title: Expression analysis of the acute phase response in channel catfish (Ictalurus punctatus) after infection with a Gram-negative bacterium.
abstract: The acute phase response (APR) is a set of metabolic and physiological reactions occurring in the host in response to tissue infection or injury and is a crucial component of the larger innate immune response. The APR is best characterized by dramatic changes in the concentration of a group of plasma proteins known as acute phase proteins (APPs) which are synthesized in the liver and function in a wide range of immunity-related activities. Utilizing a new high-density in situ oligonucleotide microarray, we have evaluated the APR in channel catfish liver following infection with Edwardsiella ictaluri, a bacterial pathogen that causes enteric septicemia of catfish. Our catfish microarray design (28K) builds upon a previous 19K channel catfish array by adding recently sequenced immune transcripts from channel catfish along with 7159 unique sequences from closely related blue catfish. The analysis of microarray results using a traditional 2-fold change in gene expression cutoff and a 10% false-discovery rate revealed a well-developed APR in catfish, with particularly high upregulation (>50-fold) of genes involved in iron homeostasis (i.e. intelectin, hemopexin, haptoglobin, ferritin, and transferrin). Other classical APP genes upregulated greater than 2-fold included coagulation factors, proteinase inhibitors, transport proteins, and complement components. Upregulation of the majority of the complement cascade was observed including the membrane attack complex components and complement inhibitors. A number of pathogen recognition receptors (PRRs) and chemokines were also differentially expressed in the liver following infection. Independent testing of a selection of differentially expressed genes with real-time RT-PCR confirmed microarray results.
authors: The Fish Molecular Genetics and Biotechnology Laboratory, Department of Fisheries and Allied Aquacultures and Program of Cell and Molecular Biosciences, Aquatic Genomics Unit, Auburn University, 203 Swingle Hall, Auburn, AL 36849, USA.
authors: Eric
authors: E
authors: Peatman
authors: Puttharat
authors: P
authors: Baoprasertkul
authors: Jeffery
authors: J
authors: Terhune
authors: Peng
authors: P
authors: Xu
authors: Samiran
authors: S
authors: Nandi
authors: Huseyin
authors: H
authors: Kucuktas
authors: Ping
authors: P
authors: Li
authors: Shaolin
authors: S
authors: Wang
authors: Benjaporn
authors: B
authors: Somridhivej
authors: Rex
authors: R
authors: Dunham
authors: Zhanjiang
authors: Z
authors: Liu
mesh_terms: D000209:Acute-Phase Proteins / Q000276:immunology / Q000378:metabolism*; D000210:Acute-Phase Reaction; D000818:Animals; D020610:Edwardsiella ictaluri; D004756:Enterobacteriaceae Infections / Q000276:immunology / Q000382:microbiology / Q000662:veterinary*; D005393:Fish Diseases / Q000276:immunology* / Q000382:microbiology; D020869:Gene Expression Profiling; D007059:Ictaluridae / Q000235:genetics / Q000276:immunology*; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis
chemical_list: D000209:Acute-Phase Proteins