title: Interactions of Streptococcus iniae with phagocytic cell line.
abstract: Streptococcus iniae has become one of the most serious aquatic pathogens in the last decade, causing large losses in wild and farmed fish worldwide. There is clear evidence that this pathogen is capable not only of causing serious disease in fish but also of being transferred to and infecting humans. In this study, we investigate the interaction of S. iniae with two murine macrophage cell lines, J774-A1 and RAW 264.7. Cytotoxicity assay demonstrated significant differences between live and UV-light killed IUSA-1 strains. The burst respiratory activity decreased to baseline after 1 and 4 h of exposure for J774-A1 and RAW 264.7, respectively. Immunofluorescent and ultrastructural study of infected cells confirmed the intracellular localization of bacteria at 1 h and 24 h post-infection. Using qRT-PCR arrays, we investigated the changes in the gene expression of immune relevant genes associated with macrophage activation. In this screening, we identified 11 of 84 genes up-regulated, we observed over-expression of pro-inflammatory response as IL-1α, IL-1β, and TNF-α, without a good anti-inflammatory response. Present findings suggest a capacity of S. iniae to modulate a mammalian macrophages cell lines to their survival and replication intracellular, which makes this cell type as a reservoir for continued infection.
authors: Institute of Animal Health (IUSA), University of Las Palmas de Gran Canaria, Arucas 35413, Spain.
authors: Fatima
authors: F
authors: El Aamri
authors: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla e Instituto IDIVAL, Santander, Spain.
authors: S
authors: S
authors: Remuzgo-Martínez
authors: Institute of Animal Health (IUSA), University of Las Palmas de Gran Canaria, Arucas 35413, Spain.
authors: Félix
authors: F
authors: Acosta
authors: Institute of Animal Health (IUSA), University of Las Palmas de Gran Canaria, Arucas 35413, Spain.
authors: Fernando
authors: F
authors: Real
authors: Servicio de Microbiología, Hospital Universitario Marqués de Valdecilla e Instituto IDIVAL, Santander, Spain; Red Española de Investigación en Patología Infecciosa (REIPI), Instituto de Salud Carlos III, Madrid, Spain.
authors: José
authors: J
authors: Ramos-Vivas
authors: Department of Anatomy and Cell Biology, University of Cantabria, Spain.
authors: José M
authors: JM
authors: Icardo
authors: Institute of Animal Health (IUSA), University of Las Palmas de Gran Canaria, Arucas 35413, Spain. Electronic address: vishakha.sabharwal@bmc.org.
authors: Daniel
authors: D
authors: Padilla
mesh_terms: D000818:Animals; D002461:Cell Line, Transformed / Q000276:immunology* / Q000382:microbiology; D005393:Fish Diseases / Q000382:microbiology; D005399:Fishes; D006801:Humans; D051379:Mice; D010586:Phagocytes / Q000276:immunology* / Q000382:microbiology; D000067996:RAW 264.7 Cells / Q000276:immunology* / Q000382:microbiology; D016897:Respiratory Burst / Q000276:immunology; D013290:Streptococcal Infections / Q000276:immunology*; D013291:Streptococcus / Q000502:physiology
keywords: Burst activity; Cytokines; Immune response; Immunofluorescent; Macrophage; Streptococcus iniae