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ORIGINAL RESEARCH article

Front. Immunol.

Sec. Cytokines and Soluble Mediators in Immunity

Volume 16 - 2025 | doi: 10.3389/fimmu.2025.1633892

IL-7 promotes the formation of DNA double strand breaks and DNA repair in murine pro-B cells

Provisionally accepted
Alessia  LamolinaraAlessia Lamolinara1,2Chiara  Di LisioChiara Di Lisio3Julie  A HixonJulie A Hixon4Pasquale  SimeonePasquale Simeone2,3Antonella  De ColaAntonella De Cola5,6Maria  D FalcoMaria D Falco7Thomas  J MeyerThomas J Meyer8Alessio  FerroneAlessio Ferrone3Domenico  GenovesiDomenico Genovesi7Paola  LanutiPaola Lanuti2,3Wenqing  LiWenqing Li4Vincenzo  De LaurenziVincenzo De Laurenzi2,9Manuela  IezziManuela Iezzi1,2Francesca  Bianca AielloFrancesca Bianca Aiello2,4,9*Scott  Kenneth DurumScott Kenneth Durum4
  • 1Department of Neurosciences, Imaging and Clinical Sciences, University of Studies G. d'Annunzio Chieti and Pescara, Chieti, Italy
  • 2Center for Advanced Studies and Technology (CAST), University of Studies G. d'Annunzio Chieti and Pescara, Chieti, Italy
  • 3Department of Medicine and Aging Sciences, University of Studies G. d'Annunzio Chieti and Pescara, Chieti, Italy
  • 4Cytokines and Immunity Section, Cancer Innovation Laboratory (CIL), National Institutes of Health (NIH), National Cancer Institute Frederick, Frederick, United States
  • 5Department of Oncology, Early Cancer Institute, University of Cambridge, Cambridge, United Kingdom
  • 6CRUK Children's Brain Tumour Centre of Excellence, University of Cambridge, Cambridge, United Kingdom
  • 7Department of Radiation Oncology, “S.S. Annunziata” Hospital, University of Studies G. d'Annunzio Chieti and Pescara, Chieti, Italy
  • 8CCR Collaborative Bioinformatics Resource (CCBR), National Institutes of Health (NIH), National Cancer Institute Frederick, Frederick, United States
  • 9Department of Innovative Technologies in Medicine and Dentistry, University of Studies G. d'Annunzio Chieti and Pescara, Chieti, Italy

The final, formatted version of the article will be published soon.

In pro-B cells, VDJ recombination at the immunoglobulin heavy chain locus is impaired. B cell progenitor recombination implies the formation of DNA double strand breaks (DSBs) by the RAG recombinase, which are subsequently repaired by specific mechanisms. We cultured primary murine pro-B cells with IL-7 to evaluate H2AX histone phosphorylation, a well-established marker of DSB formation (γ-H2AX foci) and the expression of proteins involved in DNA repair. Our results indicated that IL-7 upregulated the expression of several molecules involved in homologous recombination, the most accurate DSB repair mechanism. Quantitative analyses of γ-H2AX foci revealed that IL-7 significantly increased DSB formation in a time-dependent manner. Furthermore, γ-H2AX expression was altered in RAG2-deficient pro-B cells and absent in RAG1-deficient pro-B cells treated with IL-7, demonstrating the requirement of both RAG1 and RAG2 recombinase subunits. CD43 expression inversely correlates with the degree of cell differentiation and its level is often evaluated to assess the B lymphoid developmental stage. We observed that IL-7 upregulated CD43 expression and the percentage of large CD43/γ-H2AX double-positive cells, suggesting an effect on less differentiated, immature cells. Notably, we also found that IL-7 increased radiation-induced DSBs, while simultaneously supporting cell survival. This study uncovers novel effects of IL-7 on B cell differentiation, DSB formation, and DNA repair. It is well established that IL-7 promotes the proliferation and survival of acute lymphoblastic leukemia (ALL) cells. Our data suggest that drugs targeting IL-7 could improve ALL therapeutic protocols.

Keywords: IL-7, Pro-B cells, Double Strand Breaks, DNA Repair, Cell Survival

Received: 23 May 2025; Accepted: 17 Sep 2025.

Copyright: © 2025 Lamolinara, Di Lisio, Hixon, Simeone, De Cola, Falco, Meyer, Ferrone, Genovesi, Lanuti, Li, De Laurenzi, Iezzi, Aiello and Durum. 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) or licensor 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: Francesca Bianca Aiello, francesca.aiello@unich.it

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