Critical Role of TLR2 and MyD88 for Functional Response of Macrophages to a Group IIA-Secreted Phospholipase A(2) from Snake Venom

Author(s)

Leiguez, Elbio ^[1] ; Giannotti, Karina Cristina ^[1] ; Moreira, Vanessa ^[1] ; Matsubara, Marcio Hideki ^[1] ; Maria Gutierrez, Jose ^[2] ; Lomonte, Bruno ^[2] ; Pablo Rodriguez, Juan ^{[3, 4]} ; Balsinde, Jesus ^[4] ; Teixeira, Catarina ^[1]

Affiliation

^[1] Inst Butantan, Farmacol Lab, Sao Paulo - Brazil

^[2] Univ Costa Rica, Fac Microbiol, Inst Clodomiro Picado, San Jose - Costa Rica

^[3] Univ Nacl Nordeste, FACENA, Lab Invest Prot, Corrientes - Argentina

^[4] Inst Biol & Genet Mol, Eicosanoid Res Div, Valladolid - Spain

• Document type: Journal article
• Source: PLoS One; v. 9, n. 4 APR 9 2014.
• Web of Science Citations: 5

Abstract

The snake venom MT-III is a group IIA secreted phospholipase A(2) (sPLA(2)) enzyme with functional and structural similarities with mammalian pro-inflammatory sPLA(2)s of the same group. Previously, we demonstrated that MT-III directly activates the innate inflammatory response of macrophages, including release of inflammatory mediators and formation of lipid droplets (LDs). However, the mechanisms coordinating these processes remain unclear. In the present study, by using TLR2(-/-) or MyD88(-/-) or C57BL/6 (WT) male mice, we report that TLR2 and MyD88 signaling have a critical role in MT-III-induced inflammatory response in macrophages. MT-III caused a marked release of PGE(2), PGD(2), PGJ(2), IL-1 beta and IL-10 and increased the number of LDs in WT macrophages. In MT-III-stimulated TLR2(-/-) macrophages, formation of LDs and release of eicosanoids and cytokines were abrogated. In MyD88(-/-) macrophages, MT-III-induced release of PGE(2), IL-1 beta and IL-10 was abrogated, but release of PGD(2) and PGJ(2) was maintained. In addition, COX-2 protein expression seen in MT-III-stimulated WT macrophages was abolished in both TLR2(-/-) and MyD88(-/-) cells, while perilipin 2 expression was abolished only in MyD88 2/2 cells. We further demonstrated a reduction of saturated, monounsaturated and polyunsaturated fatty acids and a release of the TLR2 agonists palmitic and oleic acid from MT-III-stimulated WT macrophages compared with WT control cells, thus suggesting these fatty acids as major messengers for MT-III-induced engagement of TLR2/MyD88 signaling. Collectively, our findings identify for the first time a TLR2 and MyD88-dependent mechanism that underlies group IIA sPLA(2)-induced inflammatory response in macrophages. (AU)

• FAPESP's process: 10/06345-1 - Study of factors involved in lipid bodies formation induced by a Phospholipase A2, isolated from Bothrops asper snake venom: synthesis and metabolism of lipids
• Grantee: Elbio Leiguez Junior
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 11/21341-5 - Studies on the mechanisms involved in lipid body formation induced by a snake venom phospholipase A2 in isolated macrophages: participation of lipid homeosthasis factors
• Grantee: Catarina de Fatima Pereira Teixeira
• Support type: Regular Research Grants