Protein kinase antagonists inhibit invasion of mammalian cells by Fonsecaea pedrosoi.
The phosphorylation process is an important mechanism of cell signalling and regulation. It has been implicated recently in defence strategies against a variety of pathogens that alter host signalling pathways in order to facilitate their invasion and survival within host cells. In this study, the involvement of protein kinases (PKs) has been investigated in attachment and invasion by the pathogenic fungus Fonsecaea pedrosoi within epithelial cells and macrophages. The use of the PK inhibitors staurosporine, genistein and calphostin C prior to infection provided significant information about the role played by PKs in the F. pedrosoi-host cell interaction. All three PK inhibitors could reduce cell invasion by F. pedrosoi significantly. Pre-treatment of macrophages, epithelial cells or conidia with PK inhibitors decreased fungus invasion, and this effect could be overcome by okadaic acid, a phosphatase inhibitor. Immunofluorescence assays showed that tyrosine residues were phosphorylated in the first step of the interaction, while serine residues were phosphorylated in the subsequent step of entry of the parasite into the host cell. These results suggest that both host-cell and conidium PK activities are important in the interaction process, playing a significant role in cell invasion.
Limongi
Cristiana L
CL
Laboratório de Biologia Celular de Fungos1 and Laboratório de Ultraestrutura Celular Hertha Meyer2, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
De Souza
Wanderley
W
Laboratório de Biologia Celular de Fungos1 and Laboratório de Ultraestrutura Celular Hertha Meyer2, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Rozental
Sonia
S
Laboratório de Biologia Celular de Fungos1 and Laboratório de Ultraestrutura Celular Hertha Meyer2, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
D000818:Animals; D016466:CHO Cells; D002448:Cell Adhesion / Q000187:drug effects; D006224:Cricetinae; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005658:Fungi / Q000187:drug effects* / Q000502:physiology* / Q000648:ultrastructure; D019833:Genistein / Q000494:pharmacology; D009281:Naphthalenes / Q000494:pharmacology; D019319:Okadaic Acid / Q000494:pharmacology; D047428:Protein Kinase Inhibitors; D019311:Staurosporine / Q000494:pharmacology
D004791:Enzyme Inhibitors; D009281:Naphthalenes; D047428:Protein Kinase Inhibitors; D019319:Okadaic Acid; D019833:Genistein; D019311:Staurosporine; C058819:calphostin C