A phase I study to evaluate a human papillomavirus (HPV)

Abstract Human papillomavirus (HPV) infection can cause genital warts and cervical cancer. HPV types 6 and 11 cause >90% of genital wart cases; HPV16 and 18 cause 70% of cervical cancers. A prophylactic HPV (types 6, 11, 16, 18) L1 virus-like particle (VLP) vaccine may substantially reduce the incidence of these lesions. This report describes the results of a phase I study of the HPV18 component of such a vaccine. Forty women were randomized to receive either HPV18 L1 VLP vaccine or placebo. Anti-HPV18 responses were measured using a competitive radioimmunoassay (cRIA). Tolerability was evaluated using vaccination report cards (VRC). The study showed that the HPV18 L1 VLP vaccine was generally well-tolerated and highly immunogenic. Peak anti-HPV18 geometric mean titers (GMT) in vaccines were 60-fold greater than those observed in women following natural HPV18 infection. Further studies of a multivalent HPV L1 VLP vaccines are warranted

Genetic risk and a primary role for cell-mediated immune mechanisms in multiple sclerosis.

Multiple sclerosis is a common disease of the central nervous system in which the interplay between inflammatory and neurodegenerative processes typically results in intermittent neurological disturbance followed by progressive accumulation of disability. Epidemiological studies have shown that genetic factors are primarily responsible for the substantially increased frequency of the disease seen in the relatives of affected individuals, and systematic attempts to identify linkage in multiplex families have confirmed that variation within the major histocompatibility complex (MHC) exerts the greatest individual effect on risk. Modestly powered genome-wide association studies (GWAS) have enabled more than 20 additional risk loci to be identified and have shown that multiple variants exerting modest individual effects have a key role in disease susceptibility. Most of the genetic architecture underlying susceptibility to the disease remains to be defined and is anticipated to require the analysis of sample sizes that are beyond the numbers currently available to individual research groups. In a collaborative GWAS involving 9,772 cases of European descent collected by 23 research groups working in 15 different countries, we have replicated almost all of the previously suggested associations and identified at least a further 29 novel susceptibility loci. Within the MHC we have refined the identity of the HLA-DRB1 risk alleles and confirmed that variation in the HLA-A gene underlies the independent protective effect attributable to the class I region. Immunologically relevant genes are significantly overrepresented among those mapping close to the identified loci and particularly implicate T-helper-cell differentiation in the pathogenesis of multiple sclerosis

A pooled analysis of continued prophylactic efficacy of quadrivalent human papillomavirus (types 6/11/16/18) vaccine against high-grade cervical and external genital lesions

Quadrivalent human papillomavirus (HPV) vaccine has been shown to provide protection from HPV 6/11/16/18-related cervical, vaginal, and vulvar disease through 3 years. We provide an update on the efficacy of the quadrivalent HPV vaccine against high-grade cervical, vaginal, and vulvar lesions based on end-of-study data from three clinical trials. Additionally, we stratify vaccine efficacy by several baseline characteristics, including age, smoking status, and Papanicolaou (Pap) test results. A total of 18,174 females ages 16 to 26 years were randomized and allocated into one of three clinical trials (protocols 007, 013, and 015). Vaccine or placebo was given at baseline, month 2, and month 6. Pap testing was conducted at regular intervals. Cervical and anogenital swabs were collected for HPV DNA testing. Examination for the presence of vulvar and vaginal lesions was also done. Endpoints included high-grade cervical, vulvar, or vaginal lesions (CIN 2/3, VIN 2/3, or ValN 2/3). Mean follow-up time was 42 months post dose 1. Vaccine efficacy against HPV 6/11/16/18-related high-grade cervical lesions in the per-protocol and intention-to-treat populations was 98.2% [95% confidence interval (95% CI), 93.3-99.8] and 51.5% (95% CI, 40.6-60.6), respectively. Vaccine efficacy against HPV 6/11/16/18-related high-grade vulvar and vaginal lesions in the per-protocol and intention-to-treat populations was 100.0% (95% CI, 82.6-100.0) and 79.0% (95% CI, 56.4-91.0), respectively. Efficacy in the intention-to-treat population tended to be lower in older women, women with more partners, and women with abnormal Pap test results. The efficacy of quadrivalent HPV vaccine against high-grade cervical and external anogenital neoplasia remains high through 42 months post vaccination. ©2009 American Association for Cancer Research

A comparative study of the modes of activation of protein kinase C

The key signal transduction enzyme protein kinase C (PKC) is specifically activated by tumor-promoting phorbol esters. In this study, phorbol ester-activation with regards to phorbol ester hydrophobicity, interaction with filamentous actin (F-actin), membrane compositional changes and synergistic activation, was compared between conventional PKCα, novel PKCδ and ϵ, and atypical PKCζ isoforms. The modes of activation by phorbol esters were determined using purified recombinant PKC isoforms. PKC activity was determined in the presence of membrane phospholipids (lipid-dependent activity) or F-actin (lipid-independent activity). The fluorescent phorbol ester, sapintoxin D, was used to measure the binding of phorbol esters to PKC in the presence or absence of membrane phospholipids. The results suggest that PKC contains a hydrophobic binding site for phorbol esters which maintains structural specificity in the absence of phospholipids and Ca2+. Binding of phorbol esters to PKC in the absence of membrane phospholipids, mediates an activating interaction with F-actin. PKCζ and ϵ were specifically activated by phorbol esters and F-actin, while PKCζ was activated by F-actin alone. The results suggest that PKC binds to F-actin via conserved structural features of a single cysteine-rich domain that are exposed upon phorbol ester-binding to the enzyme. PKCaα and δ are shown to be sensitive to subtle changes in the composition of the membrane lipid bilayer that result in an increase in head group spacing. Marginal activator stimulation of PKCϵ, in the presence of membrane phospholipids, suggests that membrane phospholipids play a minor role in the activation of PKCϵ. PKCα contains two distinct phorbol ester binding regions of low and high affinity respectively and PKCδ contains a high affinity phorbol ester binding site. PKCα and δ, but not ϵ, were synergistically activated by diacylglycerols (DAG) and phorbol esters, the level of activity obtained in the presence of both activators, each alone at maximally stimulating concentrations, being greater than that achieved by either activator alone. This shows that the C2 domain is not an absolute requirement for synergistic activation by DAG and phorbol esters. The observed isoform differences in phorbol ester sensitivity and activation suggest that in a cell, phorbol esters specifically activate distinct PKC isoforms via various mechanisms to achieve different biological endpoints

HPV genotypes in CIN 2-3 lesions and cervical cancer: a population-based study.

To access publisher full text version of this article. Please click on the hyperlink in Additional Links fieldThe distribution of human papillomavirus (HPV) varies between countries and continents leading to different effectiveness of upcoming prophylactic HPV vaccines. This study analyses the HPV distribution in CIN 2-3, recurrent CIN 2-3 and cervical cancer in Iceland. About 80% of incident cases with CIN 2-3 lesions in 1990 and 1999, 99% of cancer cases in 1990-1994 and 1999-2003, and cases with recurrent CIN 2-3 after conization in 1990 were tested with PCR analysis for the presence of 12 oncogenic HPV types. About 95% of the CIN 2-3 and 92% of the cancer cases tested positive for the included HPV types. HPV 16 was the most frequent type followed by HPV 33, 31, 52, 35, 18, 58, 56, 39, 45, 59 in CIN 2-3 and by HPV 18, 33 45, 31, 39, 52, 35, 51, 56 in cancer. HPV 16 and 18 were associated with a significantly increased cancer risk and HPV 52 and 31 with decreased cancer risk compared to the risk of CIN 3. The HPV distribution differed between histological cancer types, stages and age groups. The number of HPV types was not a significant predictor of cancer. Oncogenic HPV types were found in all persistent or recurrent CIN 2-3 disease after conization. Vaccination against HPV 16/18 is estimated to achieve a minimum 40% reduced rate of CIN 2-3 and a minimum 60% reduced cancer rate. This rate could, however, be increased to 95% and 92% respectively by including all the 12 HPV types tested for in this study

Study Comparing Human Papillomavirus (HPV) Real-Time Multiplex PCR and Hybrid Capture II INNO-LiPA v2 HPV Genotyping PCR Assays ▿

Human papillomavirus (HPV) DNA genotyping is an essential test to establish efficacy in HPV vaccine clinical trials and HPV prevalence in natural history studies. A number of HPV DNA genotyping methods have been cited in the literature, but the comparability of the outcomes from the different methods has not been well characterized. Clinically, cytology is used to establish possible HPV infection. We evaluated the sensitivity and specificity of HPV multiplex PCR assays compared to those of the testing scheme of the Hybrid Capture II (HCII) assay followed by an HPV PCR/line hybridization assay (HCII-LiPA v2). SurePath residual samples were split into two aliquots. One aliquot was subjected to HCII testing followed by DNA extraction and LiPA v2 genotyping. The second aliquot was shipped to a second laboratory, where DNA was extracted and HPV multiplex PCR testing was performed. Comparisons were evaluated for 15 HPV types common in both assays. A slightly higher proportion of samples tested positive by the HPV multiplex PCR than by the HCII-LiPA v2 assay. The sensitivities of the multiplex PCR assay relative to those of the HCII-LiPA v2 assay for HPV types 6, 11, 16, and 18, for example, were 0.806, 0.646, 0.920, and 0.860, respectively; the specificities were 0.986, 0.998, 0.960, and 0.986, respectively. The overall comparability of detection of the 15 HPV types was quite high. Analyses of DNA genotype testing compared to cytology results demonstrated a significant discordance between cytology-negative (normal) and HPV DNA-positive results. This demonstrates the challenges of cytological diagnosis and the possibility that a significant number of HPV-infected cells may appear cytologically normal