Age-related transcript changes in type I interferon signaling in children and adolescents with long COVID

SARS-CoV-2 typically causes mild symptoms in children, but evidence suggests that persistent immunopathological changes may lead to long COVID (LC). To explore the interplay between LC and innate immunity, we assessed the type I interferon (IFN-I) response in children and adolescents with LC symptoms (LC; n = 28). This was compared with age-matched SARS-CoV-2 recovered participants without LC symptoms (MC; n = 28) and healthy controls (HC; n = 18). We measured the mRNA expression of IFN-I (IFN-α/β/ε/ω), IFN-I receptor (IFNAR1/2), and ISGs (ISG15, ISG56, MxA, IFI27, BST2, LY6E, OAS1, OAS2, OAS3, and MDA5) in PBMCs collected 3-6 months after COVID-19. LC adolescents (12-17 years) had higher transcript levels of IFN-β, IFN-ε, and IFN-ω than HC, whereas LC children (6-11 years) had lower levels than HC. In adolescents, increased levels of IFN-α, IFN-β, and IFN-ω mRNAs were found in the LC group compared with MC, while lower levels were observed in LC children than MC. Adolescents with neurological symptoms had higher IFN-α/β mRNA levels than MC. LC and MC participants showed decreased expression of ISGs and IFNAR1, but increased expression of IFNAR2, than HC. Our results show age-related changes in the expression of transcripts involved in the IFN-I signaling pathway in children and adolescents with LC.

Bioengineered Bovine Papillomavirus L1 Protein Virus-like Particle (VLP) Vaccines for Enhanced Induction of CD8 T Cell Responses through Cross-Priming

Safe and effective T cell vaccines are needed for the treatment or prevention of cancers as well as infectious agents where vaccines for neutralizing antibodies have performed poorly. Recent research highlights an important role for tissue-resident memory T cells (T_RM cells) in protective immunity and the role of a subset of dendritic cells that are capable of cross-priming for the induction of T_RM cells. However, efficient vaccine technologies that operate through cross-priming and induce robust CD8+ T cell responses are lacking. We developed a platform technology by genetically engineering the bovine papillomavirus L1 major capsid protein to insert a polyglutamic acid/cysteine motif in place of wild-type amino acids in the HI loop. Virus-like particles (VLPs) are formed by self-assembly in insect cells infected with a recombinant baculovirus. Polyarginine/cysteine-tagged antigens are linked to the VLP by a reversible disulfide bond. The VLP possesses self-adjuvanting properties due to the immunostimulatory activity of papillomavirus VLPs. Polyionic VLP vaccines induce robust CD8+ T cell responses in peripheral blood and tumor tissues. A prostate cancer polyionic VLP vaccine was more efficacious than other vaccines and immunotherapies for the treatment of prostate cancer in a physiologically relevant murine model and successfully treated more advanced diseases than the less efficacious technologies. The immunogenicity of polyionic VLP vaccines is dependent on particle size, reversible linkage of the antigen to the VLP, and an interferon type 1 and Toll-like receptor (TLR)3/7-dependent mechanism.

Immunotherapy targeting the PD-1 pathway alleviates neuroinflammation caused by chronic Toxoplasma infection

Toxoplasma gondii can infect the host brain and trigger neuroinflammation. Such neuroinflammation might persist for years if the infection is not resolved, resulting in harmful outcomes for the brain. We have previously demonstrated the efficacy of immunotherapy targeting the programmed cell death protein 1 (PD-1) pathway on clearance of Toxoplasma tissue cysts. We aimed to test whether parasite clearance would lead to the resolution of neuroinflammation in infected brains. We established chronic Toxoplasma infection in BALB/c mice using the cyst-forming Prugniaud strain. Mice then received αPD-L1 or isotype control antibodies. After completion of the therapy, mice were euthanized six weeks later. The number of brain tissue cysts, Toxoplasma-specific CD8 + T cell proliferation and IFN-γ secretion, serum cytokine and chemokine levels, and CNS inflammation were measured. In αPD-L1-treated mice, we observed reduced brain tissue cysts, increased spleen weight, elevated IFN-γ production by antigen-specific CD8 + T cells, and a general increase in multiple serum cytokines and chemokines. Importantly, αPD-L1-treated mice displayed attenuation of meningeal lymphocytes, reactive astrocytes, and C1q expression. The reduction in inflammation-related proteins is correlated with reduced parasite burden. These results suggest that promoting systemic immunity results in parasite clearance, which in turn alleviates neuroinflammation. Our study may have implications for some brain infections where neuroinflammation is a critical component.

Anti-IFN-α/-ω neutralizing antibodies from COVID-19 patients correlate with downregulation of IFN response and laboratory biomarkers of disease severity

A significant number of COVID‐19 patients were shown to have neutralizing antibodies (NAB) against IFN; however, NAB specificity, fluctuation over time, associations with biochemical and hematological parameters, and IFN gene expression are not well characterized.

Binding antibodies (BAB) to IFN‐α/‐β were screened in COVID‐19 patients’ serum. All BAB positive sera, and a subset of respiratory samples, were tested for NAB against IFN‐α/‐β/‐ω, using an antiviral bioassay. Transcript levels of IFN‐α/‐β/‐ω and IFN‐stimulated genes (ISGs) were quantified.

Anti‐IFN‐I BAB were found in 61 out of 360 (17%) of patients. Among BAB positive sera, 21.3% had a high NAB titer against IFN‐α. A total of 69.2% of anti‐IFN‐α NAB sera displayed cross‐reactivity to IFN‐ω. Anti‐IFN‐I NAB persisted in all patients. NAB to IFN‐α were also detected in 3 out of 17 (17.6%) of respiratory samples. Anti‐IFN‐I NAB were higher in males (p = 0.0017), patients admitted to the ICU (p < 0.0001), and patients with a fatal outcome (p < 0.0001). NAB were associated with higher levels of CRP, LDH, d‐Dimer, and higher counts of hematological parameters. ISG‐mRNAs were reduced in patients with persistently NAB titer.

NAB are detected in a significant proportion of severe COVID‐19. NAB positive patients presented a defective IFN response and increased levels of laboratory biomarkers of disease severity.

Serological Responses to Toxoplasma gondii and Matrix Antigen 1 Predict the Risk of Subsequent Toxoplasmic Encephalitis in People Living with HIV

BACKGROUND

Clinically useful predictors for fatal toxoplasmosis are lacking. We investigated the value of serological assays for antibodies to whole Toxoplasma antigens and to peptide antigens of the Toxoplasma cyst protein MAG1, for predicting incident toxoplasmic encephalitis (TE) in people living with HIV (PLWH).

METHODS

We performed a nested case control study, conducted within the Multicenter AIDS Cohort Study (MACS), using serum samples obtained 2 years prior to diagnosis of TE from 28 cases, and 37 HIV disease-matched Toxoplasma seropositive controls at matched time-points. Sera were tested for Toxoplasma antibodies using a commercial assay and for antibodies to MAG1_4.2 and MAG1_5.2 peptides in ELISA.

RESULTS

Two years prior to clinical diagnosis, 68% of TE cases were MAG1_4.2 seropositive compared with 16% of controls (OR 25.0, 95% CI 3.14-199.18). Corresponding results for MAG1_5.2 seropositivity were 36% and 14% (OR 3.6, 95% CI 0.95-13.42). Higher levels of antibody to MAG1_4.2 (OR 18.5 per doubling of the OD value, 95% CI 1.41-242) and to Toxoplasma (OR 2.91 for each OD unit increase, 95% CI 1.48-5.72) were also associated with the risk of TE. When seropositivity was defined as the presence of MAG1 antibody or relatively high levels of Toxoplasma antibody, the sensitivity was 89% and specificity was 68% for subsequent TE.

CONCLUSIONS

Antibodies to MAG1 showed predictive value on the occurrence of TE in PLWH, and the predictive performance was further improved by adding the levels of Toxoplasma antibody. These measures could be clinically useful for predicting subsequent diseases in multiple at-risk populations.

Rates of New Human Papillomavirus Detection and Loss of Detection in Middle-aged Women by Recent and Past Sexual Behavior

BACKGROUND

Understanding the source of newly detected human papillomavirus (HPV) in middle-aged women is important to inform preventive strategies, such as screening and HPV vaccination.

METHODS

We conducted a prospective cohort study in Baltimore, Maryland. Women aged 35-60 years underwent HPV testing and completed health and sexual behavior questionnaires every 6 months over a 2-year period. New detection/loss of detection rates were calculated and adjusted hazard ratios were used to identify risk factors for new detection.

RESULTS

The new and loss of detection analyses included 731 women, and 104 positive for high-risk HPV. The rate of new high-risk HPV detection was 5.0 per 1000 woman-months. Reporting a new sex partner was associated with higher detection rates (adjusted hazard ratio, 8.1; 95% confidence interval, 3.5-18.6), but accounted only for 19.4% of all new detections. Among monogamous and sexually abstinent women, new detection was higher in women reporting ≥5 lifetime sexual partners than in those reporting <5 (adjusted hazard ratio, 2.2; 95% confidence interval, 1.2-4.2).

CONCLUSION

Although women remain at risk of HPV acquisition from new sex partners as they age, our results suggest that most new detections in middle-aged women reflect recurrence of previously acquired HPV.

Association between the vaginal microbiota, menopause status, and signs of vulvovaginal atrophy

OBJECTIVE

The vaginal microbiota helps protect the female genital tract from disease. We sought to describe the composition of the vaginal microbiota in premenopausal, perimenopausal, and postmenopausal women and to explore the association between the microbiota and vulvovaginal atrophy (VVA).

METHODS

Eighty-seven women (aged 35-60 y) were classified as premenopausal (n = 30), perimenopausal (n = 29), or postmenopausal (n = 28) according to Stages of Reproductive Aging Workshop guidelines. Midvaginal bacterial community composition was characterized by 16S ribosomal RNA gene analysis.

RESULTS

Bacterial communities clustered into six community state types (CSTs), of which four were dominated by Lactobacillus crispatus, Lactobacillus gasseri, Lactobacillus iners, or Lactobacillus jensenii, and two (CST IV-A and CST IV-B) had low relative abundance of Lactobacillus. CST IV-A was characterized by Streptococcus and Prevotella, whereas CST IV-B was characterized by Atopobium. There were significant associations between menopause stage and CST (P = 0.004) and between VVA and CST (P = 0.002). Perimenopausal women were more likely to be classified as CST IV-A or L. gasseri CST, whereas postmenopausal women were often classified as CST IV-A. CSTs dominated by L. crispatus and L. iners were more prevalent in premenopausal women. Nineteen participants had signs of mild or moderate VVA. Compared with women with no VVA, the vaginal microbiota of women with mild or moderate atrophy had 25-fold greater odds of being classified as CST IV-A versus L. crispatus CST (adjusted odds ratio, 25.89; 95% credible interval, 2.98-406.79).

CONCLUSIONS

A distinct bacterial community state (CST IV-A) with a low relative abundance of Lactobacillus is associated with VVA. Future studies recruiting a larger number of women are needed to replicate the findings. This study provides an impetus for future longitudinal studies designed to manage, modulate, and restore vaginal microbiota homeostasis, which would provide stronger evidence for a causal relationship with VVA and ultimately improve the treatment and prevention of atrophic vaginitis in menopause.

PD-1 immune checkpoint blockade promotes brain leukocyte infiltration and diminishes cyst burden in a mouse model of Toxoplasma infection

Tissue cysts, the hallmark of chronic Toxoplasma gondii infection, are predominantly located in the brain making clearance of the parasite difficult. Currently available anti-T. gondii drugs are ineffective on cysts and fail to prevent reactivation of latent toxoplasmosis. We examined whether abrogation of inhibitory signaling pathways that maintain T cells in an exhausted state can be exploited for treating T. gondii tissue cysts. By using a mouse model of chronic toxoplasmosis, we showed immune checkpoint blockade directed against the programmed death-1 (PD-1) pathway results in a significant reduction in brain cyst number (77% lower). We showed leukocyte infiltration (CD3+ T cells, CD8+ T cells, and CD11b + cells) in the leptomeninges, choroid plexus, and subependymal tissue, which are known routes of entry of immune cells into the brain, and in proximal brain parenchyma. Our study provides proof of concept for blockade of immune checkpoint inhibitors as a therapy for chronic toxoplasmosis and potentially for other brain pathogens.

Behavioral Abnormalities in a Mouse Model of Chronic Toxoplasmosis Are Associated with MAG1 Antibody Levels and Cyst Burden

There is marked variation in the human response to Toxoplasma gondii infection. Epidemiological studies indicate associations between strain virulence and severity of toxoplasmosis. Animal studies on the pathogenic effect of chronic infection focused on relatively avirulent strains (e.g. type II) because they can easily establish latent infections in mice, defined by the presence of bradyzoite-containing cysts. To provide insight into virulent strain-related severity of human toxoplasmosis, we established a chronic model of the virulent type I strain using outbred mice. We found that type I-exposed mice displayed variable outcomes ranging from aborted to severe infections. According to antibody profiles, we found that most of mice generated antibodies against T. gondii organism but varied greatly in the production of antibodies against matrix antigen MAG1. There was a strong correlation between MAG1 antibody level and brain cyst burden in chronically infected mice (r = 0.82, p = 0.0021). We found that mice with high MAG1 antibody level displayed lower weight, behavioral changes, altered levels of gene expression and immune activation. The most striking change in behavior we discovered was a blunted response to amphetamine-trigged locomotor activity. The extent of most changes was directly correlated with levels of MAG1 antibody. These changes were not found in mice with less cyst burden or mice that were acutely but not chronically infected. Our finding highlights the critical role of cyst burden in a range of disease severity during chronic infection, the predictive value of MAG1 antibody level to brain cyst burden and to changes in behavior or other pathology in chronically infected mice. Our finding may have important implications for understanding the heterogeneous effects of T. gondii infections in human.

Chronic infection with Toxoplasma gondii, a common neurotropic pathogen, affects approximately 1 billion people worldwide. There is marked variation in the human response to infection. Epidemiological studies indicate that virulent strains of T. gondii are associated with increased frequency and severity of human toxoplasmosis. However, animal studies on the pathogenic effect of chronic infection have focused on relatively avirulent strains because they can easily establish latent infections in mice. Employing a murine model of chronic infection with virulent strain, we found that mice displayed variable outcomes ranging from aborted to severe infections. Parasite burden, as measured serologically, was found to be the critical determinant of behavioral and pathogenic changes in chronically infected mice. This study demonstrated the predictive value of serologically determined parasite burden to the levels of chronic infection. Our finding highlights the critical role of parasite burden in a range of disease severity during chronic infection. Our finding may have important implications for understanding the heterogeneous effects of T. gondii infections in human.

Human Papillomavirus (HPV) L1 Serum Antibodies and the Risk of Subsequent Oral HPV Acquisition in Men: The HIM Study

The role of antibody-mediated immunity in preventing newly acquired oral human papillomavirus (HPV) is not well understood. Among 1618 men participating in the HPV Infection in Men (HIM) Study, we evaluated oral rinses for HPV DNA and baseline sera for HPV-6, -11, -16, and -18 L1 antibodies. Thirty percent of men (486) were seropositive for ≥1 HPV type, and 25 men developed incident oral HPV infection (HPV-6 was detected in 7, HPV-11 in 0, HPV-16 in 17, and HPV-18 in 1). Cox models revealed that men with circulating antibodies to HPV-6, -11, -16, or -18 were not less likely to acquire type-specific oral HPV than men without antibodies (hazard ratio for the risk of acquiring HPV-6, -11, -16, or -18, 1.63; 95% confidence interval, .56-4.76).

Serum Antibodies to HPV16 Early Proteins Warrant Investigation as Potential Biomarkers for Risk Stratification and Recurrence of HPV-Associated Oropharyngeal Cancer

Human papillomavirus (HPV) is responsible for increasing incidence of oropharyngeal cancer. At present, there are no biomarkers in the surveillance algorithm for HPV-positive oropharyngeal cancer (HPV-OPC). HPV16 E6 antibody precedes oropharyngeal cancer diagnosis. If HPV16 E6 indeed precedes primary diagnosis, it is similarly expected to precede disease recurrence and may have a potential role as a biomarker for surveillance of HPV-OPC. To determine whether HPV antibody titers have a potential role as early markers of disease recurrence or prognosis, a retrospective pilot study was designed to determine whether HPV16 early antibody titers E6, E7, E1, and E2 decrease after treatment of HPV16-positive OPC. Trends in pretreatment, early (≤6 months after treatment), and late posttreatment (>6 months after treatment) HPV16 antibody titers were examined. There were 43, 34, and 52 subjects with serum samples available for pretreatment, early, and late posttreatment intervals. Mean pretreatment antibody levels were higher than posttreatment antibody levels. Average antibody levels decreased significantly over time for E6 (Ptrend = 0.001) and E7 (Ptrend < 0.001). Six disease recurrences were observed during the follow-up period (median, 4.4 years). In univariate analysis, a log-unit increase in pretreatment E6 titer was significantly associated with increased risk of disease recurrence (HR, 5.42; 95% CI, 1.1-25.7; P = 0.03). Therefore, levels of antibodies to HPV16 early oncoproteins decline after therapy. Higher E6 titers at diagnosis are associated with significant increases in the risk of recurrence. These data support the prospective evaluation of HPV16 antibodies as markers of surveillance and for risk stratification at diagnosis.

Prospective study of seroreactivity to JC virus T-antigen and risk of colorectal cancers and adenomas

John Cunningham virus (JCV) is a common polyomavirus classified as a possible carcinogen by the International Agency for Research on Cancer. JCV may play a role in colorectal carcinogenesis, although we previously reported no association between JCV capsid antibodies and colorectal cancer. No studies have examined the role of seroreactivity to JCV T-antigen (T-Ag) oncoprotein in colorectal cancer. A case-control study nested within a community-based prospective cohort (CLUE II) was conducted. In 1989, 25,080 residents of Washington County, Maryland, were enrolled in CLUE II, completing baseline questionnaires and providing blood samples. At follow-up, 257 incident colorectal cancer cases were identified by linkage to population-based cancer registries through 2006 and matched to controls on age, sex, race, and date of blood draw. One hundred and twenty-three colorectal adenoma cases were identified through self-report during follow-up and matched to controls on age, sex, race, date of blood draw, and colorectal cancer screening. Baseline serum samples were tested for seroreactivity to JCV T-Ag. Associations between JCV T-Ag seroreactivity and colorectal cancer/adenomas were evaluated using conditional logistic regression models. Overall, seroreactivity to JCV T-Ag was not statistically significantly associated with the risk of either colorectal cancer [OR, 1.34; 95% confidence interval (CI), 0.89-2.01] or adenoma (OR, 1.30; 95% CI, 0.70-2.42), while a borderline association with colorectal cancer was observed among women (OR, 1.82; 95% CI, 1.00-3.31). Our past evaluation of JCV capsid seropositivity, combined with current findings, does not support a notable etiologic role for JCV infection in colorectal cancer.

HIV-1, HBV, HCV, HTLV, HPV-16/18, and Treponema pallidum infections in a sample of Brazilian men who have sex with men

Background

Men who have sex with men (MSM) are more vulnerable to blood-borne infections and/or sexually-transmitted infections (STI). This study was conducted to estimate the prevalences of mono and co-infections of HIV-1 and other blood-borne/STIs in a sample of MSM in Campinas, Brazil.

Methods

Responding Driven Sampling (RDS) was used for recruitment of MSM. Serum samples collected from 558 MSM were analyzed for the presence of serological markers for HIV-1, HBV, HCV, HTLV, HPV-16/18, and T. pallidum infections.

Results

The highest prevalences of infection in serum samples were found for HPV-16 and 18 (31.9% and 20.3%, respectively). Approximately 8% of the study population showed infection with HIV-1, and within that group, 27.5% had recently become infected with HIV-1. HBV infection and syphilis were detected in 11.4% and 10% of the study population, respectively, and the rates of HTLV and HCV infection were 1.5% and 1%, respectively. With the exception of HTLV, all other studied infections were usually found as co-infections rather then mono-infections. The rates of co-infection for HCV, HPV-18, and HIV-1 were the highest among the studied infections (100%, 83%, and 85%, respectively). Interestingly, HTLV infection was usually found as a mono-infection in the study group, whereas HCV was found only as a co-infection.

Conclusions

The present findings highlight the need to educate the MSM population concerning their risk for STIs infections and methods of prevention. Campaigns to encourage vaccination against HBV and HPV could decrease the rates of these infections in MSM.

Obesity and human papillomavirus infection in perimenopausal women

INTRODUCTION

Obesity is known to increase susceptibility to certain infections in men. It is unclear whether obesity increases women's risk for human papillomavirus (HPV) infection.

METHODS

In a prospective cohort of 696 perimenopausal women enrolled in 2008-2012, we sought to determine whether obesity predicted incident HPV detection or nondetection. Obesity was defined as body mass index (BMI) ≥ 30 kg/m(2).

RESULTS

Baseline any type HPV prevalence was comparable between obese and nonobese women (18.7% vs 19.1%; P > .05). Over a median follow-up period of 17.9 months (interquartile range: 12.1-24.5), 187 new HPV detections occurred among 123 women, 60 of whom subsequently lost 76 detectable infections. When compared with nonobese participants, obese women had a similar rate of new HPV detection (7.1 vs 7.8 infections per 1000 infection-years; P > .05) or loss of detection (100.3 vs 85.8 infections per 100 infection-years; P > .05). Similar results were found after adjusting for age, menopausal status, smoking habit, and sexual exposure history.

CONCLUSIONS

Results from the current analysis suggest little effect of obesity on HPV detection and loss of detection in mid-adult women. More research is needed to determine whether adipokines or cytokines better capture the potential immune modulating effects of obesity on HPV infection.

Creation of a Merkel cell polyomavirus small T antigen-expressing murine tumor model and a DNA vaccine targeting small T antigen

BACKGROUND

Merkel cell polyomavirus (MCPyV) is a DNA virus expressing transcripts similar to the large T (LT) and small T (ST) transcripts of SV40, which has been implicated in the pathogenesis of Merkel cell carcinoma (MCC), a rare and highly aggressive neuroendocrine skin cancer. MCPyV LT antigen expression was found to be a requirement for MCC tumor maintenance and ST protein also likely contributes to the carcinogenesis of MCC. Previously, we have identified the probable immunodominant epitope of MCPyV LT and developed a DNA vaccine encoding this epitope linked to calreticulin. The LT-targeting DNA vaccine generated prolonged survival, decreased tumor size and increased LT-specific CD8+ T cells in tumor-bearing mice.

RESULTS

In this study, we developed a MCPyV ST-expressing tumor cell line from B16 mouse melanoma cells. We then utilized this ST-expressing tumor cell line to test the efficacy of a DNA vaccine encoding ST. In ST-expressing tumor-bearing mice, this vaccine, pcDNA3-MCC/ST, generated a significant number of ST antigenic peptide-specific CD8+ T cells and experienced markedly enhanced survival compared to mice vaccinated with empty vector.

CONCLUSIONS

The formation of an effective vaccine against MCPyV has the potential to advance the field of MCC therapy and may contribute to the control of this severe malignancy through immunotherapy. Both of the innovative technologies presented here provide opportunities to develop and test MCPyV-targeted therapies for the control of Merkel cell carcinoma.

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.

A cohort effect of the sexual revolution may be masking an increase in human papillomavirus detection at menopause in the United States

BACKGROUND

Cohort effects, new sex partnerships, and human papillomavirus (HPV) reactivation have been posited as explanations for the bimodal age-specific HPV prevalence observed in some populations; no studies have systematically evaluated the reasons for the lack of a second peak in the United States.

METHODS

A cohort of 843 women aged 35-60 years were enrolled into a 2-year, semiannual follow-up study. Age-specific HPV prevalence was estimated in strata defined by a lower risk of prior infection (<5 self-reported lifetime sex partners) and a higher risk of prior infection (≥ 5 lifetime sex partners). The interaction between age and lifetime sex partners was tested using likelihood ratio statistics. Population attributable risk (PAR) was estimated using Levin's formula.

RESULTS

The age-specific prevalence of 14 high-risk HPV genotypes (HR-HPV) declined with age among women with <5 lifetime sex partners but not among women with ≥ 5 lifetime sex partners (P = .01 for interaction). The PAR for HR-HPV due to ≥ 5 lifetime sex partners was higher among older women (87.2%), compared with younger women (28.0%). In contrast, the PAR associated with a new sex partner was 28% among women aged 35-49 years and 7.7% among women aged 50-60 years.

CONCLUSIONS

A lower cumulative probability of HPV infection among women with a sexual debut before the sexual revolution may be masking an age-related increase in HPV reactivation in the United States.

The Toxoplasma MAG1 peptides induce sex-based humoral immune response in mice and distinguish active from chronic human infection

To distinguish active from inactive/chronic infection in Toxoplasma gondii-seropositive individuals, we have developed an enzyme-linked immunosorbent assay (ELISA) using specific peptides derived from Toxoplasma matrix antigen MAG1. We used this assay to measure matrix specific antibodies and pilot studies with infected mice established the validity of two peptides. The immune response against MAG1 occurs in about 12 days postinfection and displays a sex difference later on in mouse model, with males producing higher antibody titers than females. Serum samples from 22 patients with clinical toxoplasmosis and from 26 patients with serological evidence of past exposure to Toxoplasma (more than one year infection history) were analyzed. Both MAG1 peptides detected antibodies significant frequently and robustly from active stage than from the chronic stage of toxoplasmosis. The results indicate that both MAG1 peptides may be used as a tool to differentiate active from inactive infection. It also may be considered in the design of potential vaccines in humans.

Strategy for eliciting antigen-specific CD8+ T cell-mediated immune response against a cryptic CTL epitope of merkel cell polyomavirus large T antigen

Background

Merkel cell carcinoma (MCC) is a relatively new addition to the expanding category of oncovirus-induced cancers. Although still comparably rare, the number of cases has risen dramatically in recent years. Further complicating this trend is that MCC is an extremely aggressive neoplasm with poor patient prognosis and limited treatment options for advanced disease. The causative agent of MCC has been identified as the merkel cell polyomavirus (MCPyV). The MCPyV-encoded large T (LT) antigen is an oncoprotein that is theorized to be essential for virus-mediated tumorigenesis and is therefore, an excellent MCC antigen for the generation of antitumor immune responses. As a foreign antigen, the LT oncoprotein avoids the obstacle of immune tolerance, which normally impedes the development of antitumor immunity. Ergo, it is an excellent target for anti-MCC immunotherapy. Since tumor-specific CD8+ T cells lead to better prognosis for MCC and numerous other cancers, we have generated a DNA vaccine that is capable of eliciting LT-specific CD8+ T cells. The DNA vaccine (pcDNA3-CRT/LT) encodes the LT antigen linked to a damage-associated molecular pattern, calreticulin (CRT), as it has been demonstrated that the linkage of CRT to antigens promotes the induction of antigen-specific CD8+ T cells.

Results

The present study shows that DNA vaccine-induced generation of LT-specific CD8+ T cells is augmented by linking CRT to the LT antigen. This is relevant since the therapeutic effects of the pcDNA3-CRT/LT DNA vaccine is mediated by LT-specific CD8+ T cells. Mice vaccinated with the DNA vaccine produced demonstrably more LT-specific CD8+ T cells. The DNA vaccine was also able to confer LT-specific CD8+ T cell-mediated protective and therapeutic effects to prolong the survival of mice with LT-expressing tumors. In the interest of determining the LT epitope which most MCC-specific CD8+ T cells recognize, we identified the amino acid sequence of the immunodominant LT epitope as aa19-27 (IAPNCYGNI) and found that it is H-2k^b-restricted.

Conclusion

The results of this study can facilitate the development of other modes of MCC treatment such as peptide-based vaccines and adoptive transfer of LT-specific CD8+ T cells. Likewise, the MCC DNA vaccine has great potential for clinical translation as the immunologic specificity is high and the treatment strategy can be exported to address other virus-induced tumors.

Contributions of recent and past sexual partnerships on incident human papillomavirus detection: acquisition and reactivation in older women

Understanding the fraction of newly detected human papillomavirus (HPV) infections due to acquisition and reactivation has important implications on screening strategies and prevention of HPV-associated neoplasia. Information on sexual activity and cervical samples for HPV DNA detection using Roche Linear Array were collected semiannually for two years from 700 women ages 35 to 60 years. Incidence and potential fraction of HPV associated with new and lifetime sexual partnerships were estimated using Poisson regression. Cox frailty models were used to estimate hazard ratios (HR) for potential risk factors of incident HPV detection. Recent and lifetime numbers of sexual partners were both strongly associated with incident HPV detection. However, only 13% of incident detections were attributed to new sexual partners, whereas 72% were attributed to 5 or more lifetime sexual partners. Furthermore, 155 of 183 (85%) incident HPV detections occurred during periods of sexual abstinence or monogamy, and were strongly associated with cumulative lifetime sexual exposure [HR: 4.1, 95% confidence interval (CI): 2.0-8.4). This association increased with increasing age. These data challenge the paradigm that incident HPV detection is driven by current sexual behavior and new viral acquisition in older women. Our observation that most incident HPV infection was attributable to past, not current, sexual behavior at older ages supports a natural history model of viral latency and reactivation. As the more highly exposed baby-boomer generation of women with sexual debut after the sexual revolution transition to menopause, the implications of HPV reactivation at older ages on cervical cancer risk and screening recommendations should be carefully evaluated.

Seroprevalence of human papillomavirus (HPV) type 6 and 16 vary by anatomic site of HPV infection in men

BACKGROUND

It is largely unknown if antihuman papillomavirus (HPV) serum antibody responses vary by anatomic site of infection in men.

METHODS

This study assessed type-specific anti-HPV serum antibody prevalence associated with corresponding HPV DNA detection in the external genitalia and the anal canal of 1,587 heterosexual men and 199 men who have sex with men (MSM).

RESULTS

We observed that HPV 6 and 16 seroprevalence was higher in the presence of same HPV-type infection in the anal canal compared with same HPV-type infection in the external genitalia only, and among MSM compared with the heterosexual men. Seropositivity to HPV 6 was strongly associated with HPV 6 DNA detection in the anal canal but not in the external genitalia alone among both heterosexual men [adjusted prevalence ratio (APR), anal+/genital+ vs. anal-/genital-: 4.2, 95% confidence interval (CI), 11.7-10.5; anal+/genital- vs. anal-/genital-: 7.9 (95% CI, 3.7-17.0)] and MSM [APR, anal+/genital+ vs. anal-/genital-: 5.6 (95% CI, 2.7-11.9); anal+/genital- vs. anal-/genital-: 3.2 (95% CI, 2.1-4.9)]. Similar associations between seropositivity to HPV 16 and anal HPV 16 DNA detection were only observed in MSM [anal+/genital+ vs. anal-/genital-: 3.1 (95% CI, 2.0-5.0); anal+/genital- vs. anal-/genital-: 2.2 (95% CI, 1.3-3.5)].

CONCLUSION

Our data showed that seroprevalence varied by anatomic site of HPV infection, suggesting differences in epithelium type present at these anatomic sites may be relevant.

IMPACT

Our finding is instrumental in advancing our understanding of immune mechanism involved in anatomic site-specific antibody response.

Abstract 5490: Prospective study of seroreactivity to JC virus T-Antigen and risk of colorectal cancers and adenomas

JC virus (JCV) has been hypothesized to play a role in the development of colorectal cancer (CRC), although findings are inconsistent across studies. Case series have reported the presence of JCV DNA in tumors, but two serological studies observed no statistically significant association between circulating antibodies to JCV capsid protein and risk of CRC. No epidemiologic study has examined the association between antibodies to the JCV oncoprotein, T-antigen, and cancer. To investigate the association between circulating levels of JCV T-Ag antibodies and the risk of CRC and adenomas, we conducted a case-control study nested within a community-based cohort established in Washington County, MD, in 1989. Cancer registries were used to identify incident cases of CRC occurring within this cohort through 2006 (n=251), and 123 colonoscopy-detected adenoma cases were initially self-reported through a follow-up questionnaire and subsequently verified through pathology report review. Controls were selected from cohort participants who did not develop CRC or adenomas and matched to cases on age, sex, race, date of blood draw, and for adenoma cases, date of endoscopy. Recombinant protein-based enzyme linked immunosorbent assays (ELISA) were used to measure JCV T-Ag antibodies in baseline pre-diagnostic plasma samples. High versus low seroreactivity was defined using the median value among the controls. Conditional logistic regression was used to calculate odds ratios (OR's) and 95% confidence intervals (CI). Overall, high JCV T-Ag seroreactivity was not associated with development of CRC (OR=1.24, 95% CI=0.84-1.84) or adenoma (OR=1.18, 95% CI=0.67-2.09). Among females, high JCV T-Ag seroreactivity was associated with an increased risk of CRC (OR=1.78, 95% CI=1.00-3.17), whereas no association was observed among males (OR=0.89, 95% CI=0.51-1.54). High JCV T-Ag seroreactivity was associated with non-statistically significant risks of rectal cancer (OR=1.55, 95% CI=0.72-3.30) and CRC diagnosed at distant stage (OR=2.25, 95% CI=0.69-7.31), but not with distal or proximal colon cancer or CRC diagnosed at local/regional stages. High JCV T-Ag seroreactivity was not associated with increased risk of adenomas overall or by gender. However, a statistically significant association was observed between high JCV T-Ag seroreactivity and adenomas of the proximal colon (OR=2.80, 95% CI=1.01-7.77), but not the distal colon. No clear differences in risk were observed when results were stratified by adenoma size or histology. These results suggest that associations between JCV infection and CRC/adenomas may differ by gender and anatomic site. Further studies incorporating multiple serologic and DNA-based markers are needed to better understand the relationship between JCV infection and CRC/adenomas.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5490. doi:1538-7445.AM2012-5490

Neutralization serotyping of BK polyomavirus infection in kidney transplant recipients

BK polyomavirus (BKV or BKPyV) associated nephropathy affects up to 10% of kidney transplant recipients (KTRs). BKV isolates are categorized into four genotypes. It is currently unclear whether the four genotypes are also serotypes. To address this issue, we developed high-throughput serological assays based on antibody-mediated neutralization of BKV genotype I and IV reporter vectors (pseudoviruses). Neutralization-based testing of sera from mice immunized with BKV-I or BKV-IV virus-like particles (VLPs) or sera from naturally infected human subjects revealed that BKV-I specific serum antibodies are poorly neutralizing against BKV-IV and vice versa. The fact that BKV-I and BKV-IV are distinct serotypes was less evident in traditional VLP-based ELISAs. BKV-I and BKV-IV neutralization assays were used to examine BKV type-specific neutralizing antibody responses in KTRs at various time points after transplantation. At study entry, sera from 5% and 49% of KTRs showed no detectable neutralizing activity for BKV-I or BKV-IV neutralization, respectively. By one year after transplantation, all KTRs were neutralization seropositive for BKV-I, and 43% of the initially BKV-IV seronegative subjects showed evidence of acute seroconversion for BKV-IV neutralization. The results suggest a model in which BKV-IV-specific seroconversion reflects a de novo BKV-IV infection in KTRs who initially lack protective antibody responses capable of neutralizing genotype IV BKVs. If this model is correct, it suggests that pre-vaccinating prospective KTRs with a multivalent VLP-based vaccine against all BKV serotypes, or administration of BKV-neutralizing antibodies, might offer protection against graft loss or dysfunction due to BKV associated nephropathy.

Age-specific human papillomavirus antibody and deoxyribonucleic acid prevalence: a global review

PURPOSE

Global data on human papillomavirus (HPV) serological and deoxyribonucleic acid (DNA) prevalence are essential to optimize HPV prophylactic vaccination strategies.

METHODS

We conducted a global review of age-specific HPV antibody and studies with both antibody and DNA prevalence for HPV-16, -18, -6, and -11.

RESULTS

One hundred seventeen studies were included; participants' ages ranged from several hours to >90 years. HPV-16 seroprevalence was generally higher in Africa, Central and South America, and North America, more prevalent among women than among men, and peaked around ages 25-40 years. HPV-18 seroprevalence was generally lower than HPV-16 with a later age peak. Data were limited for HPV-6 and -11, both of which peaked at ages similar to HPV-18. Among 9-26-year-old females, HPV-16 seroprevalence ranged from 0%-31% in North America, 21%-30% in Africa, 0%-23% in Asia/Australia, 0%-33% in Europe, and 13%-43% in Central and South America. HPV-16/-18 DNA prevalence peaked 10-15 years before corresponding HPV-16/-18 antibody prevalence.

CONCLUSIONS

Females within the HPV vaccine-eligible age-group (9-26 years) had a range of dual HPV-16 DNA and serology negativity from 81%-87%, whereas 90%-98% were HPV-16 DNA negative. Serology and DNA data are lacking worldwide for females younger than age 15 years, the prime target group for vaccination.

Development of a DNA vaccine targeting Merkel cell polyomavirus

Merkel cell carcinoma (MCC) is a rare but devastating skin disease that is increasing in incidence within the United States. The poor prognosis of MCC patients and limited understanding of MCC pathogenesis warrants innovative treatments to control MCC. Several lines of evidence have pointed to Merkel cell polyomavirus (MCPyV) as the etiological agent of MCC. In particular, the amino terminus of MCPyV large T antigen (LT) (aa1-258) is expressed in all MCPyV-positive tumors and plays an important role in MCC oncogenesis, rendering it an ideal therapeutic target for vaccination. In the current study, we developed a DNA vaccine encoding MCPyV LT aa1-258 (pcDNA3-LT). Within our pcDNA3-LT DNA vaccine, we identified that MCPyV LT aa136-160 likely contains an LT-specific CD4+ T helper epitope. We have also created an LT-expressing B16/LT tumor model using B16, a murine melanoma cell line, to characterize the potency of our DNA vaccine. Using this tumorigenic B16/LT tumor model, we found that pcDNA3-LT DNA vaccine generates antitumor effects mainly mediated by CD4+ T cells against B16/LT tumors in vaccinated C57BL/6 mice. Thus, immunotherapy using pcDNA3-LT DNA vaccine may represent a promising approach for the control of MCPyV-associated lesions. The B16/LT tumor model further serves as a useful model for testing various vaccine strategies against MCC.

Prevalent serum antibody is not a marker of immune protection against acquisition of oncogenic HPV16 in men

In women, naturally induced anti-human papilloma virus (HPV) serum antibodies are a likely marker of host immune protection against subsequent HPV acquisition and progression to precancerous lesions and cancers. However, it is unclear whether the same is the case in men. In this study, we assessed the risk of incident genital infection and 6-month persistent genital infection with HPV16 in relation to baseline serostatus in a cohort of 2,187 men over a 48-month period. Genital swabs were collected every 6 months and tested for HPV presence. Incidence proportions by serostatus were calculated at each study visit to examine whether potential immune protection attenuated over time. Overall, incidence proportions did not differ statistically between baseline seropositive and seronegative men at any study visit or over the follow-up period. The risk of incident and 6-month persistent infection was not associated with baseline serostatus or baseline serum antibody levels in the cohort. Our findings suggest that baseline HPV seropositivity in men is not associated with reduced risk of subsequent HPV16 acquisition. Thus, prevalent serum antibodies induced by prior infection may not be a suitable marker for subsequent immune protection against genital HPV16 acquisition in men.

Differences in the concentration and correlation of cervical immune markers among HPV positive and negative perimenopausal women

INTRODUCTION

Women≥45years of age with persistent HPV infections have distinct peripheral circulating immune profiles. Few studies have comprehensively evaluated the cervical immunologic microenvironment in HPV-positive and HPV-negative perimenopausal women.

METHODS

We collected cervical secretion specimens from 34 high risk HPV (HR-HPV) positive and 44 HR-HPV negative women enrolled in an ongoing prospective cohort assessing the natural history of HPV across the menopausal transition. We used these specimens to quantify concentrations of 27 different immune markers using multiplexed bead-based immunoassays.

RESULTS

HR-HPV positive women had significantly higher median concentrations of IL-5 (0.11 ng/mgtotal protein vs. 0.08 ng/mgtotal protein), IL-9 (2.7 ng/mgtotal protein vs. 2.1 ng/mgtotal protein), IL-13 (2.1 ng/mgtotal protein vs. 0.9 ng/mgtotal protein), IL-17 (2.9 ng/mgtotal protein vs. 1.1 ng/mgtotal protein), EOTAXIN (4.1 ng/mgtotal protein vs. 1.1 ng/mgtotal protein), GM-CSF (4.3 ng/mgtotal protein vs. 3.3 ng/mgtotal protein), and MIP-1α (3.5 ng/mgtotal protein vs. 1.9 ng/mgtotal protein) compared to HR-HPV negative women. A shift in the correlation of T-cell and pro-inflammatory cytokines (IFN-γ, IL-5, IL-9, IL-10, IL-12, IL-13, IL-15, and TNF-α) from IL-2 to EOTAXIN was observed between HR-HPV negative and positive women.

CONCLUSIONS

Higher local concentrations of anti-inflammatory and allergy associated markers, with a shift in T-cell associated cytokine correlation from IL-2 to EOTAXIN, are associated with HPV infection among older women.

JC virus antibody and viremia as predictors of progressive multifocal leukoencephalopathy in human immunodeficiency virus-1-infected individuals

We examined whether prediagnostic John Cunningham virus (JCV) antibodies and viremia are predictors of progressive multifocal leukoencephalopathy (PML) in 83 PML cases and 240 human immunodeficiency virus (HIV) disease-matched controls. JCV viremia was not predictive of PML, but some patients showed higher anti-JCV immunoglobulin G (IgG) responses 6 months prior to diagnosis.

Human papillomavirus (HPV) 6, 11, 16, and 18 seroprevalence is associated with sexual practice and age: results from the multinational HPV Infection in Men Study (HIM Study)

BACKGROUND

Few human papillomavirus (HPV) serology studies have evaluated type-specific seroprevalence of vaccine HPV types in men. This study investigates seroprevalence of HPV 6, 11, 16, and 18, and associated risk factors in men residing in three countries (United States, Mexico, and Brazil).

METHODS

Data from 1,477 men aged 18 to 70 enrolled in the HPV Infection in Men Study (HIM Study) were analyzed. Serum antibody testing was performed with virus-like particle-based ELISA. Potential risk factors were assessed for individual HPV types by the use of logistic regression.

RESULTS

Overall, HPV-6, 11, 16, and 18 seroprevalence was 14.8%, 17.3%, 11.2%, and 5.8%, respectively. Thirty-four percent of men were seropositive to one or more HPV types. When examined by sexual practice, 31.2% of men who had sex with women, 65.6% of men who had sex with men (MSM), and 59.4% of men who had sex with both men and women (MSMW) were seropositive to one or more HPV types. Seroprevalence increased with age among young-to-middle-aged men with significant upward age trends observed for HPV 11, 16, and 18. Men with multiple lifetime male anal sex partners were 2 to 4 times more likely to be HPV 6 or 11 seropositive and 3 to 11 times more likely to be HPV 16 or 18 seropositive.

CONCLUSION

Our data indicate that exposures to vaccine HPV types were common in men and highly prevalent among MSM and MSMW.

IMPACT

Our study provides strong evidence that the practice of same-sex anal intercourse is an independent risk factor for seroprevalence of individual vaccine HPV types. Examination of antibody responses to HPV infections at various anatomic sites in future studies is needed to elaborate on the mechanism.

Coronavirus immunoreactivity in individuals with a recent onset of psychotic symptoms

Prenatal influenza exposure increases the risk for schizophrenia and brings to question how other respiratory viruses may contribute to neuropsychiatric disease etiopathology. Human coronaviruses cause respiratory infections that range in seriousness from common colds to severe acute respiratory syndrome. Like influenza, coronaviruses can be neurotropic. To test for associations between coronaviruses and serious mental disorders, we utilized a recently developed assay and measured immunoglobulin G (IgG) response against 4 human coronavirus strains (229E, HKU1, NL63, and OC43) in 106 patients with a recent onset of psychotic symptoms and 196 nonpsychiatric controls. We expressed results quantitatively as antibody levels and qualitatively as seroprevalence relative to a defined seropositivity cutoff value. Patient IgG levels were higher than controls for HKU1, NL63, and OC43, with HKU1 and NL63 both showing highly significant patient-to-control differences (HKU1, P ≤ .002; NL63, P ≤ .00001). All 4 coronaviruses were more seroprevalent in patients vs controls, with greatest intergroup differences observed for HKU1 (93% vs 77%, P ≤ .0001). HKU1 and NL63 associations with the patient group were further supported by multivariate analyses that controlled for age, gender, race, socioeconomic status, and smoking status (HKU1, odds ratio [OR] = 1.32, 95% confidence interval [CI] = 1.03-1.67, P ≤ .027; NL63, OR = 2.42, 95% CI = 1.25-4.66, P ≤ .008). Among patients, NL63 was associated with schizophrenia-spectrum (OR = 3.10, 95% CI = 1.27-7.58, P ≤ .013) but not mood disorders. HKU1 and NL63 coronavirus exposures may represent comorbid risk factors in neuropsychiatric disease. Future studies should explore links between the timing of coronavirus infections and subsequent development of schizophrenia and other disorders with psychotic symptoms.

Chlamydia trachomatis and risk of prevalent and incident cervical premalignancy in a population-based cohort

BACKGROUND

Cofactors might affect the risk of the rare progression from infection with carcinogenic human papillomavirus (HPV) to cervical premalignancy to invasive cancer. Some studies have observed that Chlamydia trachomatis infection is associated with increased risk for cervical cancer. In a large prospective cohort, we assessed the role of C trachomatis in cervical premalignancy and addressed confounding by HPV.

METHODS

We identified 182 women with prevalent and 132 women with incident histological cervical intraepithelial neoplasia grade 2 (CIN2), grade 3 (CIN3), or cervical cancer (CIN2+) in the Costa Rica HPV Natural History Study. Control subjects were 995 (approximately 10% of the 10 049) subjects who were randomly selected from the same study. Cervical HPV status at enrollment was determined by MY09/MY11 polymerase chain reaction amplification and dot-blot hybridization. The presence of C trachomatis DNA in cervical exfoliated cells at enrollment was determined by a novel serovar-specific polymerase chain reaction-based C trachomatis detection and genotyping assay. Plasma drawn at enrollment from each subject was used to determine C trachomatis immunoglobulin G (IgG) status. Logistic regression was used to examine the association between C trachomatis and CIN2+, taking into account possible confounding by HPV.

RESULTS

C trachomatis positivity at enrollment was associated with CIN2+ and concurrent and subsequent carcinogenic HPV infection. To account for confounding by HPV status, we restricted the analysis to women positive for carcinogenic HPV DNA at enrollment and found no association between C trachomatis status (as assessed by DNA or IgG) at enrollment and combined prevalent and/or incident CIN2+ (for C trachomatis DNA positivity, odds ratio = 0.77, 95% confidence interval = 0.42 to 1.41; for C trachomatis seropositivity, odds ratio = 1.09, 95% confidence interval = 0.85 to 1.41).

CONCLUSIONS

We found no association between C trachomatis status, as assessed by DNA or IgG, and risk of cervical premalignancy, after controlling for carcinogenic HPV-positive status. Previous positive associations between C trachomatis and cervical premalignancy could have been caused, in part, by an increased susceptibility to HPV infection.

Human papillomavirus types 16, 18, and 31 serostatus and prostate cancer risk in the Prostate Cancer Prevention Trial

Since human papillomavirus (HPV) infection was first identified as a risk factor for cervical cancer, several seroepidemiologic and tissue-based studies have investigated HPV in relation to prostate cancer, another common genitourinary malignancy, with mixed results. To further inform this potential association, we conducted a large, prospective investigation of HPV types 16, 18, and 31 in relation to risk of prostate cancer in the Prostate Cancer Prevention Trial. Cases were a sample of men diagnosed with prostate cancer after visit 2 or on their end-of-study biopsy (n = 616). Controls were men not diagnosed with prostate cancer during the trial or on their end-of-study biopsy (n = 616). Controls were frequency matched to cases by age, treatment arm, and family history of prostate cancer. Sera from visit 2 were tested for IgG antibodies against HPV types 16, 18, and 31. No associations were observed for weak or strong HPV-16 [odds ratio (OR), 0.94; 95% confidence interval (95% CI), 0.53-1.64 and OR, 1.07; 95% CI, 077-1.48, respectively], HPV-18 (OR, 0.75; 95% CI, 0.27-2.04 and OR, 0.87; 95% CI, 0.47-1.63, respectively), or HPV-31 seropositivity (OR, 0.76; 95% CI, 0.45-1.28 and OR, 1.15; 95% CI, 0.80-1.64, respectively) and risk of prostate cancer. Considering this finding in the context of the HPV and prostate cancer literature, HPV does not appear to be associated with risk of prostate cancer, at least by mechanisms proposed to date, and using epidemiologic designs and laboratory techniques currently available.

Abstract 3772A: Merkel cell polyomavirus infection in Merkel cell carincoma

OBJECTIVE: The newly discovered Merkel cell polyomavirus (MCV) may play a role in the etiology of Merkel cell carcinoma (MCC), a rare neuroendocrine malignancy of the skin, as several studies have demonstrated MCV DNA in tumor tissues. However, MCV serologic data are sparse, with few studies investigating MCV DNA in tumor tissues and MCV antibodies within the same patients, and no published data on antibodies to MCV T-antigen. We conducted a pilot study to evaluate MCV antibody profiles in MCC cases versus controls and to examine the correlation between MCV DNA in tumors and MCV seroreactivity. METHODS: Plasma samples were obtained from 33 patients diagnosed and/or treated for MCC at the Moffitt Cancer Center in 2006-08, including 25 males and 8 females, ages 53-88 years. Controls were comprised of 37 patients undergoing routine skin cancer screening exams who had no history of skin cancer and were determined to be negative for all types of non-melanoma skin cancer (NMSC) by a nurse practitioner. Fresh-frozen tumor tissue was obtained from 15 MCC patients, including 9 from whom plasma was also obtained. Virus-like particle-based enzyme linked immunosorbent assays (ELISA) were used to measure IgG and IgA antibodies to the MCV VP1 capsid protein. Levels of IgG directed against MCV large T-antigen were also measured using ELISA. MCV DNA was measured in MCC tumor tissues using real-time polymerase chain reaction for the amplification of the small T-antigen region of the MCV genome. Differences in antibody levels across groups were assessed using Wilcoxon rank sum test. RESULTS: Levels of IgG directed against the MCV capsid protein were higher among MCC cases than healthy controls (mean (SD)= 1876 (4001) in cases, 1521 (4889) in controls; p=0.005), as were levels of MCV capsid IgA (mean (SD) = 0.21 (0.25) and 0.09 (0.15) p=0.005). Although levels of IgG antibodies directed against the large T-antigen were slightly higher among MCC cases compared to healthy controls (mean (SD) =0.25 (0.27) vs. 0.19(0.07)), this difference was not statistically significant. MCV DNA was observed in 10 (67%) of 15 tumor tissues tested, with viral loads ranging from 7.1 to 15.6 viral copies per cell equivalent. Levels of IgG antibodies directed against MCV capsid and T-antigen were higher among the 6 MCV DNA-positive cases than the 3 MCV DNA-negative cases for whom plasma was available (mean (SD): capsid IgG: 1040 (1210) in MCV DNA-positive, 384 (494) in MCV DNA-negative, p=0.52; T-antigen IgG: 0.26 (0.26) in MCV DNA-positive, 0.15 (0.15) in MCV DNA-negative, p=0.52). CONCLUSION: MCV seroreactivity is associated with MCC, and MCV antibody levels are higher among MCC patients with MCV DNA-positive tumor tissues. A larger study is needed to confirm these associations with greater statistical power and provide the evidence needed to establish causality between MCV infection and MCC.

Note: This abstract was not presented at the AACR 101st Annual Meeting 2010 because the presenter was unable to attend.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3772A.

Pretransplant IgG antibodies to polyoma BK virus in pediatric renal transplants

We retrospectively measured IgG antibody levels to BKV in pretransplant sera and compared levels in children who developed BK viremia to a control group who remained free of infection after transplantation. Sera from 45 renal transplant patients were available for analysis (BK viremia = 23, controls = 22). Serum BKV PCR levels ranged from 3400 to 6.5 million DNA copies/mL (mean +/- s.d.: 978K +/- 1.77 million) and were highest in patients with BK nephritis (p = 0.007). Overall, 35% of children with BK viremia were BKV-seronegative vs. 9% of children in control group (p = 0.04), but mean antibody levels were similar between viremic and control patients (p = 0.15). However, children who developed viremia later than six months post-transplantation had significantly lower antibody levels compared with controls (p = 0.004) and patients with early viremia (p = 0.007), and may represent de novo infection or reinfection, rather than recurrence of latent infection. Pretransplant antibody status was significantly associated with subsequent development of BK viremia. Although our findings identified possible factors for developing BK viremia, there was sufficient overlap of both seropositive status and antibody levels among viremic patients and the control group to question the clinical utility of pretransplant IgG antibodies.

Population dynamics of Neisseria gonorrhoeae in Shanghai, China: a comparative study

Background

Gonorrhea is a major sexually transmitted disease (STD) in many countries worldwide. The emergence of fluoroquinolone resistance has complicated efforts to control and treat this disease. We report the first study of the evolutionary processes acting on transmission dynamics of a resistant gonococcal population from Shanghai, China. We compare these findings with our previous study of the evolution of a fluoroquinolone sensitive gonococcal population from Baltimore, MD.

Methods

Ninety six gonococcal samples were collected from male patients in Shanghai, China. All samples were fluoroquinolone resistant. Seven MLST housekeeping genes, two fluoroquinolone resistance genes (gyrA and parC) and the porB gene were sequenced and subjected to population genetic and evolutionary analyses. We estimated genetic diversity, recombination, growth, and selective pressure. The evolutionary history and population dynamics of the Shanghai population were also inferred and compared with that observed in a fluoroquinolone sensitive gonococcal population from Baltimore.

Results

For both populations, mutation plays a larger role than recombination in the evolution of the porB gene, whereas the latter seems to be the main force driving the evolution of housekeeping and fluoroquinolone resistance genes. In both populations there was evidence for positively selected sites in all genes analyzed. The phylogenetic analyses showed no temporal clustering in the Shanghai gonococcal population, nor did we detect shared allelic profiles between the Shanghai and the Baltimore populations. Past population dynamics of gonococcal strains from Shanghai showed a rising relative effective population size (Ne) in MLST genes with a declining relative Ne for gyrA and parC, whereas among sensitive strains from Baltimore we previously observed concordance among these genes. In both Shanghai and Baltimore, the past population dynamics of gonococcal strains tracked changes in the prevalence of gonorrhea.

Conclusions

Our study illustrates both similarities and differences in the evolutionary processes acting on gonococcal populations in different geographic areas. An explanation of this pattern that may apply in China is the continued use of quinolone antibiotics despite widespread resistance. Population genetic analysis of gonococcal strains in conjunction with epidemiological surveillance may provide insights into the epidemic behavior of antibiotic resistant strains and help to design control measures.

Correlates of sexually transmitted infection histories in a cohort of American male health professionals

OBJECTIVE

Several epidemiologic studies have investigated sexually transmitted infections (STIs) and later risk of genitourinary conditions with suggestive positive results. While these results may reflect causal associations, other possible explanations include confounding by factors possibly related to both STI acquisition and genitourinary condition risk such as recognized STI-risk factors/correlates, and other factors not typically considered in relation to STIs (e.g., general health-related behaviors or markers of such behaviors). Very few of these factors have been investigated in older populations in which STIs and genitourinary conditions are typically studied. Therefore, we investigated STI history correlates in one such population, the Health Professionals Follow-up Study.

METHODS

We ascertained histories of potential correlates, gonorrhea, syphilis by questionnaire (n = 36,032), and performed serologic testing for Chlamydia trachomatis, Trichomonas vaginalis, human papillomavirus, and human herpesvirus type 8 infection in a subset (n = 651).

RESULTS

Positive correlations were observed for African-American race, foreign birth, southern residence, smoking, alcohol consumption, ejaculation frequency, vasectomy, and high cholesterol. Inverse correlations were observed for social integration and routine health-related examinations.

CONCLUSIONS

These findings provide useful information on potential confounders for epidemiologic investigations of STIs and chronic diseases, and interesting new hypotheses for STI prevention (e.g., STI counseling before vasectomy).

Asymptomatic reactivation of JC virus in patients treated with natalizumab

BACKGROUND

Progressive multifocal leukoencephalopathy (PML) occurs in a fraction of patients with multiple sclerosis who were treated with natalizumab. Most adults who are infected with the JC virus, the etiologic agent in PML, do not have symptoms. We sought to determine whether exposure to natalizumab causes subclinical reactivation and neurotropic transformation of JC virus.

METHODS

We followed 19 consecutive patients with multiple sclerosis who were treated with natalizumab over an 18-month period, performing quantitative polymerase-chain-reaction assays in blood and urine for JC virus reactivation; BK virus, a JC virus-related polyomavirus, was used as a control. We determined JC virus-specific T-cell responses by means of an enzyme-linked immunospot assay and antibody responses by means of an enzyme-linked immunosorbent assay and analyzed JC virus regulatory-region sequences.

RESULTS

After 12 months of natalizumab therapy, the prevalence of JC virus in the urine of the 19 patients increased from a baseline value of 19% to 63% (P=0.02). After 18 months of treatment, JC virus was detectable in 3 of 15 available plasma samples (20%) and in 9 of 15 available samples of peripheral-blood mononuclear cells (60%) (P=0.02). JC virus regulatory-region sequences in blood samples and in most of the urine samples were similar to those usually found in PML. Conversely, BK virus remained stable in urine and was undetectable in blood. The JC virus-specific cellular immune response dropped significantly between 6 and 12 months of treatment, and variations in the cellular immune response over time tended to be greater in patients in whom JC viremia developed. None of the patients had clinical or radiologic signs of PML.

CONCLUSIONS

Subclinical reactivation of JC virus occurs frequently in natalizumab-treated patients with multiple sclerosis. Viral shedding is associated with a transient drop in the JC virus-specific cellular immune response.

Fulminant JC virus encephalopathy with productive infection of cortical pyramidal neurons

The polyomavirus JC (JCV) is the causative agent of progressive multifocal leukoencephalopathy and of JCV granule cell neuronopathy. We present a human immunodeficiency virus-negative patient who experienced development of multiple cortical lesions, aphasia, and progressive cognitive decline after chemotherapy for non-small-cell lung cancer. Brain biopsy and cerebrospinal fluid polymerase chain reaction demonstrated JCV, and she had a rapidly fatal outcome. Postmortem analysis showed diffuse cortical lesions and areas of necrosis at the gray-white junction. Immunostaining showed a productive JCV infection of cortical pyramidal neurons, confirmed by electron microscopy, with limited demyelination. This novel gray matter syndrome expands the scope of JCV clinical presentation and pathogenesis.

Serological pattern consistent with infection with type I Toxoplasma gondii in mothers and risk of psychosis among adult offspring

Previous studies have shown that maternal antibodies to Toxoplasma measured during pregnancy are associated with an increased risk of schizophrenia and other psychoses in adult offspring. Recently, it has been recognized that different genotypes of Toxoplasma have distinct neuropathogenic potential. The objective of this study was to investigate whether parasite genotype is a contributing factor to disease risk. We have developed an enzyme-linked immunosorbent assay (ELISA) that uses polymorphic polypeptides specific to the three clonal parasite lineages and derived from three dense granule antigens, GRA5, GRA6 and GRA7. We used this assay to measure type-specific antibodies in the sera from 219 pregnant women whose children developed schizophrenia and affective psychotic illnesses in adult life, and 618 matched unaffected control mothers from three cohorts of the Collaborative Perinatal Project. We found that the offspring of mothers with a serological pattern consistent with Toxoplasma type capital I, Ukrainian infection were at significantly increased risk for the development of psychoses as compared with the matched unaffected control mothers (odds ratio=1.94; 95% confidence interval=1.08-3.46; p=0.03). The risk was particularly elevated for affective psychoses (OR=5.24; 95% CI=1.67-16.5; p=0.005). In contrast, we did not find an association between maternal antibodies to other genotypes and risk of psychoses in the offspring. These findings suggest an influence of the parasite genotype on increased risk of psychosis and provide further support for a substantive role of Toxoplasma in the etiology of psychosis.

Investigation of pre-diagnostic virological markers for progressive multifocal leukoencephalopathy in human immunodeficiency virus-infected patients

Progressive multifocal leukoencephalopathy (PML) is a severe neurological disorder due to JC virus (JCV) infection. Pre-diagnostic biological markers and risk factors for PML are not well understood. We conducted a case-control study nested within the Multicenter AIDS Cohort Study to examine the association between JCV viruria and viremia and serum antibody to JCV capsids, in relation to subsequent PML diagnoses, 5 months to 12 years later. Other demographic and immunologic factors were also examined. The study population included 28 incident cases of PML, 26 matched HIV-positive controls, and 50 HIV-negative controls. Prevalence of JCV viruria was 37% in cases, 42% in HIV-positive controls, and 28% in HIV-negative controls (P = 0.43). Among persons with JCV viruria, persistent viruria was more common in cases (89%) than in HIV-positive controls (33%) (P = 0.02). Presence of JCV viruria was not related to the time to PML diagnosis (OR: 1.03, 95% CI: 0.8-1.4); however, the urinary concentration of JCV DNA increased with proximity to the date of PML diagnosis in cases. JCV seropositivity did not differ between cases or controls (P = 0.42). Four cases tested JCV seronegative, including one case only 5 months prior to diagnosis with PML. JCV DNA was detected in the serum of one HIV-positive control. Smoking was the only demographic variable analyzed associated with an increased risk for PML (MOR: 9.0, 95% CI: 1.2-394.5). The results suggest that persistent JCV viruria and increasing urinary concentration of JCV DNA may be predictive of PML for some patients.