The Korea Advanced Institute of Science and Technology (KAIST) has announced that the binding between intraflagellar transport 20 (IFT20) and tumor susceptibility gene 101 (TSG101) is a significant factor in the development of immunological synapses.

According to the research team, led by Doctor Jeong Ji-ung at KAIST Graduate School of Medical Science and Engineering, CD4+ T cells have significant functions in the adaptive immune system, which necessitates the identification of antigens, costimulation, and cytokines for its intricate coordination.

Recent studies have provided new insight into the importance of the supramolecular activation cluster (SMAC), which comprises concentric circles and is involved in the amplification of CD4+ T cell activation.

However, the underlying mechanism of SMAC formation remains poorly understood. 

As a result, the research team used single-cell transcriptome analysis to identify increased expression of IFT20 in activated CD4+ T cells.

Using yeast protein hybridization and immunoprecipitation to identify proteins that bind to IFT20, the researchers discovered for the first time in the world that IFT20 binds to TSG101 and to each other.

To confirm its theory on live test subjects, the team created mice lacking TSG101 and found that CD4+ T cells lacking TSG101 had reduced immunologic synapse formation compared to normal CD4+ T cells.

The team stressed that this is significant as it reveals previously unknown roles of IFT20 and TSG101 in immunologic synapse formation, providing clues to regulate T-cell activation.

"This is an important study identifying proteins that regulate immunological synapse formation that has been poorly understood," Jeong said.

The results of the research were published in the online edition of "Cellular & Molecular Immunology" on April 7.