Campa Michael J, Moody M Anthony, Zhang Ruijun, Liao Hua-Xin, Gottlin Elizabeth B, Patz Edward F
Department of Radiology, Duke University Medical Center, Box 3808, Durham, NC, 27710, USA.
Department of Pediatrics, Duke University Medical Center, Durham, NC, 27710, USA.
Cancer Immunol Immunother. 2016 Feb;65(2):171-80. doi: 10.1007/s00262-015-1787-0. Epub 2016 Jan 6.
Intratumoral B lymphocytes are an integral part of the lung tumor microenvironment. Interrogation of the antibodies they express may improve our understanding of the host response to cancer and could be useful in elucidating novel molecular targets. We used two strategies to explore the repertoire of intratumoral B cell antibodies. First, we cloned VH and VL genes from single intratumoral B lymphocytes isolated from one lung tumor, expressed the genes as recombinant mAbs, and used the mAbs to identify the cognate tumor antigens. The Igs derived from intratumoral B cells demonstrated class switching, with a mean VH mutation frequency of 4%. Although there was no evidence for clonal expansion, these data are consistent with antigen-driven somatic hypermutation. Individual recombinant antibodies were polyreactive, although one clone demonstrated preferential immunoreactivity with tropomyosin 4 (TPM4). We found that higher levels of TPM4 antibodies were more common in cancer patients, but measurement of TPM4 antibody levels was not a sensitive test for detecting cancer. Second, in an effort to focus our recombinant antibody expression efforts on those B cells that displayed evidence of clonal expansion driven by antigen stimulation, we performed deep sequencing of the Ig genes of B cells collected from seven different tumors. Deep sequencing demonstrated somatic hypermutation but no dominant clones. These strategies may be useful for the study of B cell antibody expression, although identification of a dominant clone and unique therapeutic targets may require extensive investigation.
肿瘤内B淋巴细胞是肺肿瘤微环境的一个组成部分。对它们所表达抗体的研究可能会增进我们对宿主对癌症反应的理解，并有助于阐明新的分子靶点。我们采用了两种策略来探索肿瘤内B细胞抗体的库。首先，我们从一个肺肿瘤中分离出的单个肿瘤内B淋巴细胞中克隆VH和VL基因，将这些基因表达为重组单克隆抗体，并使用这些单克隆抗体来鉴定相关的肿瘤抗原。从肿瘤内B细胞衍生的免疫球蛋白显示出类别转换，平均VH突变频率为4%。虽然没有克隆扩增的证据，但这些数据与抗原驱动的体细胞超突变一致。单个重组抗体具有多反应性，尽管有一个克隆显示出对原肌球蛋白4（TPM4）的优先免疫反应性。我们发现，癌症患者中TPM4抗体水平较高的情况更为常见，但检测TPM4抗体水平并不是检测癌症的敏感试验。其次，为了将我们的重组抗体表达工作集中在那些显示出由抗原刺激驱动的克隆扩增证据的B细胞上，我们对从七个不同肿瘤中收集的B细胞的免疫球蛋白基因进行了深度测序。深度测序显示了体细胞超突变，但没有优势克隆。这些策略可能对B细胞抗体表达的研究有用，尽管鉴定优势克隆和独特的治疗靶点可能需要广泛的研究。
