Effect of recombinant cytokines on leucocytes and physiological changes in bovine mammary glands during early involution

Abstract

We examined the effects of administering recombinant bovine cytokines to non-lactating dairy cows and measured mammary gland leucocytes and the involution process. After the final milking, groups of cows were given an intramammary infusion of cytokine in two quarters. These cytokines were recombinant bovine interleukin-2 (rboIL-2) (2×105 units, n=6), recombinant bovine granulocyte-macrophage colony stimulating factor (rboGM-CSF) (500 μg, n=4) and recombinant bovine interleukin-1β (rboIL-1β) (10 μg, n=10). Each animal also received an infusion of phosphate-buffered saline (PBS) in the other two quarters as controls. The rboIL-2 and rboGM-CSF were produced in a yeast expression system, while rboIL-1β was produced in Escherichia coli. Leucocyte numbers, bactericidal activity of leucocytes, and concentrations of citrate and lactoferrin in quarter secretion samples were monitored after infusion of cytokine or PBS. Infusion of rboIL-2 had minimal effect on leucocyte numbers and concentrations of citrate and lactoferrin. Both rboGM-CSF and rboIL-1β induced a rapid increase in the number of neutrophils and macrophages compared with control PBS quarters. Concentrations of lactoferrin in secretions were increased by rboGM-CSF and rboIL-1β compared with control PBS quarters. In addition, infusion of glands with rboIL-1β lowered the citrate[ratio ]lactoferrin molar ratio compared with PBS control quarters. The results indicate that intramammary infusion of either rboGM-CSF or rboIL-1β at cessation of milking immediately increased the number of phagocytic cells in the gland. These cytokines, in particular rboIL-1β, also increased the rate of mammary gland involution during the early dry period.

Enhancement of the Sensitivity of the Whole-Blood Gamma Interferon Assay for Diagnosis ofMycobacterium bovisInfections in Cattle

“…The chemicals used (mono-methyl-L-arginine [MMLA] and L-methyl-tryptophan) were purchased from Sigma International (Saint Louis, MO); these products were cell culture grade, and the products had no toxicity or side effects on cells in vitro in control experiments. The bovine cytokines used here were produced in our laboratory (35). The recombinant cytokines were pure and were determined not to be contaminated by endotoxin.…”

Interleukin-1β infusion in bovine mammary glands prior to challenge with Streptococcus uberis reduces bacterial growth but causes sterile mastitis

“…Freeze-dried rbIL-1β was reconstituted in phosphate buffered saline (PBS; 0.01 M sodium phosphate, 0.137 M NaCl, pH 7.4) containing 0.1% low endotoxin bovine serum albumin at 1 μg/ml and 10 ml volumes were prepared for teat infusions. The rbIL-1β contained <0.1 endotoxin units/μg protein as determined by a limulus amoebocyte lysate assay (Sigma-Aldrich, St. Louis, MO, USA) as reported previously by Wedlock et al (2004).…”

“…Recombinant bovine interleukin-1β (rbIL-1β) was produced in Escherichia coli as described previously (Wedlock et al 2004). Freeze-dried rbIL-1β was reconstituted in phosphate buffered saline (PBS; 0.01 M sodium phosphate, 0.137 M NaCl, pH 7.4) containing 0.1% low endotoxin bovine serum albumin at 1 μg/ml and 10 ml volumes were prepared for teat infusions.…”

“…Intramammary infusion of recombinant IL-1β increases the rate of gland involution (Rejman et al 1995;Wedlock et al 2004) and causes an increase in the number of neutrophils and macrophages in the gland (Wedlock et al 2004). Treatment of S. aureus infected glands with IL-1β improves the cure rate when combined with antibiotic treatment (Daley et al 1991(Daley et al , 1993.…”

“…Several studies have investigated the effect of administrating cytokines such as IL-1β on mammary gland involution during the early dry period or during lactation (Alluwaimi 2004 (review) ;Daley 1993Rejman et al 1995, Wedlock et al 2004. Intramammary infusion of recombinant IL-1β increases the rate of gland involution (Rejman et al 1995;Wedlock et al 2004) and causes an increase in the number of neutrophils and macrophages in the gland (Wedlock et al 2004).…”