Evaluation of cytokine expression by blood monocytes of lactating Holstein cows with or without postpartum uterine disease K.N. Galvão a,c , M.J.B. Felippe a , S.B. Brittin a , R. Sper a , M. Fraga a , J.S. Galvão a , L. Caixeta b , C.L. Guard b , A. Ricci a,d , R.O. Gilbert a, * a Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA b Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA c Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA d Facultà di Medicina Veterinaria, Università di Torino, Torino, Italia Received 17 December 2010; received in revised form 3 August 2011; accepted 3 August 2011 Abstract Whereas neutrophils are the main phagocytic leukocytes, monocytes and macrophages are actively involved in immunomodu- lation after infection. Recent studies have demonstrated that neutrophil function is impaired by the state of negative energy balance around parturition, and that cows that develop uterine disease have a greater degree of negative energy balance than healthy cows. The objectives of this study were to compare monocyte gene expression and protein secretion of selected cytokines from calving to 42 d after calving in Holstein cows that did or did not develop uterine disease. Real time quantitative RT-PCR (Tumor necrosis factor- (TNF), Interleukin (IL)-1, IL-6, IL-8 and IL-10) and ELISA (TNF, IL-1 and IL-8) were used to evaluate cytokine response following in vitro stimulation of blood-derived monocytes with irradiated E. coli. Relative to unstimulated cells, E. coli-stimulated monocytes from cows with metritis had lower gene expression of key pro-inflammatory cytokines than healthy cows from calving to 14 d after calving (TNF at 0, 7, and 14 d after calving, IL-1 and IL-6 at 7 and 14 d after calving; P  0.05). There were no significant differences between groups for expression of IL-8 or the anti-inflammatory cytokine IL-10. This was due, in part, to higher gene expression in unstimulated monocytes (TNF, IL-1, IL-6 and IL-10) in early lactation from cows with metritis. Expression of mRNA in stimulated cells (relative to housekeeping genes) was lower for TNF (7 and 14 d postpartum) and for IL-10 (7 and 14 d postpartum) in cows with metritis. Concentration of TNF was lower in the culture medium of E. coli-stimulated monocytes from cows with metritis than healthy cows at calving and 7 and 21 d after calving (P  0.05). Circulating cytokine concentrations were not different between groups for IL-8 and were below the limits of detection for TNF and IL-1. Cytokine gene expression and production were similar between healthy cows and cows that developed endometritis, diagnosed cytologically at 42 d after calving. We concluded that altered levels of expression and production of pro-inflammatory cytokines postpartum could contribute to impaired inflammatory response and predispose cows to development of metritis. © 2012 Elsevier Inc. All rights reserved. Keywords: Metritis; Endometritis; Cytokines; Gene expression; Dairy cows 1. Introduction Uterine diseases are highly prevalent in Holstein dairy cows shortly after calving, with  20% of the cows developing metritis (an acute puerperal disease characterized by fetid, serous red-brownish uterine dis- * Corresponding author: Tel.: +1 607 253 3435; fax: +1 607 253 3531. E-mail address: rob.gilbert@cornell.edu (R.O. Gilbert). Available online at www.sciencedirect.com Theriogenology 77 (2012) 356 –372 www.theriojournal.com 0093-691X/$ – see front matter © 2012 Elsevier Inc. All rights reserved. doi:10.1016/j.theriogenology.2011.08.008