Extracellular vesicles released by J774A.1 macrophages reduce the bacterial load in macrophages and in an experimental mouse model of tuberculosis

Mariano García-Martínez, Luis Vázquez-Flores, Violeta D. Álvarez-Jiménez, Jessica Castañeda-Casimiro, Miguel Ibáñez-Hernández, Luvia Enid Sánchez-Torres, Jorge Barrios-Payán, Dulce Mata-Espinosa, Sergio Estrada-Parra, Rommel Chacón-Salinas, Jeanet Serafín-López, Isabel Wong-Baeza, Rogelio Hernández-Pando, Iris Estrada-García1

Research output: Contribution to journalArticlepeer-review

17 Scopus citations

Abstract

Background: Tuberculosis is the leading cause of death by an infectious microorganism worldwide. Conventional treatment lasts at least six months and has adverse effects; therefore, it is important to find therapeutic alternatives that reduce the bacterial load and may reduce the treatment duration. The immune response against tuberculosis can be modulated by several mechanisms, including extracellular vesicles (EVs), which are nano-sized membrane-bound structures that constitute an efficient communication mechanism among immune cells. Methods: The EVs released by the J774A.1 mouse macrophage cell line, both spontaneously (S-EV) and after infection with Mycobacterium tuberculosis H37Rv (Mtb-EV), were purified by ultra-centrifugation and size-exclusion chromatography. The size distribution and chemical composition of these EVs were evaluated, and their effect on the bacterial load and the production of cytokines was determined in both in vitro and in vivo models of M. tuberculosis infection. Results: Mtb-EV are larger than S-EV, they contain M. tuberculosis-specific antigens (not detected in EVs released from M. fortuitum-infected J774A.1 cells) and are rich in phosphatidylserine, present in their outer membrane layer. S-EV, but not Mtb-EV, reduced the bacterial load and the production of MCP-1 and TNF-α in M. tuberculosis-infected macrophages, and these effects were reversed when phosphatidylserine was blocked with annexin V. Both S-EV and Mtb-EV significantly reduced the lung bacterial load in mice infected with M. tuberculosis after 60 days of treatment, but they had no effect on survival or on the lung pneumonic area of these mice. Conclusion: J774A.1 macrophages infected with M. tuberculosis H37Rv released EVs that differed in size and phosphatidylserine content from spontaneously released EVs, and these EVs also had different biological effects: S-EV reduced the mycobacterial load and the cytokine production in vitro (through a phosphatidylserine-dependent mechanism), while both EVs reduced the lung bacterial load in vivo. These results are the basis for further experiments to evaluate whether EVs improve the efficiency of the conventional treatment for tuberculosis.

Original languageEnglish
Pages (from-to)6707-6719
Number of pages13
JournalInternational Journal of Nanomedicine
Volume14
DOIs
StatePublished - 2019

Keywords

  • Extracellular vesicles
  • Lung disease
  • Macrophages
  • Phosphatidylserine
  • Tuberculosis

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