Isoallergen Analysis of Pectate Lyases (Amb a 1 and Amb a 2) from Commercial Short Ragweed Pollen

Ambrosia artemisiifolia, also known as common or short ragweed, is an invasive annual flowering herbaceous plant that has its origin in North America. Nowadays, ragweed can be found in many areas worldwide. Ragweed pollen is known for its high potential to cause type I allergic reactions in late summer and autumn and represents a major health problem in America and several countries in Europe. Climate change and urbanization, as well as long distance transport capacity, enhance the spread of ragweed pollen. Therefore ragweed is becoming domestic in non-invaded areas which in turn will increase the sensitization rate. So far 11 ragweed allergens have been described and, according to IgE reactivity, Amb a 1 and Amb a 11 seem to be major allergens. Sensitization rates of the other allergens vary between 10 and 50%. Most of the allergens have already been recombinantly produced, but most of them have not been characterized regarding their allergenic activity, therefore no conclusion on the clinical relevance of all the allergens can be made, which is important and necessary for an accurate diagnosis. Pharmacotherapy is the most common treatment for ragweed pollen allergy but fails to impact on the course of allergy. Allergen-specific immunotherapy (AIT) is the only causative and disease-modifying treatment of allergy with long-lasting effects, but currently it is based on the administration of ragweed pollen extract or Amb a 1 only. In order to improve ragweed pollen AIT, new strategies are required with higher efficacy and safety.

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Pollenallergie gegen Ambrosia: Belastungen, Merkmale und Umgang mit einem importierten Allergieverursacher in Europa

Karger Kompass Dermatologie ◽

10.1159/000492639 ◽

2018 ◽

Vol 6 (4) ◽

pp. 206-207

Author(s):

Claudia Traidl-Hoffmann

Keyword(s):

Pollen Allergy ◽

Ambrosia Artemisiifolia ◽

Ragweed Pollen ◽

Pollen Extract ◽

Herbaceous Plant ◽

Type I ◽

Long Distance ◽

Allergen Specific Immunotherapy ◽

Major Health Problem ◽

Amb A 1

Ambrosia artemisiifolia, also known as common or short ragweed, is an invasive annual flowering herbaceous plant that has its origin in North America. Nowadays, ragweed can be found in many areas worldwide. Ragweed pollen is known for its high potential to cause type I allergic reactions in late summer and autumn and represents a major health problem in America and several countries in Europe. Climate change and urbanization, as well as long distance transport capacity, enhance the spread of ragweed pollen. Therefore ragweed is becoming domestic in non-invaded areas which in turn will increase the sensitization rate. So far 11 ragweed allergens have been described and, according to IgE reactivity, Amb a 1 and Amb a 11 seem to be major allergens. Sensitization rates of the other allergens vary between 10 and 50%. Most of the allergens have already been recombinantly produced, but most of them have not been characterized regarding their allergenic activity, therefore no conclusion on the clinical relevance of all the allergens can be made, which is important and necessary for an accurate diagnosis. Pharmacotherapy is the most common treatment for ragweed pollen allergy but fails to impact on the course of allergy. Allergen-specific immunotherapy (AIT) is the only causative and disease-modifying treatment of allergy with long-lasting effects, but currently it is based on the administration of ragweed pollen extract or Amb a 1 only. In order to improve ragweed pollen AIT, new strategies are required with higher efficacy and safety.

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Humoral and Cellular Cross-Reactivity between Amb a 1, the Major Ragweed Pollen Allergen, and Its Mugwort Homolog Art v 6

The Journal of Immunology ◽

10.4049/jimmunol.1102445 ◽

2011 ◽

Vol 188 (3) ◽

pp. 1559-1567 ◽

Cited By ~ 38

Author(s):

Beatrice Jahn-Schmid ◽

Michael Hauser ◽

Nicole Wopfner ◽

Peter Briza ◽

Uwe E. Berger ◽

...

Keyword(s):

Cross Reactivity ◽

Pollen Allergen ◽

Ragweed Pollen ◽

Amb A 1

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Randomized controlled trial of ragweed sublingual immunotherapy tablet in the subpopulation of Canadian children and adolescents with allergic rhinoconjunctivitis

Allergy Asthma & Clinical Immunology ◽

10.1186/s13223-021-00626-2 ◽

2021 ◽

Vol 17 (1) ◽

Author(s):

Anne K. Ellis ◽

Remi Gagnon ◽

David I. Bernstein ◽

Hendrik Nolte

Keyword(s):

Children And Adolescents ◽

Sublingual Immunotherapy ◽

Controlled Trial ◽

Mean Difference ◽

Ragweed Pollen ◽

Total Study Population ◽

Amb A 1 ◽

Secondary Endpoints ◽

Study Population ◽

Post Hoc

Abstract Background Post hoc analyses of randomized placebo-controlled trials have demonstrated efficacy and tolerability of the ragweed sublingual immunotherapy (SLIT)-tablet in Canadian adults with ragweed pollen-induced allergic rhinitis/conjunctivitis (AR/C). This post hoc analysis evaluated the efficacy and tolerability of the ragweed SLIT-tablet in the subpopulation of Canadian children and adolescents with AR/C in a previously described randomized, double-blind, placebo-controlled trial. Methods The trial (NCT02478398) was conducted in North American and European children/adolescents ages 5–17 years with ragweed pollen-induced AR/C with or without asthma (FEV1 ≥ 80% predicted). Participants were randomized to daily ragweed SLIT-tablet (12 Amb a 1-U) or placebo for up to 28 weeks. The primary endpoint was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during peak ragweed pollen season (RPS). Key secondary endpoints were TCS during the entire RPS, and DSS and DMS during peak RPS. Post hoc analyses of the primary and key secondary endpoints were conducted in the subpopulation of Canadian participants. Results Of the 1025 randomized participants, 246 (SLIT-tablet, n = 116; placebo, n = 130) were in the Canadian subpopulation. In the total study population, relative TCS (95% CI) improvement with ragweed SLIT-tablet versus placebo was − 38.3% (− 46.0%, − 29.7%; least square [LS] mean difference, − 2.73; P < 0.001) during peak RPS. In the Canadian subpopulation, relative TCS improvements with ragweed SLIT-tablet versus placebo were − 40.8% (− 54.5%, − 20.2%; LS mean difference, − 1.59; P = 0.001) during peak RPS and − 36.6% (− 50.2%, − 16.5%; LS mean difference, − 1.36; P = 0.002) during the entire RPS. DSS and DMS during peak RPS in the Canadian subpopulation improved with SLIT-tablet versus placebo by − 30.6% (− 45.2%, − 7.7%; LS mean difference, − 0.94; P = 0.010) and − 77.2% (− 97.5%, − 44.2%; LS mean difference, − 0.66; P = 0.003), respectively. No events of anaphylaxis, airway compromise, intramuscular epinephrine administration, eosinophilic esophagitis, or severe treatment-related systemic allergic reactions were reported in the overall population or Canadian subpopulation. Conclusion Efficacy and safety of the ragweed SLIT-tablet in Canadian children/adolescents with ragweed pollen-induced AR/C was consistent with the total study population. The ragweed SLIT-tablet resulted in clinically meaningful improvement in symptoms, decreased symptom-relieving medication use, and was well tolerated in Canadian children/adolescents. Trial registration: clinicaltrials.gov, NCT02478398. Registered June 23, 2015, https://clinicaltrials.gov/ct2/show/NCT02478398?term=NCT02478398&draw=2&rank=1

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Ragweed Pollen Concentration Predict Seasonal Oculo-rhinitis and Asthma Severity in Subjects Allergic to Ragweed.

10.21203/rs.3.rs-1153042/v1 ◽

2021 ◽

Author(s):

Maira Bonini ◽

GIANNA MONTI ◽

MATTEO PELAGATTI ◽

VALENTINA CERIOTTI ◽

ELISABETTA RE ◽

...

Keyword(s):

Symptom Severity ◽

Asthma Severity ◽

Temporal Variations ◽

Ragweed Pollen ◽

P Value ◽

Pollen Concentration ◽

Distributed Lag ◽

Autoregressive Distributed Lag ◽

Distributed Lag Models ◽

Amb A 1

Abstract Objectives: 1. To investigate the correlation between ragweed pollen concentration and conjunctival, nasal and asthma symptoms severity in patients allergic to ragweed using ambient pollen exposure in the Milan area during the 2014 ragweed season; 2. to calculate the pollen / symptom thresholds and 3. to assess the effectiveness of ragweed Allergen Immuno Therapy (AIT).Patients: 66 subjects allergic to Amb a 1 enrolled in the study and were divided into two cohorts: AIT treated (24) and non-AIT treated (42).Measurements: Pollen counts and daily symptom/medication patient diaries. Autoregressive Distributed Lag Models were used to develop predictive models of daily symptoms and to evaluate the short-term effects of temporal variations in pollen concentration on the onset of symptoms. Results: We found significant correlations between ragweed pollen load and the intensity of symptoms, for all three symptom categories respectively, both in non-AIT treated (𝛕= 0.341, 0.352, 0.721 and ρ = 0.48, 0.432, 0.881, p-value < 0.001) and in AIT treated patients (O= 0.46, 0.610, 0.66 and ρ = 0.692, 0.805, 0.824; p-value < 0.001). In both cohorts, we observed a positive correlation between the number of symptoms reported and drug use. Mean symptom levels were significantly greater in non-AIT treated than in AIT treated patients (p < 0.001) for all symptom categories. Pollen concentration thresholds for three symptom severity levels were calculated.Conclusions: Ragweed pollen concentration is predictive of symptom severity in ragweed (Amb a 1) allergy patients. AIT treated patients had significantly reduced mean symptom levels compared to non-AIT patients.

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Genomic insights from Monoglobus pectinilyticus: a pectin-degrading specialist bacterium in the human colon

10.26686/wgtn.12585650.v1 ◽

2020 ◽

Author(s):

CC Kim ◽

GR Healey ◽

WJ Kelly ◽

ML Patchett ◽

Z Jordens ◽

...

Keyword(s):

Cell Surface ◽

Degradation Products ◽

Model Organism ◽

Human Colon ◽

Surface Proteins ◽

Human Gut ◽

Pectate Lyases ◽

Unusual Distribution ◽

Degrading Bacteria ◽

Acetyl Esterases

© 2019, International Society for Microbial Ecology. Pectin is abundant in modern day diets, as it comprises the middle lamellae and one-third of the dry carbohydrate weight of fruit and vegetable cell walls. Currently there is no specialized model organism for studying pectin fermentation in the human colon, as our collective understanding is informed by versatile glycan-degrading bacteria rather than by specialist pectin degraders. Here we show that the genome of Monoglobus pectinilyticus possesses a highly specialized glycobiome for pectin degradation, unique amongst Firmicutes known to be in the human gut. Its genome encodes a simple set of metabolic pathways relevant to pectin sugar utilization, and its predicted glycobiome comprises an unusual distribution of carbohydrate-active enzymes (CAZymes) with numerous extracellular methyl/acetyl esterases and pectate lyases. We predict the M. pectinilyticus degradative process is facilitated by cell-surface S-layer homology (SLH) domain-containing proteins, which proteomics analysis shows are differentially expressed in response to pectin. Some of these abundant cell surface proteins of M. pectinilyticus share unique modular organizations rarely observed in human gut bacteria, featuring pectin-specific CAZyme domains and the cell wall-anchoring SLH motifs. We observed M. pectinilyticus degrades various pectins, RG-I, and galactan to produce polysaccharide degradation products (PDPs) which are presumably shared with other inhabitants of the human gut microbiome (HGM). This strain occupies a new ecological niche for a primary degrader specialized in foraging a habitually consumed plant glycan, thereby enriching our understanding of the diverse community profile of the HGM.

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