Book a Meeting


Research Highlights

One-Step Enzymatic Modification of the Cell Surface Redirects Cellular Cytotoxicity and Parasite Tropism


Research Overview

There are three approaches to engineer and functionalize the eukaryotic cell surface, which are genetic manipulation, covalent modification of glycans or lipids, and noncovalent modification using bifunctional small molecules or antibody moieties, which make it possible to visualize the molecules that are not responsive to genetic engineering, antibody function enhancement, or targeted lymphocyte engagement for therapeutics. However, the risks of de novo tumor development caused by the transfer of genetically engineered cells require alternative approaches to functionalize the plasma membrane of the lymphocyte.

In this research paper, the team of Lee Kim Swee demonstrated the conjugation of LPXTG-tagged probes and LPXTG-bearing proteins to endogenous acceptors at the plasma membrane in one step by sortase A. In addition, they also successfully combined the biotin probes to mouse hematopoietic cells, yeast cells, 293T cells, and Toxoplasma gondii.

Methods and Materials

The research adopted the following materials and experimental methods.


The team engineered the cell surface using Sortase A from bacteria by conjugating modified probes to the C-terminus of recombinant LPETG-tagged proteins and presumed that on the surface of most cells there are naturally exposed glycines amenable to sortagging.

They incubated cytotoxic OTI CD8 T cells with sdAb with/without sortase A to test whether LPETG-tagged single domain antibodies could be attached to the surface of activated CD8 T cells through sortagging. The cells ability to bind GFP was measured to monitor VHHs installation and evaluate their specificity in a cell-bound format. Data showed that sortagging of VHHs to cells only minimally affects subsequent conjugation of biotin-LPETG. They also verified that VHHs can be sortagged on the T cell and meanwhile maintaining their antigen binding capacity. Their enzymatic method presented multiple advantages, offering a new chance for the functionalization of lymphocytes with cytotoxic and therefore improve targeted therapy of tumor.

The team studied cell-cell interactions by investigating whether the Toxoplasma gondii could still invade specific host cells after modification, and obtained positive results as presumed. The sortase enzymes method can be applied to not only gram-positive bacteria, but also parasite and even viruses.

To conclude, the existence of endogenous nucleophiles provides an enzymatic approach that disposes of genetic modification or extreme chemical conditions to install designated substances on living cell surface.

Related Services

All services are only provided for research purposes and Not for clinical use.


  • *
  • *
  • *

United Kingdom