Original Research ARTICLE
Variability in German cockroach extract composition greatly impacts T cell potency in cockroach-allergic donors
- 1La Jolla Institute for Allergy and Immunology (LJI), United States
- 2Indoor Biotechnologies (United States), United States
- 3North Carolina State University, United States
- 4Department of Internal Medicine, College of Medicine, Yonsei university, South Korea
- 5Department of Microbiology and Plant Biology, University of Oklahoma, United States
- 6Pure MHC, 655 Research Parkway, Suite 556,, United States
- 7Icahn School of Medicine at Mount Sinai, United States
- 8Department of Pediatrics, Washington University School of Medicine in St. Louis, United States
- 9School of Medicine, University of California, San Diego, United States
German cockroach extract is used clinically to evaluate allergen-specific sensitization and for subcutaneous allergen-specific immunotherapy, though there are no guidelines for standardization in its manufacture. We performed an immunological evaluation of twelve different cockroach extracts prepared from different sources and their potency to induce allergen-specific T cell reactivity.
PBMC from 13 cockroach allergic donors were expanded in vitro with twelve different German cockroach extracts. After culture expansion, cells were re-stimulated with the different extracts and T cell responses were assessed by FluoroSpot (IL-5, IFNγ and IL-10 production). In parallel to the extracts, single allergen peptide pools for Bla g 1, 2, 4, 5 and 11 were tested to determine allergen immunodominance. Furthermore, to assess allergy specificity, PBMC form 13 non-allergic donors were also tested with the most potent extract and T cell responses were compared to the allergic cohort.
Dramatic variations in T cell reactivity were observed to the different cockroach extract batches. Response magnitudes varied over 3 logs within a single donor. IL-5 production in the allergic cohort was significantly higher compared to the non-allergic cohort (p=0.004). Allergen content determination by ELISA detected much lower concentrations of Bla g 5 compared to Bla g 1 and 2. Mass spectrometric analysis revealed that Bla g 5 was present in similar amounts to Bla g 1 and 2 in extracts made form whole body, whereas it was not detected in extracts made form fecal matter, suggesting that Bla g 5 is not excreted into feces. Different donors exhibit different response patterns to different extracts, potentially dependent on the donor-specific T cell allergen immunodominance pattern and the allergen content of the extract tested. These findings have dramatic implications for the selection of potent extracts used for diagnostic purposes or allergen-specific immunotherapy.
Keywords: German cockroach (Blattella germanica), T cells, Allergen extract, Cytokines, Respiratory allergy
Received: 20 Jun 2018;
Accepted: 06 Feb 2019.
Edited by:Craig M. Schramm, School of Medicine, University of Connecticut, United States
Reviewed by:Dominique M. Bullens, KU Leuven, Belgium
Roger S. Thrall, University of Connecticut Health Center, United States
Copyright: © 2019 Birrueta, Frazier, Pomés, Glesner, Filep, Schaal, Jeong, McMurtrey, VanderShans, Hildebrand, Busse, Beigelman, Bachier, Peters, Sette and Schulten. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Veronique Schulten, La Jolla Institute for Allergy and Immunology (LJI), La Jolla, California, United States, firstname.lastname@example.org