Cross-neutralizing protection of vaginal and oral mucosa from HPV challenge by vaccination in a mouse model

The species and tissue specificities of HPV (human papillomavirus) for human infection and disease complicates the process of prophylactic vaccine development in animal models. HPV pseudoviruses (PsV) that carry only a reporter plasmid have been utilized in vivo to demonstrate cell internalization in mouse mucosal epithelium. The current study sought to expand the application of this HPV PsV challenge model with both oral and vaginal inoculation and to demonstrate its utility for testing vaccine-mediated dual-site immune protection against several HPV PsV types. We observed that passive transfer of sera from mice vaccinated with the novel experimental HPV prophylactic vaccine RG1-VLPs (virus-like particles) conferred HPV16-neutralizing as well as cross-neutralizing Abs against HPV39 in naïve recipient mice. Moreover, active vaccination with RG1-VLPs also conferred protection to challenge with either HPV16 or HPV39 PsVs at both vaginal and oral sites of mucosal inoculation. These data support the use of the HPV PsV challenge model as suitable for testing against diverse HPV types at two sites of challenge (vaginal vault and oral cavity) associated with the origin of the most common HPV-associated cancers, cervical cancer and oropharyngeal cancer.

Development of an aerosol intervention for COVID-19 disease: Tolerability of soluble ACE2 (APN01) administered via nebulizer

As ACE2 is the critical SARS-CoV-2 receptor, we hypothesized that aerosol administration of clinical grade soluble human recombinant ACE2 (APN01) will neutralize SARS-CoV-2 in the airways, limit spread of infection in the lung, and mitigate lung damage caused by deregulated signaling in the renin-angiotensin (RAS) and Kinin pathways. Here, after demonstrating in vitro neutralization of SARS-CoV-2 by APN01, and after obtaining preliminary evidence of its tolerability and preventive efficacy in a mouse model, we pursued development of an aerosol formulation. As a prerequisite to a clinical trial, we evaluated both virus binding activity and enzymatic activity for cleavage of Ang II following aerosolization. We report successful aerosolization for APN01, retaining viral binding as well as catalytic RAS activity. Dose range-finding and IND-enabling repeat-dose aerosol toxicology testing were conducted in dogs. Twice daily aerosol administration for two weeks at the maximum feasible concentration revealed no notable toxicities. Based on these results, a Phase I clinical trial in healthy volunteers has now been initiated (NCT05065645), with subsequent Phase II testing planned for individuals with SARS-CoV-2 infection.

Abstract 5562: Development of a TERT-specific peptide/adjuvant vaccine in C57BL/6 mice

Telomerase plays a vital role in cell senescence and cellular replication and has been described as a leading regulator in several human cancers, including prostate, thyroid, breast, colon, and bladder cancer. Telomerase is responsible for elongating telomere length and prolonging cellular lifespan as well as acting as a transcriptional modulator in cancer signaling pathways. Because of its enhanced expression in primary tumor cells as well as incipient tumor-initiating stem cells and with limited distribution in normal somatic cells, the catalytic component of telomerase, TERT (telomerase reverse transcriptase), is regarded as a high-impact target for immunotherapeutic agents and vaccines. In order to derive a mouse TERT (mTERT)-specific vaccine which could be useful in a preventive approach, we implemented an epitope-mapping stratagem by which pools of 30-mer peptides overlapping by 5 spanning the entire mTERT sequence were used to immunize C57BL/6 mice. Several immunogenic peptides were identified by matrixed peptide pool IFN-ɣ ELISPOT screening in a 2-part process that first identified positive pools, then identified individual peptides. 15-mer and 31-mer versions of the top 7 immunogenic mTERT peptides were synthesized and used as a peptide pool combined separately with several adjuvants to optimize immunogenicity. Results suggested a peptide sequence-specific preference for TLR3-mediated Hiltonol versus TLR9-mediated CpG-based adjuvants. In addition, the majority of T cell responses specific to the TERT peptides was identified through flow cytometry as belonging to the CD4 compartment, although one class I-restricted epitope was also identified. Multifunctional CD4+ T cells expressing IFN-ɣ, TNF-α, IL-2, and CD107a were identified specific to several mTERT peptides. In vivo cytotoxic effects exerted on TERT peptide pool-loaded target cells were also uncovered that were specific to a CpG-adjuvanted version of the vaccine. Finally, multiple versions of the mTERT peptide/adjuvant vaccine with highest immunogenicity scores are being tested in a syngeneic graft mouse model using subcutaneous implantation of lung cancer-derived SPON10 cells expressing mTERT. If proven efficacious, these results will support the feasibility of a TERT peptide/adjuvant approach for prophylactically engendering broad antitumor immunity to TERT-expressing cancers. Funded by NCI Contract No. HHSN261200800001E

Citation Format: Jason D. Marshall, Yurong Song, Hamid Zarkesh, Rebecca L. Matthews, Chelsea Sanders, Simone Difilippantonio, Ligia A. Pinto, Shizuko Sei, Robert H. Shoemaker. Development of a TERT-specific peptide/adjuvant vaccine in C57BL/6 mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5562.

Using CATA and Machine Learning to Operationalize Old Constructs in New Ways: An Illustration Using U.S. Governors’ COVID-19 Press Briefings

Increased computing power and greater access to online data have led to rapid growth in the use of computer-aided text analysis (CATA) and machine learning methods. Using “big data”, researchers have not only advanced new streams of research, but also new research methodologies. Noting this trend and simultaneously recognizing the value of traditional research methods, we lay out a methodology that bridges the gap between old and new approaches to operationalize old constructs in new ways. With a combination of web scraping, CATA, and supervised machine learning, using labeled ground truth data (i.e., data with known inputs and outputs), we train a model to predict CIP (Charismatic-Ideological-Pragmatic) leadership styles from running text. To illustrate this method, we apply the model to classify U.S. state governors’ COVID-19 press briefings according to their CIP leadership style. In addition, we demonstrate content and convergent validity of the method.

Recurrent Frameshift Neoantigen Vaccine Elicits Protective Immunity With Reduced Tumor Burden and Improved Overall Survival in a Lynch Syndrome Mouse Model

BACKGROUND & AIMS

DNA mismatch repair deficiency drives microsatellite instability (MSI). Cells with MSI accumulate numerous frameshift mutations. Frameshift mutations affecting cancer-related genes may promote tumorigenesis and, therefore, are shared among independently arising MSI tumors. Consequently, such recurrent frameshift mutations can give rise to shared immunogenic frameshift peptides (FSPs) that represent ideal candidates for a vaccine against MSI cancer. Pathogenic germline variants of mismatch repair genes cause Lynch syndrome (LS), a hereditary cancer syndrome affecting approximately 20-25 million individuals worldwide. Individuals with LS are at high risk of developing MSI cancer. Previously, we demonstrated safety and immunogenicity of an FSP-based vaccine in a phase I/IIa clinical trial in patients with a history of MSI colorectal cancer. However, the cancer-preventive effect of FSP vaccination in the scenario of LS has not yet been demonstrated.

METHODS

A genome-wide database of 488,235 mouse coding mononucleotide repeats was established, from which a set of candidates was selected based on repeat length, gene expression, and mutation frequency. In silico prediction, in vivo immunogenicity testing, and epitope mapping was used to identify candidates for FSP vaccination.

RESULTS

We identified 4 shared FSP neoantigens (Nacad [FSP-1], Maz [FSP-1], Senp6 [FSP-1], Xirp1 [FSP-1]) that induced CD4/CD8 T cell responses in naïve C57BL/6 mice. Using VCMsh2 mice, which have a conditional knockout of Msh2 in the intestinal tract and develop intestinal cancer, we showed vaccination with a combination of only 4 FSPs significantly increased FSP-specific adaptive immunity, reduced intestinal tumor burden, and prolonged overall survival. Combination of FSP vaccination with daily naproxen treatment potentiated immune response, delayed tumor growth, and prolonged survival even more effectively than FSP vaccination alone.

CONCLUSIONS

Our preclinical findings support a clinical strategy of recurrent FSP neoantigen vaccination for LS cancer immunoprevention.

Development of a novel, pan-variant aerosol intervention for COVID-19

To develop a universal strategy to block SARS-CoV-2 cellular entry and infection represents a central aim for effective COVID-19 therapy. The growing impact of emerging variants of concern increases the urgency for development of effective interventions. Since ACE2 is the critical SARS-CoV-2 receptor and all tested variants bind to ACE2, some even at much increased affinity (see accompanying paper), we hypothesized that aerosol administration of clinical grade soluble human recombinant ACE2 (APN01) will neutralize SARS-CoV-2 in the airways, limit spread of infection in the lung and mitigate lung damage caused by deregulated signaling in the renin-angiotensin (RAS) and Kinin pathways. Here we show that intranasal administration of APN01 in a mouse model of SARS-CoV-2 infection dramatically reduced weight loss and prevented animal death. As a prerequisite to a clinical trial, we evaluated both virus binding activity and enzymatic activity for cleavage of Ang II following aerosolization. We report successful aerosolization for APN01, retaining viral binding as well as catalytic RAS activity. Dose range-finding and IND-enabling repeat-dose aerosol toxicology testing were conducted in dogs. Twice daily aerosol administration for two weeks at the maximum feasible concentration revealed no notable toxicities. Based on these results, a Phase I clinical trial in healthy volunteers can now be initiated, with subsequent Phase II testing in individuals with SARS-CoV-2 infection. This strategy could be used to develop a viable and rapidly actionable therapy to prevent and treat COVID-19, against all current and future SARS-CoV-2 variants.

Improvement of RG1-VLP vaccine performance in BALB/c mice by substitution of alhydrogel with the next generation polyphosphazene adjuvant PCEP

Current human papillomavirus (HPV) vaccines provide substantial protection against the most common HPV types responsible for oral and anogenital cancers, but many circulating cancer-causing types remain for which vaccine coverage is lacking. In addition, all current HPV vaccines rely on aluminum salt-based adjuvant formulations that function through unclear mechanisms with few substitutes available. In an effort to expand the toolbox of available adjuvants suitable for HPV vaccines, we compared the immunogenicity of the RG1-VLP (virus-like particle) vaccine in BALB/c mice when formulated with either the aluminum hydroxide adjuvant Alhydrogel or the novel polyphosphazene macromolecular adjuvant poly[di (carboxylatoethylphenoxy) phosphazene] (PCEP). PCEP-formulated RG1-VLPs routinely outperformed VLP/Alhydrogel in several measurements of VLP-specific humoral immunity, including consistent improvements in the magnitude of antibody (Ab) responses to both HPV16-L1 and the L2 RG1 epitope as well as neutralizing titers to HPV16 and cross-neutralization of pseudovirion (PsV) types HPV18 and HPV39. Dose-sparing studies indicated that RG1-VLPs could be reduced in dose by 75% and the presence of PCEP ensured activity comparable to a full VLP dose adjuvanted by Alhydrogel. In addition, levels of HPV16-L1 and -L2-specific Abs were achieved after two vaccinations with PCEP as adjuvant that were equivalent to or greater than levels achieved with three vaccinations with Alhydrogel alone, indicating that the presence of PCEP resulted in accelerated immune responses that could allow for a decreased dose schedule. Given the extensive clinical track record of polyphosphazenes, these data suggest that substitution of alum-based adjuvants with PCEP for the RG1-VLP vaccine could lead to rapid seropositivity requiring fewer boosts, the dose-sparing of commercial VLP-based vaccines, and the establishment of longer-lasting humoral responses to HPV.

Next generation polyphosphazene immunoadjuvant: Synthesis, self-assembly and in vivo potency with human papillomavirus VLPs-based vaccine

Poly[di(carboxylatomethylphenoxy)phosphazene] (PCMP), a new member of polyphosphazene immunoadjuvant family, is synthesized. In vitro assessment of a new macromolecule revealed hydrolytic degradation profile and immunostimulatory activity comparable to its clinical stage homologue PCPP; however, PCMP was characterized by a beneficial reduced sensitivity to the ionic environment. In vivo evaluation of PCMP potency was conducted with human papillomavirus (HPV) virus-like particles (VLPs) based RG1-VLPs vaccine. In contrast with previously reported self-assembly of polyphosphazene adjuvants with proteins, which typically results in the formation of complexes with multimeric display of antigens, PCMP surface modified VLPs in a composition dependent pattern, which at a high polymer-to VLPs ratio led to stabilization of antigenic particles. Immunization experiments in mice demonstrated that PCMP adjuvanted RG1-VLPs vaccine induced potent humoral immune responses, in particular, on the level of highly desirable protective cross-neutralizing antibodies, and outperformed PCPP and Alhydrogel adjuvanted formulations.

Optimization of RG1-VLP vaccine performance in mice with novel TLR4 agonists

Current human papilloma virus (HPV) vaccines provide substantial protection against the most common HPV types responsible for oral and anogenital cancers, but many circulating cancer-causing types remain that lack vaccine coverage. The novel RG1-VLP (virus-like particle) vaccine candidate utilizes the HPV16-L1 subunit as a backbone to display an inserted HPV16-L2 17-36 a.a. "RG1" epitope; the L2 RG1 epitope is conserved across many HPV types and the generation of cross-neutralizing antibodies (Abs) against which has been demonstrated. In an effort to heighten the immunogenicity of the RG1-VLP vaccine, we compared in BALB/c mice adjuvant formulations consisting of novel bacterial enzymatic combinatorial chemistry (BECC)-derived toll-like receptor 4 (TLR4) agonists and the aluminum hydroxide adjuvant Alhydrogel. In the presence of BECC molecules, consistent improvements in the magnitude of Ab responses to both HPV16-L1 and the L2 RG1 epitope were observed compared to Alhydrogel alone. Furthermore, neutralizing titers to HPV16 as well as cross-neutralization of pseudovirion (PsV) types HPV18 and HPV39 were augmented in the presence of BECC agonists as well. Levels of L1 and L2-specific Abs were achieved after two vaccinations with BECC/Alhydrogel adjuvant that were equivalent to or greater than levels achieved with 3 vaccinations with Alhydrogel alone, indicating that the presence of BECC molecules resulted in accelerated immune responses that could allow for a decreased dose schedule for VLP-based HPV vaccines. In addition, dose-sparing studies indicated that adjuvantation with BECC/Alhydrogel allowed for a 75% reduction in antigen dose while still retaining equivalent magnitudes of responses to the full VLP dose with Alhydrogel. These data suggest that adjuvant optimization of HPV VLP-based vaccines can lead to rapid immunity requiring fewer boosts, dose-sparing of VLPs expensive to produce, and the establishment of a longer-lasting humoral immunity.

Vaccination with synthetic long peptide formulated with CpG in an oil-in-water emulsion induces robust E7-specific CD8 T cell responses and TC-1 tumor eradication

BACKGROUND

Despite considerable efforts at developing therapeutic vaccines for cancer, clinical translation of preclinical successes has been challenging, largely due to the difficulty of inducing strong and sustained cytotoxic T lymphocyte (CTL) responses in patients. Several peptide-based cancer vaccines have failed to show sustainable tumor regression in the clinic, possibly because of a lack of optimization of both the adjuvant and antigen components of the preparations. Here, we aimed to develop and optimize a vaccine format utilizing a synthetic long peptide (SLP) containing the human papilloma virus 16 (HPV16) E7 antigen, with a centrally located defined MHC class I epitope, and evaluate its immunogenicity and efficacy in combination with various adjuvant formulations.

METHODS

E7_31-73 SLP was tested alone or in combination with toll-like receptor (TLR)3, TLR4, TLR7/8 and TLR9 agonists and formulated in oil-in-water (o/w) or water-in-oil (w/o) emulsions to determine a vaccine format inducing a robust CD8 T cell response in murine models. Once a lead vaccine format was determined, we examined its ability to inhibit tumor growth in the murine TC-1 model that expresses HPV16 E7 antigen.

RESULTS

We identified the TLR9 agonist CpG formulated in a squalene-based o/w emulsion as the most potent adjuvant, inducing the expansion of multifunctional antigen specific CD8 T cells with cytolytic potential. We also demonstrated that SLP E7_31-73 + CpG + o/w emulsion vaccine can provide prophylactic and more importantly, therapeutic benefit in the TC-1 murine tumor model.

CONCLUSIONS

Our results demonstrate that the novel vaccine format E7 SLP + CpG delivered in an o/w emulsion holds potential for the promotion of strong CTL responses and tumor eradication and encourages further development of peptide/adjuvant vaccines in cancer immunotherapy strategies.

A lipid A-based TLR4 mimetic effectively adjuvants a Yersinia pestis rF-V1 subunit vaccine in a murine challenge model

Vaccination can significantly reduce worldwide morbidity and mortality to infectious diseases, thereby reducing the health burden as a result of microbial infections. Effective vaccines contain three components: a delivery system, an antigenic component of the pathogen, and an adjuvant. With the growing use of purely recombinant or synthetic antigens, there is a need to develop novel adjuvants that enhance the protective efficacy of a vaccine against infection. Using a structure-activity relationship (SAR) model, we describe here the synthesis of a novel TLR4 ligand adjuvant compound, BECC438, by bacterial enzymatic combinatorial chemistry (BECC). This compound was identified using an in vitro screening pipeline consisting of (i) NFκB activation and cytokine production by immortalized cell lines, (ii) cytokine production by primary human PBMCs, and (iii) upregulation of surface costimulatory markers by primary human monocyte-derived dendritic cells. Using this SAR screening regimen, BECC438 was shown to produce an innate immune activation profile comparable to the well-characterized TLR4 agonist adjuvant compound, phosphorylated hexa-acyl disaccharide (PHAD). To evaluate the in vivo adjuvant activity of BECC438, we used the known protective Yersinia pestis (Yp) antigen, rF1-V, in a murine prime-boost vaccination schedule followed by lethal challenge. In addition to providing protection from lethal challenge, BECC438 stimulated production of higher levels of rF1-V-specific total IgG as compared to PHAD after both prime and boost vaccinations. Similar to PHAD, BECC438 elicited a balanced IgG1/IgG2c response, indicative of active T_H2/T_H1-driven immunity. These data demonstrate that the novel BECC-derived TLR4L adjuvant, BECC438, elicits cytokine profiles in vitro similar to PHAD, induces high antigen-specific immune titers and a T_H1-associated IgG2c immune titer skew, and protects mice against a lethal Yp challenge.

Performance of low-cost monitors to assess household air pollution

Exposure to household air pollution is a leading cause of morbidity and mortality globally. However, due to the lack of validated low-cost monitors with long-lasting batteries in indoor environments, most epidemiologic studies use self-reported data or short-term household air pollution assessments as proxies of long-term exposure. We evaluated the performance of three low-cost monitors measuring fine particulate matter (PM_2.5) and carbon monoxide (CO) in a wood-combustion experiment conducted in one household of Spain for 5 days (including the co-location of 2 units of HAPEX and 3 units of TZOA-R for PM_2.5 and 3 units of EL-USB-CO for CO; a total of 40 unit-days). We used Spearman correlation (ρ) and Concordance Correlation Coefficient (CCC) to assess accuracy of low-cost monitors versus equivalent research-grade devices. We also conducted a field study in India for 1 week (including HAPEX in 3 households and EL-USB-CO in 4 households; a total of 49 unit-days). Correlation and agreement at 5-min were moderate-high for one unit of HAPEX (ρ = 0.73 / CCC = 0.59), for one unit of TZOA-R (ρ = 0.89 / CCC = 0.62) and for three units of EL-USB-CO (ρ = 0.82-0.89 / CCC = 0.66-0.91) in Spain, although the failure or malfunction rate among low-cost units was high in both settings (60% of unit-days in Spain and 43% in India). Low-cost monitors tested here are not yet ready to replace more established exposure assessment methods in long-term household air pollution epidemiologic studies. More field validation is needed to assess evolving sensors and monitors with application to health studies.

PCPP-Adjuvanted Respiratory Syncytial Virus (RSV) sF Subunit Vaccine: Self-Assembled Supramolecular Complexes Enable Enhanced Immunogenicity and Protection

PCPP, a well-defined polyphosphazene macromolecule, has been studied as an immunoadjuvant for a soluble form of the postfusion glycoprotein of respiratory syncytial virus (RSV sF), which is an attractive vaccine candidate for inducing RSV-specific immunity in mice and humans. We demonstrate that RSV sF-PCPP formulations induce high neutralization titers to RSV comparable to alum formulations even at a low PCPP dose and protect animals against viral challenge both in the lung and in the upper respiratory tract. PCPP formulations were also characterized by Th1-biased responses, compared to Th2-biased responses that are more typical for RSV sF alone or RSV sF-alum formulations, suggesting an inherent immunostimulating activity of the polyphosphazene adjuvant. We defined these immunologically active RSV sF-PCPP formulations as self-assembled water-soluble protein-polymer complexes with distinct physicochemical parameters. The secondary structure and antigenicity of the protein in the complex were fully preserved during the spontaneous aqueous self-assembly process. These findings further advance the concept of polyphosphazene immunoadjuvants as unique dual-functionality adjuvants integrating delivery and immunostimulating modalities in one water-soluble molecule.

Rationally designed TLR4 ligands for vaccine adjuvant discovery

Adjuvant properties of bacterial cell wall components like MPLA are well described, and have gained FDA approval for use in vaccines such as Cervarix. MPLA is the product of chemically modified lipooligosaccharide (LOS), altered to diminish toxic proinflammatory effects while retaining adequate immunogenicity. Despite the virtually unlimited number of potential source bacterial strains, useable compounds within this promising class of adjuvants remain unfortunately low. We have developed bacterial enzymatic combinatorial chemistry (BECC) as a method to generate functionally diverse and rationally designed lipid A. BECC removes endogenous, or introduces exogenous, lipid A-modifying enzymes to bacteria, effectively reprogramming the lipid A biosynthetic pathway. In this study, BECC is applied within an avirulent strain of Yersinia pestis (Yp), to develop structurally distinct LOS molecules that elicit differential TLR4 activation. Using reporter cell lines that measure innate immune activated NF-κB transcription, BECC-derived molecules were screened for the ability to induce a lower pro-inflammatory response than E. coli LOS. Structures exhibit varied, dose-dependent TLR4-driven NF-κB activation with both human- and mouse-TLR4 complexes. Additional cytokine secretion screening identified molecules that induce comparable levels of TNF-α and IL-8, as compared to PHAD. Lead candidates demonstrated potent immunostimulation in mouse splenocytes, human primary PBMCs, and human monocyte-derived DC. This newly described BECC system allows for directed programming of lipid A synthesis and has the potential to generate a diverse array of TLR4 agonist candidates comparable if not preferable to PHAD and MPLA.

Development of a robust, higher throughput green fluorescent protein (GFP)-based Epstein-Barr Virus (EBV) micro-neutralization assay

The goal of most prophylactic vaccines is to elicit robust and effective neutralizing antibodies against the human pathogen target. The titer of neutralizing antibodies to Epstein-Barr Virus (EBV) is a useful biomarker for evaluating EBV vaccines. Here, the development and optimization of a 96-well micro-neutralization fluorescent imaging assay (FIA) using an EBV virus-encoding green fluorescent protein (GFP) to infect adherent EBV recipient cells is reported. The conditions were optimized for generating reproducible EBV-GFP virus, for maintaining viral infectivity for months, and for efficient viral infection of recipient cell culture. The utility of the EBV-GFP FIA neutralization assay was demonstrated in a mouse study of an investigational adjuvanted EBV gp350 subunit vaccine. This assay confirmed the generation of high titers of anti-EBV-neutralizing antibodies which correlated well with the established Raji cell-based flow cytometry-based EBV neutralization assay, as well as with anti-gp350 IgG titers. In naturally infected EBV+ human serum samples, a good correlation between anti-gp350 IgG ELISA titer and EBV-GFP FIA neutralization antibody titer was also observed. Taken together, these results demonstrate the establishment of a scalable high throughput EBV-GFP FIA micro-neutralization assay suitable to measure humoral EBV vaccine response in a large-scale human trial.

Feasibility of Freeze-Drying Oil-in-Water Emulsion Adjuvants and Subunit Proteins to Enable Single-Vial Vaccine Drug Products

To generate potent vaccine responses, subunit protein antigens typically require coformulation with an adjuvant. Oil-in-water emulsions are among the most widely investigated adjuvants, based on their demonstrated ability to elicit robust antibody and cellular immune responses in the clinic. However, most emulsions cannot be readily frozen or lyophilized, on account of the risk of phase separation, and may have a deleterious effect on protein antigen stability when stored long term as a liquid coformulation. To circumvent this, current emulsion-formulated vaccines generally require a complex multivial presentation with obvious drawbacks, making a single-vial presentation for such products highly desirable. We describe the development of a stable, lyophilized squalene emulsion adjuvant through innovative formulation and process development approaches. On reconstitution, freeze-dried emulsion preparations were found to have a minimal increase in particle size of ∼20 nm and conferred immunogenicity in BALB/c mice similar in potency to freshly prepared emulsion coformulations in liquid form.

A Novel Class of Small Molecule Agonists with Preference for Human over Mouse TLR4 Activation

The best-characterized Toll-like receptor 4 (TLR4) ligands are lipopolysaccharide (LPS) and its chemically modified and detoxified variant, monophosphoryl lipid A (MPL). Although both molecules are active for human TLR4, they demonstrate a potency preference for mouse TLR4 based on data from transfected cell lines and primary cells of both species. After a high throughput screening process of small molecule libraries, we have discovered a new class of TLR4 agonist with a species preference profile differing from MPL. Products of the 4-component Ugi synthesis reaction were demonstrated to potently trigger human TLR4-transfected HEK cells but not mouse TLR4, although inclusion of the human MD2 with mTLR4 was able to partially recover activity. Co-expression of CD14 was not required for optimal activity of Ugi compounds on transfected cells, as it is for LPS. The species preference profile for the panel of Ugi compounds was found to be strongly active for human and cynomolgus monkey primary cells, with reduced but still substantial activity for most Ugi compounds on guinea pig cells. Mouse, rat, rabbit, ferret, and cotton rat cells displayed little or no activity when exposed to Ugi compounds. However, engineering the human versions of TLR4 and MD2 to be expressed in mTLR4/MD2 deficient mice allowed for robust activity by Ugi compounds both in vitro and in vivo. These findings extend the range of compounds available for development as agonists of TLR4 and identify novel molecules which reverse the TLR4 triggering preference of MPL for mouse TLR4 over human TLR4. Such compounds may be amenable to formulation as more potent human-specific TLR4L-based adjuvants than typical MPL-based adjuvants.

Seasonality and nitrogen supply modify carbon partitioning in understory vegetation of a boreal coniferous forest

Given the strong coupling between the carbon (C) and nitrogen (N) cycles, there is substantial interest in understanding how N availability affects C cycling in terrestrial ecosystems, especially in ecosystems limited by N. However, most studies in temperate and boreal forests have focused on the effects of N addition on tree growth. By comparison, less is known about the effects of N availability on the cycling of C in understory vegetation despite some evidence that dwarf shrubs, mosses, and lichens play an important role in the forest C balance. In this study, we used an in situ 13CO2 pulse-labeling technique to examine the short-term dynamics of C partitioning in understory vegetation in three boreal Pinus sylvestris forest stands exposed to different rates of N addition: a low and high N addition that receive annual additions of NH4NO3 of 20 and 100 kg N/ha, respectively, and this is a typo. It should be an unfertilized control. Labeling was conducted at two distinct periods (early vs. late growing season), which provided a seasonal picture of how N addition affects C dynamics in understory vegetation. In contrast to what has been found in trees, there was no obvious trend in belowground C partitioning in ericaceous plants in response to N additions or seasonality. Increasing N addition led to a greater percentage of 13C being incorporated into ericaceous leaves with a high turnover, whereas high rates of N addition strongly reduced the incorporation of 13C into less degradable moss tissues. Addition of N also resulted in a greater percentage of the 13C label being respired back to the atmosphere and an overall reduction in total understory carbon use efficiency. Taken together, our results suggest a faster cycling of C in understory vegetation with increasing N additions; yet the magnitude of this general response was strongly dependent on the amount of N added and varied seasonally. These results provide some of the first in situ C and N partitioning estimates for plants growing under the complex web of resource limitations in the boreal understory.

Degeneration and plasticity of the optic pathway in Alström syndrome

BACKGROUND AND PURPOSE

Alström syndrome is a rare inherited ciliopathy in which early progressive cone-rod dystrophy leads to childhood blindness. We investigated functional and structural changes of the optic pathway in Alström syndrome by using MR imaging to provide insight into the underlying pathogenic mechanisms.

MATERIALS AND METHODS

Eleven patients with genetically proved Alström syndrome (mean age, 23 years; range, 6-45 years; 5 females) and 19 age- and sex-matched controls underwent brain MR imaging. The study protocol included conventional sequences, resting-state functional MR imaging, and diffusion tensor imaging.

RESULTS

In patients with Alström syndrome, the evaluation of the occipital regions showed the following: 1) diffuse white matter volume decrease while gray matter volume decrease spared the occipital poles (voxel-based morphometry), 2) diffuse fractional anisotropy decrease and radial diffusivity increase while mean and axial diffusivities were normal (tract-based spatial statistics), and 3) reduced connectivity in the medial visual network strikingly sparing the occipital poles (independent component analysis). After we placed seeds in both occipital poles, the seed-based analysis revealed significantly increased connectivity in patients with Alström syndrome toward the left frontal operculum, inferior and middle frontal gyri, and the medial portion of both thalami (left seed) and toward the anterior portion of the left insula (right and left seeds).

CONCLUSIONS

The protean occipital brain changes in patients with Alström syndrome likely reflect the coexistence of diffuse primary myelin derangement, anterograde trans-synaptic degeneration, and complex cortical reorganization affecting the anterior and posterior visual cortex to different degrees.

Alström syndrome is associated with short stature and reduced GH reserve

INTRODUCTION

Alström syndrome (ALMS) is a rare autosomal recessive monogenic disease included in an emerging class of genetic disorders called 'ciliopathies' and is likely to impact the central nervous system as well as metabolic and endocrine function. Individuals with ALMS present clinical features resembling a growth hormone deficiency (GHD) condition, but thus far no study has specifically investigated this aspect in a large population.

MATERIAL AND METHODS

Twenty-three patients with ALMS (age, 1-52 years; 11 males, 12 females) were evaluated for anthropometric parameters (growth charts and standard deviation score (SDS) of height, weight, BMI), GH secretion by growth hormone-releasing hormone + arginine test (GHRH-arg), bone age, and hypothalamic-pituitary magnetic resonance imaging (MRI). A group of 17 healthy subjects served as controls in the GH secretion study. Longitudinal retrospective and prospective data were utilized.

RESULTS

The length-for-age measurements from birth to 36 months showed normal growth with most values falling within -0·67 SDS to +1·28 SDS. A progressive decrease in stature-for-age was observed after 10 years of age, with a low final height in almost all ALMS subjects (>16-20 years; mean SDS, -2·22 ± 1·16). The subset of 12 patients with ALMS tested for GHRH-arg showed a significantly shorter stature than age-matched controls (154·7 ± 10·6 cm vs 162·9 ± 4·8 cm, P = 0·009) and a mild increase in BMI (Kg/m(2) ) (27·8 ± 4·8 vs 24·1 ± 2·5, P = 0·007). Peak GH after GHRH-arg was significantly lower in patients with ALMS in comparison with controls (11·9 ± 6·9 μg/l vs 86·1 ± 33·2 μg/l, P < 0·0001). Severe GHD was evident biochemically in 50% of patients with ALMS. The 10 adult ALMS patients with GHD showed a reduced height in comparison with those without GHD (149·7 ± 6·2 cm vs 161·9 ± 9·2 cm, P = 0·04). MRIs of the diencephalic and pituitary regions were normal in 11 of 12 patients. Bone age was advanced in 43% of cases.

CONCLUSIONS

Our study shows that 50% of nonobese ALMS patients have an inadequate GH reserve to GHRH-arg and may be functionally GH deficient. The short stature reported in ALMS may be at least partially influenced by impairment of GH secretion.

Hippocampal tissue of patients with refractory temporal lobe epilepsy is associated with astrocyte activation, inflammation, and altered expression of channels and receptors

Temporal lobe epilepsy (TLE) is the most common form of focal epilepsy. Previous research has demonstrated several trends in human tissue that, undoubtedly, contribute to the development and progression of TLE. In this study we examined resected human hippocampus tissue for a variety of changes including gliosis that might contribute to the development and presentation of TLE. The study subjects consisted of six TLE patients and three sudden-death controls. Clinicopathological characteristics were evaluated by H&E staining. Immunohistological staining and Western blotting methods were used to analyze the samples. Neuronal hypertrophy was observed in resected epileptic tissue. Immunohistological staining demonstrated that activation of astrocytes was significantly increased in epileptic tissue as compared to corresponding regions of the control group. The Western blot data also showed increased CX43 and AQP4 in the hippocampus and downregulation of Kir4.1, α-syntrophin, and dystrophin, the key constituents of AQP4 multi-molecular complex. These tissues also demonstrated changes in inflammatory factors (COX-2, TGF-β, NF-κB) suggesting that these molecules may play an important role in TLE pathogenesis. In addition we detected increases in metabotropic glutamate receptor (mGluR) 2/3, mGluR5 and kainic acid receptor subunits KA1 (Grik4) and KA2 (Grik5) in patients' hippocampi. We noted increased expression of the α1c subunit comprising class C L-type Ca(2+) channels and calpain expression in these tissues, suggesting that these subunits might have an integral role in TLE pathogenesis. These changes found in the resected tissue suggest that they may contribute to TLE and that the kainic acid receptor (KAR) and deregulation of GluR2 receptor may play an important role in TLE development and disease course. This study identifies alterations in number of commonly studied molecular targets associated with astrogliosis, cellular hypertrophy, water homeostasis, inflammation, and modulation of excitatory neurotransmission in hippocampal tissues from TLE patients.

Sedimentological control on Mn, and other trace elements, in groundwater of the Bengal delta

To reveal what controls the concentration and distribution of possibly hazardous (Mn, U, Se, Cd, Bi, Pb) and nonhazardous (Fe, V, Mo, PO(4)) trace elements in groundwater of the Bengal delta, we mapped their concentrations in shallow groundwater (<60 mbgl) across 102 km(2) of West Bengal. Only Mn is a potential threat to health, with 55% of well water exceeding 0.3 mg/L, the current Indian limit for drinking water in the absence of an alternate source, and 75% exceeding the desirable limit of 0.1 mg/L. Concentrations of V are <3 μg/L. Concentrations of U, Se, Pb, Ni, Bi, and Cd, are below WHO guideline values. The distributions of Fe, Mn, As, V, Mo, U, PO(4), and δ(18)O in groundwater reflect subsurface sedimentology and sources of water. Areas of less negative δ(18)O reveal recharge by sources of evaporated water. Concentrations of Fe, As, Mo, and PO(4) are high in palaeo-channel groundwaters and low in palaeo-interfluvial groundwaters. Concentrations of U, V, and Mn, are low in palaeo-channel groundwaters and high in palaeo-interfluvial groundwaters. Concentrations of Fe and Mn are highest (18 and 6 mg/L respectively) at dual reduction-fronts that form strip interfaces at depth around the edges of palaeo-interfluvial aquifers. The fronts form as focused recharge carries dissolved organic carbon into the aquifer margins, which comprise brown, iron-oxide bearing, sand. At the Mn-reduction front, concentrations of V and Mo reach peak concentrations of 3 μg/L. At the Fe-reduction front, concentrations of PO(4) and As reach concentrations 3 mg/L and 150 μg/L respectively. Many groundwaters contain >10 mg/L of Cl, showing that they are contaminated by Cl of anthropogenic origin and that organic matter from in situ sanitation may contribute to driving reduction.

Adaptation of continuous-flow cavity ring-down spectroscopy for batch analysis of δ13C of CO2 and comparison with isotope ratio mass spectrometry

Measurements of δ(13)C in CO(2) have traditionally relied on samples stored in sealed vessels and subsequently analyzed using magnetic sector isotope ratio mass spectrometry (IRMS), an accurate but expensive and high-maintenance analytical method. Recent developments in optical spectroscopy have yielded instruments that can measure δ(13)CO(2) in continuous streams of air with precision and accuracy approaching those of IRMS, but at a fraction of the cost. However, continuous sampling is unsuited for certain applications, creating a need for conversion of these instruments for batch operation. Here, we present a flask (syringe) adaptor that allows the collection and storage of small aliquots (20-30 mL air) for injection into the cavity ring-down spectroscopy (CRDS) instrument. We demonstrate that the adaptor's precision is similar to that of traditional IRMS (standard deviation of 0.3‰ for 385 ppm CO(2) standard gas). In addition, the concentration precision (±0.3% of sample concentration) was higher for CRDS than for IRMS (±7% of sample concentration). Using the adaptor in conjunction with CRDS, we sampled soil chambers and found that soil-respired δ(13)C varied between two different locations in a piñon-juniper woodland. In a second experiment, we found no significant discrimination between the respiration of a small beetle (~5 mm) and its diet. Our work shows that the CRDS system is flexible enough to be used for the analysis of batch samples as well as for continuous sampling. This flexibility broadens the range of applications for which CRDS has the potential to replace magnetic sector IRMS.

Evidence for Molecular Heterogeneity of the Specific Antigen (Fraction-1) of Pasteurella pestis

Fraction-I (F-I) protein, the specific antigen of Pasteurella pestis, appears to be a series of molecular aggregates of identical subunits, all of which have serological reactivity with specific F-I antiserum.

Local induction of a specific Th1 immune response by allergen linked immunostimulatory DNA in the nasal explants of ragweed-allergic subjects

BACKGROUND

Allergen immunotherapy is effective in allergic individuals however efforts are being made to improve its safety, convenience, and efficacy. It has recently been demonstrated that allergen-linked immunostimulatory DNA (ISS) is effective in stimulating an allergen-specific Th1 response with decreased allergenicity. The objective of this study is to investigate whether ISS linked to purified ragweed allergen Amb-a-1 (AIC) can inhibit local allergen-specific Th2 and induce allergen-specific Th1 responses in explanted nasal mucosa of ragweed-sensitive subjects. In addition, we set out to determine whether AIC is more effective compared to stimulation with unlinked Amb a 1 and ISS.

METHODS

Tissue from ragweed-sensitive patients (n = 12) was cultured with whole ragweed allergen (RW), Amb-a-1, AIC, Amb-a-1 and ISS (unlinked), or tetanus toxoid (TT) for 24 hours. IL-4, -5, -13, TNF-alpha and IFN-gamma mRNA-positive cells were visualized by in situ hybridization and T cells, B cells and neutrophils were enumerated using immunocytochemistry.

RESULTS

RW or Amb-a-1 increased the number of IL-4, IL-5, and IL-13 mRNA+ cells in the tissue compared to medium alone. AIC had similar cytokine mRNA reactivity as control tissue. AIC and TT increased IFNgamma-mRNA expression. Unlinked Amb-a-1 and ISS showed similar effects to AIC, however this response was weaker. The number of TNF mRNA+ cells, T cells, B cells and neutrophils remained unchanged.

CONCLUSIONS

AIC is effective in stimulating a local allergen-specific Th1- and abolishing Th2-cytokine mRNA reactivity in the nose and may be considered as a strong candidate for an improved approach to immunotherapy in ragweed-sensitive individuals.

Assimilation of xylem-transported 13C-labelled CO2 in leaves and branches of sycamore (Platanus occidentalis L.)

Previous reports have shown that CO(2) dissolved in xylem sap in tree stems can move upward in the transpiration stream. To determine the fate of this dissolved CO(2), the internal transport of respired CO(2) at high concentration from the bole of the tree was simulated by allowing detached young branches of sycamore (Platanus occidentalis L.) to transpire water enriched with a known quantity of (13)CO(2) in sunlight. Simultaneously, leaf net photosynthesis and CO(2) efflux from woody tissue were measured. Branch and leaf tissues were subsequently analysed for (13)C content to determine the quantity of transported (13)CO(2) label that was fixed. Treatment branches assimilated an average of 35% (SE=2.4) of the (13)CO(2) label taken up in the treatment water. The majority was fixed in the woody tissue of the branches, with smaller amounts fixed in the leaves and petioles. Overall, the fixation of internally transported (13)CO(2) label by woody tissues averaged 6% of the assimilation of CO(2) from the atmosphere by the leaves. Woody tissue assimilation rates calculated from measurements of (13)C differed from rates calculated from measurements of CO(2) efflux in the lower branch but not in the upper branch. The results of this study showed unequivocally that CO(2) transported in xylem sap can be fixed in photosynthetic cells in the leaves and branches of sycamore trees and provided evidence that recycling of xylem-transported CO(2) may be an important means by which trees reduce the carbon cost of respiration.

Immunostimulatory DNA as a vaccine adjuvant

Immunostimulatory DNA containing unmethylated CpG motifs is recognized by Toll-like receptor 9, resulting in the activation of innate immune responses that subsequently amplify the adaptive-immune response. Advances in the characterization of Toll-like receptor 9 signaling have identified immunostimulatory sequences (ISS) with distinct biological activities. Numerous animal models have demonstrated that synthetic ISS are effective adjuvants that enhance both humoral and cellular immune responses in diverse indications, ranging from infectious disease to cancer and allergy. An added benefit supporting the use of ISS as a vaccine adjuvant is that the specific activation of a pathway critical to the regulation of the immune response results in minimal toxicity. To date, clinical testing has largely affirmed the potency and safety of ISS-adjuvanted vaccines.

Molecular analysis and long-term clinical evaluation of three siblings with Alström syndrome

Alström syndrome is a rare, autosomal recessive disorder characterized by a wide spectrum of clinical features including early-onset retinal degeneration leading to blindness, sensorineural hearing loss, short stature, obesity, type 2 diabetes, hyperlipidemia and dilated cardiomyopathy. Renal, hepatic and pulmonary dysfunction may occur in the later phases of the disease. The three affected sisters, from a consanguineous Turkish family, with the characteristic features of Alström syndrome, were clinically diagnosed in 1987 and followed for 20 years. DNA sequence analysis of ALMS1, the causative gene in Alström syndrome, identified a novel homozygous disease-causing mutation, c.8164C>T, resulting in a premature termination codon in exon 10 in each of the three affected sisters. Furthermore, we describe the longitudinal disease progression in this family and report new clinical findings likely associated with Alström syndrome, such as pes planus and hyperthyroidism.

Negative regulation of TLR9-mediated IFN-alpha induction by a small-molecule, synthetic TLR7 ligand

Toll-like receptors (TLRs) are a family of molecules that function as sensors for the detection of foreign pathogens through the recognition of nonvariable microbial motifs. Although numerous studies have focused on singular TLRs, less attention has been focused on how simultaneous signaling of multiple TLRs may result in counter-regulation of the effects of each. Here, we examine the counter-regulation that occurs during simultaneous stimulation of TLR7 and TLR9 on human plasmacytoid dendritic cells (PDCs) and B cells. Interestingly, we observed that the capacity for potent IFN-alpha-induction by TLR9 ligands like CpG-C and CpG-A is markedly reduced by concurrent small molecule TLR7 stimulation. However, this inhibition is specific to particular CpG motif-containing immunostimulatory sequence (ISS) functions such as IFN-alpha induction and BDCA-2 down-regulation. Other ISS activities such as PDC expression of CD80/CD86, secretion of IL-6, and B cell proliferation are not altered by the presence of TLR7 ligands (TLR7Ls). In concordance with the ability of TLR7Ls to decrease IFN-alpha secretion induced by ISS, we also find that the expression of interferon regulatory factor-7 (IRF-7), a transcriptional factor critical for IFN-alpha expression, is reduced. Furthermore, down-regulation of TLR9 mRNA expression is accelerated after TLR7 stimulation. These data indicate that TLR7 and TLR9 costimulation do not combine synergistically for IFN-alpha induction and demonstrate that, instead, a negative feedback mechanism has evolved, possibly to prevent levels of IFN-alpha secretion potentially detrimental to the host.

ISS (ImmunoStimulatory Sequences) and Iscomatrix boost vaccine-generated HBV-specific immunity in mice (B202)

We have investigated the adjuvant activity of both CpG motif-containing ImmunoStimulatory Sequences (ISS) and the saponin/phospholipid-based Iscomatrix (IMX) on HBV-specific humoral and cell-mediated immunity in C57BL/6 mice. Mice were immunized at weeks 0 and 2 with several formulations that incorporated HBV surface antigen (HBsAg), HBV core antigen (HBcAg), ISS, and IMX. ISS was added to antigen in soluble form or conjugated with HBsAg or HBcAg. Bleeds were performed 2 weeks post 1st immunization (2wp1) and 2wp2 and sera analyzed for anti-HBV IgG1 and IgG2a levels. Mice were also splenectomized at 2wp2 and HBV-specific cell-mediated immunity was examined. HBsAg + HBcAg + 1018 ISS + IMX resulted in high levels of HBsAg-specific and HBcAg-specific IFN-g induction that exceeded that induced by either adjuvant alone. Conjugates of HBV surface or core protein to ISS ODNs also provided for higher levels of antigen-specific IFN-g production and CTL activation. These results indicate that HBV therapeutic formulations that incorporate ISS and/or IMX may stimulate for enhanced levels of anti-HBsAg antibody and augmented anti-HBcAg CMI (cell-mediated immunity) and are promising candidates to test in human clinical trials.

Promotion of physical activity by Canadian Registered Dietitians in daily practice

BACKGROUND

Dietitians are in an opportunistic position to promote healthy eating and active living. The purpose of this study was to determine counselling strategies of dietitians 1 year after attending a workshop designed to strengthen dietitians' self-efficacy for promoting physical activity (PA) as an adjunct to regular nutrition practice.

METHODS

A convenience sample of Registered Dietitians (RDs) in Alberta, Canada (n=103) responded to an invitation via an electronic newsletter to complete a web-based survey that asked about counselling practices related to PA.

RESULTS

Thirty-seven workshop attendees (n=37) were compared with a group of dietitians (n=66) who completed the survey but who did not attend the workshop. Nearly all (91%) respondents reported promoting PA in daily practice. Those who attended the workshop were more likely to refer clients to PA professionals (chi2=12.68, P<0.05) than those who were not workshop attendees.

CONCLUSIONS

Despite a relatively modest response rate, there were clear suggestions that RDs in Alberta, Canada promote PA in daily practice and attending a workshop designed to facilitate the use of specific tools and strategies for promoting PA in daily practice resulted in increased referral of their clients to exercise specialists.

A multi-species comparison of delta13C from whole wood, extractive-free wood and holocellulose

The stable carbon (C) isotope composition (delta13C) of tree rings is a powerful metric for reconstructing past physiological responses to climate variation. However, accurate measurement and interpretation are complicated by diagenesis and the translocation of compounds with distinct isotopic signatures. Isolation and analysis of cellulose minimizes these complications by eliminating variation due to biosynthetic pathways; however, isolation of cellulose is time-consuming and has no clear endpoint. A faster and better-defined analytical method is desirable. Our objectives were to determine if there is a direct relationship between the isotopic compositions of whole wood (WW), whole wood treated with solvents to remove mobile extractives (extractive-free wood; EF) and holocellulose (HC) isolated by extractive removal and subsequent bleaching. We also determined if total C concentration could explain the isotopic composition and variation among these three wood components of each sample. A set of wood samples of diverse phylogeny, anatomy and chemical composition, was examined. The mean offset or difference between HC and EF delta13C was 1.07 +/- 0.09 per thousand and the offset between HC and WW was 1.32 +/- 0.10 per thousand. Equivalence tests (with alpha = 0.05) indicated that the relationship between EF delta13C and HC delta13C had a slope significantly similar to 1 +/- 5.5%, whereas for the WW delta13C: HC delta13C relationship, the slope was significantly similar to 1 +/- 10.08%. A regression model using EF delta13C to predict HC delta13C had a slope of 0.97, which was not significantly different from unity (P = 0.264), whereas the regression for WW had a slope of 0.92 which was significantly different from unity (P = 0.0098). Carbon concentration was correlated with HC:WW offset and cellulose:EF offset (P = 0.0501 and 0.007, respectively), but neither relationship explained much of the variation (r2 = 0.12 and 0.14, respectively). We suggest that HC extraction is unnecessary for most analyses of tree-ring delta13C; a simple solvent extraction is a suitable alternative for many applications.

Induction of interferon-gamma from natural killer cells by immunostimulatory CpG DNA is mediated through plasmacytoid-dendritic-cell-produced interferon-alpha and tumour necrosis factor-alpha

Immunostimulatory sequences (ISS) that contain CpG motifs have been demonstrated to exert antipathogen and antitumour immunity in animal models through several mechanisms, including the activation of natural killer (NK) cells to secrete interferon-gamma (IFN-gamma) and to exert lytic activity. Since NK cells lack the ISS receptor TLR9, the exact pathway by which NK cells are activated by ISS is unclear. We determined that ISS-induced IFN-gamma from NK cells is primarily dependent upon IFN-alpha release from plasmacytoid dendritic cells (PDCs), which directly activates the NK cell. However, further analysis indicated that other PDC-released soluble factor(s) may contribute to IFN-gamma induction. Indeed, tumour necrosis factor-alpha (TNF-alpha) was identified as a significant contributor to ISS-mediated activation of NK cells and was observed to act in an additive fashion with IFN-alpha in the induction of IFN-gamma from NK cells and to up-regulate CD69 expression on NK cells. This activity of TNF-alpha, however, was dependent upon the presence of PDC-derived factors such as type I interferon. These results illustrate an important function for type I interferon in innate immunity, which is not only to activate effectors like NK cells directly, but also to prime them for enhanced activation by other factors such as TNF-alpha.

Familial variable expression of dilated cardiomyopathy in Alström syndrome: A report of four sibs

Alström syndrome is an autosomal recessive disorder comprised of progressive vision loss (nystagmus, photophobia, and pigmentary retinopathy), progressive sensorineural hearing loss, morbid obesity, male hypogonadism, insulin resistant diabetes, renal failure, and dilated cardiomyopathy. We report on four sibs with Alström syndrome with intra-familial variability in onset, severity, and spectrum of manifestations; the most serious manifestation being dilated cardiomyopathy. This report emphasizes the difficulty of recognizing this constellation of symptoms as Alström syndrome at an early age, the seriousness of cardiac involvement, and the intra-familial variability of phenotypic expression.

Superior activity of the type C class of ISS in vitro and in vivo across multiple species

CpG-C are a novel class of CpG motif-containing immunostimulatory sequences (ISS) that includes both a 5'-TCG element and a CpG-containing palindrome. CpG-C drive all known ISS activities and, in particular, are potent enhancers of IFN-alpha from plasmacytoid dendritic cells (PDCs). In our examination of CpG-C sequence requirements, we determined that optimal IFN-alpha-inducing activity could be achieved with longer palindromes. Longer palindromes also correlated with maintenance of the double-stranded (ds) form despite concentration and pH changes, indicating a preference for ds oligodeoxynucleotides (ODNs) by the ISS-induced signaling mechanism for IFN-alpha synthesis. This correlation did not hold for all arms of the ISS-induced immune response, since we did not observe increased B cell activity with the longer palindrome CpG-C ODNs. We further demonstrated that CpG-C retained activity in an in vitro primate system and induced the expression of several cytokines and IFN-alpha-inducible genes when CpG-C were administered in vivo to mice and primates. In conclusion, we have shown CpG-C to exert several types of immune functions across multiple species, and this novel class is thus an attractive candidate for ISS-based therapeutic strategies.

Apparent respiratory discrimination is correlated with growth rate in the shoot apex of sunflower (Helianthus annuus)

The literature offers no consensus as to whether the delta(13)C of respired CO(2) is identical to that of the respiratory substrate, perhaps because of differences in measurement technique and growth conditions. To address this issue, the delta(13)C of respired CO(2) from growing sunflower shoot apices was measured and compared with that of soluble carbohydrates extracted from the respiring tissues. Shoot apices were studied because any influence of growth and biosynthesis was expected to be maximally expressed in these rapidly growing tissues. The two most probable substrates, starch and soluble sugars, were similar in delta(13)C (P=0.46). The delta(13)C of respired CO(2) was enriched in (13)C compared with these putative substrates (P<0.0001). This apparent enrichment ranged from 2.2 per thousand-5.7 per thousand, and decreased with relative growth rate (P<0.0001). The respiratory enrichment was counterbalanced by a depletion in the tissue constructed from the residual carbohydrates. The depletion varied from 2.2 per thousand to 3.0 per thousand relative to soluble carbohydrates (P<0.05), as predicted from mass-balance arguments. These results support the idea that respired CO(2) is enriched relative to its substrates. Variation in growth rates may help to explain the variable amounts of respiratory discrimination described in the literature.

Polymyxin B enhances ISS-mediated immune responses across multiple species

The immunostimulatory effects of bacterial DNA on mammalian cells have been localized to unmethylated CpG motifs, and synthetic CpG-containing oligodeoxynucleotides that mimic these effects are known as immunostimulatory sequences (ISS). We have found that the polycationic antibiotic, polymyxin B (PMXB), associates with ISS and serum albumin in vitro and forms microparticles that greatly increase the activity of ISS on plasmacytoid dendritic cells (PDCs). Specifically, ISS/PMXB greatly enhanced IFN-alpha production from PDCs and other activities downstream of IFN-alpha, including IFN-gamma secretion, NK lytic activity, and the expression of genes dependent upon IFN-alpha/IFN-gamma. This amplification was specific for the IFN-alpha pathway since other ISS activities, including B cell proliferation, B cell IL-6 secretion, and PDC maturation, were not affected by PMXB. Both the polycationic peptide and lipophilic fatty acid side chain domains of PMXB, as well as the presence of a third party stabilizing agent such as albumin or Tween 85, were required for particle formation and enhanced ISS activity. The ISS-enhancing activity of PMXB was observed across multiple species (human, primate, and mouse) and in vivo (primate, mouse). These data illustrate the usefulness of formulating ISS with a cationic lipopeptide such as PMXB, which focuses and greatly amplifies the ISS-induced pathway of IFN-alpha-mediated responses.

IL-10 regulates plasmacytoid dendritic cell response to CpG-containing immunostimulatory sequences

Immunostimulatory sequences (ISS) are short oligonucleotides containing unmethylated cytosine-phosphate-guanine (CpG) dinucleotides that stimulate innate immune responses through Toll-like receptor-9 on B cells and plasmacytoid dendritic cell (PDC) precursors. The anti-inflammatory cytokine interleukin (IL)-10 is predicted to be a potent inhibitor of many of the activities described for ISS, and this may impact the use of ISS in disease states characterized by elevated IL-10. As the activities of ISS on PDCs are central to many clinical applications of ISS, we have studied the effects of IL-10 on PDC stimulation by 3 distinct classes of ISS. IL-10 inhibited cytokine production and survival of ISS-activated PDCs; however, IL-12 induction was much more sensitive to inhibition than interferon (IFN)-alpha induction. Within the PDC population are cells that respond to ISS by producing either IL-12 or IFN-alpha but not both cytokines. IL-12-producing PDCs require costimulation through CD40 and appear more mature than IFN-alpha-producing PDCs. The 3 distinct classes of ISS differed with respect to induction of PDC maturation and T-cell priming capacity. IL-10 regulated PDC activation but did not inhibit the subsequent T-cell-priming ability of PDCs already activated by ISS.

Novel chimeric immunomodulatory compounds containing short CpG oligodeoxyribonucleotides have differential activities in human cells

Immunostimulatory DNA sequences (ISS) containing CpG motifs induce interferon-alpha (IFN-alpha) and interferon-gamma (IFN-gamma) from human peripheral blood mononuclear cells and stimulate human B cells to proliferate and produce IL-6. We studied the motif and structural requirements for both types of activity using novel chimeric immunomodulatory compounds (CICs), which contain multiple heptameric ISS connected by non-nucleoside spacers in both linear and branched configurations. We found that the optimal motifs and structure for IFN-alpha production versus B cell activation differed. IFN-alpha production was optimal for CICs containing the sequences 5'-TCGXCGX and 5'-TCGXTCG, where X is any nucleotide. The presentation of multiple copies of these heptameric ISS with free 5'-ends via long, hydrophilic spacers, such as hexaethylene glycol, significantly enhanced the induction of IFN-alpha. Conversely, human B cell activity was predominantly dependent on ISS motif, with 5'-TCGTXXX and 5'-AACGTTC being the most active sequences. Thus, we found CICs could be 'programmed' for IFN-alpha production or B cell activation as independent variables. Additionally, CICs with separate human- and mouse-specific motifs were synthesized and these were used to confirm in vivo activity in mice. CICs may offer unique advantages over conventional ISS because identification of the optimal motifs, spacers and structures for different biological properties allows for the assembly of CICs exhibiting a defined set of activities tailored for specific clinical applications.

A minimal human immunostimulatory CpG motif that potently induces IFN-gamma and IFN-alpha production

Recent reports have shown that immunostimulatory sequences (ISS) containing CpG motifs have minimal length requirements (>/=12 bases) for the exertion of immune-enhancing function upon mammalian cells. Herein we demonstrate that short ISS (5-7 bases), which exhibit no activity on their own, induce IFN-gamma and IFN-alpha secretion from human peripheral blood mononuclear cells when adsorbed to the surface of cationic poly(D,L-lactide-co-glycolide) microparticles (cPLGA). Utilizing this technique, we discovered a minimal ISS sequence for induction of IFN-gamma and IFN-alpha from human cells: 5'-TCGXX-3'. These short ISS/cPLGA formulations targeted PDC in similar fashion to longer ISS ODN, the activity of which does not require (but is enhanced by) cPLGA. PDC stimulated with short ISS/cPLGA responded with enhanced uptake of ISS and elevated production of cytokines, including IFN-alpha. However, ISS-responsive B cells did not respond to short ISS/cPLGA, underlining the plasmacytoid dendritic cell selectivity of this formulation. These results describe a novel technique for formulating active, but very short, ISS oligodeoxynucleotide that allows for the dissection and characterization of minimal immunostimulatory CpG motifs.

Identification of a novel CpG DNA class and motif that optimally stimulate B cell and plasmacytoid dendritic cell functions

Recent reports have identified two major classes of CpG motif-containing oligodeoxynucleotide immunostimulatory sequences (ISS): uniformly modified phosphorothioate (PS) oligodeoxyribonucleotides (ODNs), which initiate B cell functions but poorly activate dendritic cells (DCs) to make interferon (IFN)-alpha, and chimeric PS/phosphodiester (PO) ODNs containing runs of six contiguous guanosines, which induce very high levels of plasmacytoid DC (PDC)-derived IFN-alpha but poorly stimulate B cells. We have generated the first reported ISS, C274, which exhibits very potent effects on all human immune cells known to recognize ISS. C274 is a potent inducer of IFN-gamma/IFN-alpha from peripheral blood mononuclear cells and exhibits accelerated kinetics of activity compared with standard ISS. This ODN also effectively stimulates B cells to proliferate, secrete cytokines, and express costimulatory antigens. In addition, C274 specifically activates PDCs to undergo maturation and secrete cytokines, including very high levels of IFN-alpha. Sequence variation studies based on C274 were used to identify the general motif requirements for this novel and distinct class of ISS. In contrast, chimeric PO/PS CpG-containing ODNs with polyguanosine sequences exert a differential pattern of ISS activity compared with C274, perhaps in part as a result of their greatly different structural nature. This pattern is composed of high IFN-alpha/IFN-gamma induction and low DC maturation in the absence of B cell stimulation. In conclusion, we have generated a novel class of ISS that transcends the limitations ascribed to classes described previously in that it provides excellent stimulation of B cells and simultaneously activates PDCs to differentiate and secrete large amounts of type I IFN.

Responses of foliar delta13C, gas exchange and leaf morphology to reduced hydraulic conductivity in Pinus monticola branches

We tested the hypothesis that branch hydraulic conductivity partly controls foliar stable carbon isotope ratio (delta13C) by its influence on stomatal conductance in Pinus monticola Dougl. Notching and phloem-girdling treatments were applied to reduce branch conductivity over the course of a growing season. Notching and phloem girdling reduced leaf-specific conductivity (LSC) by about 30 and 90%, respectively. The 90% reduction in LSC increased foliar delta13C by about 1 per thousand (P < 0.0001, n = 65), whereas the 30% reduction in LSC had no effect on foliar delta13C (P = 0.90, n = 65). Variation in the delta13C of dark respiration was similar to that of whole-tissues when compared among treatments. These isotopic measurements, in addition to instantaneous gas exchange measurements, suggested only minor adjustments in the ratio of intercellular to atmospheric CO2 partial pressures (ci/ca) in response to experimentally reduced hydraulic conductivity. A strong correlation was observed between stomatal conductance (gs) and photosynthetic demand over a tenfold range in gs. Although ci/ca and delta13C appeared to be relatively homeostatic, current-year leaf area varied linearly as a function of branch hydraulic conductivity (r2 = 0.69, P < 0.0001, n = 18). These results suggest that, for Pinus monticola, adjustment of leaf area is a more important response to reduced branch conductivity than adjustment of ci/ca.

Time-series analysis of delta13C from tree rings. I. Time trends and autocorrelation

Univariate time-series analyses were conducted on stable carbon isotope ratios obtained from tree-ring cellulose. We looked for the presence and structure of autocorrelation. Significant autocorrelation violates the statistical independence assumption and biases hypothesis tests. Its presence would indicate the existence of lagged physiological effects that persist for longer than the current year. We analyzed data from 28 trees (60-85 years old; mean = 73 years) of western white pine (Pinus monticola Dougl.), ponderosa pine (Pinus ponderosa Laws.), and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca) growing in northern Idaho. Material was obtained by the stem analysis method from rings laid down in the upper portion of the crown throughout each tree's life. The sampling protocol minimized variation caused by changing light regimes within each tree. Autoregressive moving average (ARMA) models were used to describe the autocorrelation structure over time. Three time series were analyzed for each tree: the stable carbon isotope ratio (delta(13)C); discrimination (delta); and the difference between ambient and internal CO(2) concentrations (c(a) - c(i)). The effect of converting from ring cellulose to whole-leaf tissue did not affect the analysis because it was almost completely removed by the detrending that precedes time-series analysis. A simple linear or quadratic model adequately described the time trend. The residuals from the trend had a constant mean and variance, thus ensuring stationarity, a requirement for autocorrelation analysis. The trend over time for c(a) - c(i) was particularly strong (R(2) = 0.29-0.84). Autoregressive moving average analyses of the residuals from these trends indicated that two-thirds of the individual tree series contained significant autocorrelation, whereas the remaining third were random (white noise) over time. We were unable to distinguish between individuals with and without significant autocorrelation beforehand. Significant ARMA models were all of low order, with either first- or second-order (i.e., lagged 1 or 2 years, respectively) models performing well. A simple autoregressive (AR(1)), model was the most common. The most useful generalization was that the same ARMA model holds for each of the three series (delta(13)C, delta, c(a) - c(i)) for an individual tree, if the time trend has been properly removed for each series. The mean series for the two pine species were described by first-order ARMA models (1-year lags), whereas the Douglas-fir mean series were described by second-order models (2-year lags) with negligible first-order effects. Apparently, the process of constructing a mean time series for a species preserves an underlying signal related to delta(13)C while canceling some of the random individual tree variation. Furthermore, the best model for the overall mean series (e.g., for a species) cannot be inferred from a consensus of the individual tree model forms, nor can its parameters be estimated reliably from the mean of the individual tree parameters. Because two-thirds of the individual tree time series contained significant autocorrelation, the normal assumption of a random structure over time is unwarranted, even after accounting for the time trend. The residuals of an appropriate ARMA model satisfy the independence assumption, and can be used to make hypothesis tests.

Immunostimulatory sequence DNA linked to the Amb a 1 allergen promotes T(H)1 cytokine expression while downregulating T(H)2 cytokine expression in PBMCs from human patients with ragweed allergy

BACKGROUND

Recent studies have demonstrated that bacterially derived immunostimulatory sequences (ISSs) of DNA can activate the mammalian innate immune system and promote the development of T(H)1 cells. Promotion of T(H)1 immunity by means of immunotherapy in allergic patients has led to the alleviation of symptoms that result from allergen-specific T(H)2 responses.

OBJECTIVE

Our purpose was to investigate whether the T(H)1-enhancing properties of ISSs could be used to alter the T(H)2-dominated immune response of allergic PBMCs in vitro.

METHODS

Ragweed protein-linked ISS (PLI) was generated from a specific, highly active 22-base ISS and Amb a 1, the immunodominant allergen in ragweed pollen, to combine the T(H)1-enhancing properties of ISSs with allergen selectivity, and its activity was investigated in PBMC cultures from subjects with ragweed allergy.

RESULTS

PLI was markedly successful at reversing the dominant allergen-induced T(H)2 profile while greatly enhancing IFN-gamma production. Delivering ISSs in a linked form proved to be much more effective at modulating the resulting cytokine profile than delivering free ISSs in a mixture with unlinked Amb a 1. PLI also demonstrated cytokine-modulating properties, even when used to stimulate cells that had already been primed for 6 days with Amb a 1. The antigen specificity of the action of PLI was confirmed by the observations that PLI enhances Amb a 1--specific T-cell proliferation.

CONCLUSION

These data indicate that delivery of ISSs within an antigen-specific context exhibits potent cytokine-modulating activity and, combined with its reduced allergenicity, makes this molecule a strong candidate for use in improved immunotherapy applications.

Family differences in height growth and photosynthetic traits in three conifers

We investigated variation in height growth, gas exchange, chlorophyll fluorescence and leaf stable carbon isotope ratio among wind-pollinated progenies of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca), ponderosa pine (Pinus ponderosa Dougl. ex Laws.) and western white pine (Pinus monticola Dougl. ex D. Don) from a small group of contiguous stands on the Priest River Experimental Forest in northern Idaho. Photosynthetic variables differed between height classes in the pines, but not in Douglas-fir. Among species and families, tall families of ponderosa pine regained photosynthetic capacity earliest in the spring and maintained it latest in the growing season. Tall families of western white pine had higher instantaneous water-use efficiencies and lower photosynthetic rates than short families on warm days in August.

Expression and function of IL-12 and IL-18 receptors on human tonsillar B cells

IL-12 activates murine and human B cells, but little information is available as to the expression and function of IL-12R on human B lymphocytes. Here we show that the latter cells, freshly isolated from human tonsils, expressed the transcripts of both beta1 and beta2 chains of IL-12R and that beta2 chain mRNA was selectively increased (4- to 5-fold) by incubation with Staphylococcus aureus Cowan I bacteria or IL-12. B cell stimulation with IL-12 induced de novo expression of the transcripts of the two chains of IL-18R, i.e., IL-1 receptor-related protein and accessory protein-like. Functional studies showed that both IL-12 and IL-18 signaled to B cells through the NF-kappaB pathway. In the case of IL-12, no involvement of STAT transcription factors, and in particular of STAT-4, was detected. c-rel and p50 were identified as the members of NF-kappaB family involved in IL-12-mediated signal transduction to B cells. IL-12 and IL-18 synergized in the induction of IFN-gamma production by tonsillar B cells, but not in the stimulation of B cell differentiation, although either cytokine promoted IgM secretion in culture supernatants. Finally, naive but not germinal center or memory, tonsillar B cells were identified as the exclusive IL-12 targets in terms of induction of NF-kappaB activation and of IFN-gamma production.

Carbon and nitrogen allocation to male and female reproduction in Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca, Pinaceae)

We measured carbon (respiration, photosynthesis, and production) and nitrogen allocation to male and female cones of Rocky Mountain Douglas-fir (Pseudotsuga menziesii var. glauca) to quantify gender-specific: (1) resource allocation to reproduction, and (2) contribution to carbon costs of reproduction via photosynthesis. We also measured foliar photosynthesis and nitrogen concentration ([N]) near and far from female cones to examine the relationship between reproduction and foliar physiology. Over one growing season, male cones required only 8% of all carbon allocated to reproduction, with females consuming the remaining 92%. Female cones, however, had maximum instantaneous refixation rates of 54%, which, integrated over the season, offset 6% of their total carbon requirements, while male cones were completely dependent on vegetative tissues for carbon. Male cones received 22% of all nitrogen allocated to reproduction and female cones received the remaining 78%. Foliage near female cones had elevated photosynthesis during the early stages of cone development and consistently lower [N] than foliage far from cones. Although female cones may photosynthesize, the annual sum of carbon fixed by reproductive structures is minor in comparison to the total carbon allocated to production and respiration.