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

Oostveldt, K Van; Vangroenweghe, Frédéric; Dosogne, Hilde; Burvenich, Christian

doi:10.1051/vetres:2001143

Cited by 45 publications

(40 citation statements)

References 12 publications

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“…These neutrophils were found in both the early and late stages of apoptosis, which was verified by the detection of translocated phosphatidylserine in FCM and karyopyknotic nuclei in LM. The presence of apoptotic neutrophils already in the acute-phase response can be explained as follows: (i) neutrophils have a short life-span of 1-2 days and they are predisposed for spontaneous apoptosis [17], (ii) neutrophils are recruited from the bloodstream in various age-phases [8], (iii) apoptosis in neutrophils is induced by migration into the lumen of the mammary gland [28], (iv) another, certainly non-omissible effect is the effect Figure 6. Transmission electron microscopy of macrophage with phagocytosed apoptotic neutrophils (asterisks) and bacteria (arrow).…”

Section: Discussionmentioning

confidence: 99%

Neutrophil apoptosis during experimentally induced Staphylococcus aureus mastitis

et al. 2005

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-The objective of this study was to determine whether neutrophil apoptosis and their consequent elimination by macrophages from the mammary gland is modulated by an infection caused by Staphylococcus aureus (S. aureus). The study was performed on twenty mammary glands of 5 virgin heifers. A buffered physiological solution (PBS) was administered as a means of control into the mammary glands of the heifers and after 168 h, the glands were inoculated with S. aureus. The samples of cell populations were obtained by lavages of the mammary glands in 4 intervals (24, 48, 72 and 168 h) after the experimental infection. Flow cytometry was used for determination of Annexin-V positivity and propidium iodide (PI) negativity of neutrophils. Light microscopy was used for determination of neutrophil karyopyknosis. Cytochemistry was used for the detection of myeloperoxidase-positive (MPO+) macrophages. Instillation of S. aureus resulted in an intramammary infection which persisted during the following experimental period. The total number of both Annexin-V-positive and PI negative neutrophils and karyopyknotic neutrophils peaked at 24 h after both of PBS and S. aureus administration. The highest percentages of Annexin-V-positive and PI negative neutrophils and karyopyknotic neutrophils were detected 48 and 168 h after PBS and S. aureus administration, respectively. The total number of MPO+ macrophages was the highest 24 h and 48 h after PBS and S. aureus administration, respectively; the percentage of MPO+ macrophages was the highest at 72 h in both cases. The dynamics of resolution of mastitis caused by S. aureus was very similar to the resolution of inflammatory response of the mammary gland after PBS administration. Mechanisms of cell pathogen elimination as well as inflammation resolution were very intensively involved; nevertheless, the mammary gland infection persisted. An early inclusion of the mechanisms of an acute inflammatory resolution thus paradoxically led to chronic infection.

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Section: Discussionmentioning

confidence: 99%

Neutrophil apoptosis during experimentally induced Staphylococcus aureus mastitis

et al. 2005

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“…Midlactating cows were preferred to early lactating cows to avoid possible interference caused by isolation of PMN from animals with high plasma NEFA consequent to intense lipomobilization. Furthermore, midlactation is a period during which most of the concerned cell functions are optimal in comparison with their status at early lactation (Van Oostveldt et al, 2001). Cows were selected from the dairy herd at Gent University (Biocentrum Agri-Vet, Melle, Belgium) and at the time of the study, average milk yield was approximately 23 L/d.…”

Section: Animals and Blood Sample Collectionmentioning

confidence: 99%

“…Recently, Mehrzad et al (2004Mehrzad et al ( , 2005 also demonstrated that chemiluminescence and viability of resident milk PMN (static innate immunity) play a crucial role in the severity of subsequently induced Escherichia coli mastitis. Finally, Van Oostveldt et al (2001) reported that apoptosis of circulatory and milk PMN was higher in early lactating than in midlactating cows; those researchers suggested that apoptotic and necrotic processes might explain the downregulation of PMN functions shortly after calving.…”

Section: Introductionmentioning

confidence: 99%

In Vitro Effects of Nonesterified Fatty Acids on Bovine Neutrophils Oxidative Burst and Viability

Scalia

Lacetera

Bernabucci

et al. 2006

Journal of Dairy Science

164

122

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An in vitro study was conducted to examine the influence of nonesterified fatty acids (NEFA) on bovine polymorphonuclear leukocytes (PMN). Eight healthy, midlactating Holstein cows were used as blood donors. Blood PMN were isolated and incubated with a mixture of NEFA, reflecting composition of bovine plasma NEFA at concentrations that were intended to mimic those found in blood of cows undergoing high, moderate, or low lipomobilization intensity (2, 1, 0.5, 0.25, 0.125, and 0.0625 mM). Control samples were incubated in absence of NEFA. Phagocytosis and oxidative burst activities were assessed by a 2-color flow cytometric method, which was based on oxidation of intracellular dihydrorhodamine 123 to green fluorescent rhodamine 123. Oxidative burst products were generated by incubating PMN with Staphylococcus aureus labeled with propidium iodide. A flow cytometric technique was used to detect PMN viability, necrosis, and apoptosis using fluorescein isothiocyanate-labeled annexin-V and propidium iodide. Phagocytic activity was not affected by NEFA. The highest concentration of NEFA (2 mM) was associated with a dramatic increase of phagocytosisassociated oxidative burst activities with a reduction in cell viability (48.0 vs. 97.5% in control samples) and with a marked increase of necrosis (49.4 vs. 0.5% in control samples). Conversely, the mixture of NEFA did not affect the occurrence of apoptosis. Enhancement of the oxidative burst associated with the highest concentration of NEFA might explain the reduced viability and higher percentage of necrosis observed under the same conditions. This study demonstrated a substantial resistance of bovine PMN to an overload of fatty acids. However, observation that the highest concentration of NEFA regulated some PMN functions encourages the possibility of in vivo studies to assess the rela-

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“…In cows, PMN apoptosis is influenced by stage of lactation. In one study, blood was obtained from early lactating (13 6 days after parturition) and mid-lactating (170 26 days after parturition) cows and subsequently incubated for four hours to induce apoptosis [175]. PMN isolated from the blood of early lactating cows demonstrated a higher rate of apoptosis than PMN derived from mid-lactating cows.…”

Section: Regulation Of Pmn Life Spanmentioning

confidence: 99%

The bovine neutrophil: Structure and function in blood and milk

Paape¹,

Bannerman²,

et al. 2003

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-Migration of polymorphonuclear neutrophil leukocytes (PMN) into the mammary gland provide the first line of defense against invading mastitis pathogens. Bacteria release potent toxins that activate white blood cells and epithelial cells in the mammary gland to secrete cytokines that recruit PMN that function as phagocytes at the site of infection. While freshly migrated PMN are active phagocytes, continued exposure of PMN to inhibitory factors in milk such as fat globules and casein, leads to altered PMN morphology and reduced phagocytosis. In the course of phagocytosing and destroying invading pathogens, PMN release chemicals that not only kill the pathogens but that also cause injury to the delicate lining of the mammary gland. This will result in permanent scarring and reduced numbers of milk secretory cells. The life span of PMN is limited by the onset of apoptosis. To minimize damage to mammary tissue, PMN undergo a specialized process of programmed cell death known as apoptosis. Macrophages quickly engulf and phagocytose apoptotic PMN, thereby minimizing the release of PMN granular contents that are damaging to tissue. The PMN possess an array of cell surface receptors that allow them to adhere and migrate through endothelium and to recognize and phagocytose bacteria. One receptor found on phagocytes that is receiving considerable attention in the control of infections by Gram-negative bacteria is CD14. Binding of lipopolysaccharide (LPS) to membrane bound CD14 causes release of tumor necrosis factor-a and sepsis. Binding of LPS to soluble CD14 shed from CD14-bearing cells results in neutralization of LPS and rapid recruitment of PMN to the site of infection. Recent advances in the fields of genomics and proteomics should greatly enhance our understanding of the PMN role in controlling intramammary infections in ruminants. Further, manipulation of PMN, through either recombinant proteins such as soluble CD14 that enhance PMN response or agents that mediate PMN apoptosis, may serve as novel therapeutics for the treatment of mastitis.

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

Cited by 45 publications

References 12 publications

Neutrophil apoptosis during experimentally induced Staphylococcus aureus mastitis

Neutrophil apoptosis during experimentally induced Staphylococcus aureus mastitis

In Vitro Effects of Nonesterified Fatty Acids on Bovine Neutrophils Oxidative Burst and Viability

The bovine neutrophil: Structure and function in blood and milk

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