Cooperative expression of monocyte chemoattractant protein 1 within the bovine corpus luteum: Evidence of immune cell-endothelial cell interactions in a coculture system


Endothelial cells (EC) of the bovine corpus luteum (CL) are a known source of proinflammatory mediators, including monocyte chemoattractant protein 1 (CCL2) and endothelin 1 (EDN1). Here, a coculture system was devised to determine if immune cells and PGF(2 alpha) together affect CCL2 and EDN1 secretion by EC. Luteal EC were cultured either alone or together with peripheral blood mononuclear cells (PBMC), and treated without or with PGF(2 alpha) for 48 h (n = 6 experiments). Coculture of EC with PBMC increased CCL2 secretion an average of 5-fold higher compared with either cell type alone (P 0.05). EC cocultured with concanavalin A-activated PBMC (ActPBMC) increased CCL2 secretion an average of 12-fold higher compared with controls (P 0.05). Interestingly, PGF(2 alpha) did not alter either CCL2 or EDN1 secretion, regardless of culture conditions (P > 0.05). In a second series of experiments (n = 3 experiments), mixed luteal cells (MLC) were cultured alone or with PBMC as described above. Secretion of CCL2 and EDN1 was not affected by co-culture or by PGF(2 alpha) (P > 0.05), but MLC produced less progesterone in the presence of ActPBMC (P < 0.05). Collectively, these results suggest that immune cells and EC can interact cooperatively to increase CCL2 secretion in the CL, but this interaction does not affect EDN1 secretion nor is it influenced by PGF(2 alpha). Additionally, activated immune cells appear to produce a factor that impairs progesterone production by luteal steroidogenic cells.


Molecular, Cellular and Biomedical Sciences

Publication Date


Journal Title

Biology of reproduction


Society for the Study of Reproduction

Digital Object Identifier (DOI)


Document Type



© 2005 by the Society for the Study of Reproduction, Inc.