Seroprevalence of HPV vaccine types 6, 11, 16 and 18 in HIV-infected and uninfected women from Brazil.

BACKGROUND: Information on vaccine-type HPV seroprevalence is essential for vaccine strategies; however, limited data are available on past exposure to HPV-quadrivalent vaccine types in HIV-infected woman in Brazil. OBJECTIVES: To assess the seroprevalence for HPV types 6, 11, 16 and 18 in HIV-infected and uninfected women, from Rio de Janeiro, Brazil and to investigate potential associations with age and pregnancy status. STUDY-DESIGN: 1100-sera were tested by virus-like particle (VLPs)-based ELISA for antibodies to HPV types 16, 18, 6 and 11. Statistical analysis was carried out by STATA/SE 10.1 and comparisons among HIV-infected and HIV-uninfected women were assessed by Poisson regression models with robust variance. RESULTS: HPV-6, 11, 16 and 18 seroprevalence was significantly higher among HIV-positive women (29.9%, 8.5%, 56.2% and 38.0%, respectively) compared to HIV-negative women (10.9%, 3.5%, 30.8% and 21.7%, respectively), when adjusted by age and pregnancy status. Overall, 69.4% of HIV-infected and 41.5% of HIV-uninfected women tested positive for any HPV quadrivalent vaccine type. However 4.7% and 1.1%, respectively, tested positive for all HPV vaccine type. In HIV-uninfected women who were pregnant, we found a higher HPV-11 seroprevalence (8.5% vs. 1.5%; P < 0.001) and a lower HPV 16 seroprevalence (22.6% vs. 34.2%; P = 0.010) compared to not pregnant women. HIV-uninfected women, aged 40 or more years old had a higher HPV 16 seroprevalence compared to women aged less than 40 years old. CONCLUSIONS: We did not observe a strong association between age and positive HPV antibodies nor an association between pregnancy and HPV seroprevalence. HPV seroprevalence was significantly higher among HIV-infected women compared to HIV negative women. In both populations the seroprevalence to all four HPV vaccine types was low suggesting that women may potentially benefit from the HPV vaccines.

Evolution of the human immunodeficiency virus envelope gene is dominated by purifying selection.

The evolution of the human immunodeficiency virus (HIV-1) during chronic infection involves the rapid, continuous turnover of genetic diversity. However, the role of natural selection, relative to random genetic drift, in governing this process is unclear. We tested a stochastic model of genetic drift using partial envelope sequences sampled longitudinally in 28 infected children. In each case the Bayesian posterior (empirical) distribution of coalescent genealogies was estimated using Markov chain Monte Carlo methods. Posterior predictive simulation was then used to generate a null distribution of genealogies assuming neutrality, with the null and empirical distributions compared using four genealogy-based summary statistics sensitive to nonneutral evolution. Because both null and empirical distributions were generated within a coalescent framework, we were able to explicitly account for the confounding influence of demography. From the distribution of corrected P-values across patients, we conclude that empirical genealogies are more asymmetric than expected if evolution is driven by mutation and genetic drift only, with an excess of low-frequency polymorphisms in the population. This indicates that although drift may still play an important role, natural selection has a strong influence on the evolution of HIV-1 envelope. A negative relationship between effective population size and substitution rate indicates that as the efficacy of selection increases, a smaller proportion of mutations approach fixation in the population. This suggests the presence of deleterious mutations. We therefore conclude that intrahost HIV-1 evolution in envelope is dominated by purifying selection against low-frequency deleterious mutations that do not reach fixation.

Determinants of human papillomavirus 16 serological conversion and persistence in a population-based cohort of 10 000 women in Costa Rica.

Determinants of human papillomavirus (HPV)-16 serological conversion and persistence were assessed in a population-based cohort of 10 049 women in Guanacaste, Costa Rica. Serologic responses to HPV-16 were measured in 7986 women by VLP-based enzyme-linked immunosorbent assay at both study enrollment (1993/94) and at 5-7 years of follow-up. Seropositive women were defined as >/=5 standard deviations above the mean optical density obtained for studied virgins at enrollment (n=573). Seroconnversion (n=409), persistence (n=675), and clearance (n=541) were defined based on enrollment and follow-up serology measurements. Age-specific distributions revealed that HPV-16 seroconversion was highest among 18- to 24-year-old women, steadily declining with age; HPV-16 seropersistence was lowest in women 65+ years. In age-adjusted multivariate logistic regression models, a 10-fold risk increase for HPV-16 seroconversion was associated with HPV-16 DNA detection at enrollment and follow-up; two-fold risk of seroconversion to HPV-16 was associated with increased numbers of lifetime and recent sexual partners and smoking status. Determinants of HPV-16 seropersistence included a 1.5-fold risk increase associated with having one sexual partner during follow-up, former oral contraceptive use, and a 3-fold risk increase associated with HPV-16 DNA detection at both enrollment and follow-up. Higher HPV-16 viral load at enrollment was associated with seroconversion, and higher antibody titres at enrollment were associated with seropersistence.

Poliovirus vaccination during pregnancy, maternal seroconversion to simian virus 40, and risk of childhood cancer.

Before 1963, poliovirus vaccine produced in the United States was contaminated with simian virus 40 (SV40), which causes cancer in animals. To examine whether early-life SV40 infection can cause human cancer, the authors studied 54,796 children enrolled in the US-based Collaborative Perinatal Project (CPP) in 1959-1966, 52 of whom developed cancer by their eighth birthday. Those children whose mothers had received pre-1963 poliovirus vaccine during pregnancy (22.5% of the children) had an increased incidence of neural tumors (hazard ratio = 2.6, 95% confidence interval: 1.0, 6.7; 18 cases) and hematologic malignancies (hazard ratio = 2.8, 95% confidence interval: 1.2, 6.4; 22 cases). For 50 CPP children with cancer and 200 CPP control children, the authors tested paired maternal serum samples from pregnancy for SV40 antibodies using a virus-like particle enzyme immunoassay and a plaque neutralization assay. Overall, mothers exhibited infrequent, low-level SV40 antibody reactivity, and only six case mothers seroconverted by either assay. Using the two SV40 assays, maternal SV40 seroconversion during pregnancy was not consistently related to children's case/control status or mothers' receipt of pre-1963 vaccine. The authors conclude that an increased cancer risk in CPP children whose mothers received pre-1963 poliovirus vaccine was unlikely to have been due to SV40 infection transmitted from mothers to their children.

Seroprevalence of human papillomavirus-16, -18, -31, and -45 in a population-based cohort of 10000 women in Costa Rica.

Human papillomavirus (HPV) seroprevalence and determinants of seropositivity were assessed in a 10049-woman population-based cohort in Guanacaste, Costa Rica. Serologic responses based on VLP-based ELISA were obtained from the plasma collected at study enrollment in 1993/1994 for HPV-16 (n=9949), HPV-18 (n=9928), HPV-31 (n=9932), and HPV-45 (n=3019). Seropositivity was defined as five standard deviations above the mean optical density obtained for studied virgins (n=573). HPV-16, -18, -31, and -45 seroprevalence was 15, 15, 16, and 11%, respectively. Of women DNA-positive for HPV-16, -18, -31, or -45, seropositivity was 45, 34, 51, and 28%, respectively. Peak HPV seroprevalence occurred a decade after DNA prevalence; lifetime number of sexual partners was the key determinant of seropositivity independent of DNA status and age. DNA- and sero-positive women showed the highest risk for concurrent CIN3/cancer, followed by DNA-positive, sero-negative women.

Comparison of sequencing of the por gene and typing of the opa gene for discrimination of Neisseria gonorrhoeae strains from sexual contacts.

Typing of gonococcal strains is a valuable tool for the biological confirmation of sexual contacts. We have developed a typing method based on DNA sequencing of two overlapping por gene fragments generated by a heminested PCR. We compared sequencing of the por gene (POR sequencing) and typing of the opa gene (OPA typing) for the characterization of strains from 17 sexual partnerships. Both methods were highly discriminatory. A different genotype was detected in 15 of the 17 epidemiologically unconnected couples by POR sequencing and in 16 of the 17 couples by OPA typing with restriction enzyme HpaII. Within partnerships, identical genotypes were obtained from 16 of the 17 known sex contacts by POR sequencing and from 15 of the 17 by OPA typing. Compared to OPA typing, which relies on interpretation of bands in a gel, DNA sequence data offer the advantage of being objective and portable. As costs for sequencing decline, the method should become affordable for most laboratory personnel who wish to type gonococcal strains.

The risk of cervical cancer in relation to serum concentrations of folate, vitamin B12, and homocysteine.

Due to its role in the synthesis and repair of DNA, folate may protect against the development of cervical cancer. Prospective data on the possible association between folate and cervical cancer have been lacking. There is also a paucity of prospective evidence concerning the possible associations between cervical cancer and vitamin B12, which shares pathways with folate, and homocysteine, a marker of low B vitamin concentrations. A nested case-control study was conducted to prospectively evaluate the associations between cervical cancer and serum concentrations of folate, vitamin B12, and homocysteine. Among a community-based cohort of women who donated blood in 1974 for a serum bank in Washington County, Maryland, 39 cases of cervical cancer diagnosed between 1975 and mid-1990 were included in the study (13 cases of invasive cervical cancer and 26 cases of carcinoma in situ). Two controls were matched to each case by age, race, and sex. Stored serum from the cases and controls was assayed for folate, B12, and homocysteine concentrations. For folate, adjusted odds ratios were 1.0, 0.62, and 0.60 for the low to high thirds of the serum concentrations, respectively, a trend in the protective direction that was not statistically significant (P for trend = 0.42). Overall, the results for vitamin B12 tended to mimic those for folate, whereas the associations for homocysteine tended to be in the opposite direction. None of the results of this study were statistically significant, but patterns of the associations are in accord with hypothesized mechanistic pathways concerning B vitamins and cervical cancer.

Detection of Chlamydia trachomatis DNA in archival paraffinized specimens from chronic salpingitis cases using the polymerase chain reaction.

OBJECTIVE: To identify Chlamydia trachomatis by the polymerase chain reaction (PCR) in fallopian tube tissues with chronic salpingitis. DESIGN: Retrospective case-control study. SETTING: Academic tertiary institution. PATIENT(S): Women with a pathological diagnosis of chronic salpingitis or normal fallopian tube hospitalized between September 1992 and November 1994. Initial identification of 248 specimens with final analysis of 154. INTERVENTION(S): Paraffin-embedded fallopian tube tissues were analyzed with use of PCR to detect C. trachomatis. MAIN OUTCOME MEASURE(S): Identification of C. trachomatis DNA; demographics of age, ethnicity, parity, history of sexually transmitted disease, and surgical procedure. RESULT(S): C. trachomatis DNA was detected in 9 of 77 chronic salpingitis cases. Seventy-seven controls were negative for C. trachomatis. No statistically significant difference in age or ethnicity between cases and controls was identified. Nulliparity was more frequent in cases (26 of 74) than controls (14 of 76). Sexually transmitted disease history was more prevalent in cases (24 of 74) than controls (6 of 76). Chlamydia infection was not associated with a particular surgical indication. CONCLUSION(S): Chronic salpingitis is highly associated with the presence of C. trachomatis infection as detected by PCR.

Population genetics of the porB gene of Neisseria gonorrhoeae: different dynamics in different homology groups.

The porB locus codes for the major outer membrane protein of Neisseria gonorrhoeae. Alleles of this locus have been assigned to two homology groups based on close sequence and immunological relationships and are designated as either PIA or PIB. Several population parameters were estimated and compared among these two groups using a data set of 22 PIA sequences and 91 PIB sequences obtained from diverse geographic localities and from time periods spanning approximately 50 years. Recombination appears to be extensive in the porB gene. While the recombination rates are similar for the PIA and PIB sequences, the relative contribution of recombination to genetic diversity is higher for the PIA sequences. Alleles belonging to the PIB group show greater genetic diversity than do those in the PIA group. Although phylogenetic analysis did not reveal temporal or geographic clustering of sequences, estimates of gene flow and the fixation index suggested that PIB sequences exhibit population substructure based on geographic locality. Selection acts in these homology groups in a different way. While positive Darwinian selection is the dominant force driving the evolution of the PIA sequences, purifying selection operates also on the PIB sequences. These differences may be attributable to the greater propensity of PIA strains, as compared with PIB strains, to cause disseminated gonococcal infection, which would expose the former to intense selection pressure from the host immune system. The molecular evolution of Neisseria gonorrhoeae seems to be driven by the simultaneous action of selection and recombination, but under different rates and selection pressures for the PIA and PIB homology groups.

Serum antibodies to human papillomavirus 16 proteins in women from Brazil with invasive cervical carcinoma.

Serum samples from 194 cases and 217 controls participating in a case-control study of invasive cervical cancer in Brazil were examined for antibodies to human papillomavirus (HPV) 16 virus-like particles (VLPs) by ELISA. The prevalence of antibody in cases and controls was 47.4 versus 24.4% (P < 0.001). The prevalence was higher in women who had HPV-16 DNA in the genital tract (54.2%) than in those with other HPVs (36.8%) or no HPVs (44.8%), but the differences were not statistically significant. Among cases and controls, HPV-16 VLP antibodies were associated with a greater number of lifetime sexual partners (chi2 for trend, P < 0.001). Among controls, age was inversely associated with HPV-16 VLP seroreactivity (chi2 for trend, P = 0.019). The sera were previously tested for antibodies to HPV-16 E6 and E7 oncoproteins; there was no correlation between antibody titers to HPV-16 E6 or E7 and VLPs. The HPV-16 serological assays were compared as screening tests for invasive cervical cancer. The sensitivity and specificity estimates were 47.4 and 75.6% for HPV-16 VLP serology, 63.4 and 89.9% for either HPV-16 E6 or E7 serology, and 53.6 and 93.6% for high titers of either HPV-16 E6 or E7 or VLP antibodies. The utility of HPV-16 VLP ELISA as a screening test for invasive cervical cancer is limited by a high seroprevalence in women with probable prior exposure to HVP 16 but without disease.

Emerging HIV infections with distinct subtypes of HIV-1 infection among injection drug users from geographically separate locations in Guangxi Province, China.

Heroin users from Guangxi province, a southern province of China that borders Vietnam in the south and Yunnan province in China in the west, were studied for prevalence and risk factors for HIV-1 infection. Viral env sequences from HIV-1-positive individuals were also determined for subtypes of HIV-1. The overall HIV prevalence among 227 heroin users was 40%. Most had used drugs for < or = 3 years. Sharing of injection equipment and unprotected sex were significantly associated with HIV-1 infection. Subtypes C and E HIV-1 were detected in infected heroin users and were sharply segregated in two geographic locations: only subtype C was found in a border city with Yunnan province, whereas only subtype E was found in a city bordering northern Vietnam. HIV-1 strains within each subtype were remarkably homogenous, with a mean intersubject DNA distance of 2.32% for subtype E and 1.13% for subtype C, respectively. Phylogenetic analysis of C2-V5 region of Guangxi subtype E env sequences revealed significant clustering with subtype E sequences from southern Vietnam and Cambodia. These results suggest that HIV-1 infection among heroin users in Guangxi represents two emerging epidemics initiated from distinct sources: one from Vietnam and another from Yunnan province. Factors associated with HIV-1 infection were not restricted to injection practices. Unprotected sexual behaviors are likely to increase the probability of HIV transmission beyond this high-risk population. Designing and implementing effective intervention strategies targeted toward both injection drug use and high risk sexual behavior are urgently needed to further reduce HIV-1 spread in China.

A survey of human papillomavirus 16 antibodies in patients with epithelial cancers.

Human papillomavirus (HPV), particularly HPV 16, is linked to the development of cervical cancer. However, the role of HPV 16 in a number of extra-cervical epithelial tumours is controversial. To assess exposure to HPV 16 in patients with different cancers, we conducted a large serosurvey of 905 patients with 21 types of tumours and measured IgG to HPV 16 virus-like particles (VLPs) using a well characterized enzyme linked immunosorbent assay (ELISA). Patients with cervical cancer were considered 'positive controls', as about half were expected to be specifically HPV 16-related. A non-cancer study group consisting of 48 patients with endocrine disorders (eg diabetes) was also tested. HPV 16 antibody prevalence was highest in patients with cancers of the cervix (52% +/- 7%), vulva (27% +/- 9%), vagina (27% +/- 13%) and penis (63% +/- 16%). Seroprevalence was much lower in the non-cancer group (4% +/- 3%) and all other cancer patients: uterus (9% +/- 4%); ovary (4% +/- 3%); testis (5% +/- 4%); prostate (6% +/- 4%); squamous carcinoma (6% +/- 3%) and adenocarcinoma (4% +/- 3%) of the lung; rectum (2% +/- 2%); pancreas (8% +/- 4%); colon (2% +/- 2%); stomach (0%); oesophagus (8% +/- 4%); buccal cavity (12% +/- 5%); breast (10% +/- 4%); non-melanomatous (9% +/- 6%) and melanomatous (6% +/- 3%) skin tumours; bladder (8% +/- 4%); and kidney (2% +/- 2%). The results confirm the strong relation of HPV with several lower anogenital tract tumours, but, at least in this population, fail to identify additional epithelial tumours associated with high seroprevalence of HPV 16 VLP antibodies.

Evolution of human immunodeficiency virus type 1 in relation to disease progression in children.

OBJECTIVE: To compare patterns of nonsynonymous and synonymous substitutions over time in the V1V2 and C2V3 regions of human immunodeficiency virus type 1 (HIV-1) env and in a conserved segment of pol in HIV-1-infected children with varying rates of CD4+ T-cell decline. STUDY DESIGN/METHODS: Longitudinal study of HIV-1 genetic variants sampled from peripheral blood of 3 children affected with acquired immunodeficiency syndrome (AIDS) and 4 children with slow disease progression. Nested polymerase chain reaction (PCR) was used to detect HIV-1 genetic material in plasma-derived virions and cellular DNA. Sequence variants were enumerated by screening cloned PCR products using heteroduplex mobility assay (HMA) or single-strand conformation polymorphism analysis (SSCP) and nucleotide sequencing. Frequencies of nonsynonymous and synonymous substitutions within sampling points and the accumulation rate of nucleotide substitutions over the period of observation were calculated. RESULTS: In the C2V3 region, higher rates of accumulation of nonsynonymous substitutions were associated with more precipitous declines in CD4+ cell numbers. In the V1V2 region, rates of accumulation of nonsynonymous substitutions were comparable with those in the C2V3 region, but similar rates were observed in AIDS-affected children and children with slow disease progression. The rate of accumulation of nonsynonymous substitutions in the pol region was lower than that in the C2V3 and V1V2 regions. CONCLUSIONS: Rates of accumulation of nucleotide substitutions vary across the HIV-1 genome and differ in relation to disease progression in children. The finding of greater rates of nonsynonymous substitution in the immunodominant C2V3 region in children whose disease progressed rapidly is consistent with a vigorous but inadequate immune response in children who are unable to control HIV-1 infection.

Interlaboratory agreement among results of human papillomavirus type 16 enzyme-linked immunosorbent assays.

Serological assays for measuring antibodies to human papillomavirus type 16 (HPV-16) virus-like particles (VLPs) have become important epidemiologic tools in recent years. However, the interlaboratory replicability of these assays has not been assessed. In this investigation, three laboratories tested a panel of specimens obtained from two different groups: 265 subjects in a vulvar cancer case-control study and 107 healthy volunteer blood donors. Each laboratory used an enzyme-linked immunosorbent assay (ELISA), but no attempt was made to standardize assay procedures among the three laboratories. The data showed good day-to-day intralaboratory replicability in laboratory 1 (correlation coefficient, > or = 0.88) and good intra-assay variability in laboratory 3 (correlation coefficient, > or = 0.93). Interlaboratory correlations, likewise, ranged between 0.61 and 0.80 in both case-control study subjects and healthy blood donors, indicating that ELISA optical density (OD) values between laboratories were linearly related regardless of the population. Kappa coefficients (kappa), based on each laboratory's categorical interpretation of its results (as positive or negative), showed good agreement (kappa, > 0.6) in case-control study subjects and moderate agreement (kappa, > or = 0.4) in blood donors, a population that had few strongly positive sera. When OD values near seropositive cutoffs were treated as indeterminates, there was little discordance between laboratories in either population. The data suggest that each laboratory measured the same humoral immune response and that their HPV-16 VLP ELISAs performed similarly (Pearson correlations). Interlaboratory differences, however, probably due to reagents and procedures, were considerably greater than intralaboratory day-to-day variability. Interlaboratory agreement in determining seropositivity (kappa) could be improved by sharing positive and negative serum controls and by treating marginal results as indeterminate. As part of continuing cooperation to improve interlaboratory agreement, we are preparing bulk serum control specimens to be shared and made available to interested researchers.

Antibodies to human papillomavirus 16 and subsequent in situ or invasive cancer of the cervix.

Our objective was to examine whether past infection with human papillomavirus (HPV)-16, as determined by an antibody assay, is a risk factor for subsequent cervical cancer. Incident cases of in situ or invasive cervical cancer occurring between 1975 and 1990 in a cohort of over 11,000 healthy women in Washington County, MD, were identified. The baseline sera of cases and of matched controls, collected in 1974, were examined for IgG antibodies reactive with virus-like particles of HPV-16, a cancer-associated HPV, and HPV-6, a low-risk HPV. Postdiagnosis sera of 11 cases were also assessed similarly. Fourteen cases of invasive and 28 cases of in situ cervical cancer and 83 matched controls were evaluated. The main outcome measure was the risk of cervical cancer in women who had HPV-16 or HPV-6 antibodies in prediagnostic sera. Antibodies to HPV-16 but not to HPV-6 were a marker for subsequent occurrence of cervical cancer. Case sera were reactive more often and more strongly with HPV-16 virus-like particles than were sera of matched controls. The presence of antibodies to HPV-16 was significantly associated with an increased risk of cervical cancer (odds ratio, 3.9; 95% confidence limits, 1.4, 10.7); high antibody levels to HPV-16 were associated with an even greater risk of cervical cancer (odds ratio = 7.5, 95% confidence limits 1.5, 36.3). The association with cervical cancer was strengthened after adjustment for smoking and years of education. In tests of 11 pairs of pre- and postdiagnostic sera, HPV-16 antibodies did not decline markedly over a 7-13-year time period, and seroconversion to HPV-16 appeared to have occurred in 2 cases. The serological data indicate that HPV-16 infection is associated with future risk of cervical cancer and strengthen the evidence for the etiological role of HPVs in cervical cancer.

Prevalence of antibodies to human papillomavirus (HPV) type 16 virus-like particles in relation to cervical HPV infection among college women.

A human papillomavirus type 16 (HPV-16) virus-like particle (VLP)-based enzyme-linked immunosorbent assay (ELISA) was used to measure serum antibody to capsid proteins in 376 sexually active college women who were also screened for the presence of genital HPVs by PCR and interviewed for demographic and behavioral risk factors for HPV infection. The seroprevalence was 46% in women with HPV-16 DNA in the genital tract. The corresponding values for women who harbored other HPV types or no HPV in the genital tract were 30 and 19%, respectively (HPV-16 group versus no-HPV group; odds ratio [OR], 3.7; 95% confidence interval [CI], 1.5 to 8.9). The antibody response was significantly higher among women with a high viral load than among those with a low viral load (median optical density value, 0.838 versus 0.137, P = 0.009). Comparable levels of seroreactivity were observed among women infected with HPV types distantly or closely related genetically to HPV-16. Seroreactivity was significantly associated with an age of 25 to 30 years (OR, 2.3; 95% CI, 1.2 to 4.4), three or more lifetime sexual partners (OR, 2.9; 95% CI, 1.1 to 10), and history of a sexually transmitted disease other than HPV (OR, 3.1; 95% CI, 1.5 to 6.3). The percent seropositivity increased linearly with number of lifetime sexual partners until reaching a plateau at 35% for women with more than six partners (chi for linear trend, P < 0.001). The low sensitivity of HPV-16 VLP-based ELISA may limit the usefulness of the assay as a diagnostic test for HPV-16 infection. However, the assay appears to have adequate specificity and should be useful as an epidemiological marker of HPV-16 infection and sexual behavior.

Human papillomavirus-specific serologic response in vulvar neoplasia.

Epidemiological and virological evidence suggests that invasive squamous cell carcinoma (SCC) of the vulva is etiologically heterogeneous and that basaloid or warty SCC (BWSCC) and vulvar intraepithelial neoplasia (VIN) are linked to human papillomavirus (HPV) infections while keratinizing SCC (KSCC) is a non-HPV-associated malignancy. In the present study, HPV-specific antibodies in sera of patients with BWSCC, VIN, and KSCC and of controls were examined by ELISA for antibodies reactive to HPV-16 virus-like particles (VLP) and in radioimmunoprecipitation assays for antibodies to HPV-16 E6 and E7 proteins expressed by in vitro transcription and translation. The prevalences of antibodies to HPV-16 VLPs were significantly higher in HPV-associated VIN (59.1%) and BWSCC (50.0%) than in KSCC (22.2%) and controls (18.2%). Antibodies to E6 and E7 proteins were more prevalent in BWSCC than in any other groups. Prevalence of serum antibodies to any one of the antigen preparations was significantly higher in BWSCC (64.3%) and VIN (59.1%) than in KSCC (27.8%) and controls (22.2%). Also, sera with high antibody titers were found more frequently in BWSCC and VIN cases than in controls. These data provide immunological evidence in support of the observation that VIN and BWSCC, but not KSCC, are associated with HPV infections.

Engineering an intracellular pathway for major histocompatibility complex class II presentation of antigens.

The presentation of antigenic peptides by major histocompatibility complex (MHC) class II molecules to CD4+ T cells is critical to the function of the immune system. In this study, we have utilized the sorting signal of the lysosomal-associated membrane protein LAMP-1 to target a model antigen, human papillomavirus 16 E7 (HPV-16 E7), into the endosomal and lysosomal compartments. The LAMP-1 sorting signal reroutes the antigen into the MHC class II processing pathway, resulting in enhanced presentation to CD4+ cells in vitro. In vivo immunization experiments in mice demonstrated that vaccinia containing the chimeric E7/LAMP-1 gene generated greater E7-specific lymphoproliferative activity, antibody titers, and cytotoxic T-lymphocyte activities than vaccinia containing the wild-type HPV-16 E7 gene. These results suggest that specific targeting of an antigen to the endosomal and lysosomal compartments enhances MHC class II presentation and vaccine potency.

Convergent evolution within the V3 loop domain of human immunodeficiency virus type 1 in association with disease progression.

Phylogenetic analysis was used to study in vivo genetic variation of the V3 region of human immunodeficiency virus type 1 in relation to disease progression in six infants with vertically acquired human immunodeficiency virus type 1 infection. Nucleotide sequences from each infant formed a monophyletic group with similar average branch lengths separating the sets of sequences. In contrast to the star-shaped phylogeny characteristic of interinfant viral evolution, the shape of the phylogeny formed by sequences from the infants who developed AIDS tended to be linear. A computer program, DISTRATE, was written to analyze changes in DNA distance values over time. For the six infants, the rate of divergence from the initial variant was inversely correlated with CD4 cell counts averaged over the first 11 to 15 months of life (r = -0.87, P = 0.024). To uncover evolutionary relationships that might be dictated by protein structure and function, tree-building methods were applied to inferred amino acid sequences. Trees constructed from the full-length protein fragment (92 amino acids) showed that viruses from each infant formed a monophyletic group. Unexpectedly, V3 loop protein sequences (35 amino acids) that were found at later time points from the two infants who developed AIDS clustered together. Furthermore, these sequences uniquely shared amino acids that have been shown to confer a T-cell line tropic phenotype. The evolutionary pattern suggests that viruses from these infants with AIDS acquired similar and possibly more virulent phenotypes.

Antibodies to the E4, E6, and E7 proteins of human papillomavirus (HPV) type 16 in patients with HPV-associated diseases and in the normal population.

In a cross-sectional study, titers of antibodies to the E4 and E7 proteins of human papillomavirus (HPV) type 16 were measured by peptide-based enzyme-linked immunosorbent assay in 1707 sera. Sera were obtained from healthy individuals (ages 1 to 95 years), from patients with HPV-associated infection (cervical intraepithelial neoplasia and cervical cancer), and from patients who were at high risk for HPV infection (attending a sexually transmitted disease clinic or referred to a colposcopist because of an abnormal Papanicolaou smear). The prevalence of anti-E7 antibodies increased with age, although the overall prevalence in the adult population was low (10.36%) compared to the frequent detection of HPV 16 DNA in the population. This suggests that only a fraction of patients infected with HPV 16 develop an anti-E7 response. The age distribution of anti-E4 antibodies showed a different pattern, i.e., the prevalence was low in the adult population (1.14%) but exceeded 20% in children and teenagers. As the specificity of the anti-E4 reaction was supported by a highly significant association with anti-E6 positivity in children's sera (p = 0.002), it was assumed that infection with HPV 16 can occur frequently early in life. As compared to healthy controls, patients at high risk for HPV infection had a significantly higher frequency (p < 0.001) of antibodies to the HPV 16 E4 protein (but not to the E6 or the E7 protein) in their sera. Therefore, we conclude that in adults E4-specific antibodies may be a marker for virus replication.