Stimulation of Leishmania tropica protein kinase CK2 activities by platelet-activating factor (PAF).
Leishmania tropica is one of the causative agents of cutaneous leishmaniasis. Platelet-activating factor (PAF) is a phospholipid mediator in diverse biological and pathophysiological processes. Here we show that PAF promoted a three-fold increase on ecto-protein kinase and a three-fold increase on the secreted kinase activity of L. tropica live promastigotes. When casein was added to the reaction medium, along with PAF, there was a four-fold increase on the ecto-kinase activity. When live L. tropica promastigotes were pre-incubated for 30 min in the presence of PAF-plus casein, a six-fold increase on the secreted kinase activity was observed. Also, a protein released from L. tropica promastigotes reacted with polyclonal antibodies for the mammalian CK2 alpha catalytic subunit. Furthermore, in vitro mouse macrophage infection by L. tropica was doubled when promastigotes were pre-treated for 2 h with PAF. Similar results were obtained when the interaction was performed in the presence of purified CK2 or casein. TBB and DRB, CK2 inhibitors, reversed PAF enhancement of macrophage infection by L. tropica. WEB 2086, a competitive PAF antagonist, reversed all PAF effects here described. This study shows for the first time that PAF promotes the activation of two isoforms of CK2, secreted and membrane-bound, correlating these activities to infection of mouse macrophages.
Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Rua Professor Manoel de Abreu, 444, PAPC 5 degrees andar, Vila Isabel, 20550-170, Rio de Janeiro, Brazil.
Patricia M L
PM
Dutra
Danielle P
DP
Vieira
Jose R
JR
Meyer-Fernandes
Mario A C
MA
Silva-Neto
Angela H
AH
Lopes
D000818:Animals; D047390:Casein Kinase II / Q000096:biosynthesis*; D002478:Cells, Cultured; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D007895:Leishmania tropica / Q000201:enzymology*; D017737:Macrophages, Peritoneal / Q000469:parasitology; D051379:Mice; D008807:Mice, Inbred BALB C; D010972:Platelet Activating Factor / Q000378:metabolism*; D015800:Protozoan Proteins / Q000096:biosynthesis*
D010972:Platelet Activating Factor; D015800:Protozoan Proteins; D047390:Casein Kinase II