Efficacy and safety of TOBI Podhaler in Pseudomonas aeruginosa-infected bronchiectasis patients: iBEST study.

The study aimed to determine the efficacy of a safe and well-tolerated dose and regimen of tobramycin inhalation powder (TIP) on Pseudomonas aeruginosa sputum density in patients with bronchiectasis.This is a phase II, double-blind, randomised study in bronchiectasis patients aged ≥18 years with chronic P. aeruginosa infection. Patients were randomised 1:1:1 to either cohort A: three capsules of TIP once daily (84 mg); cohort B: five capsules once daily (140 mg) or cohort C: four capsules twice daily (224 mg). Within each cohort, patients were further randomised 2:2:1 either to TIP continuously, TIP cyclically (alternating 28 days of TIP and placebo) or placebo for 16 weeks, respectively and were followed up for 8 weeks.Overall, 107 patients were randomised to cohorts A (n=34), B (n=36) and C (n=37). All three TIP doses significantly reduced the P. aeruginosa sputum density from baseline to day 29 versus placebo in a dose-dependent manner (p≤0.0001, each). A smaller proportion of patients in the continuous-TIP (34.1%) and cyclical-TIP (35.7%) groups experienced pulmonary exacerbations versus placebo (47.6%) and also required fewer anti-pseudomonal antibiotics (38.6% on continuous TIP and 42.9% on cyclical TIP) versus placebo (57.1%) although not statistically significant. Pulmonary exacerbation of bronchiectasis was the most frequent (37.4%) adverse event. Overall, TIP was well tolerated, however, 23.4% of the patients discontinued the study drug due to adverse events.Continuous- and cyclical-TIP regimens with all three doses were safe and effective in reducing the P. aeruginosa sputum density in patients with bronchiectasis and chronic P. aeruginosa infection.

Multiple breath washout in bronchiectasis clinical trials: is it feasible?

BACKGROUND: Evaluation of multiple breath washout (MBW) set-up including staff training, certification and central "over-reading" for data quality control is essential to determine the feasibility of MBW in future bronchiectasis studies. AIMS: To assess the outcomes of a MBW training, certification and central over-reading programme. METHODS: MBW training and certification was conducted in European sites collecting lung clearance index (LCI) data in the BronchUK Clinimetrics and/or i-BEST-1 studies. The blended training programme included the use of an eLearning tool and a 1-day face-to-face session. Sites submitted MBW data to trained central over-readers who determined validity and quality. RESULTS: Thirteen training days were delivered to 56 participants from 22 sites. Of 22 sites, 18 (82%) were MBW naïve. Participant knowledge and confidence increased significantly (p<0.001). By the end of the study recruitment, 15 of 22 sites (68%) had completed certification with a mean (range) time since training of 6.2 (3-14) months. In the BronchUK Clinimetrics study, 468 of 589 (79%) tests met the quality criteria following central over-reading, compared with 137 of 236 (58%) tests in the i-BEST-1 study. CONCLUSIONS: LCI is feasible in a bronchiectasis multicentre clinical trial setting; however, consideration of site experience in terms of training as well as assessment of skill drift and the need for re-training may be important to reduce time to certification and optimise data quality. Longer times to certification, a higher percentage of naïve sites and patients with worse lung function may have contributed to the lower success rate in the i-BEST-1 study.

Efficacy and safety of tobramycin inhalation powder in bronchiectasis patients with P. aeruginosa infection: Design of a dose-finding study (iBEST-1).

In patients with bronchiectasis (BE), infection with Pseudomonas aeruginosa (Pa) results in disease progression, frequent pulmonary exacerbations and lung function decline. However, at present, no inhaled antibiotics have been approved for the treatment of these patients. Tobramycin inhalation powder (TIP), approved for treatment of Pa infection in cystic fibrosis, could be a promising candidate. We aimed to assess effective and well-tolerated doses and regimens of TIP in BE patients with Pa infection. In this phase II, double-blind, placebo-controlled, randomised study, three different daily doses of TIP are administered either as continuous or cyclical regimens. The study protocol comprises 7-28 days of screening, 112 days of double-blind treatment and 56 days of follow-up. The plan was to enrol 180 patients (aged ≥18 years) with BE, documented Pa infection and a history of exacerbations. The primary outcome is change in sputum Pa density from baseline. Key secondary outcomes include number of pulmonary exacerbations, use of antipseudomonal antibiotics, serum and sputum tobramycin concentrations, quality of life and safety. Exploratory endpoints include lung clearance index, sputum inflammatory markers and microbiome analysis. As of October 2018, 107/180 patients were enrolled at 34 sites (six countries) following which recruitment was closed for administrative reasons unrelated to safety findings. Despite a reduced sample size from initially planned enrolment, the unique design may inform the benefit-risk profile of TIP in BE patients with chronic Pa infection. Moreover, several novel and exploratory endpoints (lung clearance index, inflammatory biomarkers, lung microbiome), will contribute to the advancement of research in this area.

Eradication of early P. aeruginosa infection in children <7 years of age with cystic fibrosis: The early study.

OBJECTIVE: Antibiotic eradication treatment is the standard-of-care for cystic fibrosis (CF) patients with early Pseudomonas aeruginosa (Pa)-infection; however, evidence from placebo-controlled trials is limited. METHODS: This double-blind, placebo-controlled trial randomised CF patients <7 years (N = 51) with early Pa-infection to tobramycin inhalation solution (TOBI 300 mg) or placebo (twice daily) for 28 days with an optional cross-over on Day 35. Primary endpoint was proportion of patients having throat swabs/sputum free of Pa on Day 29. RESULTS: On Day 29, 84.6% patients in the TOBI versus 24.0% in the placebo group were Pa-free (p < 0.001). At the end of the cross-over period, 76.0% patients receiving TOBI in the initial 28 days were Pa-free compared to 47.8% receiving placebo initially. Adverse events were consistent with the TOBI safety profile with no differences between TOBI and placebo. CONCLUSION: TOBI was effective in eradicating early Pa-infection with a favourable safety profile in young CF patients. TRIAL REGISTRATION NUMBER: NCT01082367.

Long-term safety of tobramycin inhalation powder in patients with cystic fibrosis: phase IV (ETOILES) study.

OBJECTIVE: Long-term treatment with inhaled antibiotics is recommended for chronic Pseudomonas aeruginosa (Pa) infection in cystic fibrosis (CF) patients. The ETOILES study (Clinicaltrials.gov identifier: NCT01519661) evaluated the safety of tobramycin inhalation powder (TIP) for 1 year. RESEARCH DESIGN AND METHODS: This single-arm, open-label, multicenter, phase IV trial, enrolled CF patients aged ≥6 years, with baseline FEV1 ≥25%-≤75% predicted and Pa infection, and assessed the safety of TIP over six cycles in terms of the incidence of treatment-emergent adverse events (AEs) and serious AEs (SAEs). Secondary endpoints included presence of airway reactivity, relative change in FEV1% predicted, and change in sputum Pa density (log10 colony forming units/g sputum). RESULTS: A total of 157 patients were enrolled, and 96 patients (61.1%) completed the study. The most commonly reported AE was infective pulmonary exacerbation of CF (55.4%). Cough was reported as an AE in 23.6% of patients; a majority were mild or moderate and two were severe (1.3%). SAEs were reported by 31.2% of patients. No deaths were reported during the study. There were no clinically meaningful changes reported in airway reactivity. Most frequently reported post-inhalation event was cough at all time points; however, it was of short duration (<4 minutes) and decreased over the course of the study, possibly due to patients becoming more experienced with the administration of TIP. The post-inhalation events resolved without intervention in most cases. FEV1% predicted remained stable from Cycles 1 to 4 and tended to decrease thereafter, although it was not statistically significant (change from baseline to study end mean [SD] = -1.9% [14.55]; P = 0.199). CONCLUSIONS: This was one of the largest studies with long-term TIP exposure. The majority of patients enrolled were adults with more advanced CF lung disease than those in previous TIP studies. No new emerging safety signals were seen and efficacy was sustained during the year.

One-year safety and efficacy of tobramycin powder for inhalation in patients with cystic fibrosis.

UNLABELLED: This is an integrated analysis of data from patients with cystic fibrosis (CF) aged 6-21 years who were treated with up to seven cycles of tobramycin powder for inhalation (TIP(TM) ) over a period of at least 1 year. Safety and key efficacy endpoints were analyzed. RESULTS: The improvement in lung function and decrease in sputum P. aeruginosa (Pa) density from baseline were sustained over the 1-year treatment period. The number of adverse events (AEs) was low and did not increase with additional cycles of TIP treatment. Some increase in tobramycin minimum inhibitory concentration (MIC) was observed, but there was no significant increase in emergence of resistant strains based on the parenteral breakpoint for tobramycin. CONCLUSION: Efficacy of TIP was maintained for up to seven cycles. Long-term treatment with TIP was generally safe and well tolerated with no increase in AEs.

The road for survival improvement of cystic fibrosis patients in Arab countries.

Cystic fibrosis (CF) is a lethal, monogenic disorder that affects multiple organ systems of the body. The incidence has been described before in the Middle East to be 1 in 2000 to 1 in 5800 live births, and the median survival was estimated to be from 10 to 20 years of age. The present article attempts to revisit various facets of this disease and specifically highlights the most important lacunae that exist in treating CF. In addition, it also tries to emphasize the steps in improving the median survival of patients with CF, in these countries.

Tobramycin inhalation powder in cystic fibrosis patients: response by age group.

BACKGROUND: Tobramycin powder for inhalation (TIP) is a drug-device combination designed to reduce treatment time and improve ease of use compared with tobramycin inhalation solution (TIS) in cystic fibrosis (CF) patients. However, the ability of patients to use dry powder inhalers, and the efficacy of the treatments, may vary by age. METHODS: The "Establish a New Gold Standard for Efficacy and Safety With Tobramycin in Cystic Fibrosis" (EAGER) trial was a randomized, 24-week, multicenter, open-label, parallel-group study designed to evaluate the safety of TIP versus TIS in 553 subjects, ages ≥ 6 years, with CF and P. aeruginosa infection. The main efficacy end point was percent-of-predicted FEV1 at week 20 (end of third cycle of treatment). A post hoc analysis was undertaken in 517 subjects who took ≥ 1 dose of study medication, to evaluate the relative efficacy and safety of TIP and TIS by age group: ≥ 6 to < 13 y (children, n = 46); ≥ 13 to < 20 y (adolescents, n = 114); and ≥ 20 y (adults, n = 357). RESULTS: Improvements in percent-of-predicted FEV1 from baseline to end of cycle 3 were greatest in the children for both TIP and TIS. The treatment differences (TIP - TIS) were 4.7% (85% CI -1.2 to 10.6), 3.7% (85% CI -0.1 to 7.5), and -0.8% (85% CI -3.1 to 1.5) in children, adolescents, and adults, respectively. Sputum P. aeruginosa density decreased from baseline with both treatments, with comparable treatment differences across the age groups after 3 cycles: children -0.93 (85% CI -2.4 to 0.5), adolescents -0.17 (85% CI -1.2 to 0.8), and adults -0.89 (85% CI -1.3 to -0.4). Overall, subject satisfaction scores were greater in all subjects with TIP, irrespective of age group. With the exception of cough and dysphonia, the safety profile of TIP was comparable to TIS, irrespective of age. CONCLUSIONS: TIP is comparable to TIS in efficacy outcomes and safety profile but had greater patient satisfaction in all the age groups.

Tobramycin inhalation powder manufactured by improved process in cystic fibrosis: the randomized EDIT trial.

BACKGROUND: Tobramycin inhalation powder (TIP) was reported to be effective in two Phase III studies in patients with cystic fibrosis (CF) chronically infected with Pseudomonas aeruginosa (Pa). The EDIT study evaluated the efficacy and safety of TIP manufactured by an improved process in CF subjects aged 6-21 years. METHODS: CF patients with a forced expiratory volume in 1 second (FEV1) ≥25% to ≤80% predicted, positive Pa cultures and inhaled antipseudomonal therapy naïve (or at least for past 4 months) were enrolled into this double-blind, multicenter trial. Patients were randomized to receive TIP or placebo (1:1) twice daily for one treatment cycle (28.5 days on drug, 28 days off drug). The primary endpoint was relative change in FEV1 percentage predicted from baseline to day 29. A pre-specified sensitivity analysis evaluated absolute change in FEV1% predicted. Other endpoints included Pa sputum density and safety. RESULTS: A total of 62 patients out of a target of 100 (mean age 12.9 years, baseline FEV1 59.2% predicted, Pa sputum density 7.4 log10 colony forming units [CFU] per gram) were randomized. Mean treatment differences (TIP - placebo) were 5.9% (p=0.148) and 4.4% (p<0.05) for relative and absolute change in FEV1% predicted respectively. TIP significantly reduced Pa sputum density by -1.2 log10 CFU (p=0.002). Treatment with TIP was well tolerated. CONCLUSIONS: Relative change in FEV1% predicted with TIP treatment was in the expected range based on the literature, but did not reach statistical significance versus placebo. Placebo control and use of treatment naïve patients led to significant recruitment challenges and an underpowered study with consequent impact on the generated data. However, significant improvements in other outcomes including absolute change in FEV1% predicted and reduction in Pa sputum density indicate that TIP is efficacious and well tolerated in CF patients. CLINICALTRIALS.GOV IDENTIFIER: NCT00918957.

A network meta-analysis of the efficacy of inhaled antibiotics for chronic Pseudomonas infections in cystic fibrosis.

BACKGROUND: Various inhaled antibiotics are currently used for treating chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) patients, however their relative efficacies are unclear. We compared the efficacy of the inhaled antibiotics tobramycin (TIP, TIS-T, TIS-B), colistimethate sodium (colistin) and aztreonam lysine for inhalation (AZLI) based on data from randomised controlled trials. METHODS: In the base case, efficacies of antibiotics were compared using a network meta-analysis of seven trials including change from baseline in forced expiratory volume in 1 second (FEV(1)) % predicted, P. aeruginosa sputum density and acute exacerbations. RESULTS: The tobramycin preparations, AZLI and colistin, showed comparable improvements in efficacy in terms of FEV1% predicted at 4 weeks; the difference in % change from baseline (95%CrI) for TIP was compared to TIS-T (-0.55, -3.5;2.4), TIS-B (-0.64, -7.1;5.7), AZLI (3.64, -1.0;8.3) and colistin (5.77, -1.2;12.8). CONCLUSION: We conclude that all studied antibiotics have comparable efficacies for the treatment of chronic P. aeruginosa lung infection in CF.

Safety, efficacy and convenience of tobramycin inhalation powder in cystic fibrosis patients: The EAGER trial.

BACKGROUND: A light-porous-particle, dry-powder formulation of tobramycin was developed, using PulmoSphere® technology, to improve airway delivery efficiency, substantially reduce delivery time, and improve patient convenience and satisfaction. We evaluated the safety, efficacy and convenience of tobramycin inhalation powder (TIP™) versus tobramycin inhalation solution (TIS, TOBI®) for treating Pseudomonas aeruginosa infection in cystic fibrosis (CF) patients aged ≥6 years. METHODS: In this open-label study, 553 patients were randomized 3:2 to TIP (total 112mg tobramycin) via the Novartis T-326 Inhaler or TIS 300mg/5mL via PARI LC® PLUS nebulizer twice daily for three treatment cycles (28 days on-drug, 28 days off-drug). Safety, efficacy, and treatment satisfaction outcomes were evaluated. RESULTS: TIP was generally well-tolerated; adverse events were similar in both groups. The rate of cough suspected to be study drug related was higher in TIP-treated patients (TIP: 25.3%; TIS: 4.3%), as was the overall discontinuation rate (TIP: 26.9%; TIS: 18.2%). Increases in FEV(1)% predicted from baseline to Day 28 of Cycle 3 were similar between groups; the mean reduction in sputum P. aeruginosa density (log(10) CFU/g) on Day 28 of Cycle 3 was also comparable between groups. Administration time was significantly less for TIP (mean: 5.6 versus 19.7min, p<0.0001). Treatment satisfaction was significantly higher for TIP for effectiveness, convenience, and global satisfaction. CONCLUSIONS: TIP has a safety and efficacy profile comparable with TIS, and offers a far more convenient treatment option for pseudomonas lung infection in CF.

Tobramycin inhalation powder for P. aeruginosa infection in cystic fibrosis: the EVOLVE trial.

Tobramycin inhalation solution is used to treat chronic Pseudomonas aeruginosa lung infection in cystic fibrosis (CF) patients. We evaluated the efficacy and safety of a novel, light-porous particle, dry-powder formulation of tobramycin, which was developed to improve delivery efficiency to the airways and substantially reduce the delivery time. In this randomized, double-blind study, patients with CF (age 6-21 years) received tobramycin inhalation powder (112 mg tobramycin) twice daily (n = 46) or placebo (n = 49) via the T-326 Inhaler for one cycle, followed by two open-label cycles (all patients). Cycles were 28 days on, 28 days off treatment. The primary endpoint was change in forced expiratory volume in 1 sec (FEV1) % predicted from baseline to Day 28 of Cycle 1. The study was terminated early based on positive results in the interim analysis. Tobramycin inhalation powder significantly improved FEV1 % predicted versus placebo at Day 28 (difference 13.3, 95% CI: 5.31-21.28; P = 0.0016). Similar changes in FEV1 were seen in patients switching from placebo to tobramycin inhalation powder in Cycle 2; improvements were maintained over time. Tobramycin inhalation powder also reduced sputum P. aeruginosa density, respiratory-related hospitalization and antipseudomonal antibiotic use versus placebo. The most common adverse event was cough; the frequency of cough was higher in patients receiving placebo (26.5%) versus tobramycin inhalation powder (13.0%) in Cycle 1. Tobramycin inhalation powder was not associated with ototoxicity or nephrotoxicity. Administration time was between 4 and 6 min. In conclusion, tobramycin inhalation powder was effective and well tolerated in CF patients, and may offer an important treatment option to decrease the treatment burden of CF pseudomonas lung infections.

Treatment of early Pseudomonas aeruginosa infection in patients with cystic fibrosis: the ELITE trial.

RATIONALE: Antibiotic therapy for early Pseudomonas aeruginosa infection in patients with cystic fibrosis (CF) is effective, but the optimal therapeutic regimen and duration for early treatment remains unclear. The EarLy Inhaled Tobramycin for Eradication (ELITE) study was designed to assess the efficacy and safety of two regimens (28 and 56 days) of tobramycin inhalation solution (TIS) 300 mg/5 ml twice daily for the treatment of early onset P aeruginosa infection in patients with CF. METHODS: In this open-label randomised multicentre study, patients with CF (aged > or = 6 months) with early P aeruginosa infection were treated for 28 days with TIS twice daily administered by the PARI LC PLUS (PARI GmbH, Starnberg, Germany) jet nebuliser. After 28 days, patients were randomised 1:1 to either stop TIS (n=45) or to receive a further 28 days of TIS (n=43). The primary endpoint was the median time to recurrence of P aeruginosa (any strain). Secondary endpoints included the proportion of patients free of P aeruginosa infection 1 month after cessation of therapy and safety assessments. RESULTS: The median time to recurrence of P aeruginosa (any strain) was similar between the two groups. In total, 93% and 92% of the patients were free of P aeruginosa infection 1 month after the end of treatment and 66% and 69% remained free at the final visit in the 28-day and 56-day groups, respectively. TIS was well tolerated. CONCLUSIONS: Treatment with TIS for 28 days is an effective and well tolerated therapy for early P aeruginosa infection in patients with CF. TRIAL REGISTRATION NUMBER: NCT00391976.

Aminoglycoside therapy against Pseudomonas aeruginosa in cystic fibrosis: a review.

In patients with cystic fibrosis (CF), respiratory infections with the opportunistic bacterial pathogen Pseudomonas aeruginosa have a major impact on morbidity and mortality. Aminoglycosides, especially tobramycin, have been used successfully to combat these infections. Aminoglycoside penetration of bronchial secretions is poor when the antibiotic is administered intravenously. Nebulization allows direct delivery of the drug to the sites of infection within the airways, while avoiding systemic exposure. Published clinical data show that inhaled tobramycin reduces the bacterial load, improves lung function and reduces the number of hospital admissions. Inhaled tobramycin has been used successfully to eradicate P. aeruginosa in patients with early infection. Maintaining clinical benefits requires chronic tobramycin treatment, and the concept of chronic intermittent inhaled treatment (typically, alternating drug and drug-free periods of 28 days) was introduced to minimize the emergence of aminoglycoside resistant P. aeruginosa strains. Other therapeutic advances include the development of different tobramycin formulations and nebulizers that reduce delivery time without compromising efficacy. An optimal treatment regimen for patients with CF with early or intermittent P. aeruginosa infections remains a high priority to maintain long-term lung health.

Peptide-binding assays and HLA II transgenic Abeta degrees mice are consistent and complementary tools for identifying HLA II-restricted peptides.

The identification of MHC class II-restricted peptides has become a priority for the development of peptide-based prophylactic and therapeutic vaccines. The aim of this study was to assess the correlations between peptide-binding assays on purified HLA II molecules and immunization of human HLA II transgenic mice deficient in murine class II molecules (Abeta degrees ). We used as models two MHC class II-restricted peptides, one derived from the HIV Nef regulatory protein (Nef (56-68)) and the other from the Schistosoma mansoni 28-kDa glutathione-S-transferase (Sm28GST (190-211)). High correlations were found between the two approaches, which showed that the Nef (56-68) and Sm28GST (190-211) peptides may represent promiscuous ligands for HLA-DQ and for HLA-DR molecules, respectively. We suggest a rational method based on the combination of peptide-binding assays and HLA II transgenic mice experiments as consistent and complementary tools for selecting T helper epitopes.

Effect of glycoamphiphiles on the solubilization and dendritic cell uptake of a lipopeptide: a preliminary study.

The selective delivery of antigens to professional antigen-presenting cells represents a promising approach to improve vaccine efficacy. Addition of a glycoamphiphile to a lipopeptide, whose interest for vaccination is now well-established, greatly favors its solubilization in aqueous solutions through the formation of mixed vesicles. Flow cytometry experiments indicate that this formulation does not diminish the uptake of the lipopeptide by the dendritic cells (DCs). These preliminary results suggest a possible straightforward, noncovalent targeting of cocktail-lipopeptide vaccines to the DCs via carbohydrate receptor-mediated endocytosis.

Comparison of HLA-DR1-restricted T cell response induced in HLA-DR1 transgenic mice deficient for murine MHC class II and HLA-DR1 transgenic mice expressing endogenous murine MHC class II molecules.

Transgenic mice expressing human HLA class II molecules provide a useful model for identifying HLA-restricted CD4+ epitopes. However, the influence of endogenous murine H-2-restricted T cell responses on HLA-restricted responses is not known. In the present study, we show that HLA-DR1 transgenic mice deficient for H-2 class II expression (HLA-DR1+/+/IAbeta0/0) exhibit an equivalent expression level of the transgene HLA-DR1 and a similar diversity in the TCR repertoire, but a slightly different number of CD4+ peripheral T cells, when compared to HLA-DR1 transgenic mice in which H-2 class II molecules were retained (HLA-DR1+/+/IAbeta+/+). More importantly, a strong antigen-specific HLA-DR1-restricted response was observed in nearly all HLA-DR1+/+/IAbeta0/0 mice immunized with HBV envelope protein (HBs) or capsid protein (HBc), whereas weak HBs- or HBc-specific HLA-DR1-restricted responses were detected in half of the immunized HLA-DR1+/+/IAbeta+/+ mice. Conversely, strong HBs- or HBc-specific H-2-restricted T cell responses were detected in HLA-DR1+/+/IAbeta+/+ mice but not in HLA-DR1+/+/IAbeta0/0 mice. Our results indicate that the coexpression of endogenous H-2 class II molecules reduces the intensity of HLA-DR1-restricted antigen-specific responses in transgenic mice, by favoring murine over human MHC recognition and education. Thus, HLA-DR1+/+/IAbeta0/0 mice represent a better model for identifying and characterizing HLA-DR1-restricted epitopes relevant for human disease.

Grafting of synthetic mannose receptor-ligands onto onion vectors for human dendritic cells targeting.

A practical preparation of onion vesicles targeted to dendritic cells involves the grafting of mannose-mimetic clusters, bearing a hydrazino group, onto the surface of onion vesicles containing an aldehyde functionalized lipid.

Involvement of the mannose receptor in the uptake of Der p 1, a major mite allergen, by human dendritic cells.

BACKGROUND: Immature dendritic cells (DCs) take up antigens in peripheral tissues and, after antigen processing, mature to efficiently stimulate T cells in secondary lymph nodes. In allergic airway diseases DCs have been shown to be involved in the induction and maintenance of a T(H)2-type profile. OBJECTIVE: The present study was undertaken to determine pathways of Der p 1 (a house dust mite allergen) uptake by human DCs and to compare Der p 1 uptake between DCs from patients with house dust mite allergy and DCs from healthy donors. METHODS: Monocyte-derived DCs (MD-DCs) were obtained from patients with house dust mite allergy (n = 13) and healthy donors (n = 11). Der p 1 was labeled with rhodamine. Der p 1 uptake by MD-DCs was analyzed by means of flow cytometry and confocal microscopy. RESULTS: Rhodamine- labeled Der p 1 was demonstrated to be taken up by MD-DCs in a dose-, time-, and temperature- dependent manner. The involvement of the mannose receptor (MR) in the Der p 1 uptake was demonstrated by using (1) inhibitors of the MR- mediated endocytosis (mannan and blocking anti-MR mAb), which inhibited the Der p 1 uptake from 40 % to 50 %, and (2) confocal microscopy showing the colocalization of rhodamine-labeled Der p 1 with FITC-dextran. Interestingly, compared with DCs from healthy donors, DCs from allergic patients expressed more MR and were more efficient in Der p 1 uptake. CONCLUSION: These results suggest that the MR could play a key role in the Der p 1 allergen uptake by DCs and in the pathogenesis of allergic diseases in dust mite -sensitive patients.

Synthesis and mannose receptor-mediated uptake of clustered glycomimetics by human dendritic cells: effect of charge.

Effect of charge and shape of multivalent lysine-based cluster glycomimetics on their mannose receptor-mediated uptake by human dendritic cells has been evaluated: The capture is strongly affected by the shape of the ligands. The effect of charge is less pronounced although positive charges on the ligands seem to favor non-specific endocytosis capture.