Plant & Animal Genomes XI Conference

January 11-15, 2003
Town & Country Convention Center
San Diego, CA

Poster: Functional Analysis
            

COMPARATIVE GENE EXPRESSION ANALYSIS IN CIRCULATING BOVINE GAMMA/DELTA T CELL SUBSETS DEFINES DISTINCT IMMUNOREGULATORY PHENOTYPES AND SUPPORTS THEIR RELATIONSHIP TO MYELOID CELLS

¹ Montana State University, Bozeman, Montana, 59717, USA

² University of Minnesota, St. Paul, Minnesota, 55108, USA

Gene expression profiles were compared in circulating bovine GD3.5+ (CD8-) and GD3.5- (predominantly CD8+) gamma/delta T cells using serial-analysis-of-gene-expression (SAGE). Over 15,000 unique cDNA tags were identified. A comparison of the two libraries demonstrated 297 and 173 tags representing genes with five-fold differential expression in GD3.5+ and GD3.5- gamma/delta T cells, respectively. Consistent with their localization into sites of inflammation, GD3.5+ gamma/delta T cells appeared transcriptionally and translationally more active as opposed to GD3.5- gamma/delta cells. GD3.5- gamma/delta T cells demonstrated higher expression of the cell proliferation inhibitor BAP 37 cells, which was associated with their less activated gene expression phenotype. The immune regulatory and apoptosis-inducing molecule, galectin-1, was identified as a high abundant molecule and was higher in GD3.5+gamma/delta T cells. Surface molecules attributed to myeloid cells, such as CD14, CD68, and scavenger receptor-1 were identified in both populations. Furthermore, expression of B lymphocyte induced maturation protein (BLIMP-1), a master regulator of B cell and myeloid cell differentiation, was identified by SAGE analysis and confirmed at the RNA level to be selectively expressed in gamma/delta T cells. These results provide new insights into inherent differences between circulating bovine gamma/delta T cell subsets, and support a myeloid association of gamma/delta T cells, as well as their role in innate immunity. Funded by USDA IFAFS.