Allergens - Science topic

Genotoxicity assessment, Toxins, Particulate matters, allergens, heat waves, Climate change, human health, chromosome aberration

Hello,

does somebody know an in vitro test which can predict if a treatment abolishes the allergenic potential of a substance. E.g. if pollen are treated with a treatment x, is it possible to test in vitro if the treated pollen is still an allergen to people suffering from that pollen allergy?

Thanks a lot in advance for your suggestions and thoughts

Guido

I am working with an allergen and i am working using PCR, the result that offers the kit is copies DNA, although i need to give a result in mg/kg. Is any possible way?

Thank you in advance,

Kiriakos

Hi,

Well, epitopes that bind with MHC are considered antigenic. my question is what is the need to predict antigenicity or allergenicity? I mean if we have predicted epitope data and we know that an epitope with binding affinity <50nm is considered a strong binder and <500nm a weak binder then all we have to do is to filter out all those non-binding data using these cut-offs.

I am looking for different opinions please help

Thank you

I am trying to measure reactive oxygen species in a solution of leukocytes exposed to different antigens such as vaccine excipients or allergens. What do you suggest?

I am developing mites to prepare allergenic extract, so i would like to know, how the companies and labs. separate mites from media culture, what methodology is used in this step of the process?

TKS

Everton.

What could be the possible allergen in case of Allergic stomatitis to green tea?

β-Lactam antibiotics: the most common allergens among drugs.

doi: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4692812/

I was thinking that it could be due to the fact that beta-lactam antibiotics as Penicillins & Cephalosporins, are used in relatively higher amounts (e.g. 500 - 1000mg)

Also, maybe the mode of administration should play a role: other drugs used in the same weight range are given only orally (Vs. antibiotics which are often given parenterally)??

And then this could be all on the chemical identity of these drugs...

What is the current status about regulation of trace ammounts of allergenic food materials in food which have not been intentionally added ? I am interested especially in European regulation, but also about the rest of the world.

I will write down, what my impression is from browsing the internet so far, but, if I missed something, please, help me by letting me know:

My impressions:

1. So far in the European Union, but also in other countries, the food manufacturer is obligated to declare only those food ingredients, which were added knowingly and intentionally. Accidental trace contamination is not regulated yet.

2. There are two initiatives about voluntary labeling, which consider the amount of allergen:

a) Voluntary Incidental Trace Allergen Labelling (VITAL)- for which countries does it apply ??? It recommends to list traces of allergens, if they are at or above the dose of ED01 - the dose which creates the response in 1% of allergic people

b) WHO/FAO - they recommends to list traces of allergens, if they are at or above the dose of ED05 - the dose which creates the response in 5% of allergic people

3. People expect there will be EU regulation created about trace allergen contaminants at 2024 (correct ???). Do we expect it to be based on VITAL or on WHO/FAO ?

Please, correct me or respond to the sub-questions if you know the answer.

Hi dear friends,

The attached image is belong to a 12-year-old boy, who developed such complications on the surface of his body (two legs, back, face and abdomen). It was occurred about 3 days after the injection of Sinofarm vaccine, and is accompanied by severe itching. The boy is currently in hospital. The COVID-19 test was negative in this child, but it seems to have been a side effect of the vaccine.

Dear specialists, if you have experience or a solution for this treatment, I would be grateful for your valued comment.

Thanks in anticipated

Kindly regards

Jalil

To systematically investigate indoor pollen levels and pollen components, one can draw upon the wealth of experience in the field of pollen monitoring in outdoor air. When focusing on indoor air, the following issues need to be systematically addressed:

The systematic investigation of these issues can answer questions on the health-related significance of allergenic pollen indoors as well as on specific measures for the reduction of indoor pollen counts.

The aim of this communication is to find co-operation partners with an interest in this topic and to develop a joint research proposal.

contact: s.nehr@eufh.de

I have rat lung cells that I want to make into an astmhatic model by sensitized and challange has anyone any method that would be useable to do this I want to use dust mites

secondly once challenged a method to test the imflammation of the allergen

Greetings,

I made the prediction of the three-dimensional structure of certain allergenic proteins using LOMETS server, now I want to check the quality of the models obtained, what do you suggest as tools and is it possible to calculate RMSD for these models

Tanks in advance

Hi:

I have lung tissues I can homogenize to measure different cytokines. I am also interested in measuring some Mast cells proteases if possible(specifically mMCP-1). The problem is, lung tissues were collected 48 hours after the mice received the last challenge with HDM(house dust mite allergen) intranasally. I can't find in the literature the accuracy on the half-life time of this protease in the lungs.

Does anyone know if 48 hours is too late to try to measure this protein?

Also, if you have recommendations of what type of assay to use to measure this protease, I would truly appreciate it.

I know there are bioinformatic tools that allow epitope prediction to determine if a certain peptide would trigger an immune response. I also read that for allergen diagnoses IgE of sensitised patients is sometimes used to do an immunoblot to check for IgE epitopes on putative allergens. These IgE epitopes are sometimes published.

My question is: Can the peptides that can bind to IgE be used to trigger an immune response in mice and raise polyclonal Igg antibody?

I have used 'AllerTOP v. 2.0' & 'AlgPred' for allergenicity prediction of more than 225 different proteins/peptides. For many proteins the results from above mentioned tools are different. For example: A protein sequence 'TAGPAIRASVKQCQKTLKATRLFTVSCKGKNGCK' was predicted 'Probable non-allergen' by Allertop v. 2.0 whereas it was predicted as 'Potential allergen' by 'AlgPred' tool.

Kindly enlighten me in this regard,

Thanks & regards,

Dr. Ashwini Kumar Dubey,

NIB, Noida

Hi everyone,

i am currently testing new antibodies for its compatibility for a sandwich ELISA and at the moment, their cross-reactivity should be determined. Normally, we have to extract allergens freshly from our cross-reactive materials and use them with our new antibodies (both capture and conjugate).

There was an idea of coating the microtiter plate with cross-reactive allergens. Then, we can just add our antibody of interest (direct ELISA format) and detect the signal. Compared all measured values with the blank, we can then see the antibody cross-reactivity. I did this a few times but the results are variable and did not match well with the freshly-extracted-allergen approach. I was told that we have to do the later anyway but i think it's also a good idea to gain knowledge early on about the cross-reactivity of antibody.

Have anyone already done this before and what are your advice on this? Thank you guys in advance :).

In the age of Mutiresistant drug bacterium(s) and eukaryotic pathogenic organisms or superbugs, we are in a constant lookout for new treatments and especially antibiotic drugs. Two approaches, in particular, have been given a lot of attention, i.e.., Phage therapy and antimicrobial peptides, etc. Antimicrobial peptides are compounds produced by all eukaryotic lifeforms and may serve in every line of immune defense. But they are not living systems and are biochemical compounds. Therefore are subjected to resistance and increased allergenicity by virtue of their quaternary, tertiary or point of origin, and subjection to the subject (i.e.., treating humans or animals with a plant AMPs).

So are AMPs worth it? (in comparison to the phage therapy)

I'm quite new to the field with a basic level of understanding. I hope researchers with expertise or Good knowledge will be able to answer this question.

Thank you

I am looking for non-protein allergens, please write name of database or repository or link maintain list of allergens.

How are the patients with severe damage in corneal or retinal surfaces being treated currently? As far as I understand, for such implantation the shortage of donor, poor graft survival and allergenic rejection of natural graft are some of the biggest problems. I am curious if any synthetic implant could successfully pass through FDA channel? Please share if any knowledge on this. Thanks!

I want to know how to produce cytokines in PBMC after being stimulated by allergens / antigens (e.g. house dust mites). Are stimulation by allergens 'alone' sufficient, or does it require additional reagents (e.g. anti-CD3 and / or anti-CD28)?

Does anyone know in which species the grass allergen Phl p5 occurs? It was originally isolated from the grass species Phleum pratense so it must at least occur in that species. It stand to reason that it might also occur in other species of the genus Phleum. A few papers states that it is universal in many grasses, but with poor documentation.

Can anyone provide conclusive evidence and/or references in which the authors state in which species (or cultivars) the allergen occurs and/or have been isolated from? I welcome answers from all researchers along with special interest from expert knowledge primarily from plant ecology, aerobiology, immunology and other health professionals.

DNA from Bartonella, a gram-negative bacteria, have been found in mite droppings, and gram-bacteria like rods have been identified 'budding' off the walls of the mite's gut. Positive identification is needed as the endotoxin from the bacteria may be one of the many allergens from the mite Dermatophagoides.

Hi community:

I was wondering if you could give me more tips on the following.

I am looking at cytokines levels of lungs exposed to an allergen. Specifically, I am looking at intracellular cytokines, from lung homogenates. So I homogenated my lung with a buffer containing protease inhibitor, and run my cytokine assay which is a bead multiplex assay using flow cytometry.

Now i want to normalize the results given in pg/ml to mg per protein found on each sample.

I selected the BCA assay because is compatible with my buffer, and I am also using the same amount of volume (25 ul) from my sample than the volume I used to perform the cytokine assay.

My questions are the following:

-What dilution should I use for lung homogenates to run my Pierce BCA protein assay? Should I dilute my sample even more than the dilution I used to homogenize it and run the cytokine assay?

-My lungs contained a good amount of blood, because the homogenates are pink, but will the hemoglobin interfere that much in my BCA assay??

I am in need of literature to help me identify airborne fungal spores, and have found only two books so far. "The Air Spora" by Lacey and West, as well as "Sampling and identifying allergenic pollens and molds" by Smith.

Are there more books I can look into, especially concerning the tropics?

Hygiene hypothesis posits that hygienic conditions create more immune disorders such as allergies, while exposure to allergens (pathogens) might be better to manage our immune responses. I think it is a beautiful hypothesis, but is mostly criticised.

I'm working on the development of a method for the quantitation of allergens in cookies

This question come from the role of dendritic cell as antigen presenting cell recognition allergen and also as link between innate and adaptive immunity

Concern about mold in food is mainly beacise of mycotoxins, but little seems to be known about allergic response by food intake

basophil activation test in food and drugs allergens

The dtection of known Food allergen from food matrix and its antibody binding is a long way and approach require a lot of batch process and experiment. These days several method is coming according to different prodcut or matrix homogenous or heterogenous food matrix. My question is for homogenous food, one food matrix have also various allergenic protein and identify all of them together is not so easy with efficiency. I would like to get some expert comments and suggestion to apply the best way to detect maximum allergen together and its antigen binding efficiency and if possible then modification in technique?

Thank You all

Want to carry out a cellulase digestion of a Xantham gum sample to help prevent formation of a gel on extraction of allergens for analysis. What is the best way to do this?

how should one perform an ELISA to detect antigen-specific IgE?

what blocking and buffer do you use?

do you dilute the serum?

what detection method are you using?

The IL-4 cytokine increase PPAR-γ expression in T lymphocytes. In contrast, natural and synthetic ligands of PPAR-γ decrease IL-4 production in murine models of asthma and allergic airway inflammation. Moreover, the expression of PPAR-γ mRNA in murine Th2 cells upregulated after sensitization and challenge with HDM allergen. Does PPAR-γ inhibit IL-4 production in a negative feedback loop or not?

- Best quality and reliable ELISA kits.

- Journal / Article references used for crustacean allergen quantification.

- If possible approximate price/ cost of that ELISA kit.

I understand people connected it with mountains, but was it connected to high altitudes in specific? (I think some people connected it to allergens in mountains.) 

Does anyone stimulate T cells via allergens such as ovalbumin? I need a protocol for that. I will stimulate T cells with ovalbumin for FACS staining (extra and intra cellular). How many hours should I wait to get the optimum condition?

I have done one time TEM experiment to observe the peanut protein(Ara h1).The process was simply with 3 microlitre protein sample diluted into 1 ml PBS(Buffer) and then a drop of diluted sample was applied to the grid and observed under TEM machine. Unfortunate nothing was seen. 

what was the exact problem for TEM in this case?

Once any researchers have methodology about sample preparation for TEM, especially protein, requested to provide. 

A growing number of companies are selling products with insects - most commonly crickets and mealworms but others also.  We dont really know what the allergenicity risks are. 

Has anyone investigated this?

Please advise me the standard methods to estimate the shrimp allergen and also to identify the associated protein of shrimp allergen.

Prick Test can be evaluated in relation to the histamine control  with 2 methods 

* we consider the Histamine control   as = ++  , 

when less than Histamine control = +  

, if more= +++

or ++++ if very large and with irregular extensions.

* others consider Histamine control =+++ and they compare in relation to this!

(page 13)

on the other hand  we can evaluate it abstractly ( without relating it to Histamine control) :

* >3mm, <4mm = +

>4mm,<5mm= ++

>5mm,<6mm =+++

>6mm=++++

others consider 3mm-4mm as=  ++  !!

My question is 

I need to add the results of all my patients in a study and it should be in mm and not in (+) and I can't transform the results from (+) into mm and ask if there is a standard to do this.

for  example : a patient with Histamine control 9mm  and had a reaction to an allergen of 7mm .

with the use of the first method so he has (+) or (++)

with the use of the abstract method so he has (++++)!!!!

so how can I give a certain value in mm  if I have the corresponding reading in (+) 

Many thanks in advance

Pollen of Paper mulberry

I work in cross-reactivity between house dust mites (HDM) and shrimp (L. vannamei). We have characterized a fatty acid binding protein as an allergen from L. vannamei, we found it homology with Blo t 13, an allergen from HDM.

I want to use atopy patch test with aeroallergens (cat dander, house dust mite etc.) in one of my experimental studies. Does anyone know a distributor of such tests? I have tried to contact Stallergens, but they do not sell this product anymore.

In peer-reviewed articles, mostly authors have mentioned that they have compared the IgE binding ability of a recombinant allergen to the native allergen with allergic patient sera. But I am interested to know how they can find the folding /aggregation pattern of a recombinant allergen. Or IgE binding test is enough to conclude that there were no considerable folding / aggregation occurs during the process. 

What is the domain used for initial internalization and presentation, e.g. nuclear proteins (ANA) or for ANCA or common allergens?  What is the receptor?

I am reading some papers, where researchers have used pooled serum along with individual sera to check the IgE reactivity of allergen molecules on immunoblotting. What are the possible reasons for performing this type of experiment?

Will shortly methylisothiazolinone/methylchloroisothiazolinone (MI/MCI) replace nickel as the most frequent patch test positive allergen? The epidemic of allergic contact dermatitis to MI/MCI is becoming a huge problem. In 2014 MI/MCI was the second most frequent allergen in our patch test unit with 13.3% positive tests, following 14.7%  positive tests to nickel, and preceding 6.3% positive tests to cobalt, 6.3% to fragrance mix I and 4.9% to chromium.  

Dear colleagues,

Currently I'm trying to predict probable IgE-binding regions in one of the allergenic proteins and reveal candidate residues for mutation in order to design a hypoallergenic derivative.

I made a prediction of B-cell epitopes with few sequence-based and few structure-based tools. In parallel I predicted the surface-exposed regions in the protein by another software. Moreover, I looked to the homologous protein for which the IgE-binding regions were predicted experimentally and projected these residues on my protein.

Finally, when I tried to integrate the data of all these predictions I've found that they don't match. I'm confused about this. What results should I prefer in the case when data of different predictions don't match? What results are of a higher value?

Would be grateful for any suggestions.

Some time ago I heard that Group 1 allergens like Der p1 are not detected on IgE immunoblots, but I can't find a publication describing it.

How can we ensure that there is no trace of almond in it? For an ingredient study trying to decide whether allergen content is supposed to be stated in a product that contains Amaretto.

I have only found companies that sell dead mites.

A complicated question, but even partial answers are wellcome:

What is the legal liability for people, who are developing or commercially resp. non-commercially administering the analytical methods for the detection of food allergens? I mean the legal aspects of analytical methods, which are used to enforce the existing worldwide law on listing the food allergens on food packages. I am most interested in DNA-based methods. If an analytical method is not good or has a flaw, who takes legal responsibility for potential problems? The producer of problem-causing food, the inventor of the method, or the facility which does the testing? If there are standards (norms) published by ISO or CEN or other institutions, are they actually a law, or just expert recommendations? There is a European standard "EN 15842:2010 Foodstuffs - Detection of food allergens - General considerations and validation of methods (European Commitee on Standardization, 2010)". If I develop / want to commercially perform a new method for use in EU, must I validate it according to this European standard, or is it only a voluntary enterprise, which I can brag about, but am not obligated to do? Is there a review article on these issues? Partial answers (e.g. only your country outside EU, anecdotal experiences at the legal court etc) are also appreciated.

For preparing whey protein based health drinks, removal of allergenic active principle is necessary, otherwise allergic reactions may occur.

Please tell me how to remove allergenic active principle present in Whey Protein ?

Autoanalyzer tests like Immunocap method of Thermo/Phadia or HYCOR. Manual Method where entire kit i.e., well plate, reagent and calibrator are present in same kit and test is based on antigen antibody reaction in specific wells.

Some pulmonologists want to follow IgG4 concentration of the allergen during desensitization because IgG4 must increase for good result. This test is often contested.

Also, do we have separate kits for reagents, conjugate and calibrators for Allergen Specific IgE or the complete thing comes in one kit? 

Some literature use SPT to determine allergy incidence in grass mix and cereal mix, or include an array of grass species and additionally includes barley, wheat, oat and maize. Grasses are dominant in the vegetation of my study area. My aim is to have a minimum battery. I initially selected one species representing a grass subfamily, assuming cross-reactivity. Most cereals a part of the Pooide subfamily also represented by Poa or Phleum.

Any comments are appreciated.

Do I need to study the tertiary structure of a protein allergen or not?

Molecular docking simulation is one of the computational techniques commonly used to predict the biological interaction between molecules. I am currently studying on the molecular interactions between antigen-specific IgE antibody and recombinant allergens. As I am quite new to this, does anyone know any reliable docking simulation softwares used for the allergen-antibody interaction study?

There are controversial issues on the use of SIT in atopic eczema.

Safety and efficacy

Mainly for plant extraction.

Does anybody know if it's possible to buy allergen-specific IgE antibodies?