Finding of a novel fungal immunomodulatory protein coding sequence in Ganoderma australe

Among the most common human diseases with immune system compromise are autoimmune diseases, cancer, and the acquired immunodeficiency syndrome (AIDS). Many of these diseases still have no treatment or their therapies have undesirable side effects. This has aroused a great interest in the search for new natural products with therapeutic potential and scientifically proven effects, showing minimal side effects. Formal clinical and pharmacological investigation in various medicinal fungi of the genus Ganoderma (Ganodermataceae) has shown immunomodulatory effects and tumor growth inhibition in mammals, attributable to the presence of immunomodulatory proteins and other secondary metabolites. To date, six fungal immunomodulatory proteins (FIPs) have been reported in Ganoderma. This paper seeks to advance in the discovery of immunomodulatory proteins present in Ganoderma australe, through mycelium transcriptome 454 Roche® pyrosequencing (RNA-seq) and bioinformatics analyses. The results suggest the presence of gene sequences related to an immunomodulatory protein which has been reported only once in other fungal species Taiwanofungus camphoratus. The candidate gene sequences found in G. australe exhibit high identity values in their amino acid composition and predicted protein secondary structure with the protein reported for Tai. camphoratus. According to present knowledge about the action mechanisms of these proteins, it is possible to suggest that this is a promising molecule for the treatment and prevention of diseases associated with certain immune deficiencies, cancer, and other diseases with compromised immune systems. Future studies are proposed in order to determine its immunomodulatory potential using in vitro and in vivo assays.