Elucidating the natural function of cordycepin, a metabolite of the fungus Cordyceps militaris

Supervisors: Dr Graham Teakle and Dr Dave Chandler

Funded by: BBSRC

Project summary

Entomopathogenic fungi (EPF) infect and kill insects. They have a large potential for use in integrated pest management (IPM) and those used currently in the UK include Beauveria bassiana, Metarhizium brunneum and Lecanicillium muscarium.

Galleria mellonella cadavers infected with B. bassiana

Cordyceps militaris is an EPF that is widely distributed and morphologically diverse, although it rarely occurs in the UK. Its most common hosts are lepidopteran larvae and pupae. It produces the secondary metabolite cordycepin (3’-deoxyadenosine) which is thought to facilitate infection of host insects, however little is known about the mechanisms behind this. Previous research into cordycepin has focused on its medicinal potential, with publications showing its anti-tumour, anti-angiogenic, anti- inflammatory and anti-ageing properties. Understanding the function of cordycepin in natural infection could benefit this medicinal research. It may also show the potential of this compound for use as a biopesticide or in conjunction with traditional biopesticides as part of an IPM strategy.

Injection of G. mellonella during bioassays

This project focuses on elucidating the natural function of cordycepin, concentrating on its impact on the insect immune system. A series of bioassays and qRT-PCR analyses have been carried out in Galleria mellonella and Drosophila melanogaster cells. They have found that cordycepin is able to inhibit the immune response by reducing the expression of anti-microbial peptides (AMPs). This indicates that cordycepin is likely to have an important role in facilitating the infection of insects in nature and the mechanism by which it does this may underlie its medicinal properties.

v.woolley@warwick.ac.uk