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Published on: August 11, 2014
Pathogen-associated gene expression profiles in rainbow trout macrophages
Dimitar B Iliev1, Giles W Goetz, Simon Mackenzie
1Great Lakes WATER Institute, University of Wisconsin-Milwaukee, 600 E. Greenfield Ave., Milwaukee, Wisconsin 53204, USA; University of Notre Dame, Department of Biological Sciences, Notre Dame, Indiana 46556, USA.
Abstract:
Pathogens can be distinctively recognized by the cells of the immune system through interactions between the Pathogen-Associated Molecular Patterns (PAMPs) that they produce and the innate immune receptors of leukocytes. The present paper reports on the PAMP-modulated expression of a group of genes expressed in trout macrophages. The genes were identified in subtracted libraries from lipopolysaccharide (LPS)-stimulated macrophages and their expression was analyzed using quantitative real time PCR following stimulation of the cells with E. coli LPS, poly (I:C) and zymosan; representing Gram-negative bacteria, viruses and fungi, respectively. Genes (SPINT1L, DDIT4L, STEAP4, and TNFAIP3), the expression of which was induced by LPS and zymosan, were not significantly up-regulated by poly(I:C) and the opposite was found for transcripts (HMGB1 and PSMB9) up-regulated by poly(I:C). Overall, the differences in gene expression were greater at a later stage of macrophage activation (24 h) at a time when stimulation with poly(I:C) resulted in substantially different responses as compared to LPS and, to a lesser extent, zymosan.
Insights
Trout macrophages recognize pathogens via Pathogen-Associated Molecular Patterns (PAMPs). Gene expression varied significantly based on the PAMP type and activation time, revealing distinct immune responses to bacteria, viruses, and fungi.
Area of Science:
- Immunology
- Molecular Biology
- Fish Health
Background:
- Immune cells recognize pathogens through Pathogen-Associated Molecular Patterns (PAMPs) interacting with innate immune receptors.
- Understanding these interactions is crucial for developing strategies against fish diseases.
Purpose of the Study:
- To investigate PAMP-modulated gene expression in trout macrophages.
- To identify specific genes responsive to different microbial stimuli.
Main Methods:
- Trout macrophages were stimulated with lipopolysaccharide (LPS), poly (I:C), and zymosan, representing bacterial, viral, and fungal PAMPs.
- Gene expression was analyzed using quantitative real-time PCR at different time points (e.g., 24 hours).
Main Results:
- Specific genes (SPINT1L, DDIT4L, STEAP4, TNFAIP3) were induced by LPS and zymosan but not poly(I:C).
- Other genes (HMGB1, PSMB9) were upregulated by poly(I:C).
- Gene expression differences were more pronounced at 24 hours, with poly(I:C) eliciting distinct responses.
Conclusions:
- Trout macrophages exhibit differential gene expression patterns in response to various PAMPs.
- The timing of immune cell activation influences the magnitude and specificity of the response.
