 26415892
lung cancer; KI polyomavirus; WU polyomavirus; Merkel cell polyomavirus; HPV
2.  A population-based case-control study of genetic variation in cytokine genes associated with risk of cervical and vulvar cancers 
Gynecologic oncology  2015;139(1):90-96.
Persistent infection with oncogenic human papillomavirus (HPV) is known to be the necessary cause of cervical cancer and a majority of vulvar cancers. Persistent HPV infections must evade host immune responses, including cytokines released by activated T-helper (Th) cells. In this study, we investigated the risk of cervical and vulvar cancer associated with common genetic variations in 560 tagging single-nucleotide polymorphisms (SNPs) in candidate cytokine genes.
The study included 399 invasive squamous cell carcinomas (SCC) and 502 in situ or invasive adenocarcinomas (AC) of the cervix; 357 in situ or invasive vulvar SCC; and 1,109 controls from the Seattle-area case-control studies of HPV-related cancers. Logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) using a log additive model, with adjustment for multiple testing.
Statistically significant risks were observed for HPV16-containing SCC of the cervix with the variant allele rs879576 in IL17RA and rs2229094 in TNF [OR, 95% CI and multiple-testing corrected p: 1.91(1.30-2.79), p= 0.018 and 0.61 (0.45-0.83), p= 0.02, respectively). We also observed significantly increased risk of HPV-positive vulvar cancers associated with variant alleles in CSF2 (rs25882 and rs27438, 26-28% increased risk) and IL-12B (rs2569254 and rs3181225, 40-41% increased risk) genes.
We found that variation in several Th-cytokine genes are significantly associated with cervical and vulvar cancer risk. The strong association between these HPV-related cancers and common variation in cytokine genes in the Th1 and Th17 pathways may be important for development of new therapies.
PMCID: PMC4587291  PMID: 26241630
Cervical cancer; Vulvar cancer; T-helper 1 pathways; T-helper 2 pathway; T-helper 17 pathway; genetic variation
3.  Analysis of Liquid Bead Microarray Antibody Assay Data for Epidemiologic Studies of Pathogen-Cancer Associations 
Liquid bead microarray antibody (LBMA) assays are used to assess pathogen-cancer associations. However, studies analyze LBMA data differently, limiting comparability.
We generated 10,000 Monte Carlo-type simulations of log-normal antibody distributions (exposure) with 200 cases and 200 controls (outcome). We estimated type I error rates, statistical power, and bias associated with t-tests, logistic regression with a linear exposure and with the exposure dichotomized at 200 units, 400 units, the mean among controls plus two standard deviations, and the value corresponding to the optimal sensitivity and specificity. We also applied these models, and data visualizations (kernel density plots, receiver operating characteristic (ROC) curves, predicted probability plots, and Q-Q plots), to two empirical datasets to assess the consistency of the exposure-outcome relationship.
All strategies had acceptable type I error rates (0.03≤P≤0.048), except for the dichotomization according to optimal sensitivity and specificity, which had a type I error rate of 0.27. Among the remaining methods, logistic regression with a linear predictor (Power=1.00) and t-tests (Power=1.00) had the highest power to detect a mean difference of 1.0 MFI (median fluorescence intensity) on the log scale and were unbiased. Dichotomization methods upwardly biased the risk estimates.
These results indicate that logistic regression with linear predictors and unpaired t-tests are superior to logistic regression with dichotomized predictors for assessing disease associations with LBMA data. Logistic regression with continuous linear predictors and t-tests are preferable to commonly used LBMA dichotomization methods.
PMCID: PMC4604026  PMID: 26071614
liquid bead microarray antibody assay; median fluorescence intensity; cut-point; dichotomization; visualization
4.  Human papillomaviruses: shared and distinct pathways for pathogenesis 
Over 200 types of human papillomaviruses (HPV) have been identified that infect epithelial cells at different anatomic locations. HPVs are grouped into five genra with the alpha and beta viruses being the most commonly studied. Members of the alpha HPV genus infect genital epithelia and are the causative agents of many anogenital cancers. Beta HPVs infect cutaneous epithelia and have been suggested as co-factors in the development of non-melanoma skin cancers. Recent studies have shown that activation of DNA damage pathways is important for the productive life cycle of the alpha HPVs while the beta viruses suppress their activation. These differences likely contribute to the varying types of lesions and malignancies that are associated with these viruses.
PMCID: PMC4628885  PMID: 26398222
6.  Minimally Mutated HIV-1 Broadly Neutralizing Antibodies to Guide Reductionist Vaccine Design 
PLoS Pathogens  2016;12(8):e1005815.
An optimal HIV vaccine should induce broadly neutralizing antibodies (bnAbs) that neutralize diverse viral strains and subtypes. However, potent bnAbs develop in only a small fraction of HIV-infected individuals, all contain rare features such as extensive mutation, insertions, deletions, and/or long complementarity-determining regions, and some are polyreactive, casting doubt on whether bnAbs to HIV can be reliably induced by vaccination. We engineered two potent VRC01-class bnAbs that minimized rare features. According to a quantitative features frequency analysis, the set of features for one of these minimally mutated bnAbs compared favorably with all 68 HIV bnAbs analyzed and was similar to antibodies elicited by common vaccines. This same minimally mutated bnAb lacked polyreactivity in four different assays. We then divided the minimal mutations into spatial clusters and dissected the epitope components interacting with those clusters, by mutational and crystallographic analyses coupled with neutralization assays. Finally, by synthesizing available data, we developed a working-concept boosting strategy to select the mutation clusters in a logical order following a germline-targeting prime. We have thus developed potent HIV bnAbs that may be more tractable vaccine goals compared to existing bnAbs, and we have proposed a strategy to elicit them. This reductionist approach to vaccine design, guided by antibody and antigen structure, could be applied to design candidate vaccines for other HIV bnAbs or protective Abs against other pathogens.
Author Summary
Many HIV vaccine design efforts aim to elicit so-called broadly neutralizing antibodies that bind and neutralize diverse strains and subtypes of the virus. However, these efforts are guided by very unusual antibodies isolated from HIV-infected individuals. These antibodies have rare features that limit their use as direct vaccine templates, because it is unlikely that any vaccine could consistently elicit similar antibodies. We engineered HIV broadly neutralizing antibodies that minimized these rare features and may therefore serve as better leads for HIV vaccine design. Antibodies generally gain affinity for their target epitope by accumulating mutations in a natural process of maturation. Figuring out how to use vaccines to elicit particular kinds of antibodies, with particular kinds of helpful mutations, is a major unsolved challenge for vaccine design. We were able to determine which mutations in our new antibodies are most important and which epitope structures are needed to induce those mutations. This analysis allowed us to deduce a logical strategy, which remains to be tested, for how to guide the maturation of these types of antibodies by vaccination. We propose that this reductionist approach to vaccine design, guided by molecular structure and engineering-oriented to allow for optimization, has promise for designing vaccines against HIV and many other pathogens.
PMCID: PMC4999182  PMID: 27560183
7.  Natural Antibodies to Human Papillomavirus 16 and Recurrence of Vulvar High-Grade Intraepithelial Neoplasia (VIN3) 
Recurrence of high-grade intraepithelial neoplasia of the vulva (VIN3) was less frequent among women with detectable human papillomavirus 16 antibodies.
Approximately 30% of women treated for squamous high-grade intraepithelial neoplasia (VIN3), often associated with human papillomavirus (HPV), have recurrent disease. In this study, we assess predictors of recurrence that may provide targets for early prevention or treatment.
Materials and Methods
Women with VIN3 who participated in a previous population-based case-control study with blood and tumor samples completed a follow-up telephone interview an average of 5 years after initial diagnosis. The risk of recurrence was determined by proportional hazards modeling.
Women with VIN3 in the follow-up study (n = 65) were similar to women with VIN3 in the parent study (n = 215) with regard to age at primary diagnosis, level of current cigarette smoking (>60%), and lifetime number of partners. We found that 22 (33.8%) of 65 participants had a vulvar recurrence and that 73.4% recurred within 3 years of treatment. Recurrences occurred more often among women with common warts in the decade before diagnosis (hazard ratio [HR] = 2.5, 95% CI = 1.1–5.8) and among those with a previous anogenital cancer (HR = 2.7, 95% CI = 1.2–6.3). Interestingly, recurrence was less frequent among women who mounted a natural antibody response to HPV16 (HR = 0.4, 95% CI = 0.2–0.9).
These data provide strong preliminary evidence that VIN3 recurrence was less frequent among those with HPV16 antibodies. Vaccination with the currently licensed HPV vaccine as part of adjunctive therapy for VIN3 would increase antibody response and may decrease risk of recurrence. Randomized controlled trials are needed to determine whether HPV vaccination is effective against VIN3 recurrence.
PMCID: PMC4920724  PMID: 27224532
high-grade vulvar intraepithelial neoplasia (VIN3); HPV antibodies; vulvar recurrence
8.  A Single Human Papillomavirus Vaccine Dose Improves B Cell Memory in Previously Infected Subjects 
EBioMedicine  2016;10:55-64.
Although licensed human papillomavirus (HPV) vaccines are most efficacious in persons never infected with HPV, they also reduce infection and disease in previously infected subjects, indicating natural immunity is not entirely protective against HPV re-infection. The aim of this exploratory study was to examine the B cell memory elicited by HPV infection and evaluate whether vaccination merely boosts antibody (Ab) levels in previously infected subjects or also improves the quality of B cell memory. Toward this end, the memory B cells (Bmem) of five unvaccinated, HPV-seropositive subjects were isolated and characterized, and subject recall responses to a single HPV vaccine dose were analyzed. Vaccination boosted Ab levels 24- to 930-fold (median 77-fold) and Bmem numbers 3- to 27-fold (median 6-fold). In addition, Abs cloned from naturally elicited Bmem were generally non-neutralizing, whereas all those isolated following vaccination were neutralizing. Moreover, Ab and plasmablast responses indicative of memory recall responses were only observed in two subjects. These results suggest HPV vaccination augments both the magnitude and quality of natural immunity and demonstrate that sexually active persons could also benefit from HPV vaccination. This study may have important public policy implications, especially for the older ‘catch-up’ group within the vaccine's target population.
•Five women with naturally elicited human papillomavirus (HPV) 16 antibodies (Abs) were given a single HPV vaccine dose.•Vaccination boosted anti-HPV Ab levels, memory B cell numbers, and frequency of neutralizing Abs cloned from memory B cells.•Therefore, HPV vaccine augments natural immunity to HPV.
Persons infected with oncogenic human papillomavirus (HPV) types may remain susceptible to re-infection despite eliciting immune responses to HPV. It is unclear whether licensed HPV vaccines can provide additional immunologic benefit to these persons. To investigate this question, the B cell memory of five previously infected subjects was examined before and after they received an HPV vaccine dose. Vaccination increased HPV-specific antibody and memory B cell levels. We also found more antibodies cloned from post-vaccination, HPV-specific memory B cells were potently neutralizing than those cloned from pre-vaccination cells. These results show vaccination augments natural HPV immunity in previously infected subjects.
PMCID: PMC5006801  PMID: 27423190
Human papillomavirus; Vaccine; Memory B cells
9.  Absence of an association of human polyomavirus and papillomavirus infection with lung cancer in China: a nested case–control study 
BMC Cancer  2016;16:342.
Studies of human polyomavirus (HPyV) infection and lung cancer are limited and those regarding the association of human papillomavirus (HPV) infection and lung cancer have produced inconsistent results.
We conducted a nested case–control study to assess the association between incident lung cancer of various histologies and evidence of prior infection with HPyVs and HPVs. We selected serum from 183 cases and 217 frequency matched controls from the Yunnan Tin Miner’s Cohort study, which was designed to identify biomarkers for early detection of lung cancer. Using multiplex liquid bead microarray (LBMA) antibody assays, we tested for antibodies to the VP1 structural protein and small T antigen (ST-Ag) of Merkel cell, KI, and WU HPyVs. We also tested for antibodies against HPV L1 structural proteins (high-risk types 16, 18, 31, 33, 52, and 58 and low-risk types 6 and 11) and E6 and E7 oncoproteins (high risk types 16 and 18). Measures of antibody reactivity were log transformed and analyzed using logistic regression.
We found no association between KIV, WUV, and MCV antibody levels and incident lung cancer (P-corrected for multiple comparisons >0.10 for all trend tests). We also found no association with HPV-16, 18, 31, 33, 52, and 58 seropositivity (P-corrected for multiple comparisons >0.05 for all).
Future studies of infectious etiologies of lung cancer should look beyond HPyVs and HPVs as candidate infectious agents.
Electronic supplementary material
The online version of this article (doi:10.1186/s12885-016-2381-3) contains supplementary material, which is available to authorized users.
PMCID: PMC4888628  PMID: 27246610
Lung cancer; Human polyomavirus; KI polyomavirus; WU polyomavirus; Merkel cell polyomavirus; Human papillomavirus
Oral diseases  2014;21(3):349-354.
We conducted a cross-sectional study to describe the prevalence and correlates of type-specific human papillomavirus DNA in the oral cavities of persons with Fanconi Anemia.
Materials and Methods
Oral swabs were collected from 67 participants with Fanconi Anemia and tested for 27 human papillomavirus genotypes using polymerase chain reaction-based methods.
Participants were a mean of 18.6 (standard deviation, 10.0) years of age (range 4 to 47 years). The prevalence of oral human papillomavirus infection was 7.5%, and the prevalence of high-risk human papillomavirus infection was 6.0%. Human papillomavirus type 16 was not detected in any samples. Prevalence was higher in adults than in children (13.3% versus 2.7% in those ≥18 versus <18 years of age). Among adults, prevalence was higher in males than in females (25.0% versus 9.1% respectively).
Prevalence of oral human papillomavirus infection in persons with Fanconi Anemia was comparable to estimates from other studies in the general population. However, in contrast to previous studies, we did not identify human papillomavirus type 16 (the type found in most human papillomavirus-related head and neck cancers) in any participants.
PMCID: PMC4344428  PMID: 25158861
Fanconi Anemia; oral human papillomavirus; head and neck squamous cell carcinoma
11.  Skin and Mucosal Human Papillomavirus Seroprevalence in Persons with Fanconi Anemia 
Persons with Fanconi anemia (FA) are at risk for human papillomavirus (HPV)-associated cancers; however, their natural HPV exposure and infection rates are unknown as is the adequacy with which they mount antibodies to HPV vaccination. This study aimed to determine, in 62 persons with FA, the seroprevalence of skin and mucosal HPV types, the seroprevalence in individuals self-reporting a history of HPV vaccination, and the factors associated with HPV seropositivity. A bead Luminex assay was used to determine seropositivity for HPV1, -2, and -4 (low-risk skin), -6 and -11 (low-risk mucosal, included in one HPV vaccine), -16 and -18 (high-risk mucosal, included in both HPV vaccines), and -52 and -58 (high-risk mucosal). Health- and behavior-related questionnaires were completed. Type-specific seroprevalence estimates and participant characteristics associated with seroprevalence were calculated; 48% reported HPV vaccination. Type-specific seropositivity in unvaccinated persons ranged from 7 to 21% for skin HPV types and 7 to 38% for mucosal HPV types. Among the unvaccinated participants, adults versus children demonstrated increased HPV1, -6, -16, and -58 seroprevalence of 45% versus 6%, 64% versus 22%, 64% versus 17%, and 36% versus 0%, respectively (all P < 0.05). The vaccinated participants versus the nonvaccinated participants demonstrated increased seroprevalence of HPV6, -11, -16, and -18 of 92% versus 38%, 92% versus 24%, 96% versus 34%, and 75% versus 7%, respectively (all P < 0.0001). Our data demonstrate that the unvaccinated participants had serologic evidence of prior skin and mucosal HPV infections and that seroprevalence increased among adults; in self-reported vaccinees, seroprevalence of HPV vaccine types was 75 to 96%.
PMCID: PMC4375352  PMID: 25651924
13.  β-HPV 5 and 8 E6 Disrupt Homology Dependent Double Strand Break Repair by Attenuating BRCA1 and BRCA2 Expression and Foci Formation 
PLoS Pathogens  2015;11(3):e1004687.
Recent work has explored a putative role for the E6 protein from some β-human papillomavirus genus (β-HPVs) in the development of non-melanoma skin cancers, specifically β-HPV 5 and 8 E6. Because these viruses are not required for tumor maintenance, they are hypothesized to act as co-factors that enhance the mutagenic capacity of UV-exposure by disrupting the repair of the resulting DNA damage. Supporting this proposal, we have previously demonstrated that UV damage signaling is hindered by β-HPV 5 and 8 E6 resulting in an increase in both thymine dimers and UV-induced double strand breaks (DSBs). Here we show that β-HPV 5 and 8 E6 further disrupt the repair of these DSBs and provide a mechanism for this attenuation. By binding and destabilizing a histone acetyltransferase, p300, β-HPV 5 and 8 E6 reduce the enrichment of the transcription factor at the promoter of two genes critical to the homology dependent repair of DSBs (BRCA1 and BRCA2). The resulting diminished BRCA1/2 transcription not only leads to lower protein levels but also curtails the ability of these proteins to form repair foci at DSBs. Using a GFP-based reporter, we confirm that this reduced foci formation leads to significantly diminished homology dependent repair of DSBs. By deleting the p300 binding domain of β-HPV 8 E6, we demonstrate that the loss of robust repair is dependent on viral-mediated degradation of p300 and confirm this observation using a combination of p300 mutants that are β-HPV 8 E6 destabilization resistant and p300 knock-out cells. In conclusion, this work establishes an expanded ability of β-HPV 5 and 8 E6 to attenuate UV damage repair, thus adding further support to the hypothesis that β-HPV infections play a role in skin cancer development by increasing the oncogenic potential of UV exposure.
Author Summary
Human Papillomaviruses are a family of viruses with over 100 different members that infect mucous membranes and skin. Infections with some of these viruses are linked to cancers of the cervix and oropharynx. In this work, we explore the question of whether other members of this virus family may also contribute to skin cancer by inhibiting the ability of cells to repair the damage caused from UV exposure. Here, we build on our previous work showing that the E6 protein from two of these viruses (β-HPV 5 and 8) reduces the cellular response to UV damage by decreasing the abundance of two cellular proteins (p300 and ATR) involved in repairing the UV-damaged DNA, leading to more double strand DNA breaks following UV exposure. Here we show that the loss of p300 has further deleterious consequences, specifically that it results in diminished expression of two proteins (BRCA1 and BRCA2) involved in the repair of double strand breaks. Our data shows that this results in fewer BRCA1 and BRCA2 repair foci forming at sites of damage and ultimately in attenuated repair of these lesions. Together, this work provides further support for a link between β-HPV infections and skin cancer.
PMCID: PMC4372404  PMID: 25803638
14.  Genetic variation in the TLR and NF-κB genetic pathways and cervical and vulvar cancer risk: a population-based case-control study 
Genital infection with the oncogenic human papillomavirus (HPV) is the necessary cause of cervical cancer and of a large fraction of vulvar cancers. The toll-like receptor (TLR) and the nuclear factor κB (NF-κB) signaling pathways have been implicated in inflammation, autoimmune disease and cancer, but whether common nucleotide variation in these pathways is associated with the risk of cervical and vulvar cancers has received little study. Using data from a population-based case-control study of cervical and vulvar cancers, we genotyped 205 single nucleotide polymorphisms (SNPs) in and around 32 candidate gene regions within these pathways. Gene-based analyses were employed to estimate the associations between individual gene regions and the risk of cervical and vulvar cancers. Odds ratio (OR) and 95% confidence intervals (CI) were calculated to assess the risk of cervical and vulvar cancers for each SNP. P-values were adjusted for multiple testing. A total of 876 cervical cancer cases, 517 vulvar cancer cases and 1,100 controls were included in the analysis. The TNF region was significantly associated with the risks of cervical cancer (gene-based P-value: 2.0×10−4) and vulvar cancer (gene-based P-value: 1.0×10−4). The rare allele (A) of SNP rs2239704 in the 5′ UTR of the LTA gene was significantly associated with increased risks of cervical cancer (OR=1.31, 95% CI: 1.15–1.50; adjusted P-value: 0.013) and vulvar cancer (OR=1.51, 95% CI: 1.30–1.75; adjusted P-value: 1.9×10−5). These findings add to the evidence of the importance of the immune system in the etiology of cervical and vulvar cancers.
PMCID: PMC3883910  PMID: 23824834
cervical cancer; vulvar cancer; toll-like receptor; nuclear factor-κB; tumor necrosis factor
15.  Cohort Profile: The Skin Cancer After Organ Transplant Study 
The Skin Cancer after Organ Transplant (SCOT) study was designed to investigate the link between genus beta human papillomavirus (HPV) and squamous cell skin cancer (SCSC). We focused on a population receiving immunosuppressive therapy for extended periods, transplant patients, as they are at extremely high risk for developing SCSC. Two complementary projects were conducted in the Seattle area: (i) a retrospective cohort with interview data from 2004 recipients of renal or cardiac transplants between 1995 and 2010 and (ii) a prospective cohort with interview data from 328 people on the transplant waiting lists between 2009 and 2011. Within the retrospective cohort, we developed a nested case–control study (172 cases and 337 control subjects) to assess risk of SCSC associated with markers of HPV in SCSC tumour tissue and eyebrow hair bulb DNA (HPV genotypes) and blood (HPV antibodies). In the prospective cohort, 135 participants had a 1-year post-transplant visit and 71 completed a 2-year post-transplant visit. In both arms of the cohort, we collected samples to assess markers of HPV infection such as acquisition of new types, proportion positive for each type, persistence of types at consecutive visits and number of HPV types detected. In the prospective cohort, we will also examine these HPV markers in relation to levels of cell-mediated immunity. The goal of the SCOT study is to use the data we collected to gain a more complete understanding of the role of immune suppression in HPV kinetics and of genus beta HPV types in SCSC. For more information, please contact the principal investigator through the study website:
PMCID: PMC3887562  PMID: 23171871
16.  Beta Human Papillomavirus E6 Expression Inhibits Stabilization of p53 and Increases Tolerance of Genomic Instability 
Journal of Virology  2014;88(11):6112-6127.
Infections with the beta genus of human papillomaviruses (β-HPVs) may contribute to the development of nonmelanoma skin cancers. However, β-HPV genomes are found at too low a copy number in tumors for the virus to be necessary for tumor maintenance. Instead, they are hypothesized to destabilize the host genome by allowing the persistence of mutations that can drive tumorigenesis independently of the viral genome. Supporting this premise is our previous finding that the expression of some β-HPV E6 proteins can attenuate p53 signaling in response to DNA damage. We show that β-HPV E6 proteins can prevent the stabilization of p53 in response to two types of genome-destabilizing events, aberrant mitosis and dysregulated centrosome duplication. The inability to stabilize p53 in response to these stimuli allows cells expressing HPV5, HPV8, or HPV38 E6 to remain proliferatively active, leading to further genome deterioration in a proportion of these cells. These phenotypes are lost by the introduction of a mutation into the p300 binding domain of HPV8 E6 or by the transfection of mutated p300 that is resistant to the degradation mediated by HPV5 or HPV8 E6. These findings expand the understanding of the role played by p300 in promoting the faithful resolution of mitotic figures as well as proper centrosome duplication. Finally, we describe a phenomenon by which binucleated cells are resolved via cytokinesis into two cells, each with one nucleus. These data support the hypothesis that β-HPV infections may promote tumorigenesis via genome destabilization.
IMPORTANCE The work described in this report provides support for the hypothesis that β-HPV infections may contribute to nonmelanoma skin cancer by increasing the likelihood that tumorigenic mutations are introduced into the host cell's genome. We demonstrate that expression of the E6 proteins from some of these viruses increases the tolerance of two genome-destabilizing events, aberrant cell division and dysregulated centrosome duplication. Typically, these mutagenic occurrences elicit the stabilization of the tumor suppressor p53, which prevents further propagation of cells containing these errors. We show that the expression of β-HPV E6 restricts this stabilization of p53, leading not only to continued cellular proliferation but also to further accumulation of similar mutagenic events. Finally, in addition to supporting a role for β-HPV infections in certain skin cancers, we present studies with a mutated β-HPV E6 protein suggesting that the histone acetyltransferase p300 plays a role in promoting genome stability during replication.
PMCID: PMC4093859  PMID: 24648447
17.  An unbiased in vivo screen reveals multiple transcription factors that control HPV E6-regulated hTERT in keratinocytes 
Virology  2013;446(0):17-24.
Activation of telomerase by human papillomavirus 16 (HPV16) E6 is a critical step for cell immortalization and transformation in human foreskin keratinocytes (HFKs). Multiple transcription factors have been identified as being involved in E6-induced hTERT expression. Here, we adapted an unbiased in vivo screen using a LacO-LacI system in human cells to discover hTERT promoter-interacting regulators. This approach allowed us to identify a novel hTERT repressor, Maz, which bound the hTERT promoter. E6 expression reduced Maz binding and correspondingly increased Sp1 binding at the hTERT promoter. Knockdown of Maz further increased histone acetylation, as well as hTERT expression in the presence of E6. Overall, these data indicate the utility of a novel screen for promoter-interacting and transcription-regulating proteins. These data also highlight multiple factors that normally regulate hTERT repression in HFKs, and therefore are targeted by E6 for hTERT expression.
PMCID: PMC3787310  PMID: 24074563
HPV E6; hTERT; Keratinocytes; Maz; Sp1
18.  Characteristics of Memory B Cells Elicited by a Highly Efficacious HPV Vaccine in Subjects with No Pre-existing Immunity 
PLoS Pathogens  2014;10(10):e1004461.
Licensed human papillomavirus (HPV) vaccines provide near complete protection against the types of HPV that most commonly cause anogenital and oropharyngeal cancers (HPV 16 and 18) when administered to individuals naive to these types. These vaccines, like most other prophylactic vaccines, appear to protect by generating antibodies. However, almost nothing is known about the immunological memory that forms following HPV vaccination, which is required for long-term immunity. Here, we have identified and isolated HPV 16-specific memory B cells from female adolescents and young women who received the quadrivalent HPV vaccine in the absence of pre-existing immunity, using fluorescently conjugated HPV 16 pseudoviruses to label antigen receptors on the surface of memory B cells. Antibodies cloned and expressed from these singly sorted HPV 16-pseudovirus labeled memory B cells were predominantly IgG (>IgA>IgM), utilized diverse variable genes, and potently neutralized HPV 16 pseudoviruses in vitro despite possessing only average levels of somatic mutation. These findings suggest that the quadrivalent HPV vaccine provides an excellent model for studying the development of B cell memory; and, in the context of what is known about memory B cells elicited by influenza vaccination/infection, HIV-1 infection, or tetanus toxoid vaccination, indicates that extensive somatic hypermutation is not required to achieve potent vaccine-specific neutralizing antibody responses.
Author Summary
There is an urgent need to better understand how to reliably generate effective vaccines, particularly subunit vaccines, as certain pathogens are considered to pose too great of a safety risk to be developed as live, attenuated or killed vaccines (e.g., HIV-1). The human papillomavirus (HPV) vaccines are two of the most effective subunit vaccines ever developed and have continued to show protection against HPV associated disease up to and beyond five years post-vaccination. Moreover, the target population for these vaccines have essentially no pre-existing immunity to the HPV types covered by the vaccine; therefore, these vaccines provide an excellent model for studying the immunity elicited by a highly effective subunit vaccine. As the HPV vaccines, like most vaccines, protect by generating antibodies, we are interested in characterizing the memory B cells elicited by the HPV vaccine. Memory B cells help to sustain antibody levels over time by rapidly differentiating into antibody secreting cells upon pathogen re-exposure. Although previous studies have provided evidence that the HPV vaccines elicit memory B cells, they did not characterize these cells. Here, we have isolated HPV-specific memory B cells from adolescent females and women who received the quadrivalent HPV vaccine and have cloned antibodies from these cells. Importantly, we find that these antibodies potently inhibit HPV and that the memory B cells from which they derive exhibit hallmarks of long-lived memory B cells.
PMCID: PMC4199765  PMID: 25330199
19.  Risk of squamous cell skin cancer after organ transplant associated with antibodies to cutaneous papillomaviruses, polyomaviruses, and TMC6/8 (EVER1/2) variants 
Cancer Medicine  2014;3(5):1440-1447.
Squamous cell skin cancer (SCSC) disproportionately affects organ transplant recipients, and may be related to increased viral replication in the setting of immune suppression. We conducted a nested case–control study among transplant recipients to determine whether SCSC is associated with antibodies to cutaneous human papillomaviruses (HPV), to genes associated with a rare genetic susceptibility to HPV (TMC6/TMC8), or to human polyomaviruses (HPyV). Cases (n = 149) had histologically confirmed SCSC, and controls (n = 290) were individually matched to cases on time since transplant, type of transplant, gender, and race. All subjects had serum drawn immediately prior to transplant surgery. Antibodies to 25 cutaneous HPVs and six HPyVs were assayed by detection of binding to virus-like particles, and 11 TMC6/8 variants were genotyped. After correction for multiple comparisons, only antibodies to HPV37 were associated with SCSC (OR 2.0, 95% CI 1.2–3.4). Common genetic variants of TMC6/8 were not associated with SCSC, but three variants in TMC8 (rs12452890, rs412611, and rs7208422) were associated with greater seropositivity for species 2 betapapillomaviruses among controls. This study suggests that some betaHPVs, but not polyomaviruses, may play a role in the excess risk of SCSC among transplant recipients.
PMCID: PMC4302694  PMID: 24913986
Cutaneous human papillomavirus; epidemiology; organ transplant; polyomavirus; squamous cell skin cancer
20.  HPV 5 and 8 E6 Expression Reduces ATM Protein Levels and Attenuates LINE-1 Retrotransposition 
Virology  2013;443(1):10.1016/j.virol.2013.04.022.
The expression of the E6 protein from certain members of the HPV genus β (β HPV 5 and 8 E6) can disrupt p53 signaling by diminishing the steady state levels of two p53 modifying enzymes, ATR and p300. Here, we show that β-HPV 5 and 8 E6 are also capable of reducing the steady state levels of another p53 modifying enzyme, ATM, and as a result restrict LINE-1 retrotransposition. Furthermore, we show that the reduction of both ATM and LINE-1 retrotransposition is dependent upon the ability of β-HPV 8 E6 to bind and degrade p300. We use inhibitors and dominant negative mutants to confirm that ATM is needed for efficient LINE-1 retrotransposition. Furthermore, neither sensitivity to LINE-1 expression nor LINE-1 induced DSB formation is altered in an ATM deficient background. Together, these data illustrate the broad impact some β-HPVs have on DNA damage signaling by promoting p300 degradation.
PMCID: PMC3873879  PMID: 23706308
Retrotransposition; ATM; LINE-1; beta HPV E6; DNA Damage Repair
21.  Redetection of Cervical Human Papillomavirus Type 16 (HPV16) in Women With a History of HPV16 
The Journal of Infectious Diseases  2013;208(3):403-412.
Background. The purpose of this study was to examine the rate of and risks for cervical human papillomavirus type 16 (HPV16) redetection in women with documented or suspected HPV16 infection.
Methods. A convenience sample of women aged 13–21 years were seen at 4-month intervals for HPV DNA testing and cytology. Serum samples were obtained at baseline and annually.
Results. A total of 1543 women entered the study. Of the 295 women with detection of HPV16 DNA and subsequent clearance, 18.1% had HPV16 redetected by 8.5 years (88% cleared this second detection by 3 years). Of the 247 women who had antibodies to HPV16 and were HPV16 DNA negative at baseline, 15.3% had HPV16 redetected by year 5. Risks for redetection included douching, current use of medroxyprogesterone, reporting >1 sex partner or having a new sex partner, and having a sexually transmitted infection. Development of cervical intraepithelial neoplasia 2/3 was rare in women with redetection, except for those with prevalent HPV16 infection.
Conclusions. Reappearance of HPV16 DNA was observed in 18% of women. Most are associated with sexual exposure and appear benign. Interpretation of the studies is more complex in women with prevalent infections as it appears that this small subset reflects women with persistence already present at entry.
PMCID: PMC3699002  PMID: 23599313
redetection of HPV16; reactivation; risk for acquisition; risk for clearance
22.  Nucleotide variation in IL10 and IL12 and their receptors and cervical and vulvar cancer risk: a hybrid case-parent triad and case-control study 
Given the important role of cell mediated immunity in viral clearance and control of premalignant lesions, we hypothesize that variation in the IL12/IL10 cytokine and cytokine receptor genes may influence cervical and vulvar cancer risk. We evaluated 76 tagSNPs from 7 candidate genes (IL10, IL12A, IL12B, IL10RA, IL10RB, IL12RB1, and IL12RB2) in case-parent sets (n=43 cervical squamous cell carcinoma (SCC), n=96 cervical adenocarcinoma, n=53 vulvar SCC), additional cases (n=356 cervical SCC, n=406 cervical adenocarcinoma, and n=473 vulvar SCC) and population based controls (1,111). We calculated log-additive odds ratios (ORs) and 95% confidence intervals (CIs) for the association between tagSNP and cancer risk using a pseudo-likelihood based method which combined genotype information on cases, parents, and population controls. After correction for multiple comparisons, we identified several statistically significant SNP associations. Cervical SCC risk was associated with the minor alleles of the IL10RA rs9610 3′ UTR SNP (OR=1.76, 95% CI= 1.15–2.68) and two synonymous IL12RB2 SNPs (rs4297265, OR=0.46, 95% CI=0.26–0.82; rs2229546, OR=0.43, 95% CI=0.21–0.87). Cervical adenocarcinoma risk was associated with the minor alleles of the IL10RA rs4252314 intronic SNP (OR=2.23, 95% CI = 1.26–3.96) and IL12RB1 rs11575934 non-synonymous SNP (OR=1.51, 95% CI=1.12–2.05). Finally, the minor allele of the IL12B rs3181224 3′ UTR SNP was associated with a reduced risk of vulvar SCC (OR=0.30, 95% CI=0.12–0.74). These results raise the possibility that a shift in the balance of the immune response due to genetic variants in key cytokine genes could influence the development of cervical and vulvar cancer.
PMCID: PMC3833442  PMID: 23280621
Cervical cancer; vulvar cancer; case-parent; interleukin 12; interleukin 10
23.  Risk of Cervical Cancer Associated with Chlamydia trachomatis Antibodies by Histology, HPV Type, and HPV Cofactors 
Human papillomavirus (HPV) is the central etiologic factor for cervical cancer, and prior studies suggested C. trachomatis may act as an HPV cofactor. We examined the C. trachomatis—cervical cancer association by serotype, histology, HPV type in the tumor, and other HPV cofactors. We conducted a population-based study in the Seattle-Puget Sound area of 302 women with invasive squamous cell carcinomas (SCC), 185 women with adenocarcinomas of the cervix (AC), and 318 HPV seropositive control women. The risk of SCC associated with antibodies to C. trachomatis was increased (OR 1.6, 95% CI 1.1–2.2) but not for AC (OR 1.0, 95% CI 0.6–1.5). This association was independent of HPV type in the SCC tumor tissue. There was an association between specific serotypes of C. trachomatis and SCC for 6 of the 10 serotypes: B (OR 3.6, 95% CI 1.5–8.4), D (OR 2.1, 95% CI 1.2–3.5), E (OR 2.4, 95% CI 1.4–3.9), G (OR 3.0, 95% CI 1.1–7.9), I (OR 4.2, 95% CI 1.5–11.7), and J (OR 2.3, 95% CI 1.0–5.1), but not for the 4 types (C, F, H, and K) that were present at very low prevalence in this population. There was an increased risk of SCC, but not AC, associated with antibodies to C. trachomatis that was not serotype specific.
PMCID: PMC4049152  PMID: 17096345
Chlamydia trachomatis; HPV; cervical cancer; histologic type; microimmunofluorescence
Journal of medical virology  2009;81(4):713-721.
Human papillomavirus (HPV) RNA levels may be a more sensitive early indicator of predisposition to carcinogenesis than DNA levels. We evaluated whether levels of HPV-16 and HPV-18 DNA and messenger RNA (mRNA) in newly detected infections are associated with cervical lesion development. Female university students were recruited from 1990-2004. Cervical samples for HPV DNA, HPV mRNA, and Papanicolaou testing were collected tri-annually, and women were referred for colposcopically-directed biopsy when indicated. Quantitative real-time polymerase chain reaction of L1 and E7 DNA and E7 mRNA was performed on samples from women with HPV-16 and HPV-18 infections that were incidently detected by consensus PCR. Adjusting for other HPV types, increasing E7 cervical HPV-16 mRNA levels at the time of incident HPV-16 DNA detection were associated with an increased risk of cervical intraepithelial neoplasia grade 2 to 3 (HR per 1 log10 increase in mRNA=6.36,95%CI=2.00-20.23). Increasing HPV-16 mRNA levels were also associated with an increased risk of cervical squamous intraepithelial lesions; the risk was highest at the incident positive visit and decreased over time. Neither HPV-16 E7 DNA levels nor HPV-18 E7 DNA nor mRNA levels were significantly associated with cervical lesion development. Report of >1 new partner in the past 8 months (relative to no new partners) was associated with increased HPV mRNA (viral level ratio [VLR]=10.05,95%CI=1.09-92.56) and increased HPV DNA (VLR=16.80,95%CI=1.46-193.01). In newly detected HPV-16 infections, increasing levels of E7 mRNA appear to be associated with an increased risk of developing cervical pre-cancer.
PMCID: PMC3984467  PMID: 19235870
HPV; viral load; mRNA; cervical pre-cancer
25.  A history of allergies is associated with reduced risk of oral squamous cell carcinoma 
Cancer causes & control : CCC  2012;23(12):1911-1919.
A history of allergies is associated with a decreased risk of several types of cancers. Potential mechanisms include enhanced immune surveillance against tumor cells early in disease development and/or carcinogenic infectious agents. We tested whether allergies are inversely associated with oral squamous cell carcinoma (OSCC), accounting for factors that may modify the association, such as tumor site, stage, and HPV infection.
We estimated odds ratios (OR) and 95% confidence intervals (CI) for the association between allergy history (including different types of allergies) and OSCC, adjusted for potential confounders, among 400 cases and 613 controls. Analyses were also stratified by site, stage, and measures of HPV infection.
We observed a weak inverse association between history of any allergy and OSCC (OR=0.81, 95% CI, 0.61–1.08). This association was present only for allergies to airborne allergens (dust/pollen/mold); OR=0.67; 95% CI, 0.48–0.93. The inverse associations with airborne allergies were slightly stronger for oropharyngeal SCC (OR=0.56; 95% CI, 0.35–0.90) than for oral cavity SCC (OR=0.71; 95% CI, 0.49–1.05), and present only for later stage cancers (OR=0.42; 95% CI, 0.26–0.66) as opposed to earlier stage cancers (OR=0.98; 95% CI, 0.66–1.46). Inverse associations were not particularly present or stronger among HPV-16 seropositive individuals or for HPV DNA positive OSCC.
There is an inverse association between history of allergies to dust, pollen or mold and OSCC. Whether the inverse association involves heightened immune surveillance, increased immune response to HPV or other antigen, or other carcinogenic mechanism, remains to be determined in more definitive studies.
PMCID: PMC3499679  PMID: 23011537
allergies; oral squamous cell carcinoma; HPV; HSV

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