Genome sequencing reveals underdiagnosis of primary ciliary dyskinesia in bronchiectasis

BACKGROUND

Bronchiectasis can result from infectious, genetic, immunological and allergic causes. 60-80% of cases are idiopathic, but a well-recognised genetic cause is the motile ciliopathy, primary ciliary dyskinesia (PCD). Diagnosis of PCD has management implications including addressing comorbidities, implementing genetic and fertility counselling and future access to PCD-specific treatments. Diagnostic testing can be complex; however, PCD genetic testing is moving rapidly from research into clinical diagnostics and would confirm the cause of bronchiectasis.

METHODS

This observational study used genetic data from severe bronchiectasis patients recruited to the UK 100,000 Genomes Project and patients referred for gene panel testing within a tertiary respiratory hospital. Patients referred for genetic testing due to clinical suspicion of PCD were excluded from both analyses. Data were accessed from the British Thoracic Society audit, to investigate whether motile ciliopathies are underdiagnosed in people with bronchiectasis in the UK.

RESULTS

Pathogenic or likely pathogenic variants were identified in motile ciliopathy genes in 17 (12%) out of 142 individuals by whole-genome sequencing. Similarly, in a single centre with access to pathological diagnostic facilities, 5-10% of patients received a PCD diagnosis by gene panel, often linked to normal/inconclusive nasal nitric oxide and cilia functional test results. In 4898 audited patients with bronchiectasis, <2% were tested for PCD and <1% received genetic testing.

CONCLUSIONS

PCD is underdiagnosed as a cause of bronchiectasis. Increased uptake of genetic testing may help to identify bronchiectasis due to motile ciliopathies and ensure appropriate management.

Challenges in Cardiovascular Pharmacogenomics Implementation: A viewpoint from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

Pharmacogenomics promises to advance cardiovascular therapy, but there remain pragmatic barriers to implementation. These are particularly important to explore within Europe, as there are differences in the populations, availability of resources and expertise, as well as in ethico-legal frameworks. Differences in healthcare delivery across Europe present a challenge, but also opportunities to collaborate on PGx implementation. Clinical work force upskilling is already in progress but will require substantial input. Digital infrastructure and clinical support tools are likely to prove crucial. It is important that widespread implementation serves to narrow rather than widen any existing gaps in health equality between populations. This viewpoint supplements the working group position paper on cardiovascular pharmacogenomics to address these important themes.

The Role of Pharmacogenomics in Contemporary Cardiovascular Therapy: A position statement from the European Society of Cardiology Working Group on Cardiovascular Pharmacotherapy

There is a strong and ever-growing body of evidence regarding the use of pharmacogenomics to inform cardiovascular pharmacology. However, there is no common position taken by international cardiovascular societies to unite diverse availability, interpretation and application of such data, nor is there recognition of the challenges of variation in clinical practice between countries within Europe. Aside from the considerable barriers to implementing pharmacogenomic testing and the complexities of clinically actioning results, there are differences in the availability of resources and expertise internationally within Europe. Diverse legal and ethical approaches to genomic testing and clinical therapeutic application also require serious thought. As direct-to-consumer genomic testing becomes more common, it can be anticipated that data may be brought in by patients themselves, which will require critical assessment by the clinical cardiovascular prescriber. In a modern, pluralistic and multi-ethnic Europe, self-identified race/ethnicity may not be concordant with genetically detected ancestry and thus may not accurately convey polymorphism prevalence. Given the broad relevance of pharmacogenomics to areas such as thrombosis and coagulation, interventional cardiology, heart failure, arrhythmias, clinical trials, and policy/regulatory activity within cardiovascular medicine, as well as to genomic and pharmacology subspecialists, this position statement attempts to address these issues at a wide-ranging level.

Partial oxidation of alkanes by dioxiranes formed in situ at low temperature

Partial oxidation catalysts capable of efficiently operating at low temperatures may limit the over-oxidation of alkane substrates and thereby improve selectivity. This work focuses on examining alkane oxidation using completely metal-free organocatalysts, dioxiranes. The dioxiranes employed here are synthesized by oxidation of a ketone using a terminal oxidant, such as hydrogen peroxide. Our work generates the dioxirane in situ, so that the process can be catalytic with respect to the ketone. To date, we have demonstrated selective partial oxidation of adamantane using ketone catalysts resulting in yields upwards of 60% towards 1-adamantanol with greater than 99% selectivity. Furthermore, we have demonstrated that changing the electrophilic character of the ketone R groups to contain more electron-donating ligands facilitates the dioxirane ring formation and improves overall oxidation yields. Isotopic labelling studies using H₂¹⁸O₂ show the preferential incorporation of an ¹⁸O label into the parent ketone, providing evidence for a dioxirane intermediate formed in situ The isotopic labelling studies, along with solvent effect studies, suggest the formation of peracetic acid as a reactive intermediate.This article is part of a discussion meeting issue 'Providing sustainable catalytic solutions for a rapidly changing world'.

Effect of Alternative Aluminum Adjuvants on the Absorption and Immunogenicity of HPV16 L1 VLPs in Mice

Aluminum adjuvants are commonly used in prophylactic vaccines to enhance antigen immunogenicity through induction of high-titer antibody responses. Three major forms of aluminum adjuvants with substantially different physical and chemical properties have been described: aluminum phosphate (AlPO(4)), aluminum hydroxide (AlOH) and amorphous aluminum hydroxyphosphate sulfate (AAHS). Here we describe the effect of these different aluminum adjuvants on the formulation and subsequent immunogenicity in mice of virus-like particles (VLPs) consisting of the L1 protein of Human Papillomavirus (HPV) Type 16. Electron microscopy demonstrated that the physical appearance of the phosphate-containing aluminum adjuvants was markedly different from that of aluminum hydroxide. All three aluminum adjuvants were found to display unique surface charge profiles over a range of pH, while AAHS demonstrated the greatest inherent capacity for adsorption of L1 VLPs. These differences were associated with differences in immunogenicity: anti-HPV L1 VLP responses from mice immunized with AAHS-formulated HPV16 vaccine were substantially greater than those produced by mice immunized with the same antigen formulated with aluminum hydroxide. In addition, HPV L1 VLPs formulated on AAHS also induced a substantial interferon-gamma secreting T cell response to L1 peptides indicating the potential for an enhanced memory response to this antigen. These results indicate that the chemical composition of aluminum adjuvants can have a profound influence on the magnitude and quality of the immune response to HPV VLP vaccines.

Rapid, quantitative mapping of anti-HIV type 1 envelope serum antibody specificities

A new generation of extremely broad and potent neutralizing antibodies (bNAbs) has been isolated from HIV-infected subjects. This has refocused interest in the sites of vulnerability targeted by these bNAbs and in the potential for designing Envelope (Env) immunogens that display these sites. Standard methods for evaluating HIV-1 vaccine candidates do not enable epitope mapping on the HIV Env spike, the target for NAbs. To meet the need for rapid analysis of Ab specificity, we designed a multiplexed, quantitative mapping assay that can test for serum Ab competition for the binding of an HIV-1 Env gp120 to a panel of bNAbs directed to different sites of vulnerability on the Env that do not compete for one another in the assay. Using serum samples from rabbits immunized with various DNA prime/gp120 protein boost vaccines we were able to detect serum Ab competition for multiple classes of bNAbs in the postimmune samples that were significantly higher than background competition detected in samples obtained prior to vaccination. Importantly, application of this novel assay to our ongoing HIV-1 Env viral vector studies in mice has allowed us to distinguish qualitative differences in the Ab elicited by various regimens that ELISA cannot. Furthermore, pooled immunoglobulin from HIV-infected donors (HIVIg) competes for binding to the bNAb panel whereas a control pool from HIV-negative donors does not, highlighting the utility of this assay for human studies. This novel assay will add value in rational immunogen design and in the detailed, qualitative evaluation of binding and, potentially, neutralizing Abs elicited by natural infections and HIV-1 vaccine candidates.

Asymmetric recognition of the HIV-1 trimer by broadly neutralizing antibody PG9

PG9 is the founder member of an expanding family of glycan-dependent human antibodies that preferentially bind the HIV (HIV-1) envelope (Env) glycoprotein (gp) trimer and broadly neutralize the virus. Here, we show that a soluble SOSIP.664 gp140 trimer constructed from the Clade A BG505 sequence binds PG9 with high affinity (∼11 nM), enabling structural and biophysical characterizations of the PG9:Env trimer complex. The BG505 SOSIP.664 gp140 trimer is remarkably stable as assessed by electron microscopy (EM) and differential scanning calorimetry. EM, small angle X-ray scattering, size exclusion chromatography with inline multiangle light scattering and isothermal titration calorimetry all indicate that only a single PG9 fragment antigen-binding (Fab) binds to the Env trimer. An ∼18 Å EM reconstruction demonstrates that PG9 recognizes the trimer asymmetrically at its apex via contact with two of the three gp120 protomers, possibly contributing to its reported preference for a quaternary epitope. Molecular modeling and isothermal titration calorimetry binding experiments with an engineered PG9 mutant suggest that, in addition to the N156 and N160 glycan interactions observed in crystal structures of PG9 with a scaffolded V1/V2 domain, PG9 makes secondary interactions with an N160 glycan from an adjacent gp120 protomer in the antibody-trimer complex. Together, these structural and biophysical findings should facilitate the design of HIV-1 immunogens that possess all elements of the quaternary PG9 epitope required to induce broadly neutralizing antibodies against this region.

Varicella zoster virus-specific immune responses to a herpes zoster vaccine in elderly recipients with major depression and the impact of antidepressant medications

BACKGROUND

The Depression Substudy of the Shingles Prevention Study (SPS) was designed to evaluate the association between major depression and immune responses to a high-titer live attenuated varicella zoster virus (VZV) vaccine (zoster vaccine), which boosts cell-mediated immunity (CMI) to VZV and decreases the incidence and severity of herpes zoster (HZ). The Depression Substudy was a 2-year longitudinal cohort study in 92 community-dwelling adults≥60 years of age who were enrolled in the SPS, a large, double-blind, placebo-controlled Veterans Affairs Cooperative zoster vaccine efficacy study.

METHODS

Forty subjects with major depressive disorder, stratified by use of antidepressant medications, and 52 age- and sex-matched controls with no history of depression or other mental illness had their VZV-CMI measured prior to vaccination with zoster vaccine or placebo and at 6 weeks, 1 year, and 2 years postvaccination.

RESULTS

Depressed subjects who were not treated with antidepressant medications had lower levels of VZV-CMI following administration of zoster vaccine than nondepressed controls or depressed subjects receiving antidepressants even when antidepressant medications failed to alter depressive symptom severity (P<.005). Similar results were obtained taking into account the time-varying status of depression and use of antidepressant medications, as well as changes in depressive symptoms, during the postvaccination period.

CONCLUSIONS

Depressed patients have diminished VZV-CMI responses to zoster vaccine, and treatment with antidepressant medication is associated with normalization of these responses. Because higher levels of VZV-CMI correlate with lower risk and severity of HZ, untreated depression may increase the risk and severity of HZ and reduce the efficacy of zoster vaccine.

Major depressive disorder and immunity to varicella-zoster virus in the elderly

Major depressive disorder has been associated with activation of inflammatory processes as well as with reductions in innate, adaptive and non-specific immune responses. The objective of this study was to evaluate the association between major depression and a disease-relevant immunologic response, namely varicella-zoster virus (VZV)-specific immunity, in elderly adults. A cross-sectional cohort study was conducted in 104 elderly community dwelling adults ≥ 60years of age who were enrolled in the depression substudy of the shingles prevention study, a double blind, placebo-controlled vaccine efficacy trial. Fifty-two subjects had a current major depressive disorder, and 52 age- and sex-matched controls had no history of depression or any mental illness. VZV-specific cell-mediated immunity (VZV-CMI) was measured by VZV responder cell frequency (VZV-RCF) and interferon-γ enzyme-linked immunospot (ELISPOT) assays, and antibody to VZV was measured by an enzyme-linked immunosorbent assay against affinity-purified VZV glycoproteins (gpELISA). VZV-CMI, measured by VZV-RCF, was significantly lower in the depressed group than in the controls (p<0.001), and VZV-RCF was inversely correlated with the severity of depressive symptoms in the depressed patients. In addition, an age-related reduction in VZV-RCF was observed in the depressed patients, but not in the controls. Furthermore, there was a trend for depressive symptom severity to be associated with lower ELISPOT counts. Finally, VZV-RCF was higher in depressed patients treated with antidepressant medications as compared to untreated depressed patients. Since lower levels of VZV-RCF appear to explain the increased risk and severity of herpes zoster observed in older adults, these findings suggest that, in addition to increasing age, depression may increase the risk and severity of herpes zoster.

Small molecule mimetics of an HIV-1 gp41 fusion intermediate as vaccine leads

We describe here a novel platform technology for the discovery of small molecule mimetics of conformational epitopes on protein antigens. As a model system, we selected mimetics of a conserved hydrophobic pocket within the N-heptad repeat region of the HIV-1 envelope protein, gp41. The human monoclonal antibody, D5, binds to this target and exhibits broadly neutralizing activity against HIV-1. We exploited the antigen-binding property of D5 to select complementary small molecules using a high throughput screen of a diverse chemical collection. The resulting small molecule leads were rendered immunogenic by linking them to a carrier protein and were shown to elicit N-heptad repeat-binding antibodies in a fraction of immunized mice. Plasma from HIV-1-infected subjects shown previously to contain broadly neutralizing antibodies was found to contain antibodies capable of binding to haptens represented in the benzylpiperidine leads identified as a result of the high throughput screen, further validating these molecules as vaccine leads. Our results suggest a new paradigm for vaccine discovery using a medicinal chemistry approach to identify lead molecules that, when optimized, could become vaccine candidates for infectious diseases that have been refractory to conventional vaccine development.

Revaccination with a 23-valent pneumococcal polysaccharide vaccine induces elevated and persistent functional antibody responses in adults aged 65 > or = years

BACKGROUND

Older adults are at high risk of developing invasive pneumococcal disease, but the optimal timing and number of vaccine doses needed to prevent disease among this group are unknown. We compared revaccination with 23-valent pneumococcal polysaccharide vaccine (PN23) with primary vaccination for eliciting initial and persistent functional antibody responses.

METHODS

Subjects aged > or = 65 years were enrolled. Functional (opsonic) and total immunoglobulin (Ig) G antibody levels were measured following either PN23 primary vaccination (n = 60) or revaccination 3-5 years after receiving a first PN23 vaccination (n = 60). Antibody against vaccine serotypes 4, 14, and 23F was measured at prevaccination (day 0), 30 days after vaccination, and 5 years after vaccination.

RESULTS

By day 30, both primary vaccination and revaccination induced significant increases in opsonic and IgG antibody levels. Day 30 levels following revaccination were slightly lower but not significantly different than those after primary vaccination. Year 5 levels were similar in both groups and remained significantly higher than prevaccination levels for primary vaccination subjects. There was good agreement between postvaccination opsonic and IgG antibody levels.

CONCLUSIONS

Revaccination of older adults with PN23 was comparable to primary vaccination for inducing elevated and persistent functional and IgG antibody responses.

Varicella-zoster virus-specific immune responses to herpes zoster in elderly participants in a trial of a clinically effective zoster vaccine

BACKGROUND

The objectives of this study were to evaluate the association between varicella-zoster virus (VZV)-specific humoral and cell-mediated immunity (CMI) to herpes zoster (HZ) and protection against HZ morbidity and to compare immune responses to HZ and zoster vaccine.

METHODS

In 981 elderly persons who developed HZ during a zoster vaccine efficacy trial (321 vaccinees and 660 placebo recipients) and 1362 without HZ (682 vaccinees and 680 placebo recipients), CMI was measured by VZV responder cell frequency and interferon-gamma enzyme-linked immunospot, and antibodies were measured by VZV enzyme-linked immunosorbent assay against affinity-purified VZV glycoproteins (gpELISA).

RESULTS

Robust VZV CMI at HZ onset correlated with reduced HZ morbidity, whereas VZV gpELISA titers did not. Three weeks after HZ onset, gpELISA titers were highest in those with more severe HZ and were slightly increased in placebo recipients (compared with zoster vaccine recipients) and in older individuals. VZV CMI responses to HZ were similar in zoster vaccine and placebo recipients and were not affected by demographic characteristics or antiviral therapy, except for responder cell frequency at HZ onset, which decreased with age. When responses to zoster vaccine and HZ could be compared, VZV CMI values were similar, but antibody titers were lower.

CONCLUSIONS

Higher VZV CMI at HZ onset was associated with reduced HZ severity and less postherpetic neuralgia. Higher antibody titers were associated with increased HZ severity and occurrence of postherpetic neuralgia. HZ and zoster vaccine generated comparable VZV CMI.

Varicella-zoster virus-specific immune responses in elderly recipients of a herpes zoster vaccine

BACKGROUND

A double-blind, placebo-controlled trial that involved 38,546 subjects > or =60 years old demonstrated efficacy of a high-potency live-attenuated Oka/Merck varicella-zoster virus (VZV) vaccine. The trial included an immunology substudy to determine the relationship of VZV-specific immune responses to vaccination and clinical outcome.

METHODS

The immunology substudy enrolled 1395 subjects at 2 sites where blood samples obtained prior to vaccination, at 6 weeks after vaccination, and at 1, 2, and 3 years thereafter were tested for VZV-specific cell-mediated immunity (VZV-CMI) by gamma-interferon ELISPOT and responder cell frequency assays and for VZV antibody by glycoprotein ELISA.

RESULTS

VZV-CMI and VZV antibodies were significantly increased in vaccine recipients at 6 weeks after vaccination. The vaccine-induced increases in VZV-CMI persisted during the 3 years of follow-up, although their magnitude decreased over time. The magnitude of these VZV-specific immune responses was greater in subjects 60-69 years old than in subjects > or =70 years old.

CONCLUSIONS

The zoster vaccine induced a significant increase in VZV-CMI and VZV antibody. The magnitude and duration of the boost in VZV-CMI in vaccine recipients and the relationship of this boost to age paralleled the clinical effects of the vaccine observed during the efficacy trial. These findings support the hypothesis that boosting VZV-CMI protects older adults against herpes zoster and postherpetic neuralgia.

A novel automated method for enumeration of Chlamydia trachomatis inclusion forming units

Chlamydia trachomatis is an obligate intracellular pathogen that primarily infects epithelial cells. Traditional methods for quantification of inclusion forming units (IFUs) rely upon infection of epithelial cell monolayers in vitro. Following incubation for approximately 2 days, inclusion bodies that result from infection of cells are detected by immunofluorescent staining with an antibody conjugated to a fluorescent dye. These inclusion bodies are then manually counted by microscopic examination of multiple, randomly selected fields of view. This requires substantial operator time and is subject to investigator bias. We have developed a novel method in which we utilize an automated microplate ImmunoSpot reader to count C. trachomatis IFUs. Following infection of epithelial cells in a 96-well plate and subsequent incubation, IFUs are fixed and detected with an anti-C. trachomatis LPS monoclonal antibody. Immobilized antibody is detected with a biotinylated secondary antibody and visualized enzymatically with streptavidin-alkaline phosphatase and the colorimetric substrate nitro-blue tetrazolium chloride/5-bromo-4-chloro-3-indolyl-phospate (NBT/BCIP). IFUs are then enumerated with the ImmunoSpot system. This method has been used to quantify IFUs from all cell lines traditionally used for chlamydial propagation, including L929, McCoy, HeLa and HaK cells. IFU numbers obtained are comparable to those determined by traditional microscopic counting. In addition, the method can be applied to rapid determination of serum-neutralizing titers for vaccine studies, and we have also applied this approach to quantify Chlamydia recovered from vaginal swabs collected from infected animals. This method provides for rapid enumeration of IFU counts while minimizing investigator bias and has potential applications for both research and diagnostic use.

Establishing acceptance criteria for cell-mediated-immunity assays using frozen peripheral blood mononuclear cells stored under optimal and suboptimal conditions

The enzyme-linked immunospot (ELISPOT) assay is a powerful tool for measuring antigen-specific cellular immune responses. The ability to use frozen peripheral blood mononuclear cells (PBMC) facilitates testing samples in multicenter clinical trials; however, unreliable ELISPOT responses may result if samples are not handled properly. Exposure of frozen PBMC to suboptimal storage temperature (-20 degrees C) or repeated cycling between more optimal storage temperatures (less than -130 degrees C and -70 degrees C) reduced the quality of frozen PBMC, as assessed by cell viability and functional ELISPOT response measures. Cell viability as assessed by trypan blue dye exclusion was reduced, and the percentage of apoptotic cells, as determined by the Guava Nexin assay, was significantly increased after these events. The functional gamma interferon ELISPOT responses to phytohemagglutinin (PHA) mitogen, a CD4 T-cell-specific antigen (varicella-zoster virus), and a CD8 T-cell-specific antigen (pool containing known cytomegalovirus, Epstein-Barr virus, and influenza virus peptides) were all significantly reduced after suboptimal storage events. However, for a given suboptimal storage event, the magnitude of the reduction varied between individuals and even among aliquots within an individual bleed, indicating the need for sample-specific acceptance criteria (AC). The percent viable or percent apoptotic cells after thaw, as well as the functional ELISPOT response to PHA, were all effective when applied with limits as AC for separating samples damaged during storage from valid control samples. Although all three AC measures could be effectively applied, the apoptosis AC limit applied was best for separating samples that could respond to antigenic stimulation from samples that could not effectively respond.

Evaluation of cellular immune responses in subjects chronically infected with HIV type 1

The importance of host cellular immune responses, particularly CD8(+) cytotoxic T-lymphocyte (CTL) responses, in control of human immunodeficiency virus type 1 (HIV-1) infection has been demonstrated in many clinical studies. These studies, along with vaccination challenge studies in rhesus macaques, indicate the importance of cellular immune responses against HIV-1. Toward this end, we evaluated anti-HIV-1 cellular immune responses in a cohort of 54 subjects who were chronically infected with HIV-1. By validation of IFN-gamma ELISpot assay, we established a dual cut-off criterion for scoring a positive response. The magnitude and frequency of cellular immune responses were measured against HIV-1 antigens (Gag, Pol, Nef, Rev, and Tat), using synthetic peptides as antigens in ELISpot assay. Here we showed that HIV-1 Gag, Pol, and Nef were frequent targets of T cell responses in these subjects, whereas Tat and Rev were less frequently recognized. We further evaluated the possible association between host cellular immune responses and corresponding plasma viral loads in this cohort. By performing ranking correlation analysis, we demonstrated a positive correlation between host viral loads and ELISpot responses of HIV Gag and Pol in untreated subjects. For the subjects under antiviral regimens, however, we did not find any significant association. Our findings suggest that the high levels of ELISpot responses in chronically infected subjects were reflective of their persistent viral infection.

Safety, tolerability, and immunogenicity of a two-dose regimen of high-titer varicella vaccine in subjects ≥13 years of age

A new manufacturing process, known as process upgrade varicella vaccine (PUVV) was developed for a refrigerated formulation of varicella vaccine and for an investigational zoster vaccine. Safety and tolerability of a two-dose regimen of high-titered (approximately 50,000 PFU) PUVV were compared to a lower-titer formulation (approximately 5400 PFU) of VARIVAX; in 1366 healthy subjects > or =13 years old. Only one vaccine-related clinical serious adverse experience (pruritus; no hospitalization) was reported, in the VARIVAX group. Injection-site adverse experiences following any dose were higher in the PUVV group, 70.0%, than in the VARIVAX group, 56.2%, but generally were mild. Immunogenicity were similar in both groups in seronegative subjects. PUVV was generally well tolerated, and elicited an immune response similar to that induced by the marketed formulation of VARIVAX.

A novel Staphylococcus aureus vaccine: iron surface determinant B induces rapid antibody responses in rhesus macaques and specific increased survival in a murine S. aureus sepsis model

Staphylococcus aureus is a major cause of nosocomial infections worldwide, and the rate of resistance to clinically relevant antibiotics, such as methicillin, is increasing; furthermore, there has been an increase in the number of methicillin-resistant S. aureus community-acquired infections. Effective treatment and prevention strategies are urgently needed. We investigated the potential of the S. aureus surface protein iron surface determinant B (IsdB) as a prophylactic vaccine against S. aureus infection. IsdB is an iron-sequestering protein that is conserved in diverse S. aureus clinical isolates, both methicillin resistant and methicillin sensitive, and it is expressed on the surface of all isolates tested. The vaccine was highly immunogenic in mice when it was formulated with amorphous aluminum hydroxyphosphate sulfate adjuvant, and the resulting antibody responses were associated with reproducible and significant protection in animal models of infection. The specificity of the protective immune responses in mice was demonstrated by using an S. aureus strain deficient for IsdB and HarA, a protein with a high level of identity to IsdB. We also demonstrated that IsdB is highly immunogenic in rhesus macaques, inducing a more-than-fivefold increase in antibody titers after a single immunization. Based on the data presented here, IsdB has excellent prospects for use as a vaccine against S. aureus disease in humans.

Memory T-cell response to rotavirus detected with a gamma interferon enzyme-linked immunospot assay

Measurements of serum-neutralizing antibody and anti-rotavirus immunoglobulin A (IgA) are the current standard for assessing immune responses following rotavirus vaccination. However, there is ongoing debate as to whether antibody titers correlate with protection against rotavirus gastroenteritis. Children recovering from rotavirus gastroenteritis have increased gamma interferon release from cultured peripheral blood mononuclear cells (PBMCs), suggesting that cell-mediated immunity (CMI) may play a role in viral clearance and protection from subsequent gastroenteritis. We have developed a gamma interferon enzyme-linked immunospot (ELISPOT) assay for evaluation of CMI responses to rotavirus using frozen PBMCs obtained from healthy adults. Responses to three different rotavirus antigen types were analyzed-a peptide pool based on the human VP6 sequence; reassortant human:bovine vaccine strains; and cell culture-adapted (CCA) human G1, G2, G3, G4, and bovine (WC3) G6 strains. The reassortant strains consist of a bovine WC3 genome background expressing the human rotavirus surface proteins VP7 (G1, G2, G3, or G4) or VP4 (P1). Responses to titrations of the peptide pool as well as CCA and reassortant strains were assessed. Gamma interferon ELISPOT responses were similar for CCA and reassortant strains, whether live or UV inactivated, and when tested either individually or pooled. For most subjects, responses to the VP6 peptide pool positively correlated with responses to CCA and reassortant strains. Cell depletion studies indicate the memory responses detected with these frozen adult PBMCs were primarily due to the CD4+ T-cell population. This gamma interferon ELISPOT assay provides a new tool to apply in clinical studies for the characterization of natural or vaccine-induced CMI to rotavirus.

High-throughput imaging of bacterial colonies grown on filter plates with application to serum bactericidal assays

The ability to accurately enumerate viable bacteria has applications in antibiotic screening assays, toxicology testing, and serological assays for functional antibodies. An impediment to high-throughput bacterial assays is the requirement to grow bacteria as individual colonies on semisolid media containing agar. We have now developed a method for growth, staining, and counting of bacterial colonies in 96-well filter plates. A unique feature of the method is that colony size is inversely proportional to the number of colonies in each well, presumably due to nutrient depletion. As a result, as many as 300 colony-forming units (cfu) can be detected as discrete colonies within a single assay well. The resulting colonies can be counted automatically using an imaging system originally developed for ELISPOT assays. The method has been applied to the measurement of serum bactericidal activity (SBA) in human sera.

Adjuvant synergy in the response to hepatitis B vaccines

The adjuvant properties of interleukin-12 (IL-12) and a phosphorothioate oligodeoxynucleotide (S-ODN) hexamer consisting of the sequence, 5'-GACGTT-3', were evaluated in mice using hepatitis B (HBs) protein and DNA vaccines. GACGTT was an effective adjuvant when co-injected with HBs protein intramuscularly or when injected at the same anatomic site within 1 day before or 1 day after injection of the protein. Surprisingly, IL-12 had a negligible adjuvant effect when co-injected with HBsAg; however, when bound to "alum", IL-12 stimulated a dramatic increase in anti-HBs titers and a switch from a TH2 to a TH1 response profile as evidenced by an increase in IgG2a subclass anti-HBs antibodies and the ability to secrete interferon-gamma (IFN-gamma) upon in vitro stimulation with an HBs peptide. Interestingly, aluminum phosphate was a far better co-adjuvant (with IL-12) than was aluminum hydroxide even though both "alums" bound >99% of the IL-12. Finally, the combination of IL-12, GACGTT, and aluminum phosphate was found to elicit a markedly polarized TH1 response. The results indicate that aluminum phosphate is highly effective at delivering an antigen (HBsAg) together with TH1 adjuvants such as IL-12 and GACGTT resulting in a shift from a TH2 to a TH1 response.

Identification of T-cell epitopes using ELISpot and peptide pool arrays

Here we describe a method for T-cell epitope identification using a modified ELISpot assay that is both simple and efficient. By using a carefully constructed array of pools of overlapping peptides spanning the entire antigen sequence to stimulate T-cell responses, we are able to detect antigen-specific cytokine responses by both CD8+ and CD4+ T cells and identify the specific peptides to which the cells are responding. Additionally, by performing magnetic bead depletion of either CD8+ or CD4+ cells prior to the assay, we are able to determine the phenotype of the responding cells to each of the peptide epitopes identified. Use of this method will allow the identification of both CD4+ and CD8+ T-cell epitopes without the need for MHC allele-matched reagents and without the need for highly specialized instrumentation. By using an array of peptide pools, this method also dramatically reduces the number of immune cells required to test the entire antigen sequence, often a limiting factor in vaccine testing and other studies.

Genes and hypertension

The combination of investigation of rare Mendelian forms of hypertension, candidate gene studies, comparative mapping and genome-wide screening in both animal models and man has led to significant progress in determining new mechanisms of blood pressure control. In this review, the newly discovered blood pressure/cardiovascular genes, WNK kinases and angiotensin converting enzyme 2 and the development of a new anti-hypertensive agent PST2238 are discussed. Major genes causing essential hypertension have yet to be discovered, however, there are now over 20 published genome-wide screens for blood pressure controlling genes. Several regions demonstrate suggestive linkage to the trait and there is some overlap of regions between the different studies. It is hoped that new blood pressure genes will ultimately be discovered using this method. Pharmacogenetic studies in hypertension have only been initiated recently, some are described in this paper. Small studies upon single candidate genes, suggest that the contribution of genetics to the inter-individual variation in blood pressure response to anti-hypertensive therapy, is small, approximately 3-5%. Recently micro-arrays with multiple polymorphisms in multiple genes have been used. After accounting for the additive affects of multiple blood pressure loci, an individual's genetic profile appeared to explain up to 50% of the variation in blood pressure response to therapy. Knowledge of the genetic variants that cause hypertension and influence response to anti-hypertensive therapy will ultimately provide a greater understanding of the molecular mechanisms underlying blood pressure control.

Decline in varicella-zoster virus (VZV)-specific cell-mediated immunity with increasing age and boosting with a high-dose VZV vaccine

The safety and immunogenecity of a booster dose of live attenuated varicella-zoster virus (VZV) vaccine was evaluated in 196 healthy subjects, >or=60 years old, who had already received a VZV vaccine >5 years before. This repeat booster dose was well tolerated. Cell-mediated immunity (CMI) to VZV was measured by an interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot-forming cell (ELISPOT) assay and a limiting dilution responder cell frequency (RCF) assay. Prevaccination responses decreased as a function of increasing age but were detectable in all subjects by use of the IFN-gamma ELISPOT assay. In most subjects, VZV-specific CMI was increased at 6 weeks postvaccination. The magnitude of the vaccine-induced IFN-gamma ELISPOT response was inversely related to prevaccination values. Although there was a significant correlation between the IFN-gamma ELISPOT and RCF assays, the ELISPOT assay had greater sensitivity and a wider dynamic range. A live attenuated VZV vaccine is safe and immunogenic in an elderly population, and the vaccine-induced immunity may be monitored by the IFN-gamma ELISPOT assay.

Comparison of methods to identify individuals at increased risk of coronary disease from the general population

OBJECTIVES

To evaluate the guidelines on measurement of cholesterol in the national service framework for coronary heart disease and to compare alternative strategies for identifying people at high risk of coronary disease in the general population.

DESIGN

Comparison of methods (national service framework criteria, Sheffield tables, age threshold of 50 years, estimated risk assessment using fixed cholesterol values) for identifying people with a 10 year coronary event risk of 15% or greater.

SETTING

Health survey for England 1998.

SUBJECTS

6307 people aged between 30 and 74 years with no history of myocardial infarction, stroke, or angina.

MAIN OUTCOME MEASURES

Proportion of the total population selected for measurement of cholesterol and proportion of people at 15% or greater risk identified.

RESULTS

The national service framework guidelines selected 43.4% (95% confidence interval 42.2% to 44.6%) of the study population for cholesterol measurement and identified 81.2% (80.2% to 82.2%) of those at 15% or greater risk. The Sheffield tables selected 73.1% (72.0% to 74.2%) for cholesterol measurement and identified 99.91% (99.83% to 99.99%) of those at 15% or greater risk. An age threshold of 50 years selected 46.3% (45.1% to 47.5%) for cholesterol measurement and identified 92.8% (92.1% to 93.4%) of those at 15% or greater risk. Estimated risk assessments using fixed cholesterol values selected 17.8% (16.8% to 18.7%) for cholesterol measurement and identified 75.9% (74.8% to 76.9%) of those at 15% or greater risk.

CONCLUSION

Measuring the cholesterol concentration of everyone aged 50 years and over is a simple and efficient method of identifying people at high risk of coronary disease in the general population.

Measurement of cell-mediated immunity with a Varicella-Zoster Virus-specific interferon-gamma ELISPOT assay: responses in an elderly population receiving a booster immunization

An interferon-gamma ELISPOT assay has been developed for assessment of cellular immune responses to Varicella-Zoster Virus (VZV) in large, multi-center clinical vaccine trials. We show that the assay performed best when testing peripheral blood mononuclear cells (PBMCs) that had been isolated and then frozen on the same day as blood was drawn, and that freezing PBMCs from blood that was stored overnight before processing resulted in dramatically reduced responses. This assay was used to monitor cell-mediated immunity (CMI) in response to a booster immunization with an investigational live, attenuated VZV vaccine in an elderly population that had been vaccinated 8-10 years previously. The booster vaccine elicited a 1.6- to 1.7-fold rise in the VZV-specific cellular immune response as measured by the ELISPOT assay. The increase from pre to post booster vaccination response was more pronounced (approximately 2.2-fold rise) in a subset of subjects who had received two prior immunizations with a live, attenuated vaccine.

Comparative immunogenicity in rhesus monkeys of DNA plasmid, recombinant vaccinia virus, and replication-defective adenovirus vectors expressing a human immunodeficiency virus type 1 gag gene

Cellular immune responses, particularly those associated with CD3(+) CD8(+) cytotoxic T lymphocytes (CTL), play a primary role in controlling viral infection, including persistent infection with human immunodeficiency virus type 1 (HIV-1). Accordingly, recent HIV-1 vaccine research efforts have focused on establishing the optimal means of eliciting such antiviral CTL immune responses. We evaluated several DNA vaccine formulations, a modified vaccinia virus Ankara vector, and a replication-defective adenovirus serotype 5 (Ad5) vector, each expressing the same codon-optimized HIV-1 gag gene for immunogenicity in rhesus monkeys. The DNA vaccines were formulated with and without one of two chemical adjuvants (aluminum phosphate and CRL1005). The Ad5-gag vector was the most effective in eliciting anti-Gag CTL. The vaccine produced both CD4(+) and CD8(+) T-cell responses, with the latter consistently being the dominant component. To determine the effect of existing antiadenovirus immunity on Ad5-gag-induced immune responses, monkeys were exposed to adenovirus subtype 5 that did not encode antigen prior to immunization with Ad5-gag. The resulting anti-Gag T-cell responses were attenuated but not abolished. Regimens that involved priming with different DNA vaccine formulations followed by boosting with the adenovirus vector were also compared. Of the formulations tested, the DNA-CRL1005 vaccine primed T-cell responses most effectively and provided the best overall immune responses after boosting with Ad5-gag. These results are suggestive of an immunization strategy for humans that are centered on use of the adenovirus vector and in which existing adenovirus immunity may be overcome by combined immunization with adjuvanted DNA and adenovirus vector boosting.

Human chromosome 17 in essential hypertension

Hypertension affects up to 30% of the adult population in Western societies and is a major risk factor for kidney disease, stroke and coronary heart disease. It is a complex trait thought to be influenced by a number of genes and environmental factors, although the precise aetiology remains unknown at this time. A number of methods have been successfully used to identify mutations that cause Mendelian traits and these are now being applied to the investigation of complex diseases. This review summarises the data gathered, using such approaches, that suggest there is a gene or genes on chromosome 17 causing human essential hypertension. Studies in rodent models are discussed first, followed by studies of human hypertension that include the investigation of pseudohypoaldosteronism type II, a monogenic trait that manifests with hypertension alongside other phenotypic variables. In addition, candidate gene studies, genome screens and linkage studies based on comparative mapping are outlined. To date no gene has been identified on human chromosome 17 that influences blood pressure and causes human essential hypertension. However, results of ongoing fine mapping and candidate gene studies in both rodents and man are eagerly awaited.

Sustained peptide-specific gamma interferon T-cell response in rhesus macaques immunized with human immunodeficiency virus gag DNA vaccines

We examined the influence of dose and method of antigen delivery on the dynamics and durability of T-cell responses to candidate human immunodeficiency virus (HIV) vaccines. Codon-optimized sequences from the HIV gag gene were inserted into alternative DNA vaccine vectors to express the coding sequence with or without the tissue plasminogen activator leader sequence. We delivered the vaccines by intramuscular injection as plasmid DNA without adjuvant or as plasmid DNA formulated with a novel block copolymer adjuvant (CRL8623) and then monitored the ensuing T-cell responses by using a gamma interferon enzyme-linked immunospot assay. We demonstrated persistence of the cell-mediated immune (CMI) response in rhesus macaques for at least 18 months following a four-dose vaccination regimen. The plasmid vaccine, with or without CRL8623, was immunogenic in macaques; however, the form coadministered with adjuvant exhibited improved T-cell responses, with a bias toward more antigen-specific CD8(+) T cells. Finally, we examined the fine specificity of the T-cell response to the gag vaccines by testing the response of 23 vaccinated macaques to individual Gag 20-mer peptides. Collectively, the monkeys responded to 25 epitopes, and, on average, each monkey recognized a minimum of 2.7 epitopes. The results indicate that a broad and durable CMI response to HIV DNA vaccines can be induced in a relevant nonhuman primate model.

Pharmaceutical and immunological evaluation of a single-shot hepatitis B vaccine formulated with PLGA microspheres

A single-shot Hepatitis B vaccine formulation using poly(d,l)-lactide-co-glycolide acid (PLGA) microspheres as a delivery system was examined using a variety of biophysical and biochemical techniques as well as immunological evaluation in C3H mice. PLGA microsphere encapsulation of the Hepatitis B surface antigen (HBsAg), a lipoprotein particle, resulted in good recoveries of protein mass, protein particle conformational integrity, and in vitro antigenicity. Some partial delipidation of the HBsAg, however, was observed. The loading and encapsulation efficiency of HBsAg into the PLGA microspheres were measured along with the morphology and size distribution of the vaccine-loaded PLGA microspheres. The in vitro release kinetics of HBsAg from the PLGA microspheres was evaluated and found to be affected by experimental conditions such as stirring rate. HBsAg showed enhanced storage stability at 37 degrees C in the slightly acidic pH range reported to be found inside PLGA microspheres; thus, the antigen is relatively stable under conditions of temperature and pH that may mimic in vivo conditions. The immunogenicity of the microsphere formulations of HBsAg was compared with conventional aluminum adjuvant formulated HBsAg vaccine in C3H mice. Comparisons were made between aluminum formulations (one and two injections), PLGA microsphere formulations (single injection), and a mixture of aluminum and PLGA microsphere formulations (single injection). The nine-month serum antibody titers indicate that a single injection of a mixture of aluminum and PLGA-formulated HBsAg results in equal or better immune responses than two injections of aluminum-formulated HBsAg vaccine. Based on these in vitro and in vivo studies, it is concluded that HBsAg can be successfully encapsulated and recovered from the PLGA microspheres and a mixture of aluminum-adjuvanted and PLGA-formulated HBsAg can auto-boost an immune response in manner comparable to multiple injections of an aluminum-formulated vaccine.

Replication-incompetent adenoviral vaccine vector elicits effective anti-immunodeficiency-virus immunity

Recent studies of human immunodeficiency virus type 1 (HIV-1) infection in humans and of simian immunodeficiency virus (SIV) in rhesus monkeys have shown that resolution of the acute viral infection and control of the subsequent persistent infection are mediated by the antiviral cellular immune response. We comparatively assessed several vaccine vector delivery systems-three formulations of a plasmid DNA vector, the modified vaccinia Ankara (MVA) virus, and a replication incompetent adenovirus type 5 (Ad5) vector-expressing the SIV gag protein for their ability to elicit such immune responses in monkeys. The vaccines were tested either as a single modality or in combined modality regimens. Here we show that the most effective responses were elicited by a replication-incompetent Ad5 vector, used either alone or as a booster inoculation after priming with a DNA vector. After challenge with a pathogenic HIV-SIV hybrid virus (SHIV), the animals immunized with Ad5 vector exhibited the most pronounced attenuation of the virus infection. The replication-defective adenovirus is a promising vaccine vector for development of an HIV-1 vaccine.

Novel cross-linked polyacrylamide matrices: an investigation using gradient gel electrophoresis

Gradient gel electrophoresis was used to examine the separation properties of novel cross-linking compounds for polyacrylamide (PAAm). At low %T and at the same %C protein migration difference is accentuated for bismethacrylamide cross-linked networks relative to bisacrylamide cross-linked networks. Similar properties were observed for cyclic monomers at low %T. This trend is maintained throughout the gradient. However, at higher %T migration differential relative to N,N'-methylenebisacrylamide (Bis) was less pronounced. Evidence from gradient gels suggests that reactivity and functionality of vinyl groups impose an overriding control over network formation.

Development and validation of a gamma interferon ELISPOT assay for quantitation of cellular immune responses to varicella-zoster virus

Cell-mediated immunity appears to be critical for the prevention and control of varicella-zoster virus (VZV) infection and complications arising from zoster. Current assays of VZV-specific cell-mediated immunity are cumbersome or lack sensitivity. We have developed a gamma interferon ELISPOT assay that provides a direct measure of the number of T cells secreting a cytokine following stimulation with antigen. This assay is extremely sensitive and specific, with the ability to detect gamma interferon spot-forming cells (SFC) in the range of 10 to 1,000 SFC per million peripheral blood mononuclear cells (PBMCs). This assay has been validated by demonstrating the following: (i) the response detected is mediated almost entirely by CD4+ T cells, (ii) ELISPOT responses from fresh-frozen PBMCs are equivalent to those from freshly isolated cells, (iii) frozen PBMCs can be shipped on dry ice for up to 48 h without loss of activity, (iv) frozen PBMC samples can be stored in liquid nitrogen over long periods (>22 months) without any significant change in response, and (v) the numbers of ELISPOTs counted using a computer-based imaging system are equivalent to those counted by humans but have lower variability. The ability to use frozen cells is facilitated by the use of a recombinant nuclease (Benzonase) that can prevent cell clumping when samples are thawed. Frozen PBMC samples can be cycled through multiple changes in storage between liquid nitrogen and dry ice without any change in response being detected. This facilitates collection of samples at one site and testing performed at a remote location. This VZV ELISPOT assay provides a new versatile tool for monitoring cellular immune responses either during a herpes zoster disease outbreak or following vaccination.

A simple and efficient method for the monitoring of antigen-specific T cell responses using peptide pool arrays in a modified ELISpot assay

In this study, we describe a simple and efficient method for both the monitoring of antigen-specific CD4 and CD8 T cell responses as well as the identification of novel CD4 and CD8 T cell epitopes using a modified ELISpot assay and pools of 20mer peptides. We have demonstrated that pools containing as many as 64 20mer peptides may be used to screen for CD4 and CD8 T cell responses to HPV16 L1, E1, and E7 in mice. Using arrays of pools of overlapping 20mer peptides, we have identified novel CD4 and CD8 epitopes in both HPV16L1 and HPV16E1 which are presented in Balb/c mice. We have further shown that the use of 20mer peptides is equivalent to using minimal 9mer epitopes for the stimulation of CD8 T cell responses in our assay. While our experiments are conducted in mice, the use of peptide pool arrays allows for the identification of epitope-specific responses using far fewer cells than is required for testing a panel of overlapping peptides individually, making this strategy particularly useful in clinical settings where immune cells may be limiting.

Immunogenicity of a hexavalent combination vaccine in rhesus monkeys

Preclinical immunogenicity studies were conducted in rhesus monkeys to determine whether there is immune interference in the response to one or more components of a hexavalent vaccine (Hexavac) that contains antigens from Haemophilus influenzae (Hib), hepatitis B (HB), diphtheria (D), tetanus (T), acellular pertussis (aP) and inactivated polio virus (IPV). Antibody responses were measured following co-administration of the components at three separate anatomical sites or administration as a hexavalent combination in a single site. After three injections of the hexavalent vaccine, the peak antibody responses to each component of the vaccine were >100-fold above pre-immune titers and persisted at levels >10-fold above pre-immune titers at approximately 1 year. Immune interference was observed in the peak response to HB, D and pertussis toxin, but was not seen at later time points. The results indicate that the rhesus monkey model may be useful for pre-clinical evaluation of combination vaccines.

Investigation of chromosome 17q as a locus for human essential hypertension in African Caribbeans

Essential hypertension is a major risk factor for cardiovascular disease in humans, and originates from both genetic and environmental factors. Data from animal and more recently human studies have indicated the presence of a gene influencing blood pressure on human chromosome 17. This study tested for linkage of markers located on chromosome 17q to essential hypertension in African Caribbean hypertensive families. No support of linkage was found between the markers studied and hypertension, however only genes of a lamda sib value of less than 1.8 could be excluded Journal of Human Hypertension (2000) 14, 385-387

Genetics of hypertension

In the past year, substantial progress has been made in both mapping and fine mapping the genes involved in blood pressure regulation. Genome scans have been carried out in humans and mice and these reveal many new potential chromosomal locations for blood pressure susceptibility loci. The chromosomal regions containing blood pressure genes for many of the inbred hypertensive rat models have been refined using new congenic strains. Further genetic studies support a role for antiotensinogen, aldosterone synthase and a region close to the epithelial sodium channel in blood pressure regulation. Finally, comprehensive single-nucleotide polymorphism analysis of cardiovascular genes has been undertaken using chip technology.

1990-2000: progress in determining high blood pressure genes

INTRODUCTION

This article attempts to summarise the genetic research that has taken place during the past decade to determine the identity of genes causing high blood pressure.

METHODS

Candidate gene studies and genome-wide scanning have been the methods primarily employed, and studies have been performed in both experimental models (rats and mice) and human volunteers (sibling-pairs and case-control). Key studies from the past 10 years are discussed, in addition to the congenic strains.

RESULTS

Genome-wide scans and candidate gene studies in both rat and man have generated many chromosomal regions and loci involved in blood pressure regulation. However, much work is still required to fine map the large chromosomal regions found in the genome-wide scans and to isolate variants in candidate genes and prove that they are disease-causing.

CONCLUSIONS

It is anticipated that within the next 5 to 10 years at least one blood pressure susceptibility gene will be identified in rat and possibly some in man. It is hoped that the identification of genes controlling blood pressure will enable investigators to determine physiological/biochemical pathways defective in hypertensive patients. This information may then be utilised to identify specific hypertensive phenotypes, to tailor therapy appropriately for patients and hopefully to develop novel therapeutic agents for hypertension.

Enhanced type I immune response to a hepatitis B DNA vaccine by formulation with calcium- or aluminum phosphate

DNA vaccines induce protective humoral and cell-mediated immune responses in several animal models. When compared with conventional vaccines, however, DNA vaccines often induce lower antibody titers. We have now found that formulation of a DNA vaccine encoding hepatitis B surface antigen with calcium- or aluminum phosphate adjuvants can increase antibody titers by 10-100-fold and decrease the immunogenic dose of DNA by 10-fold. Furthermore, boosting an HBs protein-primed response with the adjuvanted DNA vaccine resulted in a dramatic increase in the HBs-specific IgG2a response reflecting a shift towards a TH1 response. The mechanism by which aluminum phosphate exerts its adjuvant effect is not through increased expression of HBsAg in vivo; rather, the adjuvant appears to increase the number and affinity of HBs peptide antigen-specific IFN-gamma and IL-2 secreting T cells.

Enhancement of DNA vaccine potency using conventional aluminum adjuvants

The immunogenicity and protective efficacy of DNA vaccines have been amply demonstrated in numerous animal models of infectious disease. However, the feasibility of DNA vaccines for human use is not yet known. In order to investigate potential means of increasing the potency of DNA vaccines, conventional adjuvants such as aluminum salts were tested. Coadministration of these adjuvants with DNA vaccines substantially enhanced the ability of these vaccines to induce antibody responses up to 100-fold in mice and guinea pigs, and 5-10-fold in non-human primates. Effective formulations had no demonstrable effect on the levels of antigen expression in situ and consisted of adjuvants that did not form complexes with the plasmid DNA; rather they exerted their effects on antigen after expression in situ. Therefore, the potency of DNA vaccines both in laboratory rodents and in non-human primates can be substantially increased by simple formulation with conventional aluminum adjuvants.

Constitutive expression of the Wilms tumor suppressor gene (WT1) in renal cell carcinoma

The expression of the Wilms tumor suppressor gene WT1 is largely restricted to elements of the developing urogenital system. In the fetal kidney, WT1 transcripts are present at low levels in the condensing mesenchyme and at much higher levels in differentiating glomerular epithelium and are not detected in other mesenchymal-derived epithelial structures such as the proximal and distal tubules. However, WT1 expression is observed in tubule-like elements found in some Wilms tumors. As renal cell carcinoma (RCC) of the clear cell type is one of the most prevalent adult tumors of the kidney, and is thought to originate from the epithelial cells of the proximal tubules, we studied WT1 expression in RCCs. Despite the absence of WT1 in normal primary epithelial cells derived from proximal tubules, RCC tumors and tumor-derived cell lines expressed WT1 RNA. Immunocytochemical analyses of tumor cryosections showed widespread expression throughout the poorly differentiated epithelial components of the tumor. Immunoblots of RCC samples detected a normal size WT I protein and reciprocal antibody immunoprecipitations of RCC cell extracts indicated that WT I interacts with p53 as has been demonstrated for normal human fetal kidney. The aberrant expression of functional WT1 in RCC may represent a reversion to a more de-differentiated phenotype and may contribute to the tumorigenic phenotype by inappropriately activating or repressing genes involved in growth regulation.