{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,28]],"date-time":"2026-07-28T18:59:43Z","timestamp":1785265183843,"version":"3.55.0"},"reference-count":44,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T00:00:00Z","timestamp":1775001600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"\n Introduction<\/jats:title>\n \n The B-cell-specific marker CD20 is expressed in various B-cell malignancies, including B-cell acute lymphoblastic leukemia (B-ALL) and serves as a key target for immunotherapies. Reduced or absent CD20 expression has been associated with diminished responses to anti-CD20 antibodies and CD20 directed CAR T-cells. Antigen loss may arise from alternative splicing or transcriptional downregulation of\n MS4A1<\/jats:italic>\n , the gene coding for CD20, a processes influenced by RNA- and DNA-binding proteins.\n NONO<\/jats:italic>\n , a non-POU domain-containing octamer-binding protein implicated in several cancers, regulates CD20 surface expression.\n <\/jats:p>\n <\/jats:sec>\n \n Methods<\/jats:title>\n \n To explore factors associated with heterogeneous CD20 expression, we quantified\n MS4A1<\/jats:italic>\n transcript levels, profiled\n MS4A1<\/jats:italic>\n messenger RNA (mRNA) isoforms, and analyzed\n NONO<\/jats:italic>\n mRNA in pediatric B-ALL samples. In addition, we used an\n in vitro<\/jats:italic>\n CRISPR\/Cas9 knockout model to assess the effects of\n NONO<\/jats:italic>\n loss on\n MS4A1<\/jats:italic>\n transcript abundance, isoform distribution, and transcript stability. Plasmid-based overexpression of\n MS4A1<\/jats:italic>\n was used to examine its effect on splicing.\n <\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n \n Loss of\n NONO<\/jats:italic>\n was associated with increased\n MS4A1<\/jats:italic>\n transcript levels without detectable changes in isoform distribution or stability, and\n NONO<\/jats:italic>\n mRNA expression was negatively associated with\n MS4A1<\/jats:italic>\n mRNA expression in CD20-positive blasts. At diagnosis, two\n MS4A1<\/jats:italic>\n mRNA isoforms were detected in CD20-positive blasts: The wild-type (WT-CD20) and a shorter variant (D393-CD20), a \u03944\u20136 multi\u2013exon\u2013skipped isoform that yields a truncated intracellular protein inaccessible to CD20-directed immunotherapies. Although WT-CD20 was the dominant splice isoform, the D393\/WT-CD20 ratio correlated positively with overall\n MS4A1<\/jats:italic>\n transcript abundance. High WT-CD20 transcript abundance further biased splicing toward the D393-CD20 isoform, indicating involvement of cryptic splice sites and potential re-splicing events at the level of mature\n MS4A1<\/jats:italic>\n mRNA.\n <\/jats:p>\n <\/jats:sec>\n \n Discussion<\/jats:title>\n \n Together, these findings are consistent with a model in which\n NONO<\/jats:italic>\n expression and transcript-level dynamics of\n MS4A1<\/jats:italic>\n are associated with CD20 heterogeneity in pediatric B-ALL. These observations may contribute to understanding variability in CD20 expression and antigen availability in pediatric B-ALL.\n <\/jats:p>\n <\/jats:sec>","DOI":"10.3389\/fimmu.2026.1763413","type":"journal-article","created":{"date-parts":[[2026,4,1]],"date-time":"2026-04-01T04:45:32Z","timestamp":1775018732000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["Dual-trigger model of CD20 escape: NONO regulation and cryptic splicing induced by transcript overload in pediatric B-ALL"],"prefix":"10.3389","volume":"17","author":[{"given":"Moein","family":"Kermani","sequence":"first","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sebastian","family":"Maxeiner","sequence":"additional","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Francesca","family":"Alt","sequence":"additional","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nicole","family":"Ziegler","sequence":"additional","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Julian","family":"K\u00f6nig","sequence":"additional","affiliation":[{"name":"Theodor Boveri Institute, Julius Maximilians University W\u00fcrzburg, Biocenter","place":["W\u00fcrzburg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Claudia","family":"Paret","sequence":"additional","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]},{"name":"University Cancer Center (UCT), University Medical Center of the Johannes Gutenberg University Mainz","place":["Mainz, Germany"]},{"name":"German Cancer Consortium (DKTK), Site Frankfurt\/Mainz, Germany, German Cancer Research Center (DKFZ)","place":["Heidelberg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J\u00f6rg","family":"Faber","sequence":"additional","affiliation":[{"name":"University Medical Center of the Johannes Gutenberg-University Mainz, Department of Pediatric Hematology\/Oncology, Center for Pediatric and Adolescent Medicine","place":["Mainz, Germany"]},{"name":"University Cancer Center (UCT), University Medical Center of the Johannes Gutenberg University Mainz","place":["Mainz, Germany"]},{"name":"German Cancer Consortium (DKTK), Site Frankfurt\/Mainz, Germany, German Cancer Research Center (DKFZ)","place":["Heidelberg, Germany"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,4,1]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1182\/asheducation-2018.1.137","article-title":"Genetics and prognosis of ALL in children vs adults","volume":"2018","author":"Roberts","year":"2018","journal-title":"Hematol Am Soc Hematol Educ Program"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1002\/jlb.5a0721-361r","article-title":"Genomic heterogeneity contributed to different prognosis between adult and pediatric acute lymphoblastic","volume":"112","author":"Chen","year":"2022","journal-title":"J Leukoc Biol"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1158\/2643-3230.bcd-25-0036","article-title":"Overcoming B-ALL resistance to targeted and immune therapies by rational combination strategies","volume":"6","author":"Quijada-\u00c1lamo","year":"2025","journal-title":"Blood Cancer Discov"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1056\/nejmoa1605085","article-title":"Rituximab in B-lineage adult acute lymphoblastic leukemia","volume":"375","author":"Maury","year":"2016","journal-title":"N Engl J Med"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1002\/cyto.b.20516","article-title":"Modulation of antigen expression in B-cell precursor acute lymphoblastic leukemia during induction therapy is partly transient: evidence for a drug-induced regulatory phenomenon. 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