Single Cell Proteomics Platform

Challenges for Cancer Immunotherapy

Cancer immunotherapy is a method of treating cancer by modulating an immune response, including monoclonal antibody (mAb) treatment and adoptive cell transfer (ACT) treatment for immune cells. mAb therapy, based on stimulating T cell function by blocking or activating immunoregulatory pathways, has achieved significant clinical responses in a variety of tumor types. However, not all patients can maintain a durable immune response after treatment. Therefore, it is critical to identify predictive biomarkers to select patients who will benefit from the therapy. However, the complexity of the tumor microenvironment and the dynamic nature of the immune response make this attempt difficult and requires a new tool to address immune and tumor-immune interactions at single-cell level.

Advantages for Single Cell Proteomics

Understanding cell characteristics and interactions from each other at single-cell level can provide more valuable information for intercellular heterogeneity in biological systems. Single-cell proteomics is the most common and effective method for studying cellular function and heterogeneity by systematically analyzing functional protein levels in many single cells from different cell types. Single-cell proteomics provides a clinical tool for assessing the immune system, immune cells manipulated in tumor microenvironment.

As an important molecule involved in various physiological processes in cells, protein is typically generated or released in multiple, transient pulses, and low abundance. Because genomic analysis lacks efficient PCR-like amplification techniques, for single-cell proteomics, Single Cell uses multiple analytical techniques to evaluate a range of important parameters from immune diversity, intratumoral heterogeneity, to intercellular communication. We developed diverse single cell proteomics platforms including:

Single Cell Flow Cytometry Platform

• Single Cell Fluorescence Flow Cytometry. The target protein in the cells is labeled by a fluorophore, and the bound antibody is detected one by one by high-throughput by laser-activated fluorescence.
• Single Cell Mass Cytometry (CyTOF). Mass cytometry. Antibody labeling using rare metal isotopes instead of fluorophores breaks through the multiple capacity limits of FFC.
• Single Cell Enzyme-Linked Immunospot (ELISpot). The ELISpot assay is a widely used, sensitive method for single-cell cytokine secretion monitoring based on sandwich immunoassay.

Single Cell Microchip-Based Platform

• Single Cell Image Cytometry. It is a technology that integrates the advantages of image analysis and microfluidics. Microfluidic tools have the unique advantage of precise control and operation of sub-microliter volumetric fluids.
• Single Cell Microengraving Method. Microengraving, based on isolating single cells in microwells with a glass slide coated with antigen or primary antibody, is a miniaturized, high-throughput FluoroSpot assay.
• Single Cell Barcode Microchip. Protein analysis was performed by spatially immobilized primary antibody barcodes of high uniformity and density.
• Single Cell Western Blotting. Single-cell western blotting is a miniaturized analysis tool for single-cell intracellular proteins based on conventional western blotting and immunoassays.

DNA Barcoding Method

DNA barcode-based protein measurement method converts protein signals into barcoded oligonucleotide probes and amplifies signals by nucleic acid amplification for ultra-sensitive detection, even detecting single-molecule levels, making it ideal for detecting cancer low abundance surface markers of cells or rare molecular tumor cells.