Sialoglycoproteins in morphological distinct stages of Mucor polymorphosporus and their influence on phagocytosis by human blood phagocytes.
The possible role of sialic acids in host cells-fungi interaction and their association with glycoproteins were evaluated using a clinical isolate of the dimorphic fungus Mucor polymorphosporus. Lectin-binding assays with spores and yeast cells denoted the presence of surface sialoglycoconjugates containing 2,3- and 2,6-linked sialylglycosyl groups. Western blotting with peroxidase-labeled Limulus polyphemus agglutinin revealed the occurrence of different sialoglycoprotein types in both cell lysates and cell wall protein extracts of mycelia, spores, and yeasts of M. polymorphosporus. Sialic acids contributed to the surface negative charge of spores and yeast forms as evaluated by adherence to a cationic substrate. Sialidase-treated spores were less resistant to phagocytosis by human neutrophils and monocytes from healthy individuals than control (untreated) fungal suspensions. The results suggest that sialic acids are terminal units of various glycoproteins of M. polymorphosporus, contributing to negative charge of yeasts and spore cells and protecting infectious propagules from destruction by host cells.
Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, sala 050, Rio de Janeiro, RJ, CEP: 21941-902, Brazil, catiamancio@yahoo.com.br.
Catia Amancio
CA
Almeida
Galba Maria
GM
de Campos-Takaki
Maristela Barbosa
MB
Portela
Luiz R
LR
Travassos
Celuta Sales
CS
Alviano
Daniela Sales
DS
Alviano
D001769:Blood / Q000276:immunology*; D006801:Humans; D025301:Hyphae / Q000737:chemistry / Q000276:immunology; D037102:Lectins / Q000378:metabolism; D009089:Mucor / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D009091:Mucormycosis / Q000382:microbiology; D010586:Phagocytes / Q000276:immunology*; D010587:Phagocytosis / Q000187:drug effects*; D011485:Protein Binding; D012795:Sialoglycoproteins / Q000276:immunology* / Q000378:metabolism*; D013172:Spores, Fungal / Q000737:chemistry / Q000276:immunology; D055672:Static Electricity
D037102:Lectins; D012795:Sialoglycoproteins