{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,27]],"date-time":"2026-03-27T02:46:09Z","timestamp":1774579569385,"version":"3.50.1"},"reference-count":33,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T00:00:00Z","timestamp":1637625600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000024","name":"Canadian Institutes of Health Research","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100000024","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Oral immunotherapy (OIT) is an emerging treatment for cow\u2019s milk protein (CMP) allergy in children. The mechanisms driving tolerance following OIT are not well understood. Regulatory T cells (T<jats:sub>REG<\/jats:sub>) cells are key inhibitors of allergic responses and promoters of allergen-specific tolerance. In an exploratory study, we sought to detect induction of allergen-specific T<jats:sub>REG<\/jats:sub> in a cohort of subjects undergoing OIT.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Pediatric patients with a history of allergic reaction to cow\u2019s milk and a positive Skin Pick Test (SPT) and\/or CMP-specific IgE &amp;gt;0.35 kU, as well as a positive oral challenge to CMP underwent OIT with escalating doses of milk and were followed for up to 6 months. At specific milestones during the dose escalation and maintenance phases, casein-specific CD4<jats:sup>+<\/jats:sup> T cells were expanded from patient blood by culturing unfractionated PBMCs with casein <jats:italic>in vitro.<\/jats:italic> The CD4<jats:sup>+<\/jats:sup> T cell phenotypes were quantified by flow cytometry.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Our culture system induced activated casein-specific FOXP3<jats:sup>+<\/jats:sup>Helios<jats:sup>+<\/jats:sup> T<jats:sub>REG<\/jats:sub> cells and FOXP3<jats:sup>-<\/jats:sup> T<jats:sub>EFF<\/jats:sub> cells, discriminated by expression of CD137 (4-1BB) and CD154 (CD40L) respectively. The frequency of casein-specific T<jats:sub>REG<\/jats:sub> cells increased significantly with escalating doses of milk during OIT while casein-specific T<jats:sub>EFF<\/jats:sub> cell frequencies remained constant. Moreover, expanded casein-specific T<jats:sub>REG<\/jats:sub> cells expressed higher levels of FOXP3 compared to polyclonal T<jats:sub>REG<\/jats:sub> cells, suggesting a more robust T<jats:sub>REG<\/jats:sub> phenotype. The induction of casein-specific T<jats:sub>REG<\/jats:sub> cells increased with successful CMP desensitization and correlated with increased frequencies of casein-specific Th1 cells among OIT subjects. The level of casein-specific T<jats:sub>REG<\/jats:sub> cells negatively correlated with the time required to reach the maintenance phase of desensitization.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Overall, effective CMP-OIT successfully promoted the expansion of casein-specific, functionally-stable FOXP3<jats:sup>+<\/jats:sup> T<jats:sub>REG<\/jats:sub> cells while mitigating Th2 responses in children receiving OIT. Our exploratory study proposes that an <jats:italic>in vitro<\/jats:italic> T<jats:sub>REG<\/jats:sub> response to casein may correlate with the time to reach maintenance in CMP-OIT.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fimmu.2021.705615","type":"journal-article","created":{"date-parts":[[2021,11,30]],"date-time":"2021-11-30T14:07:35Z","timestamp":1638281255000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":11,"title":["Successful Milk Oral Immunotherapy Promotes Generation of Casein-Specific CD137+ FOXP3+ Regulatory T Cells Detectable in Peripheral Blood"],"prefix":"10.3389","volume":"12","author":[{"given":"Yi","family":"Zhang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lei","family":"Li","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Genevi\u00e8ve","family":"Genest","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wei","family":"Zhao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dan","family":"Ke","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sabrina","family":"Bartolucci","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nils","family":"Pavey","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tho-Alfakar","family":"Al-Aubodah","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Duncan","family":"Lejtenyi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bahar","family":"Torabi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Moshe","family":"Ben-Shoshan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bruce","family":"Mazer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ciriaco A.","family":"Piccirillo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2021,11,23]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1177\/0009922816664512","article-title":"Cow\u2019s Milk Protein Allergy","volume":"55","author":"Mousan","year":"2016","journal-title":"Clin Pediatr (Phila)"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaip.2014.06.009","article-title":"Prevalence and Predictors of Food Allergy in Canada: A Focus on Vulnerable Populations","volume":"3","author":"Soller","year":"2015","journal-title":"J Allergy Clin Immunol Pract"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.18176\/jiaci.0143","article-title":"Oral Immunotherapy for Food Allergy","volume":"27","author":"Wood","year":"2017","journal-title":"J Investig Allergol Clin Immunol"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1016\/j.jaip.2019.02.007","article-title":"Adverse Events in Oral Immunotherapy for the Desensitization of Cow\u2019s Milk Allergy in Children: A Randomized Controlled Trial","volume":"7","author":"De Schryver","year":"2019","journal-title":"J Allergy Clin Immunol Pract"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1007\/s12016-018-8677-0","article-title":"Oral and Sublingual Immunotherapy for Treatment of IgE-Mediated Food Allergy","volume":"55","author":"Scurlock","year":"2018","journal-title":"Clin Rev Allergy Immunol"},{"key":"B6","doi-asserted-by":"publisher","first-page":"448","DOI":"10.1016\/j.jaci.2011.10.023","article-title":"The Safety and Efficacy of Sublingual and Oral Immunotherapy for Milk Allergy","volume":"129","author":"Keet","year":"2012","journal-title":"J Allergy Clin Immunol"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.18176\/jiaci.0177","article-title":"Oral Immunotherapy for Food Allergy: A Spanish Guideline. 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