NEW YORK – Backed by a recent €12.5 million ($14.7 million) award from the European Innovation Council (EIC) Accelerator, Swedish proteomics firm Pixelgen is looking to expand the applications of its spatial proteomics technology.

纽约——瑞典蛋白质组学公司 Pixelgen 近日获得欧洲创新委员会 (EIC) 加速器 1250 万欧元（1470 万美元）的资助，正寻求拓展其空间蛋白质组学技术的应用。

The company's new assay chemistry, which is detailed in a

该公司新的检测化学方法，其详细信息见

BioRxiv

生物预印本（BioRxiv）

preprint

预印本

published this week, will allow it to move into areas including protein-protein interaction research and cell-to-cell signaling, said Simon Fredriksson, Pixelgen's cofounder and CEO.

本周出版，将使其能够进入包括蛋白质-蛋白质相互作用研究和细胞间信号传导在内的领域，Pixelgen 的联合创始人兼首席执行官 Simon Fredriksson 表示。

Founded in 2020, Stockholm-based Pixelgen uses DNA-tagged antibodies to quantify and locate proteins on the surface of single cells, allowing researchers to better understand patterns of cell surface protein localization and interaction.

成立于2020年，总部位于斯德哥尔摩的Pixelgen利用带有DNA标记的抗体对单细胞表面的蛋白质进行量化和定位，使研究人员能够更好地理解细胞表面蛋白质的定位和相互作用模式。

The company's initial product, its Single Cell Spatial Proteomics (SCSP) Kit, used incubation of fixed single cells with nucleic acid-tagged antibodies to cell surface proteins of interest. Users then treated the cells with pieces of DNA containing sequences designed to fuse with the DNA tag on the antibody.

该公司最初的产品是其单细胞空间蛋白质组学（SCSP）试剂盒，该试剂盒通过将固定的单细胞与标记有核酸的抗体孵育，以结合感兴趣的细胞表面蛋白。用户随后用含有设计为与抗体上的DNA标签融合的序列的DNA片段处理这些细胞。

The final step of the assay used elongation to link all of these DNA pixels to each other, forming a grid of DNA tags that allowed researchers to identify both which proteins were present on the cell surface and where on the cell they are located. Readout of the grid was done using next-generation sequencing on Illumina instruments..

该检测的最后一步利用延伸将所有这些DNA像素连接在一起，形成一个DNA标签网格，使研究人员能够识别细胞表面存在哪些蛋白质以及它们在细胞上的位置。网格的读取是通过Illumina仪器上的下一代测序完成的。

Pixelgen's new assay chemistry improves upon this initial product by linking the nucleic-acid tagged detection antibody bound to proteins of interest directly to other detection antibodies bound to nearby proteins. In the assay, called the Pixelgen Proxiome Kit, the nucleic acid tags bound to a detection antibody undergo rolling circle amplification, producing a number of copies that can then be linked to the nucleic acid tags of other nearby antibodies by hybridization of a linker sequence.

Pixelgen的新检测化学技术通过将与目标蛋白结合的核酸标记检测抗体直接连接到与邻近蛋白结合的其他检测抗体，改进了这一初始产品。在名为Pixelgen Proxiome Kit的检测中，与检测抗体结合的核酸标签会经历滚环扩增，产生多个拷贝，然后通过连接序列的杂交，这些拷贝可以连接到其他附近抗体的核酸标签上。

Gap-fill ligation is then used to produce oligonucleotide sequences containing the nucleic acid tag from both antibodies, which can then be read out via sequencing..

然后使用缺口连接法生成包含来自两种抗体的核酸标签的寡核苷酸序列，之后可以通过测序读取。

With the SCSP, 'we generated 1,500 spatial zones across the surface of the cell,' Fredriksson said. 'But now [with the Proxiome Kit], we have 40,000 unique spatial positions … so the resolution is much higher.'

“通过SCSP，‘我们在细胞表面生成了1500个空间区域，’弗雷德里克森说。‘但现在[使用Proxiome试剂盒]，我们有40,000个独特的空间位置……所以分辨率要高得多。’”

That higher resolution makes the assay useful for studying not just protein localization and colocalization but also protein-protein interactions, Fredriksson said.

Fredriksson 表示，更高的分辨率使该检测方法不仅适用于研究蛋白质定位和共定位，还适用于研究蛋白质-蛋白质相互作用。

'That's what we are pushing for now,' he said. 'The true mechanism of how cells operate is by proteins, and they don't work alone. They work together by interacting with other proteins. That's what we need to study to get to the next level of functional insights into cell behavior in health and disease.'.

“这正是我们目前所追求的，”他说道。“细胞运作的真正机制在于蛋白质，而且它们并非单独工作。它们通过与其他蛋白质相互作用来共同发挥作用。要深入了解健康和疾病中细胞行为的功能，这就是我们需要研究的方向。”

Fredriksson said that the quantitative protein data provided by the Proxiome system allows it to more confidently identify protein-protein interactions.

弗雷德里克松表示，Proxiome系统提供的定量蛋白质数据使其能够更可靠地识别蛋白质-蛋白质相互作用。

'We can normalize each network for abundance,' he said. 'If you have two proteins that are very abundant, they will naturally be close to each other more often just by random chance. We normalize our data based on what would be predicted by random chance and how much each pairwise colocalization event deviates from that random prediction.'.

‘我们可以根据丰度对每个网络进行标准化，’他说。‘如果你有两种非常丰富的蛋白质，它们自然会由于随机机会更频繁地靠近彼此。我们基于随机机会的预测以及每对共定位事件与该随机预测的偏差来标准化我们的数据。’

Pixelgen launched the first Proxiome Kit, the Immuno 155, in February. That assay contains antibodies to 155 immune cell surface targets, mapping up to 50,000 proteins per cell with an average spatial resolution of 50 nanometers. Fredriksson said that a single researcher can process around two kits per week, with each kit processing eight samples and each sample containing 1,000 cells..

今年2月，Pixelgen推出了首个Proxiome试剂盒Immuno 155。该检测包含针对155个免疫细胞表面靶标的抗体，能够以平均50纳米的空间分辨率对每个细胞最多映射50,000种蛋白质。Fredriksson表示，一名研究人员每周大约可以处理两个试剂盒，每个试剂盒可处理八个样本，每个样本包含1,000个细胞。

Fredriksson said Pixelgen has seen strong interest in its kits from researchers in areas like hematological oncology and CAR T research, where scientists are interested in studying the spatial organization of proteins on CAR T cells under development and how it correlates with their function, he said..

弗雷德里克松说，Pixelgen 已经看到了研究人员对这些工具包的浓厚兴趣，特别是在血液肿瘤学和 CAR-T 研究领域，科学家们有兴趣研究正在开发中的 CAR-T 细胞上蛋白质的空间组织，以及它如何与它们的功能相关联。

He declined to say how many kits the company has sold to date.

他拒绝透露公司迄今为止已经卖出了多少套件。

Moving forward, Pixelgen is looking to explore applications such as cell-to-cell interaction studies and mapping of intracellular proteins and protein-protein interactions.

展望未来，Pixelgen正寻求探索诸如细胞间相互作用研究以及细胞内蛋白质和蛋白质-蛋白质相互作用的映射等应用。

Regarding cell-to-cell interactions, Fredriksson said the company aims first to enable researchers to map proteins on the cell surfaces of cells as they exist in cell-to-cell complexes. A longer-term goal is the study of interactions between proteins on different cells that are in complex with each other..

关于细胞间相互作用，Fredriksson表示，公司首先旨在帮助研究人员绘制存在于细胞间复合体中的细胞表面蛋白质。更长期的目标是研究彼此形成复合体的不同细胞上蛋白质之间的相互作用。

Enabling this second mode is both a chemistry challenge in terms of sourcing suitable antibodies and a data-analysis challenge in terms of developing the necessary algorithms, Fredriksson said.

弗雷德里克森说，启用这种第二种模式既是一个化学挑战，涉及获取合适的抗体，也是一个数据分析挑战，涉及开发必要的算法。

The data-analysis challenge will also grow as Pixelgen scales its protein content, he said. 'It becomes a lot more data to crunch, both in terms of the algorithms [needed] and just the computer processing.'

他说，随着Pixelgen扩展其蛋白质含量，数据分析挑战也将增加。“无论是就[所需]算法而言，还是仅仅是计算机处理能力，都需要处理更多的数据。”

While the Immuno 155 kit measures up to 155 proteins, Fredriksson said he expects there are around 500 to 800 cell surface proteins that could be of interest to researchers.

虽然Immuno 155试剂盒可以测量多达155种蛋白质，但Fredriksson表示，他认为大约有500到800种细胞表面蛋白质可能引起研究人员的兴趣。

The intracellular proteome is much larger, he noted. 'There are so many interesting signaling cascades to study there in immunology and other research areas.'

他指出，细胞内蛋白质组要大得多。‘在免疫学和其他研究领域，有许多有趣的信号级联需要研究。’

The recent EIC award will support Pixelgen's efforts to move into these areas. One of 40 awards announced this week by the EIC, it consists of €2.5 million in grant funding and a €10 million equity investment.

最近的EIC奖项将支持Pixelgen进军这些领域。这是EIC本周宣布的40个奖项之一，包含250万欧元的拨款和1000万欧元的股权投资。

The award follows a $7.3 million

该奖项紧随一笔730万美元的金额之后。

Series A

A轮

funding round

融资轮次

Pixelgen closed in 2023 and a $6 million

Pixelgen于2023年关闭，市值达600万美元。

seed round

种子轮

it closed in 2022.

它于2022年关闭。