Sophisticated Functions for a Simple Molecule: The Role of Glucosylceramides in Fungal Cells

Professor Luiz R. Travassos and the study of surface structures of fungal pathogens

Brazilian medical mycology considerably expanded in the last decades due to the efforts of several pioneers who started and expanded mycology during the twentieth century. In this manuscript, we highlight some of the contributions of one of these pioneers: Professor Luiz R. Travassos, who started his career in the field of microbiology in the 1960s. We will discuss his contributions to the areas of medical mycology and glycobiology, with a focus on glycosphingolipids, sialic acids, and surface enzymes.

Transcriptome Analysis of Choke Stroma and Asymptomatic Inflorescence Tissues Reveals Changes in Gene Expression in Both Epichloë festucae and Its Host Plant Festuca rubra subsp. rubra

Many cool-season grasses have symbiotic relationships with Epichloë (Ascomycota, Clavicipitaceae) fungal endophytes that inhabit the intercellular spaces of the above-ground parts of the host plants. The presence of the Epichloë endophytes is generally beneficial to the hosts due to enhanced tolerance to biotic and abiotic stresses conferred by the endophytes. Many Epichloë spp. are asexual, and those infections always remain asymptomatic. However, some Epichloë spp. have a sexual stage and produce a macroscopic fruiting body, a stroma, that envelops the developing inflorescence causing a syndrome termed "choke disease". Here, we report a fungal and plant gene expression analysis of choke stroma tissue and asymptomatic inflorescence tissue of Epichloë festucae-infected strong creeping red fescue (Festuca rubra subsp. rubra). Hundreds of fungal genes and over 10% of the plant genes were differentially expressed when comparing the two tissue types. The differentially expressed fungal genes in the choke stroma tissue indicated a change in carbohydrate and lipid metabolism, as well as a change in expression of numerous genes for candidate effector proteins. Plant stress-related genes were up-regulated in the stroma tissue, suggesting the plant host was responding to the epiphytic stage of E. festucae as a pathogen.

Antifungal and antitumor models of bioactive protective peptides

Peptides are remarkably reactive molecules produced by a great variety of species and able to display a number of functions in uni-and multicellular organisms as mediators, agonists and regulating substances. Some of them exert cytotoxic effects on cells other than those that produced them, and may have a role in controlling subpopulations and protecting certain species or cell types. Presently, we focus on antifungal and antitumor peptides and discuss a few models in which specific sequences and structures exerted direct inhibitory effects or stimulated a protective immune response. The killer peptide, deduced from an antiidiotypic antibody, with several antimicrobial activities and other Ig-derived peptides with cytotoxic activities including antitumor effects, are models studied in vitro and in vivo. Peptide 10 from gp43 of P. brasiliensis (P10) and the vaccine perspective against paracoccidioidomycosis is another topic illustrating the protective effect in vivo against a pathogenic fungus. The cationic antimicrobial peptides with antitumor activities are mostly reviewed here. Local treatment of murine melanoma by the peptide gomesin is another model studied at the Experimental Oncology Unit of UNIFESP.