Measurement of changes in mRNA for IL-5 in noninvasive scrapings of nasal epithelium taken from patients undergoing nasal allergen challenge

Nasal Lipopolysaccharide Challenge and Cytokine Measurement Reflects Innate Mucosal Immune Responsiveness

Background

Practical methods of monitoring innate immune mucosal responsiveness are lacking. Lipopolysaccharide (LPS) is a component of the cell wall of Gram negative bacteria and a potent activator of Toll-like receptor (TLR)-4. To measure LPS responsiveness of the nasal mucosa, we administered LPS as a nasal spray and quantified chemokine and cytokine levels in mucosal lining fluid (MLF).

Methods

We performed a 5-way cross-over, single blind, placebo-controlled study in 15 healthy non-atopic subjects (n = 14 per protocol). Doses of ultrapure LPS (1, 10, 30 or 100μg/100μl) or placebo were administered by a single nasal spray to each nostril. Using the recently developed method of nasosorption with synthetic adsorptive matrices (SAM), a series of samples were taken. A panel of seven cytokines/chemokines were measured by multiplex immunoassay in MLF. mRNA for intercellular cell adhesion molecule-1 (ICAM-1) was quantified from nasal epithelial curettage samples taken before and after challenge.

Results

Topical nasal LPS was well tolerated, causing no symptoms and no visible changes to the nasal mucosa. LPS induced dose-related increases in MLF levels of IL-1β, IL-6, CXCL8 (IL-8) and CCL3 (MIP-1α) (AUC at 0.5 to 10h, compared to placebo, p<0.05 at 30 and 100μg LPS). At 100μg LPS, IL-10, IFN-α and TNF-α were also increased (p<0.05). Dose-related changes in mucosal ICAM-1 mRNA were also seen after challenge, and neutrophils appeared to peak in MLF at 8h. However, 2 subjects with high baseline cytokine levels showed prominent cytokine and chemokine responses to relatively low LPS doses (10μg and 30μg LPS).

Conclusions

Topical nasal LPS causes dose-dependent increases in cytokines, chemokines, mRNA and cells. However, responsiveness can show unpredictable variations, possibly because baseline innate tone is affected by environmental factors. We believe that this new technique will have wide application in the study of the innate immune responses of the respiratory mucosa.

Key Messages

Ultrapure LPS was used as innate immune stimulus in a human nasal challenge model, with serial sampling of nasal mucosal lining fluid (MLF) by nasosorption using a synthetic absorptive matrix (SAM), and nasal curettage of mucosal cells. A dose response could be demonstrated in terms of levels of IL-1β, IL-6, CXCL8 and CCL3 in MLF, as well as ICAM-1 mRNA in nasal curettage specimens, and levels of neutrophils in nasal lavage. Depending on higher baseline levels of inflammation, there were occasional magnified innate inflammatory responses to LPS.

Trial Registration

Clinical Trials.gov NCT02284074

IL-23 promotes TCR-mediated negative selection of thymocytes through the upregulation of IL-23 receptor and RORγt

Transient thymic involution is frequently found during inflammation, yet the mode of action of inflammatory cytokines is not well defined. Here we report that interleukin-23 (IL-23) production by the thymic dendritic cells (DCs) promotes apoptosis of the CD4^hiCD8^hi double positive (DP) thymocytes. A deficiency in IL-23 signaling interferes with negative selection in the male D^b/H-Y T-cell receptor (TCR) transgenic mice. IL-23 plus TCR signaling results in significant up-regulation of IL-23 receptor (IL-23R) expressed predominantly on CD4^hiCD8^hiCD3⁺αβTCR⁺ DP thymocytes, and leads to RORγt dependent apoptosis. These results extend the action of IL-23 beyond its peripheral effects to a unique role in TCR mediated negative selection including elimination of natural T regulatory cells in the thymus.

Oral delivery of a probiotic induced changes at the nasal mucosa of seasonal allergic rhinitis subjects after local allergen challenge: a randomised clinical trial

Objective

To determine effects of probiotic consumption on clinical and immunological parameters of seasonal allergic rhinitis (SAR) in an out-of-season single nasal allergen challenge.

Methods

In a study registered at ClinicalTrials.Gov (NCT01123252), a 16-week dietary intervention was undertaken in 60 patients with allergic rhinitis (>16 years old). Using a double-blinded, placebo-controlled anonymised design, the patients were divided equally into two groups. One group was given a dairy drink containing Lactobacillus casei Shirota to ingest daily while the other consumed a similar drink without bacteria. Participants attended the clinic on two consecutive days before the intervention and then again at the end of the study period. On the first day of each 2-day visit, following clinical examination, assessments were made of total nasal symptoms scores and peak nasal inspiratory flow. Nasal scrapings, nasal lavage and blood were collected for laboratory analyses of cellular phenotypes, soluble mediator release and in vitro responses to pollen allergen. These procedures were repeated 24 hours following nasal allergen challenge.

Results

Prior to and following intervention there were no detectable differences between study groups in measured clinical outcome. After intervention, there were differences between groups in their percentages of CD86+ epithelial cells (p = 0.0148), CD86+CD252+ non-epithelial cells (p = 0.0347), sIL-1RII release (p = 0.0289) and IL-1β (p = 0.0224) levels at the nasal mucosa. Delivery of probiotic also suppressed production of sCD23 (p = 0.0081), TGF-β (p = 0.0283) and induced increased production of IFN-γ (p = 0.0351) in supernatants of cultured peripheral blood.

Conclusions & Clinical Relevance

This study did not show significant probiotic-associated changes with respect to the primary clinical endpoint. An absence of overt clinical benefit may be due to an inability of single nasal challenges to accurately represent natural allergen exposure. Nevertheless, oral delivery of probiotics produced changes of the immunological microenvironment at the nasal mucosa in individuals affected by SAR.

Trial Registration

ClinicalTrials.Gov NCT01123252

A phase 1, randomized, placebo-controlled, dose-escalation study of an anti-IL-13 monoclonal antibody in healthy subjects and mild asthmatics

AIMS

IL-13 is implicated as an important mediator of the pathology of asthma. This first clinical study with GSK679586, a novel humanized anti-IL-13 IgG1 monoclonal antibody, evaluated the safety, pharmacokinetics and pharmacodynamics of escalating single and repeat doses of GSK679586.

METHODS

In this randomized, double-blind study, healthy subjects received single intravenous infusions of GSK679586 (0.005, 0.05, 0.5, 2.5, 10 mg kg(-1)) or placebo and mild intermittent asthmatics received two once monthly intravenous infusions of GSK679586 (2.5, 10, 20 mg kg(-1)) or placebo.

RESULTS

GSK679586 displayed approximately linear pharmacokinetics (based on AUC and C(max)) with limited accumulation upon repeat administration. In mild intermittent asthmatics, treatment with GSK679586 produced an increase in serum total IL-13 concentrations, indicative of GSK679586-IL-13 complex formation. Additionally, mean levels of exhaled nitric oxide (FeNO), a marker of pulmonary inflammation, were reduced relative to baseline at 2.5, 10 and 20 mg kg(-1) doses of GSK679586 at both 2 weeks (19%, 44% and 52% decreases) and 8 weeks (29%, 55% and 42% decreases) after the second infusion. GSK679586 was well tolerated; the incidence of AEs was comparable across all presumed biologically active doses and there were no treatment-related SAEs.

CONCLUSIONS

GSK679586 demonstrated dose-dependent pharmacological activity in the lungs of mild intermittent asthmatics. These findings, together with the favourable safety profile and advantageous PK characteristics of a monoclonal antibody (e.g. a long half-life supporting less frequent dosing), warrant further investigation of GSK679586 in a broader asthma patient population.

Cleavage of p53-vimentin complex enhances tumor necrosis factor-related apoptosis-inducing ligand-mediated apoptosis of rheumatoid arthritis synovial fibroblasts

Rheumatoid arthritis synovial fibroblasts (RASFs) contribute to arthritic cartilage degradation. Although RASFs are normally resistant to apoptosis, Apo2L/tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-based gene therapy has been successfully used in a mouse model of arthritis. We investigated this further by treating human RASFs with nontoxic doses of the proteasome inhibitor lactacystin. Treatment induced cytosolic accumulation of p53 and enhanced the susceptibility of RASFs to apoptosis mediated by TRAIL-R2 (DR5) but not Fas. A specific role for p53 in TRAIL-R2-mediated apoptosis was indicated by the ability of p53 siRNA to significantly reduce RASF apoptosis and by the reduced apoptosis of RASFs bearing p53 mutations on treatment with anti-DR5 antibody or anti-DR5 antibody plus lactacystin. p53 immunoprecipitation followed by mass spectrometry identified a vimentin-p53 complex, an interaction that was confirmed by reciprocal vimentin-p53 immunoprecipitation and by co-immunofluorescence. Interestingly, human caspase-4 cleaved human vimentin, and blockade of caspase-4 with a chemical inhibitor or with specific siRNA significantly inhibited TRAIL-R2-mediated apoptosis of RASFs. Furthermore, blockade of caspase-4 was paralleled by persistence of a cytosolic pattern of p53 and absence of p53 translocation to the nucleus. Taken together, our findings suggest a unique role for caspase-4 in cleaving vimentin and releasing cytosolic p53 for nuclear translocation, events that may regulate the sensitivity of RASFs to receptor-mediated apoptosis.

Dose dependence and time course of the immunologic response to administration of standardized cat allergen extract

BACKGROUND

The immunologic response to allergen immunotherapy with 3 serial 5-fold doses of cat extract has been studied after approximately 5 weeks of immunotherapy. The highest dose containing 15 mug of Fel d 1 produced the most consistent and favorable response. It is unknown whether the comparative response on reaching a maintenance dose is maintained with long-term maintenance therapy.

OBJECTIVE

The purpose of this investigation was to evaluate the immunologic responses with these 3 serial doses of cat hair and dander extract at baseline, after reaching the maintenance dose (approximately 5 weeks), and after 1 year of maintenance immunotherapy.

METHODS

Twenty-eight patients with cat allergy randomized in a double-blind study were assigned to one of 4 treatment groups: placebo or cat hair and dander extract containing 0.6 mug of Fel d 1, 3 mug of Fel d 1, and 15 mug of Fel d 1 at maintenance. Studies included skin prick tests and late cutaneous reactions with cat hair and dander extract, titrated nasal challenges with the extract, serum cat allergen-specific IgG4 and IgE measurement, and flow cytometric and ELISA analysis of whole blood and intranasal cytokines (TGF-beta, IL-10, IFN-gamma, IL-4, and IL-5).

RESULTS

Twenty-six subjects completed the study. After both 5 weeks and 1 year, significant and dose-dependent differences were seen with total symptom scores on nasal challenge ( P < .0001), with titrated skin prick testing with cat dander extract at 5 weeks ( P = .014) and 1 year ( P < .0001), and with cat-specific IgG4 measurement at 5 weeks ( P = .004) and 1 year ( P = .003). At 1 year, neither flow cytometry of whole blood nor ELISA evaluation of nasal cytokines demonstrated any significant differences among the treatment groups.

CONCLUSION

The response to titrated nasal allergen challenge, titrated skin prick testing, and allergen-specific IgG4 measurement to cat immunotherapy at 5 weeks is predictive of the response at 1 year.

Comparison of frozen and RNALater solid tissue storage methods for use in RNA expression microarrays

BACKGROUND

Primary human tissues are an invaluable widely used tool for discovery of gene expression patterns which characterize disease states. Tissue processing methods remain unstandardized, leading to unanswered concerns of how to best store collected tissues and maintain reproducibility between laboratories. We subdivided uterine myometrial tissue specimens and stored split aliquots using the most common tissue processing methods (fresh, frozen, RNALater) before comparing quantitative RNA expression profiles on the Affymetrix U133 human expression array. Split samples and inclusion of duplicates within each processing group allowed us to undertake a formal genome-wide analysis comparing the magnitude of result variation contributed by sample source (different patients), processing protocol (fresh vs. frozen vs. 24 or 72 hours RNALater), and random background (duplicates). The dataset was randomly permuted to define a baseline pattern of ANOVA test statistic values against which the observed results could be interpreted.

RESULTS

14,639 of 22,283 genes were expressed in at least one sample. Patient subjects provided the greatest sources of variation in the mixed model ANOVA, with replicates and processing method the least. The magnitude of variation conferred by processing method (24 hours RNALater vs 72 hours RNALater vs. fresh vs frozen) was similar to the variability seen within replicates. Subset analysis of the test statistic according to gene functional class showed that the frequency of "outlier" ANOVA results within each functional class is overall no greater than expected by chance.

CONCLUSIONS

Ambient storage of tissues for 24 or 72 hours in RNALater did not contribute any systematic shift in quantitative RNA expression results relative to the alternatives of fresh or frozen tissue. This nontoxic preservative enables decentralized tissue collection for expression array analysis without a requirement for specialized equipment.

IL-12 Inhibits Thymic Involution by Enhancing IL-7- and IL-2-Induced Thymocyte Proliferation

IL-12 has been reported to affect thymic T cell selection, but the role of IL-12 in thymic involution has not been studied. We found that in vivo, IL-12b knockout (IL-12b(-/-)) mice exhibited accelerated thymic involution compared with wild-type (WT) B6 mice. This is characterized by an increase in thymocytes with the early development stage phenotype of CD25(-)CD44(+)CD4(-)CD8(-) in aged IL-12b(-/-) mice. Histologically, there were accelerated degeneration of thymic extracellular matrix and blood vessels, a significantly decreased thymic cortex/medulla ratio, and increased apoptotic cells in aged IL-12b(-/-) mice compared with WT mice. There was, however, no apparent defect in thymic structure and thymocyte development in young IL-12(-/-) mice. These results suggest the importance of IL-12 in maintaining thymic integrity and function during the aging process. Surprisingly, in WT B6 mice, there was no age-related decrease in the levels of IL-12 produced from thymic dendritic cells. Stimulation of thymocytes with IL-12 alone also did not enhance the thymocyte proliferative response in vitro. IL-12, however, provided a strong synergistic effect to augment the IL-7 or IL-2 induced thymocyte proliferative response, especially in aged WT and IL-12b(-/-) mice. Our data strongly support the role of IL-12 as an enhancement cytokine, which acts through its interactions with other cytokines to maintain thymic T cell function and development during aging.

Novel tumor necrosis factor ?-regulated genes in rheumatoid arthritis

OBJECTIVE

To determine novel genes regulated by tumor necrosis factor alpha (TNFalpha) signaling in primary rheumatoid arthritis synovial fibroblasts (RASFs).

METHODS

Oligonucleotide microarrays were used to measure gene expression levels in 6 independent replicate samples of RASFs. RASFs were transfected for 18 hours with AdIkappaB-dominant negative (AdIkappaB-DN) (n = 3) or with control AdTet expressing the reverse tetracycline trans-activator (n = 3). The cells were stimulated for 3 hours with TNFalpha, and total RNA was prepared. Several novel parametric and nonparametric methods were used to rank genes in terms of the magnitude and significance of intergroup differences. Microarray expression differences were confirmed by real-time quantitative reverse transcription-polymerase chain reaction. Small interfering RNA (siRNA) was used to specifically down-modulate microarray-identified genes to demonstrate their role in the promotion of apoptosis, proliferation, or matrix metalloproteinase (MMP) expression.

RESULTS

Blocking of NF-kappaB by AdIkappaB-DN was associated with a down-modulation of antiapoptosis genes, including BIRC-3, and several novel genes, including GG2-1, a TNFalpha-inducible FLIP-like gene. Other families of genes that were significantly down-regulated by AdIkappaB-DN included cytokines/chemokines (interleukin-1beta [IL-1beta], IL-8, IL-15, and RANTES), adhesion molecule (vascular cell adhesion molecule 1, intercellular adhesion molecule 1), and unique genes that have not previously been reported to be regulated by TNFalpha in RA. Inhibition of the GG2-1 gene using the siRNA technique resulted in significantly enhanced apoptosis, decreased proliferation, and decreased production of MMP-1 in TNFalpha-stimulated RASFs.

CONCLUSION

These studies provide a comprehensive analysis of genes that are differentially regulated by TNFalpha signaling and NF-kappaB nuclear translocation in RASFs and demonstrate methods for confirming the expression and functional significance of such genes.

A double-blind, placebo-controlled immunotherapy dose-response study with standardized cat extract

BACKGROUND

Allergen immunotherapy with doses of cat extract containing approximately 15 microg of the major allergen, Fel d 1, have been proved clinically effective in several double-blind, placebo-controlled studies. However, the maintenance doses used in allergy practice in the United States are often considerably less than this proven dose.

OBJECTIVE

The purpose of this investigation was to determine whether maintenance immunotherapy with cat dander extract containing 0.6 microg or 3.0 microg of Fel d 1 was more effective than placebo and similar in efficacy to treatment with extracts containing 15.0 microg Fel d 1, immunologic parameters being used as the outcome.

METHODS

Twenty-eight cat-allergic patients were randomly entered, 7 in each group, into a double-blind, placebo-controlled comparison of the immunologic response to treatment with placebo or cat dander extract containing 0.6 microg, 3.0 microg, or 15.0 microg of Fel d 1. Maintenance doses were achieved in 8 visits over a period of 4 weeks through use of a cluster regimen; each subject then received 1 weekly maintenance injection before posttreatment measurements were made. The response to immunotherapy was assessed before immunotherapy and after the first weekly maintenance injection. Studies included responses to titrated skin prick tests to cat extract and an unrelated allergen and serum allergen-specific IgE and IgG4. Titrated nasal challenges were performed with cat extract; measurement of mRNA and secreted cytokines (IL-4, IL-5, and IFN-gamma) was done at 6 hours. Serum cytokines (IL-4, IL-5, IFN-gamma) were measured, and flow cytometric analysis of intracellular cytokines (IL-4, IL-5, IFN-gamma) was performed. Cat allergen-stimulated lymphocyte proliferation was performed with measurement of cytokines in the supernatant (IL-4, IL-5, IFN-gamma).

RESULTS

All 28 subjects completed the study. Significant and dose-dependent differences were encountered in the titrated skin prick tests (P =.008), the cat-specific IgG(4) (P =.01), and the reduction in CD4+/IL-4+ PBMCs on flow cytometry (P =.03). There were no significant differences between placebo and cat dander extract containing Fel d 1 0.6 microg. Both extracts containing 3.0 microg and 15.0 microg produced significant decreases in skin prick test sensitivity (P =.02 and P =.002, respectively). The extracts containing 3.0 microg and 15.0 microg produced significant increases in cat-specific IgG4 (P =.01 and P =.006, respectively). Only the 15.0-microg-per-dose extract produced a significant reduction in the percent of CD4+/IL-4+ PBMCs (P =.003).

CONCLUSION

In this double-blind, placebo-controlled study, a maintenance dose of cat dander extract containing 15.0 microg Fel d 1 produced the most consistent immunologic response. A dose of 3.0 microg reduced skin prick test sensitivity and increased cat-specific IgG4 but did not reduce the circulating CD4+/IL-4+ PBMCs, a change that is likely related to the clinically significant response to allergen immunotherapy. These findings suggest that a maintenance dose of 15.0 microg of Fel d 1 is most apt to be clinically effective for allergen immunotherapy.