Research Article CK2 Secreted by Leishmania braziliensis Mediates Macrophage Association Invasion: A Comparative Study between Virulent and Avirulent Promastigotes Ana Madeira Brito Zylbersztejn, 1 Carlos Gustavo Vieira de Morais, 1,2 Ana Karina Castro Lima, 1 Joyce Eliza de Oliveira Souza, 1 Angela Hampshire Lopes, 3 Sílvia Amaral Gonçalves Da-Silva, 4 Mário Alberto Cardoso Silva-Neto, 5 and Patrícia Maria Lourenço Dutra 1 1 Laborat´ orio de Bioqu´ ımica de Protozo´ arios e Imunoisiologia do Exerc´ ıcio, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Rua Professor Manuel de Abreu, 444, Pavilh˜ ao Am´ erico Piquet Carneiro, 5 ∘ Andar, 20550-170 Rio de Janeiro, RJ, Brazil 2 Programa de P´ os Graduac ¸˜ ao em Microbiologia/FCM/UERJ, Av. Professor Manuel de Abreu, 444, Pavilh˜ ao Am´ erico Piquet Carneiro, 3 ∘ andar, Vila Isabel, 20550-170, Rio de Janeiro, RJ, Brazil 3 Instituto de Microbiologia Paulo de G´ oes-CCS, Universidade Federal do Rio de Janeiro (UFRJ), Avenida Carlos Chagas Filho, 373, CCS, Bloco I, Ilha do Fund˜ ao, 21941-590 Rio de Janeiro, RJ, Brazil 4 Laborat´ orio de Imunofarmacologia Parasit´ aria, Disciplina de Parasitologia, DMIP, FCM, Universidade do Estado do Rio de Janeiro, Rua Professor Manuel de Abreu 444, Pavilh˜ ao Am´ erico Piquet Carneiro, 5 ∘ Andar, 20550-170 Rio de Janeiro, RJ, Brazil 5 Laborat´ orio de Sinalizac ¸˜ ao Celular, Instituto de Bioqu´ ımica M´ edica-CCS, Universidade Federal do Rio de Janeiro (UFRJ), Avenida Carlos Chagas Filho, 373, CCS, Bloco H, Ilha do Fund˜ ao, 21941-590 Rio de Janeiro, RJ, Brazil Correspondence should be addressed to Patr´ ıcia Maria Lourenc ¸o Dutra; pmldutra@gmail.com Received 27 June 2014; Accepted 28 August 2014 Academic Editor: Miriam Rodriguez-Sosa Copyright © 2015 Ana Madeira Brito Zylbersztejn et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. CK2 is a protein kinase distributed in diferent compartments of Leishmania braziliensis: an externally oriented ecto-CK2, an intracellular CK2, and a secreted CK2. his latter form is constitutively secreted from the parasite (CsCK2), but such secretion may be highly enhanced by the association of speciic molecules, including enzyme substrates, which lead to a higher enzymatic activity, called inductively secreted CK2 (IsCK2). Here, we examined the inluence of secreted CK2 (sCK2) activity on the infectivity of a virulent L. braziliensis strain. he virulent strain presented 121-fold higher total CK2 activity than those found in an avirulent strain. he use of speciic CK2 inhibitors (TBB, DRB, or heparin) inhibited virulent parasite growth, whereas no efect was observed in the avirulent parasites. When these inhibitors were added to the interaction assays between the virulent L. braziliensis strain and macrophages, association index was drastically inhibited. Polyamines enhanced sCK2 activity and increased the association index between parasites and macrophages. Finally, sCK2 and the supernatant of the virulent strain increased the association index between the avirulent strain and macrophages, which was inhibited by TBB. hus, the kinase enzyme CK2 seems to be important to invasion mechanisms of L. braziliensis. 1. Introduction Leishmania braziliensis is an etiological agent of leishmaniasis in the New World [1] that can diferentiate from avirulent to virulent promastigotes in the sandly midgut and from pro- mastigotes to amastigotes in mammalian macrophages. he relationship between the parasite and host cells commonly involves signal transduction pathways that are triggered upon Hindawi Publishing Corporation BioMed Research International Volume 2015, Article ID 167323, 11 pages http://dx.doi.org/10.1155/2015/167323