Cancila Valeria, Bertolazzi Giorgio, Chan Allison Sy, Medico Giovanni, Bastianello Giulia, Morello Gaia, Paysan Daniel, Lai Clemence, Hong Liang, Shenoy Girija, Jaynes Patrick W, Schiavoni Giovanna, Mattei Fabrizio, Piconese Silvia, Revuelta Maria V, Noto Francesco, Businaro Luca, De Ninno Adele, Cammarata Ilenia, Pagni Fabio, Venkatachalapathy Saradha, Sangaletti Sabina, Di Napoli Arianna, Cicio Giada, Vacca Davide, Lonardi Silvia, Lorenzi Luisa, Ferreri Andrés Jm, Belmonte Beatrice, Liu Min, Lakshmanan Manikandan, Ong Michelle Sn, Zhang Biyan, See Tingyi, Lam Kong-Peng, Varano Gabriele, Colombo Mario P, Bicciato Silvio, Inghirami Giorgio, Cerchietti Leandro, Ponzoni Maurilio, Zappasodi Roberta, Metzger Evelyn, Beechem Joseph, Facchetti Fabio, Foiani Marco, Casola Stefano, Jeyasekharan Anand D, Tripodo Claudio
Tumor Immunology Unit, Department of Health Sciences, University of Palermo, Palermo, Italy.
Department of Medicine and Surgery, Kore University of Enna, Enna, Italy.
J Clin Invest. 2025 Jul 17. doi: 10.1172/JCI187371.
The germinal center (GC) dark zone (DZ) and light zone (LZ) represent distinct anatomical regions in lymphoid tissue where B-cell proliferation, immunoglobulin diversification, and selection are coordinated. Diffuse Large B-cell Lymphomas (DLBCL) with DZ-like gene expression profiles exhibit poor outcomes, though reasons are unclear and are not directly related to proliferation. Physiological DZs exhibit an exclusion of T-cells, prompting exploration for whether T-cell paucity contributes to DZ-like DLBCL. We used spatial transcriptomic approaches to achieve higher resolution of T-cell spatial heterogeneity in the GC and to derive potential pathways that underlie T-cell exclusion. We showed that T-cell exclusion from the DZ was linked to DNA damage response (DDR) and chromatin compaction molecular features characterizing the spatial DZ signature, and that these programs were independent of AID deaminase activity. As ATR is a key regulator of DDR, we tested its role in the T-cell inhibitory DZ transcriptional imprint. ATR inhibition reversed not only the DZ transcriptional signature but also DZ T-cell exclusion in DZ-like DLBCL in vitro microfluidic models and in in vivo samples of murine lymphoid tissue. These findings highlight that ATR activity underpins a physiological scenario of immune silencing. ATR inhibition may reverse the immune silent state and enhance T-cell based immunotherapy in aggressive lymphomas with GC DZ-like characteristics.
生发中心（GC）的暗区（DZ）和亮区（LZ）代表淋巴组织中不同的解剖区域，B细胞增殖、免疫球蛋白多样化和选择在此处相互协调。具有DZ样基因表达谱的弥漫性大B细胞淋巴瘤（DLBCL）预后较差，但其原因尚不清楚，且与增殖无直接关系。生理性DZ表现为T细胞的排除，这促使人们探究T细胞缺乏是否导致DZ样DLBCL。我们使用空间转录组学方法来实现GC中T细胞空间异质性的更高分辨率，并推导T细胞排除背后的潜在途径。我们发现，DZ中T细胞的排除与DNA损伤反应（DDR）和表征空间DZ特征的染色质压缩分子特征有关，并且这些程序独立于AID脱氨酶活性。由于ATR是DDR的关键调节因子，我们测试了其在T细胞抑制性DZ转录印记中的作用。在体外微流控模型和小鼠淋巴组织的体内样本中，ATR抑制不仅逆转了DZ样DLBCL中的DZ转录特征，还逆转了DZ T细胞排除。这些发现突出表明，ATR活性是免疫沉默生理场景的基础。ATR抑制可能会逆转免疫沉默状态，并增强对具有GC DZ样特征的侵袭性淋巴瘤基于T细胞的免疫治疗。
