Tumor-promoting function and regulatory landscape of PD-L2 in B-cell lymphoma
Tumor-promoting function and regulatory landscape of PD-L2 in B-cell lymphoma
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PD-L2 在 B 细胞淋巴瘤中的促肿瘤功能和调控格局
DOI：
10.1038/s41375-022-01772-1
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发表时间：
2022
期刊：
影响因子：
11.4
通讯作者：
Kataoka K
中科院分区：
文献类型：
--
作者：
Shingaki S;Koya J;Yuasa M;Saito Y;Tabata M;McClure MB;Ogawa S;Katayama K;Togashi Y;Imoto S;Kogure Y;Kataoka K
与PD-L1不同，人们对另一种PD-1配体PD-L2在癌症中的生物学相关性和调节机制知之甚少[1]。来自各种癌症类型的RNA测序(RNA-seq)数据表明，PD-L2在有限的癌症类型中高度表达，特别是在弥漫性大B细胞淋巴瘤(DLBCL)中(图1A，B；补充图1A，B；补充表1-5)[2，3]。在DLBCL中，生发中心B细胞起源和PD-L2基因改变(扩增和重排)[4]与PD-L2高表达相关(补充图1C-E；补充表3)[3]。其他淋巴瘤亚型，特别是原发纵隔B细胞淋巴瘤(PMBL)，也有高PD-L2表达，几个B细胞系也有高PD-L2表面表达(补充图1F-H)。总的来说，PD-L2/PD-L1的表达与细胞溶解活性有不同程度的相关性，反映了获得性免疫反应[5，6]。重要的是，与PDL2/PD-L1表达水平相似的未改变样本相比，PD-L2/PD-L1改变的样本显示出较低的细胞杀伤活性，这表明这些肿瘤的抗肿瘤免疫功能减弱(补充图1I)[6]。然后，我们比较了PD-L1和PD-L2在成分表达水平相近时对肿瘤微环境(TME)的影响。因此，我们建立了一个缺乏PD-L1的A20-卵清蛋白(OVA)小鼠B细胞淋巴瘤株，并引入了小鼠PD-L1或PD-L2的表达(补充图2A-E)。同基因移植显示，PD-L1/PD-L2过表达促进了肿瘤的生长，并减少了CD8+T细胞对肿瘤的渗透，这一点可通过抗PD-1抗体恢复(补充图2F-J)。此外，我们从模拟/PD-L1-/PD-L2表达的A20-OVA肿瘤中构建了22,116个非恶性CD45+细胞的单细胞转录、表面表型(抗体衍生标签[ADT])和T/B细胞受体(TCR/BCR)图谱(图1C，D；补充图3A，B；补充表6，7)[7]。重要的是，表达PD-L1/PDL2的肿瘤在TME中表现出相似的细胞动力学以及转录和表面表型变化(补充表8-10)。在PD-L1/PD-L2表达的肿瘤中，CD8+T细胞，特别是显示高克隆性的耗尽的CD8+T细胞(CD8Tex)和调节性T细胞减少(图1E；补充图3B)。有趣的是，在PD-L1/PD-L2表达的肿瘤中，髓系细胞，包括单核/巨噬细胞(Mono/Macs)和浆细胞样树突状细胞(PDCs)增加或倾向于增加(图1E)。在PD-L1/PD-L2表达的肿瘤中，M1和M2巨噬细胞签名分别下调和上调，而其他免疫相关签名是相似的(补充图3D-F)。在表达PD-L1/PD-L2的肿瘤的Mono/MACs中，对细菌分子(包括脂多糖)的反应在转录上下调，提示M2样抗炎、促肿瘤表型(图1F)[8]。此外，在传统DC和PDDC中，抗原提呈通路受到抑制。一贯地，在PD-L1/PD-L2表达的肿瘤中，促炎症细胞因子诱导的标记物，如Ly6A/E和IA/IE，在不同的簇中下调(图1G；补充图4A，B)。值得注意的是，用抗BST2抗体耗尽PDC抑制了PD-L1-/PD-L2表达的肿瘤的生长(图1H；补充图4C)，表明pDC的促肿瘤作用。总之，我们的单细胞分析描绘了PD-L1和PD-L2共享的多效性外部效应，主要增强微环境…中的抗炎和促肿瘤反应。
Unlike PD-L1, little is known about the biological relevance and regulatory mechanism of PD-L2, another PD-1 ligand, in cancer [1]. RNA-sequencing (RNA-seq) data from a variety of cancer types revealed that PD-L2 was highly expressed in limited cancer types, particularly in diffuse large B-cell lymphoma (DLBCL)(Fig. 1 A, B; Supplementary Fig. 1A, B; Supplementary Tables 1-5)[2, 3]. In DLBCL, germinal center B-cell origin and PD-L2 genetic alterations (amplifications and rearrangements)[4] were associated with high PD-L2 expression (Supplementary Fig. 1C-E; Supplementary Table 3)[3]. Other lymphoma subtypes, especially primary mediastinal B-cell lymphoma (PMBL), also had high PD-L2 expression and several B-cell lines showed high PD-L2 surface expression (Supplementary Fig. 1F-H). In general, PD-L2/PD-L1 expression was correlated with cytolytic activity to varying degrees, reflecting adaptive immune response [5, 6]. Importantly, PD-L2/PD-L1-altered samples exhibited a decreased cytolytic activity, compared to non-altered samples showing similar PDL2/PD-L1 expression levels, suggesting an attenuation of antitumor immunity in these tumors (Supplementary Fig. 1I)[6]. Then, we compared the effects of PD-L1 and PD-L2 on the tumor microenvironment (TME) when constitutively expressed at a similar level. Hence, we generated a A20-ovalbumin (OVA) murine B-cell lymphoma line lacking Pd-l1 and introduced murine Pd-l1 or Pd-l2 expression (Supplementary Fig. 2A-E). Syngeneic transplantation revealed that Pd-l1/Pd-l2 overexpression enhanced tumor growth and attenuated CD8+ T-cell infiltration into tumors, which was restored by anti-PD-1 antibody (Supplementary Fig. 2F-J). Furthermore, we constructed single-cell transcriptomic, surface phenotypic (antibody-derived tag [ADT]), and T/B-cell receptor (TCR/BCR) repertoire maps of 22,116 nonmalignant CD45+ cells from mock-/Pd-l1-/Pd-l2-expressing A20-OVA tumors (Fig. 1 C, D; Supplementary Fig. 3A, B; Supplementary Tables 6, 7)[7]. Importantly, Pd-l1-/Pdl2-expressing tumors exhibited similar cellular dynamics and transcriptomic and surface phenotypic changes in the TME (Supplementary Tables 8-10). CD8+ T cells, particularly exhausted CD8+ T cells (CD8Tex) showing high clonality, and regulatory T cells were decreased in Pd-l1/Pd-l2-expressing tumors (Fig. 1 E; Supplementary Fig. 3B). Interestingly, myeloid cells, including monocytes/macrophages (Mono/Macs) and plasmacytoid dendritic cells (pDCs), were or tended to be increased in Pd-l1/Pd-l2-expressing tumors (Fig. 1 E). M1 and M2 macrophage signatures were downregulated and upregulated in Pd-l1/Pd-l2-expressing tumors, respectively, whereas other immune-related signatures were comparable (Supplementary Fig. 3D-F). Responses to bacterial molecules, including lipopolysaccharide, were transcriptionally downregulated in Mono/Macs from Pd-l1/Pd-l2-expressing tumors, suggestive of M2-like antiinflammatory, pro-tumorigenic phenotype (Fig. 1 F)[8]. Furthermore, antigen presentation pathways were suppressed in conventional DCs and pDCs. Consistently, pro-inflammatory cytokine‒inducible markers, such as Ly6A/E and IA/IE, were downregulated in various clusters from Pd-l1/Pd-l2-expressing tumors (Fig. 1 G; Supplementary Fig. 4A, B). Notably, pDC depletion with anti-BST2 antibody inhibited growth of Pd-l1-/Pd-l2-expressing tumors (Fig. 1 H; Supplementary Fig. 4C), suggesting the pro-tumorigenic role of pDCs. Together, our single-cell analysis delineates pleiotropic extrinsic effects shared by PD-L1 and PD-L2, mainly enhancing anti-inflammatory, protumorigenic responses in microenvironmental …