|Waldbieser, Geoffrey - Geoff|
Submitted to: Developmental and Comparative Immunology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/28/2008
Publication Date: 2/1/2009
Citation: Majji, S., Thodima, V., Arnizaut, A., Deng, Y., May, W., Sittman, D., Waldbieser, G.C., Hanson, L., Cuchens, M.A., Bengten, E., Chinchar, V.G. 2009. Expression Profiles of Cloned Channel Catfish (Ictalurus punctatus) Lymphoid Cell Lines and Mixed Lymphocyte Cultures. Developmental and Comparative Immunology. 33:224-234. Interpretive Summary: In addition to its commercial importance in aquaculture, the channel catfish (Ictalurus punctatus) is a powerful model for identifying immune mechanisms in lower vertebrates and elucidating the evolution of the vertebrate immune system. Unlike other fish models, catfish are long-lived, easily reared in captivity, and a source of abundant quantities of immune cells that can be readily (and repeatedly) isolated from individual fish and monitored in vitro for cytotoxicity, responsiveness to mitogens, phagocytosis, and other immunological phenomena. However, little is known regarding the genetic mechanism underlying the immune pathways in these cells. This research was performed to simultaneously measure levels of expression for more than 100 genes in different catfish immune cell lines. The results showed cell lines derived from B-lymphocytes, T-lymphocytes, and a mixture of leukocytes could be distinguished by their patterns of gene expression, and distinctive subsets of genes were active in different cell lines. This research provided baseline measures of gene expression that will be a reference for further experiments that investigate cellular responses to pathogens both in cell lines and fish. A better understanding of catfish immune responses will aid in the identification and utilization of catfish with improved survival in commercial culture.
Technical Abstract: Clonal channel catfish lymphoid cell lines and mixed lymphocyte cultures (MLC) have proven extremely useful in examining immune responses at the cellular and molecular levels. To date clonal catfish cell lines and MLC have been biologically and phenotypically characterized using a variety of techniques including reverse transcription PCR (RT-PCR), as well as Northern and Southern Blotting. To expand the molecular characterization of these cultures, microarray analysis was employed. Clonal B (3B11), macrophage (42TA), and cytotoxic T cell (TS32.15 and TS32.17) lines and MLC were examined using a cDNA array containing ~ 2500 probes derived from EST libraries prepared from the 42TA macrophage cell line, a MLC, and 5 - 14 day old catfish fry. Analysis showed that each cell line displayed a unique RNA expression profile that included a variety of immune-related genes. Pearson correlation analysis indicated that one cytotoxic T cell line (TS32.15) clustered with the MLC, whereas a second cytotoxic T cell line (TS32.17) was more closely associated with a second cluster containing B cells and macrophages. This study illustrates the utility of microarray analyses in profiling RNA expression patterns in catfish lymphoid cell lines and will serve as a platform for examining catfish immune responses following virus infection or poly [I:C] treatment.