Pimenta Erica Maria, De Saurav, Weiss Ryan, Feng Di, Hall Kelly, Kilic Sarah, Bhanot Gyan, Ganesan Shridar, Ran Sophia, Barnes Betsy J
1] Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers Biomedical and Health Sciences, Newark, NJ, USA [2] Rutgers Biomedical and Health Sciences, New Jersey Medical School-Cancer Center, UMDNJ, Newark, NJ, USA.
Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL, USA.
Immunol Cell Biol. 2015 May-Jun;93(5):486-99. doi: 10.1038/icb.2014.110. Epub 2014 Dec 23.
Clinical studies using prognostic and predictive signatures have shown that an immune signal emanating from whole tumors reflects the level of immune cell infiltration--a high immune signal linked to improved outcome. Factors regulating immune cell trafficking to the tumor, however, are not known. Previous work has shown that expression of interferon regulatory factor 5 (IRF5), a critical immune regulator, is lost in ~80% of invasive ductal carcinomas examined. We postulated that IRF5-positive and -negative breast tumors would differentially regulate immune cell trafficking to the tumor. Using a focused tumor inflammatory array, differences in cytokine and chemokine expression were examined between IRF5-positive and -negative MDA-MB-231 cells grown in three-dimensional culture. A number of cytokines/chemokines were found to be dysregulated between cultures. CXCL13 was identified as a direct target of IRF5 resulting in the enhanced recruitment of B and T cells to IRF5-positive tumor-conditioned media. The ability of IRF5 to regulate mediators of cell migration was confirmed by enzyme-linked immunosorbent assay, chromatin immunoprecipitation assay, small interfering RNA knockdown and immunofluorescence staining of human breast tumor tissues. Analysis of primary immune cell subsets revealed that IRF5 specifically recruits CXCR5(+) B and T cells to the tumor; CXCR5 is the receptor for CXCL13. Analysis of primary breast tumor tissues revealed a significant correlation between IRF5 and CXCL13 expression providing clinical relevance to the study. Together, these data support that IRF5 directly regulates a network of genes that shapes a tumor immune response and may, in combination with CXCL13, serve as a novel prognostic marker for antitumor immunity.
使用预后和预测特征的临床研究表明，源自整个肿瘤的免疫信号反映了免疫细胞浸润水平——高免疫信号与更好的预后相关。然而，调节免疫细胞向肿瘤运输的因素尚不清楚。先前的研究表明，在约80%检测的浸润性导管癌中，关键免疫调节因子干扰素调节因子5（IRF5）的表达缺失。我们推测，IRF5阳性和阴性的乳腺肿瘤会对免疫细胞向肿瘤的运输产生不同的调节作用。使用聚焦肿瘤炎症阵列，检测了在三维培养中生长的IRF5阳性和阴性MDA-MB-231细胞之间细胞因子和趋化因子表达的差异。发现多种细胞因子/趋化因子在培养物之间失调。CXCL13被确定为IRF5的直接靶点，导致B细胞和T细胞向IRF5阳性肿瘤条件培养基的募集增强。通过酶联免疫吸附测定、染色质免疫沉淀测定、小干扰RNA敲低和人乳腺肿瘤组织的免疫荧光染色，证实了IRF5调节细胞迁移介质的能力。对原发性免疫细胞亚群的分析表明，IRF5特异性地将CXCR5(+) B细胞和T细胞募集到肿瘤；CXCR5是CXCL13的受体。对原发性乳腺肿瘤组织的分析表明，IRF5与CXCL13表达之间存在显著相关性，为该研究提供了临床相关性。总之，这些数据支持IRF5直接调节塑造肿瘤免疫反应的基因网络，并且可能与CXCL13一起作为抗肿瘤免疫的新型预后标志物。
