Blocking Effect of Chaga Mushroom (Inonotus oliquus) Extract for Immune Checkpoint CTLA-4/CD80 Interaction

Tae In Kim,Hwan-Suck Chung,Ji Hye Kim,Jang-Gi Choi,Wei Li

doi:10.3390/app10175774

Abstract

Inonotus obliquus, also known as the Chaga mushroom, has been used as a traditional medicine to treat many different diseases in Asia. Ethanol and water extraction were performed to examine the blocking effect of the Chaga mushroom on the CTLA-4/CD80 interaction. The inhibitory activities of the Chaga mushroom/70% EtOH extract (CME) and the Chaga mushroom/water extract (CMW) were confirmed using several cell-based assays. To identify the contents of major compounds CME and CMW, we performed HPLC analysis. The content of lanosterol (1) in CME was 0.41%. Our findings provide experimental evidence that the Chaga mushroom can develop a small-molecule inhibitor that blocks the CTLA-4/CD80 interaction.

Highlights

Inonotus obliquus, commonly known as the Chaga mushroom, belongs to the familyHymenochaetaceae, and is a parasite mainly found on the birch tree
We previously reported compounds derived from the medicinal plant that inhibit the immune checkpoint interactions PD-1/PD-L1 and CTLA-4/CD80 [9]
We investigated an immune checkpoint inhibitor that blocks the CTLA-4/CD80 interaction, using a cell-based assay and HPLC analysis

Summary

Introduction

Commonly known as the Chaga mushroom, belongs to the familyHymenochaetaceae, and is a parasite mainly found on the birch tree (betula platyphlla var. japonica). It is widely distributed in Russia, China, and Alaska, and has diverse bioactivities, such as anti-inflammatory effects [1], anti-nociceptive effects [2], and inhibition of cell cycle progression [3]. Several constituents, including triterpenoids [4,5], phenolic acids [6], and polysaccharides [7], have previously been reported as contributing to these bioactivities. Research on the Chaga mushroom is ongoing, its potential to block immune checkpoints, especially CTLA-4/CD80, is not well understood. We previously reported compounds derived from the medicinal plant that inhibit the immune checkpoint interactions PD-1/PD-L1 and CTLA-4/CD80 [9]. We investigate the blocking effect of Chaga mushroom extract on the CTLA-4/CD80 interaction, by using in vitro assay and HPLC analysis

Methods

Results

Discussion

Conclusion