Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation

T cell activation is the final key event (KE4) in the adverse outcome pathway (AOP) of skin sensitization. However, validated new approach methodologies (NAMs) for evaluating this step are missing. Accordingly, chemicals that activate an unusually high frequency of T cells, as does the most prevalen...

Full description

Saved in:
Bibliographic Details
Main Authors: Nele Fritsch, Marina Aparicio-Soto, Caterina Curato, Franziska Riedel, Hermann-Josef Thierse, Andreas Luch, Katherina Siewert
Format: Article
Language:English
Published: MDPI AG 2024-11-01
Series:Toxics
Subjects:
Online Access:https://www.mdpi.com/2305-6304/12/11/802
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1846152320598933504
author Nele Fritsch
Marina Aparicio-Soto
Caterina Curato
Franziska Riedel
Hermann-Josef Thierse
Andreas Luch
Katherina Siewert
author_facet Nele Fritsch
Marina Aparicio-Soto
Caterina Curato
Franziska Riedel
Hermann-Josef Thierse
Andreas Luch
Katherina Siewert
author_sort Nele Fritsch
collection DOAJ
description T cell activation is the final key event (KE4) in the adverse outcome pathway (AOP) of skin sensitization. However, validated new approach methodologies (NAMs) for evaluating this step are missing. Accordingly, chemicals that activate an unusually high frequency of T cells, as does the most prevalent metal allergen nickel, are not yet identified in a regulatory context. T cell reactivity to chemical sensitizers might be especially relevant in real-life scenarios, where skin injury, co-exposure to irritants in chemical mixtures, or infections may trigger the heterologous innate immune stimulation necessary to induce adaptive T cell responses. Additionally, cross-reactivity, which underlies cross-allergies, can only be assessed by T cell tests. To date, several experimental T cell tests are available that use primary naïve and memory CD4+ and CD8+ T cells from human blood. These include priming and lymphocyte proliferation tests and, most recently, activation-induced marker (AIM) assays. All approaches are challenged by chemical-mediated toxicity, inefficient or unknown generation of T cell epitopes, and a low throughput. Here, we summarize solutions and strategies to confirm in vitro T cell signals. Broader application and standardization are necessary to possibly define chemical applicability domains and to strengthen the role of T cell tests in regulatory risk assessment.
format Article
id doaj-art-17351e7e871d4c7ca170bf7d74bccce1
institution Kabale University
issn 2305-6304
language English
publishDate 2024-11-01
publisher MDPI AG
record_format Article
series Toxics
spelling doaj-art-17351e7e871d4c7ca170bf7d74bccce12024-11-26T18:23:51ZengMDPI AGToxics2305-63042024-11-01121180210.3390/toxics12110802Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization EvaluationNele Fritsch0Marina Aparicio-Soto1Caterina Curato2Franziska Riedel3Hermann-Josef Thierse4Andreas Luch5Katherina Siewert6German Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyGerman Federal Institute for Risk Assessment (BfR), Department of Chemical and Product Safety, Dermatotoxicology Study Centre, 10589 Berlin, GermanyT cell activation is the final key event (KE4) in the adverse outcome pathway (AOP) of skin sensitization. However, validated new approach methodologies (NAMs) for evaluating this step are missing. Accordingly, chemicals that activate an unusually high frequency of T cells, as does the most prevalent metal allergen nickel, are not yet identified in a regulatory context. T cell reactivity to chemical sensitizers might be especially relevant in real-life scenarios, where skin injury, co-exposure to irritants in chemical mixtures, or infections may trigger the heterologous innate immune stimulation necessary to induce adaptive T cell responses. Additionally, cross-reactivity, which underlies cross-allergies, can only be assessed by T cell tests. To date, several experimental T cell tests are available that use primary naïve and memory CD4+ and CD8+ T cells from human blood. These include priming and lymphocyte proliferation tests and, most recently, activation-induced marker (AIM) assays. All approaches are challenged by chemical-mediated toxicity, inefficient or unknown generation of T cell epitopes, and a low throughput. Here, we summarize solutions and strategies to confirm in vitro T cell signals. Broader application and standardization are necessary to possibly define chemical applicability domains and to strengthen the role of T cell tests in regulatory risk assessment.https://www.mdpi.com/2305-6304/12/11/802adverse outcome pathwayallergic contact dermatitischemical-induced T cell epitopescontact allergensin vitro T cell testkey events
spellingShingle Nele Fritsch
Marina Aparicio-Soto
Caterina Curato
Franziska Riedel
Hermann-Josef Thierse
Andreas Luch
Katherina Siewert
Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
Toxics
adverse outcome pathway
allergic contact dermatitis
chemical-induced T cell epitopes
contact allergens
in vitro T cell test
key events
title Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
title_full Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
title_fullStr Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
title_full_unstemmed Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
title_short Chemical-Specific T Cell Tests Aim to Bridge a Gap in Skin Sensitization Evaluation
title_sort chemical specific t cell tests aim to bridge a gap in skin sensitization evaluation
topic adverse outcome pathway
allergic contact dermatitis
chemical-induced T cell epitopes
contact allergens
in vitro T cell test
key events
url https://www.mdpi.com/2305-6304/12/11/802
work_keys_str_mv AT nelefritsch chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT marinaapariciosoto chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT caterinacurato chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT franziskariedel chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT hermannjosefthierse chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT andreasluch chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation
AT katherinasiewert chemicalspecifictcelltestsaimtobridgeagapinskinsensitizationevaluation