Innate immune responses and monocyte-derived phagocyte recruitment in protective immunity to pathogenic bacteria: insights from Legionella pneumophila

Author(s)

Mascarenhas, Danielle P. A. ; Zamboni, Dario S.

• Document type: Journal article
• Source: Current Opinion in Microbiology; v. 80, p. 8-pg., 2024-06-21.

Abstract

Legionella species are Gram-negative intracellular bacteria that evolved in soil and freshwater environments, where they infect and replicate within various unicellular protozoa. The primary virulence factor of Legionella is the expression of a type IV secretion system (T4SS), which contributes to the translocation of effector proteins that subvert biological processes of the host cells. Because of its evolution in unicellular organisms, T4SS effector proteins are not adapted to subvert specific mammalian signaling pathways and immunity. Consequently, Legionella pneumophila has emerged as an interesting infection model for investigating immune responses against pathogenic bacteria in multicellular organisms. This review highlights recent advances in our understanding of mammalian innate immunity derived from studies involving L. pneumophila. This includes recent insights into inflammasome-mediated mechanisms restricting bacterial replication in macrophages, mechanisms inducing cell death in response to infection, induction of effector-triggered immunity, activation of specific pulmonary cell types in mammalian lungs, and the protective role of recruiting monocyte-derived cells to infected lungs. (AU)

• FAPESP's process: 23/07075-8 - Mechanisms and consequences of activation of cytoplasmic receptors by intracellular pathogens (TT5)
• Grantee: Danielle Pini Alves Mascarenhas
• Support Opportunities: Scholarships in Brazil - Technical Training Program - Technical Training
• FAPESP's process: 13/08216-2 - CRID - Center for Research in Inflammatory Diseases
• Grantee: Fernando de Queiroz Cunha
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 19/11342-6 - Mechanisms and consequences of the activation of cytoplasmic receptors by intracellular pathogens
• Grantee: Dario Simões Zamboni
• Support Opportunities: Research Projects - Thematic Grants