Mycobacterium tuberculosis expressing phospholipase C subverts PGE(2) synthesis and induces necrosis in alveolar macrophages

Author(s)

Assis, Patricia A. ^{[1, 2]} ; Espindola, Milena S. ^{[1, 2]} ; Paula-Silva, Francisco W. G. ^[1] ; Rios, Wendy M. ^[2] ; Pereira, Priscilla A. T. ^[1] ; Leao, Sylvia C. ^[3] ; Silva, Celio L. ^[2] ; Faccioli, Lucia H. ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Anal Clin Toxicol & Bromatol, BR-14040903 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Ciencias Farmaceut Ribeirao Preto, Dept Bioquim & Imunol, BR-14040903 Ribeirao Preto, SP - Brazil

^[3] Univ Fed Sao Paulo, Escola Paulista Med, Dept Microbiol Imunol & Parasitol, Sao Paulo - Brazil

• Document type: Journal article
• Source: BMC Microbiology; v. 14, MAY 19 2014.
• Web of Science Citations: 14

Abstract

Background: Phospholipases C (PLCs) are virulence factors found in several bacteria. In Mycobacterium tuberculosis (Mtb) they exhibit cytotoxic effects on macrophages, but the mechanisms involved in PLC-induced cell death are not fully understood. It has been reported that induction of cell necrosis by virulent Mtb is coordinated by subversion of PGE(2), an essential factor in cell membrane protection. Results: Using two Mtb clinical isolates carrying genetic variations in PLC genes, we show that the isolate 97-1505, which bears plcA and plcB genes, is more resistant to alveolar macrophage microbicidal activity than the isolate 97-1200, which has all PLC genes deleted. The isolate 97-1505 also induced higher rates of alveolar macrophage necrosis, and likewise inhibited COX-2 expression and PGE(2) production. To address the direct effect of mycobacterial PLC on cell necrosis and PGE(2) inhibition, both isolates were treated with PLC inhibitors prior to macrophage infection. Interestingly, inhibition of PLCs affected the ability of the isolate 97-1505 to induce necrosis, leading to cell death rates similar to those induced by the isolate 97-1200. Finally, PGE(2) production by Mtb 97-1505-infected macrophages was restored to levels similar to those produced by 97-1200-infected cells. Conclusions: Mycobacterium tuberculosis bearing PLCs genes induces alveolar macrophage necrosis, which is associated to subversion of PGE(2) production. (AU)

• FAPESP's process: 09/07169-5 - Lipid mediators as regulators of immune response
• Grantee: Lúcia Helena Faccioli
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 11/01845-9 - Study of intracellular signaling involved in eicosanoid production which are dependent on the expression of phospholipase C from Mycobacterium tuberculosis
• Grantee: Patricia Aparecida de Assis
• Support Opportunities: Scholarships in Brazil - Doctorate