Diapedesis across mammary epithelium reduces phagocytic and oxidative burst of bovine neutrophils

Smits, Elke; Burvenich, Christian; Guidry, A.J.; Heyneman, Roger; Massart-Leën, Annemie

doi:10.1016/s0165-2427(99)00019-7

Cited by 39 publications

(35 citation statements)

References 16 publications

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“…However, neutrophil migration induced by C5a did not change electric resistance over the cell layer over a short period. Moreover, cell lysis or epithelial detachment were not observed [216][217][218]. The above mentioned findings are in agreement with the basic concept that paracellular migration of neutrophils is locally modulated and that release of proteolytic enzymes in the matrix (e.g.…”

Section: Do Trafficking Neutrophils Cause Damage?supporting

confidence: 89%

Severity of E. coli mastitis is mainly determined by cow factors

et al. 2003

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-Intramammary infections of dairy cows with Gram-positive bacteria such as Staphylococcus aureus (major cause of mastitis) have received a lot of attention because of their major economic impact on the dairy farm through production losses induced by an increase in somatic cell count. Management strategies, including greater awareness for efficient milking and hygienic measures, have limited the spread of Gram-positive bacteria and resulted in a significant decrease of proportion of S. aureus isolates and subclinical mastitis worldwide. Other organisms such as coliform subspecies and Streptococcus uberis, both environmental bacteria that cause clinical mastitis, have received less attention. Escherichia coli causes inflammation of the mammary gland in dairy cows around parturition and during early lactation with striking local and sometimes severe systemic clinical symptoms. This disease affects many high producing cows in dairy herds and may cause several cases of death per year in the most severe cases. It is well known that bacterial, cow and environmental factors are interdependent and influence mastitis susceptibility. Many studies, executed during the last decade, indicate that the severity of E. coli mastitis is mainly determined by cow factors rather than by E. coli pathogenicity. During E. coli mastitis, the host defense status is a cardinal factor determining the outcome of the disease. Today, we know that the neutrophil is a key factor in the cows' defense against intramammary infection with E. coli. Effective elimination of the pathogen by neutrophils is important for the resolution of infection and the outcome of E. coli mastitis. This review is a compilation of some major findings over the last 15 years concerning mainly host factors that modulate and influence neutrophil function and the mammary inflammatory reaction. The individual chapters address: virulence factors of E. coli strains, how neutrophils kill E. coli, connection between endotoxins, tumor necrosis factor-a and nitric oxide, severity classification of E. coli mastitis, lifespan of neutrophils, host factors that influence severity, tissue damage and production loss.

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Section: Do Trafficking Neutrophils Cause Damage?supporting

confidence: 89%

Severity of E. coli mastitis is mainly determined by cow factors

et al. 2003

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“…Many previous studies have shown that the functions of milk PMN are decreased compared to blood PMN [6][7][8][10][11]. In vitro diapedesis of bovine PMN through a monolayer of isolated mammary gland epithelial cells induced a decreased phagocytosis and respiratory burst capacity of PMN [17]. Apoptosis of PMN following diapedesis could explain this phenomenon.…”

Section: Discussionmentioning

confidence: 99%

Apoptosis and necrosis of blood and milk polymorphonuclear leukocytes in early and midlactating healthy cows

et al. 2001

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-Increased milk somatic cell counts (SCC) are used as an indicator for bovine mastitis. During mastitis, polymorphonuclear leukocytes (PMN) become the predominant cell type. Shortly after parturition, the severity of mastitis is increased and several PMN functions are downregulated. Apoptotic and necrotic processes of PMN could influence SCC and PMN functions. In this study, the percentages of apoptotic and necrotic PMN in blood and milk from early and midlactating healthy cows were compared. Apoptosis and necrosis of PMN were quantified using a dual-color flow cytometric procedure with fluorescein labeled annexin-V (green) and propidium iodide (red). Using this technique three different subpopulations of bovine PMN could be detected: apoptotic cells (high intensive green fluorescence), necrotic cells (high intensive green and high intensive red fluorescence) and viable cells (low intensive green and low intensive red fluorescence). Following a 4 h incubation of blood from both groups of cows at 37°C to induce apoptosis, the mean percentage of apoptotic blood PMN was significantly higher (P < 0.01) in early lactating cows (15.1%, n = 9) compared with midlactating cows (5.3%, n = 10). The mean percentage of necrotic PMN remained lower than 5% in all cows. In contrast to blood, no significant difference was found between the percentage of apoptotic PMN in milk from early (41.2%, n = 7) and midlactating cows (34.0%, n = 8). The percentage of necrotic PMN in milk from early lactating cows (25.9%, n = 7) was significantly higher than that in midlactating cows (14.2%, n = 8) (P < 0.05). Higher percentages of apoptotic as well as necrotic PMN were consistently found in milk compared to blood in all cows. From these results, it can be concluded that spontaneously induced apoptosis was higher in blood PMN from early lactating cows than in blood PMN from midlactating cows. The higher percentage of necrotic milk PMN in early lactating cows than in midlactating cows could be explained by the induction of secondary necrosis. bovine neutrophil / apoptosis / necrosis / blood / milk Vet. Res. 32 (2001) 617-622 617

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“…chimioluminescence / leucocyte polymorphonucléaire / lipopolysaccharide / lait / sang apoptosis and their decreased ROI generation following diapedesis [35]. Although the CL of milk PMN is lower than their blood counterparts (Mehrzad et al, unpublished results), the resident milk PMN could play an important role in the intramammary defense system against invading bacteria and their endotoxins because a significant influx of PMN from the circulation is not observed until 8 h after infection.…”

Section: Introductionmentioning

confidence: 99%

Local and systemic effects of endotoxin mastitis on the chemiluminescence of milk and blood neutrophils in dairy cows

et al. 2001

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-The local and systemic effects of intramammary lipopolysaccharide (LPS) injection on the chemiluminescence (CL) of milk and blood polymorphonuclear leukocytes (PMN) were investigated in six healthy early lactation cows. Clinical signs of acute mastitis such as fever, increased heart rate and a decreased milk production were observed in all cows. Before LPS challenge, the CL activity of milk PMN was significantly lower than that of blood PMN (P < 0.01). A significant negative correlation was found between pre-challenge milk and blood PMN CL and, the decreased milk production in unchallenged quarters. The CL activity of milk PMN from LPS-injected quarters increased following LPS challenge, whereas it remained unchanged in control quarters. The CL activity of blood PMN showed a biphasic increase, with two peaks and a valley below pre-challenge CL activity (P < 0.01). At post-challenge hours (PCH) 6 and 12, the CL activity of milk PMN from LPS-injected quarters exceeded that of blood PMN (P < 0.05 and P < 0.001, respectively). The decreased CL activity of blood PMN and the enhanced CL activity of milk PMN during endotoxin-induced mastitis was reflected by changes in the shape of the CL curve. In blood PMN, a decrease of the second peak of the CL curve suggests that the myeloperoxidase (MPO)-H 2 O 2 system is impaired during endotoxin-induced mastitis. In contrast, the MPO-H 2 O 2 system was enhanced in milk PMN from challenged quarters. The highest duration and intensity of reactive oxygen intermediate (ROI) production was observed in milk PMN from LPS-injected quarters at PCH 12. The increased viability of PMN in LPS-injected quarters and to a lesser extent in control quarters suggests possible effects of both facilitated diapedesis and inflammatory mediators on milk PMN survival. In conclusion, our results suggest that a combination of local and systemic action of E. coli endotoxin is involved in the priming of milk PMN during mastitis. chemiluminescence / polymorphonuclear leukocyte / lipopolysaccharide / milk / blood Vet. Res. 32 (2001) [131][132][133][134][135][136][137][138][139][140][141][142][143][144] 131

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Diapedesis across mammary epithelium reduces phagocytic and oxidative burst of bovine neutrophils

Cited by 39 publications

References 16 publications

Severity of E. coli mastitis is mainly determined by cow factors

Severity of E. coli mastitis is mainly determined by cow factors

Apoptosis and necrosis of blood and milk polymorphonuclear leukocytes in early and midlactating healthy cows

Local and systemic effects of endotoxin mastitis on the chemiluminescence of milk and blood neutrophils in dairy cows

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