PARENT SESSION
SLIDE SESSION 20: GENE EXPRESSION AND HORMONE / CYTOKINE REGULATION IN THE CORPUS LUTEUM
Chairs: Milo Wiltbank, Richard Stouffer, Matthew Cannon (Trainee)
Univ Ottawa-Monpetit 203
1:30 PM-3:30 PM

MONOCYTE CHEMOATTRACTANT PROTEIN-1 (MCP-1) IN THE BOVINE CORPUS LUTEUM: REGULATION BY CYTOKINES IN LUTEAL CELL CULTURES CONTAINING ENDOTHELIAL CELLS.

Townson, David¹, Cavicchio, Victoria¹, Pru, James², Hendry, Isabella³, Davis, John³, Rueda, Bo², ^{1 2 3}

ABSTRACT- MCP-1 is thought to facilitate immune cell recruitment in the bovine corpus luteum, yet there is little information available regarding the cellular source(s) and regulation of MCP-1 expression in this tissue. Here we examined the secretion of MCP-1 by cultured bovine luteal cells in response to prostaglandin F2 (PGF), tumor necrosis factor- (TNF), and interferon- (IFN). In addition, we investigated whether endothelial cells are a potential source of MCP-1 by comparing the secretion of this chemokine in cultures containing both endothelial and steroidogenic cells (mixed) and those containing primarily steroidogenic cells. Briefly, bovine corpora lutea (n= 4 cows) were dissociated and placed in culture for 36 hrs with insulin-transferrin-selenium (ITS) or 5% fetal calf serum to diminish or maintain, respectively, numbers of endothelial cells. Following conversion to serum free conditions, cultures were exposed to vehicle (control), PGF (1M), TNF (100ng/ml), IFN (200 IU/ml), or TNF+IFN for 24 hrs. Conditioned medium was assayed for MCP-1 using an ELISA. There was a significant effect of treatment (p<0.001) and of primary culture composition (p<0.05) on MCP-1 secretion; culture medium from mixed cultures contained more MCP-1 than cultures with steroidogenic cells. Basal expression of MCP-1 was evident in both types of cultures (mean, 65 pg/ml), and this was not affected by PGF treatment (p>0.05). In contrast, TNF and IFN stimulated (p<0.05) MCP-1 expression 2- to 4-fold in both mixed cell and steroidogenic cell cultures. Co-treatment with TNF+IFN increased MCP-1 production 4- to 7-fold compared to controls (p<0.05). In conclusion, endothelial cells of the bovine corpus luteum are a source of MCP-1 and respond to TNF and IFN stimulation. Supported by USDA 97-35208-4705 (DHT), HD 35934 (BRR, JSD), and the Vincent Center for Reproductive Biology (BRR).

KEY WORDS: Corpus Luteum, MCP-1, Cytokines, Immunology