Emily Barr

Human papillomavirus (HPV) causes cervical, vulvar, and vaginal cancers, precancerous dysplasia, and genital warts. We report data for the longest efficacy evaluation to date of a prophylactic HPV vaccine. In total, 552 women (16-23 years) were enrolled in a randomised, placebo-controlled study of a quadrivalent HPV 6/11/16/18 L1 virus-like-particle vaccine with vaccination at months 0, 2, and 6. At regular intervals through 3 years, subjects underwent gynaecologic examination, cervicovaginal sampling for HPV DNA, serum anti-HPV testing, and Pap testing, with follow-up biopsy as indicated. A subset of 241 subjects underwent two further years of follow-up. At 5 years post enrollment, the combined incidence of HPV 6/11/16/18-related persistent infection or disease was reduced in vaccine-recipients by 96% (two cases vaccine versus 46 placebo). There were no cases of HPV 6/11/16/18-related precancerous cervical dysplasia or genital warts in vaccine recipients, and six cases in placebo recipients (efficacy = 100%; 95% CI:12-100%). Through 5 years, vaccine-induced anti-HPV geometric mean titres remained at or above those following natural infection. In conclusion, a prophylactic quadrivalent HPV vaccine was effective through 5 years for prevention of persistent infection and disease caused by HPV 6/11/16/18. This duration supports vaccination of adolescents and young adults, which is expected to greatly reduce the burden of cervical and genital cancers, precancerous dysplasia, and genital warts.

Vascular smooth muscle cell (VSMC) proliferation after arterial injury is important in the pathogenesis of a number of vascular proliferative disorders, including atherosclerosis and restenosis after balloon angioplasty. Thus, a better understanding of the molecular mechanisms underlying VSMC proliferation in response to arterial injury would have important therapeutic implications for patients with atherosclerotic vascular disease. The p21 protein is a negative regulator of mammalian cell cycle progression that functions both by inhibiting cyclin dependent kinases (CDKs) required for the initiation of S phase, and by binding to and inhibiting the DNA polymerase delta co-factor, proliferating cell nuclear antigen (PCNA). In this report, we show that adenovirus-mediated over-expression of human p21 inhibits growth factor-stimulated VSMC proliferation in vitro by efficiently arresting VSMCs in the G1 phase of the cell cycle. This p21-associated cell cycle arrest is associated both with significant inhibition of the phosphorylation of the retinoblastoma gene product (Rb) and with the formation of complexes between p21 and PCNA in VSMCs. In addition, we demonstrate that localized arterial infection with a p21-encoding adenovirus at the time of balloon angioplasty significantly reduced neointimal hyperplasia in the rat carotid artery model of restenosis. Taken together, these studies demonstrate the important role of p21 in regulating Rb phosphorylation and cell cycle progression in VSMC, and suggest a novel cytostatic gene therapy approach for restenosis and related vascular proliferative disorders.

The lifetime risk of human papillomavirus (HPV) infection exceeds 50%. HPV infection causes >550,000 cases of cervical and anogenital cancer worldwide annually. Infection also causes precancerous lesions and genital warts. HPV types 16 and 18 cause approximately 70% of HPV-related cancers, and HPV types 6 and 11 cause approximately 90% of cases of genital warts. A quadrivalent vaccine for HPV types 6, 11, 16, and 18 (HPV 6/11/16/18) has been developed for prevention of cervical cancer, genital warts, and vulvar and vaginal precancerous lesions. Prophylactic vaccination of young women was 96%-100% effective in preventing HPV 6/11/16/18-related cervical and anogenital precancers and genital warts. Efficacy remained high for at least 5 years following vaccination. Postvaccination anti-HPV levels in adolescents were superior to those observed in women (the population in which efficacy was shown). Vaccination was generally well tolerated. The vaccine is licensed in >80 countries. It has been added to national vaccination programs, including that of the United States. Widespread use of HPV 6/11/16/18 vaccine is expected to greatly reduce the incidence of HPV-related cancers, precancers, and genital warts.

The ability to express recombinant genes in the coronary vasculature and the myocardium holds promise for the treatment of a number of acquired and inherited cardiovascular diseases. Previous in vivo gene transfer approaches in the heart have been limited by relatively low efficiencies of gene transduction. In this report, we demonstrate that catheter-mediated infusion of replication-defective adenovirus into the coronary arterial circulation in vivo represents a novel and efficient method for the induction of recombinant gene expression in both the coronary arteries and the myocardium. A single intracoronary infusion of 2 x 10(9) - 1 x 10(10) p.f.u. of adenovirus resulted in high level recombinant gene expression in both the coronary arteries and surrounding myocardium of adult rabbits for at least 2 weeks. No inflammatory response or myocardial necrosis was observed following the adenovirus infusions. The polymerase chain reaction (PCR) was used to assess the tissue distribution of infection following intracoronary infusion of adenovirus. Adenovirus DNA was detected by PCR in the livers, kidneys, lungs, brains and testes of animals 5 days after virus infusion. Percutaneous transluminal gene transfer (PTGT) into the heart by intracoronary infusion of replication-defective adenovirus represents a relatively non-invasive and efficient method of inducing recombinant gene expression both in the coronary arterial wall and in the surrounding myocardium.

Background In early-phase trials, a human papillomavirus 16 (HPV16) virus-like particle (VLP) vaccine has been shown to be well tolerated, immunogenic, and protective against HPV16 in women, most of whom were taking oral contraceptives. Previous studies have not determined whether HPV immunization results in specific antibody levels in the human genital tract or whether these levels might vary during contraceptive or ovulatory cycles. Therefore, we determined the levels of total and specific antibodies in the cervical secretions of women who had been immunized with HPV16 VLPs and examined the influence of the menstrual cycle and oral contraceptive use on these levels. Methods Two groups of women were immunized, seven who were taking oral contraceptives and 11 who were ovulating. After seroconversion, serum and cervical secretions were collected twice weekly for 5 weeks. Total immunoglobulins (IgG and IgA) and vaccine-specific IgGs were determined by enzyme-linked immunosorbent assay. Nonparametric statistical analyses were used to determine the statistical significance of differences in IgG levels between groups, and correlations between serum- and cervical-specific IgG levels were determined by the Spearman correlation coefficient. Results All participants developed detectable titers of anti-HPV16 VLP IgGs in their cervical secretions after immunization. The cervical titers of specific IgG and total IgGs and IgAs among participants in the contraceptive group were relatively constant throughout the contraceptive cycle. In contrast, the cervical titers of specific IgG and total IgGs and IgAs among participants in the ovulatory group varied during the menstrual cycle, being highest during the proliferative phase, decreasing approximately ninefold around ovulation, and increasing approximately threefold during the luteal phase. Serum- and cervical-specific IgG levels were correlated (r =.86) in women in the contraceptive group but not in women in the ovulatory group (r =.27). Conclusions The relatively high titer of anti-HPV16 antibodies at the cervix is promising in terms of vaccine efficacy; however, the decrease in antibody titer around ovulation raises the possibility that the HPV16 VLP vaccine might be less effective during the peri-ovulatory phase.