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1.
OBJECTIVE: To develop an in vitro model of the bovine alveolar-capillary interface and to evaluate the roles of interleukin-8 (IL-8) and platelet-activating factor (PAF) in neutrophil-mediated endothelial injury induced by infection with Mannheimia haemolytica. SAMPLE POPULATION: Cultured bovine pulmonary microvascular endothelial cells, freshly isolated bovine neutrophils, and monocyte-derived bovine macrophages. PROCEDURE: A coculture system was developed in which endothelial cells were grown to confluence in tissue culture inserts, neutrophils were added to the inserts, and macrophages were added to tissue culture wells. Mannheimia haemolytica-derived lipopolysaccharide (LPS) or supernatant was added to activate macrophages, and inhibitors of PAF or IL-8 were added to the insert. Endothelial cell cytotoxicity and permeability (ie, albumin leakage) and neutrophil activation (ie, adhesion, degranulation [lactoferrin expression], and superoxide production) were assessed. RESULTS: The addition of M haemolytica-derived LPS to bovine macrophages in the coculture system resulted in significant increases in endothelial cell cytotoxicity and permeability and neutrophil degranulation and adhesion. Inhibition of IL-8 reduced endothelial cell permeability and neutrophil degranulation induced by exposure to M haemolytica-derived supernatant, whereas inhibition of PAF decreased superoxide release by neutrophils. CONCLUSIONS AND CLINICAL RELEVANCE: In vitro activation of bovine macrophages by M haemolytica-derived LPS resulted in neutrophil activation and neutrophil-mediated endothelial damage. Neutrophil-mediated endothelial injury and neutrophil degranulation were, at least in part, mediated by IL8, whereas PAF promoted superoxide release by neutrophils in this in vitro system designed to mimic the in vivo events that occur during the early stages of bovine pneumonic pasteurellosis. 相似文献
2.
S K Salgar M J Paape B Alston-Mills R H Miller 《American journal of veterinary research》1991,52(8):1201-1207
A flow cytometric procedure was evaluated to measure the oxidative burst activity (hydrogen peroxide formation) of bovine neutrophils. The method involves measuring the oxidation of intracellular dichlorofluorescein to fluorescent dichlorofluorescein (DCF). Phorbol myristate acetate (PMA) was used to perturb the neutrophil plasma membrane. The sources of variation introduced into the DCF assay were also examined. The sources of variation were attributable to the isolation of neutrophils from blood, variation between duplicate assays and duplicate flow cytometric determinations of oxidative product formation, variation in neutrophil oxidative product formation among cows, and the variation (over repeated daily and weekly neutrophil isolations) in neutrophil oxidative product formation. A final objective was to determine effects of dexamethasone on oxidative product formation, and whether differences existed between blood and mammary neutrophils in oxidative product formation. There was an increasing trend in the formation of DCF with increasing time of incubation and with increasing PMA concentration. Increasing the concentration of PMA decreased lag time and increased the rate of oxidative product formation. The increase in DCF formation was statistically significant up to a PMA concentration of 10 ng/ml. This concentration was considered optimal for bovine neutrophils.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
De Guise S Erickson K Blanchard M DiMolfetto L Lepper HD Stott JL Ferrick DA 《Veterinary immunology and immunopathology》2004,97(3-4):195-206
The specificity of F21.A, a monoclonal antibody raised against bottlenose dolphin leucocytes, was characterized in killer whale on the basis of immunoprecipitation of a protein of 94 kDa, as well as flow cytometric analysis. While minimally expressed on resting cells, F21.A labeled a homologue to beta-2 integrin in 89-97% of PMA-activated neutrophils, 53-66% of activated monocytes, and activated B cells but not T cells. Activation of neutrophils reached its maximum 10 min after PMA stimulation. F21.A did not label intracellular stores as did both cross-reacting anti-canine CD11b and CD18, suggesting that an activation-induced conformational change would expose a neoepitope recognized by F21.A. F21.A labeling was largely inhibited by pre-incubation with plasma, suggesting a binding site closely related to that for fibrinogen. In vitro phagocytosis and respiratory burst were almost fully inhibited upon pre-incubation with F21.A, demonstrating its functional importance. This antibody is foreseen as a possible valuable diagnostic and research tool in cetacean immunology. 相似文献
4.
McClenahan D Fagliari J Evanson O Weiss D 《American journal of veterinary research》2000,61(5):492-498
OBJECTIVE: To determine the capacity of inflammatory mediators tumor necrosis factor-alpha (TNF-alpha), interleukin-8 (IL-8), platelet-activating factor (PAF), lipopolysaccharide (LPS), and leukotoxin to prime, activate, or alter deformability of adult bovine neutrophils. SAMPLE POPULATION: Blood collected from 5 healthy adult Holstein cows. PROCEDURE: Isolated neutrophils or whole blood was incubated with TNF-alpha, IL-8, PAF, LPS, or leukotoxin, and neutrophil chemiluminescence, degranulation, deformability, shape change, CD11b expression, and size distribution was measured. RESULTS: Incubation with TNF-alpha, IL-8, PAF, and LPS primed neutrophils for oxygen radical release but caused minimal oxygen radical release by themselves. None of the inflammatory mediators induced degranulation. Incubation with TNF-alpha and PAF resulted in a decrease in neutrophil deformability and induced shape change in neutrophils. Incubation with PAF consistently resulted in an increase in neutrophil size as measured by use of flow cytometry. Only IL-8 caused an increase in expression of CD11b by neutrophils. CONCLUSIONS AND CLINICAL RELEVANCE: Inflammatory mediators tested had minimal effects on neutrophil oxygen radical production or degranulation but did prime neutrophils for oxygen radical production. Incubation with PAF and TNF-alpha caused a decrease in neutrophil deformability and altered neutrophil shape and size. Results of our study indicate that PAF- and TNF-alpha-induced changes in neutrophil deformability and size may cause integrin- and selectin-independent trapping of neutrophils in the lungs of cattle with pneumonic pasteurellosis. 相似文献
5.
Functional and biochemical properties of ovine neutrophils 总被引：1，自引：0，他引：1
R Buchta 《Veterinary immunology and immunopathology》1990,24(2):97-112
Ovine neutrophils were isolated and characterised by their morphology, biochemical and functional responses. Two major granule types were observed, peroxidase positive and peroxidase negative, which were identified as the ovine equivalent of the human azurophil and specific granules respectively. A third type of granule identified, which was present at low frequency and was peroxidase negative, was possibly the ovine equivalent of the bovine large granule. Superoxide production following stimulation with PMA, A23187, PAF, ConA and opsonized zymosan (ZC), was 20-50% less, compared to bovine and human neutrophils. Coincubation of PMA with either PAF or A23187 enhanced superoxide production by 4 to 5 fold above that of the latter stimulants alone. The amount of beta-glucuronidase was similar to, while myeloperoxidase was more than twice that found in bovine neutrophils. Vitamin B12 binding protein was found in very small amounts, compared to that of bovine or human neutrophils. It was observed that coincubation of PMA with PAF, or A23187 resulted in an inhibition of beta-glucuronidase secretion and an enhancement of myeloperoxidase secretion, respectively. Phagocytic capability of ovine neutrophils was found to be optimal at a neutrophil to ZC ratio of 1:10, and which corresponded with an enhanced myeloperoxidase secretion. 相似文献
6.
Association among filamentous actin content, CD11b expression, and membrane deformability in stimulated and unstimulated bovine neutrophils 总被引：2，自引：0，他引：2
McClenahan DJ Evanson OA Walcheck BK Weiss DJ 《American journal of veterinary research》2000,61(4):380-386
OBJECTIVE: To investigate rheologic properties of bovine neutrophils that may result in adhesion molecule-independent sequestration of neutrophils in inflamed lungs of cattle. ANIMALS: Healthy 2- to 4-week-old male Holstein calves. PROCEDURES: Neutrophil deformability, filamentous actin (F-actin) content, and CD11b expression was determined for unstimulated bovine neutrophils and bovine neutrophils incubated with the inflammatory mediators tumor necrosis factor-alpha (TNF), platelet-activating factor (PAF), interleukin-8 (IL-8), zymosan-activated plasma (ZAP), Pasteurella haemolytica-derived lipopolysaccharide (LPS), and P haemolytica leukotoxin. Neutrophils were separated into 3 subpopulations on the basis of size. The Factin content and CD11 b expression were evaluated by use of flow cytometry. Leukocyte deformability was evaluated by filtration of dilute whole blood. RESULTS: The subpopulation of the smallest-sized neutrophils (>90% of neutrophils) contained little F-actin. A subpopulation of slightly larger neutrophils had a profound increase in F-actin content and CD11 b expression. The subpopulation of the largest neutrophils had increased F-actin content and CD11b expression, compared with those for both subpopulations of smaller neutrophils. Incubation of neutrophils with PAF and ZAP but not TNF, IL-8, LPS, or leukotoxin, resulted in decreased neutrophil deformability and increased F-actin content. Incubation with PAF and TNF induced an increase in size of neutrophils. CONCLUSIONS AND CLINICAL RELEVANCE: Size can be used to identify subpopulations of large and rigid neutrophils in blood samples from healthy calves. Platelet-activating factor and activated complement fragments are potent inducers of F-actin formation and neutrophil rigidity. Physical changes in neutrophils may impede their transit through lung microvasculature and result in leukocyte trapping independent of adhesion molecule interactions with endothelial cells. 相似文献
7.
Diez-Fraile A Meyer E Duchateau L Burvenich C 《American journal of veterinary research》2004,65(10):1421-1426
OBJECTIVE: To determine whether proinflammatory mediators and glucocorticoids affect CD62L(L-selectin) expression on peripheral blood neutrophils from cows in various stages of lactation. ANIMALS: 100 healthy dairy cows during early (13.1 +/- 0.79 days after parturition; n = 31), peak (58.7 +/- 1.64 days after parturition; 31), and mid (137.2 +/- 2.59 days after parturition; 38) lactation. PROCEDURE: In vitro effects of relevant proinflammatory mediators that are released in response to mastitis caused by gram-negative bacteria such as lipopolysaccharide (endotoxin), tumor necrosis factor-alpha, and platelet-activating factor (PAF) on CD62L expression on bovine neutrophils were assessed by flow cytometry. Influences of cortisol and dexamethasone on CD62L expression on bovine neutrophils were also investigated. RESULTS: Basal CD62L expression on neutrophils from cows during early, peak, and mid lactation were similar. Lipopolysaccharide and tumor necrosis factor-alpha had no effect on CD62L expression on neutrophils from cows at any stage of lactation. Conversely, PAF elicited a time- and dose-dependent, down regulatory effect on CD62L expression. However, no differential shedding of CD62L from neutrophils of cows at any stage of lactation were detected. In addition, no effects on CD62L expression on bovine neutrophils after whole blood incubation with cortisol or dexamethasone were observed. Incubation with glucocorticoids did not prevent the down regulatory effect of PAF on CD62L expression. CONCLUSIONS AND CLINICAL RELEVANCE: Comparable basal CD62L expression on bovine neutrophils and equal amounts of CD62L shedding from bovine neutrophils during all stages of lactation suggest that variations in CD62L density are not a likely cause of susceptibility of cows to coliform-induced mastitis during early lactation. 相似文献
8.
9.
C B Thomas P Van Ess L J Wolfgram J Riebe P Sharp R D Schultz 《Veterinary immunology and immunopathology》1991,27(4):365-381
The adherence of viable and heat-treated Mycoplasma bovis to bovine peripheral blood neutrophils was studied by specific immunofluorescence staining and flow cytometry. Viable and heat-treated M. bovis cells, adhered to bovine neutrophils in dose-dependent fashion within a 30 min incubation. Fluorescence quenching using crystal violet indicated that unopsonized M. bovis cells remained on the surface of bovine neutrophils without experiencing significant ingestion. The effect of M. bovis adherence on neutrophil microbicidal function was examined by measuring luminol enhanced chemiluminescence (CL). Adherent M. bovis cells did not elicit a bovine neutrophil CL response over a 75 min incubation period. M. bovis inhibited the capacity of bovine neutrophils to mount a CL response. Inhibition occurred whether viable or heat-treated M. bovis cells were used and it occurred when neutrophils were stimulated with opsonized zymosan (OZ) or phorbol myristate acetate (PMA). Inhibition of the PMA stimulated neutrophil CL response required cytadherence by M. bovis cells. These findings suggest that activation of the bovine neutrophil respiratory burst was inhibited at or distal in the pathway to the activation of protein kinase C (PKC), the site of PMA stimulation, and that it was mediated by a direct interaction between the adhering M. bovis cells and the bovine neutrophil membrane. 相似文献
10.
S D Swain D W Siemsen A J Hanson M T Quinn 《American journal of veterinary research》2001,62(11):1776-1781
OBJECTIVE: To characterize mobilization of secretory granules in bovine neutrophils. SAMPLE POPULATION: Neutrophils obtained from four 6- to 18-month-old Holstein cattle. PROCEDURE: Mobilization of secretory granules in bovine neutrophils was determined by measuring changes in cell-surface alkaline phosphatase activity on cells treated with various inflammatory mediators. Subcellular distribution of the alkaline phosphatase activity was determined by analysis of bovine neutrophil homogenates fractionated on density gradients. RESULTS: Alkaline phosphatase-containing secretory granules of bovine neutrophils were readily mobilized by a number of inflammatory agents, including platelet-activating factor, interleukin-8, tumor necrosis factor-alpha, lipopolysaccharide, leukotriene B4, and zymosan-activated plasma. In contrast, N-formyl-methionyl-leucyl-phenylalanine did not have a significant effect. Phorbol myristate acetate induced a biphasic response with up-regulation of cell-surface alkaline phosphatase at low doses and a return to baseline or even a reduction in cell-surface alkaline phosphatase at higher doses (> or = 10 ng/ml). Subcellular fractionation of bovine neutrophil homogenates revealed that alkaline phosphatase activity resided in light-density membrane vesicles (ie, location of secretory granules), which were distinct from specific, azurophil, and large granules. CONCLUSIONS AND CLINICAL RELEVANCE: Bovine neutrophils respond to various inflammatory mediators by mobilizing alkaline phosphatase-containing secretory granules. This suggests that the process is an important early step in the host-defense response of bovine neutrophils. 相似文献
11.
Claudia Concha María Daniella Carretta Pablo Alarcón Ivan Conejeros Diego Gallardo Alejandra Isabel Hidalgo Nestor Tadich Dante Daniel Cáceres María Angélica Hidalgo Rafael Agustín Burgos 《Journal of veterinary science (Suw?n-si, Korea)》2014,15(2):217-224
Reactive oxygen species (ROS) production is one of the main mechanisms used to kill microbes during innate immune response. D-lactic acid, which is augmented during acute ruminal acidosis, reduces platelet activating factor (PAF)-induced ROS production and L-selectin shedding in bovine neutrophils in vitro. This study was conducted to investigate whether acute ruminal acidosis induced by acute oligofructose overload in heifers interferes with ROS production and L-selectin shedding in blood neutrophils. Blood neutrophils and plasma were obtained by jugular venipuncture, while ruminal samples were collected using rumenocentesis. Lactic acid from plasma and ruminal samples was measured by HPLC. PAF-induced ROS production and L-selectin shedding were measured in vitro in bovine neutrophils by a luminol chemiluminescence assay and flow cytometry, respectively. A significant increase in ruminal and plasma lactic acid was recorded in these animals. Specifically, a decrease in PAF-induced ROS production was observed 8 h after oligofructose overload, and this was sustained until 48 h post oligofructose overload. A reduction in PAF-induced L-selectin shedding was observed at 16 h and 32 h post oligofructose overload. Overall, the results indicated that neutrophil PAF responses were altered in heifers with ruminal acidosis, suggesting a potential dysfunction of the innate immune response. 相似文献
12.
Elastase release, oxidant production and cytoplasmic Ca2+ fluxes by bovine and human neutrophils were compared using sensitive kinetic assays on a photon-counting spectrofluorometer. The stimulants used were phorbol myristate acetate (PMA), cytochalasin B, zymosan opsonized with bovine complement (bOZ) or human complement (hOZ), calcium ionophore, formyl-methionyl-leucyl-phenylalanine (FMLP) and concanavalin A (Con A). The respiratory burst of bovine and human neutrophils was stimulated by PMA and OZ but not by cytochalasin B, or calcium ionophore. Con A weakly stimulated this response in human neutrophils but not bovine. FMLP stimulated the respiratory burst of human but not bovine neutrophils. For evaluation of elastase release, human neutrophils were pretreated with cytochalasin B for 5 min and then stimulated. Cytochalasin B alone did not stimulate elastase release from human neutrophils. Phorbol myristate acetate, calcium ionophore, hOZ, FMLP and Con A did stimulate human neutrophils pretreated with cytochalasin B to release elastase. Human serum OZ was also able to stimulate elastase release from human neutrophils not pretreated with cytochalasin B. Some bovine neutrophils released elastase in response to cytochalasin B alone. Those bovine neutrophils that did not release elastase in response to cytochalasin B alone released elastase when stimulated with Con A or calcium ionophore after cytochalasin B pretreatment. Bovine neutrophils did not release elastase in response to FMLP or PMA with or without cytochalasin B pretreatment, but did release elastase in response to bOZ alone. Total elastase activity of bovine neutrophils was determined to be about 50 times less than that of human neutrophils. Intracellular calcium fluxes were stimulated in human neutrophils by calcium ionophore, FMLP, hOZ and Con A but not by PMA or cytochalasin B. Bovine neutrophil calcium fluxes were stimulated by calcium ionophore, Con A and bOZ; cytochalasin B also stimulated bovine neutrophils to increase cytoplasmic calcium concentration. Cytoplasmic calcium fluxes were not stimulated in bovine neutrophils by PMA or FMLP. In summary, human and bovine neutrophils respond similarly to calcium ionophore and OZ, but differently to PMA, cytochalasin B, Con A and FMLP. 相似文献
13.
This study describes a chemotaxis assay of ferret polymorphonuclear cells (PMNs). The optimal conditions for this chemotaxis assay were investigated for three chemoattractants: zymosan activated serum (ZAS), recombinant human interleukin-8 (rhIL-8) and N-formyl-Met-Leu- Phe (fMLF). In this study, ferret polymorphonuclear cells (PMNs) reacted to ZAS and rhIL-8, but not fMLF. The optimal concentration of ZAS and rhIL-8 were 5% and 100 ng/ml, respectively. The optimal incubation time of each reagent was 60 min. Due to the lack of response shown from fMLF, the existence of formyl peptide receptors (FPR) on ferret PMNs was investigated by evaluating FPR binding using flow cytometry. The receptor was not detected, implying that ferret neutrophils may lack FPR. This study confirms the fundamental experimental conditions for ferret PMNs chemotaxis and elucidates new findings concerning FPR in ferret neutrophils. 相似文献
14.
Casey J. LeBlanc Amy K. LeBlanc Meredith M. Jones Joseph W. Bartges Stephen A. Kania 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2010,39(2):157-163
Background: Peripheral blood neutrophils of untreated human cancer patients have been shown to have normal, increased, and decreased phagocytic activity, killing capacity, and/or oxidative burst activities. Objectives: The objectives of this study were to evaluate oxidative burst and phagocytic activities of peripheral blood neutrophils from tumor‐bearing dogs before therapy and compare them with neutrophil function of healthy control dogs. Methods: Heparinized whole blood was obtained from dogs with high‐grade lymphoma (n=23), sarcoma (n=13), or carcinoma (n=11), and healthy control dogs (n=11) for flow cytometric evaluation of oxidative burst and phagocytic activities. Percentage of bursting cells and amount of oxidative burst activity were determined after stimulation with phorbol 12‐myristate 13‐acetate (PMA) or Escherichia coli. Percentage of phagocytic cells and amount of phagocytic activity were determined after incubation with fluorescent E. coli. Results: Compared with control dogs, dogs with sarcoma (P=.004) and carcinoma (P=.05) had a lower percentage of neutrophils exhibiting oxidative burst activity after stimulation with PMA. Phagocytic activity was significantly lower in dogs with sarcomas compared with control dogs (P<.0001) and dogs with lymphoma (P=.01). Conclusions: Untreated carcinomas and sarcomas in dogs may suppress the percentage of neutrophils capable of oxidative burst when stimulated by PMA. Furthermore, sarcomas also may suppress the amount of phagocytic activity per neutrophil. Until further studies can be performed, the clinical significance of these findings is unknown. 相似文献
15.
Shiraishi R Itou T Sugisawa H Shoji Y Endo T Sakai T 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(8):711-714
To investigate the early host defense function in aquatic animals, the respiratory burst activity of bottlenose dolphin neutrophils against soluble and particulate stimulants was measured by luminol-dependent chemiluminescence assays and compared with those of bovine and human. Dolphin neutrophils generated the respiratory burst in response to phorbol 12-myristate 13-acetate (PMA), concanavalinA (ConA), heated-plasma (HP), and homologous-plasma opsonized zymosan except N-formyl-Met-Leu-Phe (fMLP). However, the respiratory burst of dolphin neutrophils stimulated by lipopolysaccharide and Staphylococcus aureus was inferior to those of bovine and human. Furthermore, DP-OZ also induced the respiratory burst of bovine and human neutrophils. In conclusion, dolphin neutrophils responded to several soluble and particulate stimulants as well as human neutrophils, but were refractory or slightly responded to bacterial agents. 相似文献
16.
Enriched populations of neutrophils and mononuclear leukocytes from 9 cattle persistently infected with noncytopathic bovine viral diarrhea virus were analyzed for frequency of association with virus, using flow cytometric procedures. Trypsinization of neutrophils decreased the frequency of viral association from 0.82% to 0.49%. Similar treatment of mononuclear leukocytes decreased the frequency of viral association from 5.53% to 4.81%. Results of immunocytochemical procedures to locate viral antigen were inconclusive for neutrophils, but viral antigen was found in the cytoplasm of mononuclear leukocytes. A distinct and highly pure population of eosinophils was identified during flow cytometric analysis of neutrophil populations from 2 of 9 cattle. 相似文献
17.
Kingston JK Bayly WM Sellon DC Meyers KM Wardrop KJ 《American journal of veterinary research》2002,63(6):840-844
OBJECTIVE: To investigate the effects of formaldehyde fixation on equine platelets using flow cytometric methods to evaluate markers of platelet activation. SAMPLE POPULATION: Blood samples from 6 Thoroughbreds. PROCEDURE: The degree of fluorescence associated with binding of fluorescein isothiocyanate (FITC)-conjugated anti-human fibrinogen antibody and FITC-annexin V in unactivated and adenosine diphosphate (ADP)-, platelet activating factor (PAF)-, and A23187-activated platelet samples in unfixed and 0.5, 1.0, and 2.0% formaldehyde-fixed samples was assessed by use of flow cytometry. RESULTS: In samples incubated with FITC-anti-human fibrinogen antibody prior to fixation, addition of 2.0% formaldehyde resulted in a 30% increase in total fluorescence in ADP- and PAF-activated samples and a 60% increase in A23187-activated samples. Fixation for 24 hours prior to addition of antibody resulted in reduced fluorescence of samples containing antihuman fibrinogen antibody for all 3 concentrations of formaldehyde in PAF-activated samples. The addition of all 3 concentrations of formaldehyde after incubation with FITC-annexin V resulted in significant increases in fluorescence in unactivated and activated platelet samples. As length of fixation time increased, there was a gradual increase in fluorescence that was significant at 24 hours. CONCLUSIONS: Because fixation with 2.0% formaldehyde results in significant changes in fluorescence in activated platelet samples containing anti-fibrinogen antibody, lower concentrations of formaldehyde should be used to fix equine platelet samples. Formaldehyde-fixed platelet samples should be analyzed within 12 hours of fixation to avoid artifactual increases in fluorescence. Fixation of samples containing FITC-annexin V should be avoided because of significant increases in fluorescence that may interfere with interpretation of results. 相似文献
18.
Flow cytometry and sorting proved to be a rapid method that facilitated the identification of different leukocyte populations in bovine blood and milk. After briefly incubating whole blood and milk samples in a hypotonic phosphate buffer, containing supravital acridine orange, 5 classes of leukocytes were found in the blood (lymphocytes, neutrophils, eosinophils, basophils, and monocytes) and 4 in the milk (lymphocytes, neutrophils, monocytes, and macrophages) by flow cytometry. Cells were morphologically identified by fluorescent microscopy after flow cytometric sorting and by light microscopy after Papanicolaous staining. Udder parenchymal and ductal tissue cells (secretory and epithelial cells) were not found in the milk samples evaluated. Large differences in the total and differential cell counts were found in the different milk secretions. 相似文献
19.
H Nagahata H Nochi K Tamoto H Noda G J Kociba 《Canadian journal of veterinary research》1995,59(1):1-7
Expression of CD18 on bovine neutrophils in response to stimulation by zymosan activated serum (ZAS) and phorbol myristate acetate (PMA) and the effects of monoclonal antibodies (MAB) recognizing CD18 or bovine neutrophil surface antigens (S2G8 and S5F8G10) on adherence, chemotactic responses and phagocytosis of bovine neutrophils were evaluated. CD18 expression of neutrophils was increased after ZAS and PMA treatment by 12.2 and 54.2% respectively, and were significantly (p < 0.05, p < 0.01) different from those of untreated neutrophils. CD18 expression by neutrophils from a Holstein-Friesian heifer affected with leukocyte adhesion deficiency was within negative controls when stimulated by ZAS and PMA. Adherence, chemotactic responses, and phagocytosis were significantly decreased (p < 0.01) in neutrophils continuously treated with anti-CD18 MAB (MHM 23). Adherence was also significantly decreased in anti-CD18 pretreated neutrophils. Significant (p < 0.01) differences of chemotactic responses and phagocytosis of neutrophils were found between neutrophils pretreated and continuously treated with anti-CD18 MAB (MHM 23). Monoclonal antibodies to other surface antigens did not significantly alter neutrophil adherence, chemotaxis or phagocytosis. This study demonstrated that CD18 expression on bovine neutrophils is increased significantly by stimulation with ZAS and PMA and that the adhesion molecule CD18 plays an important role in adhesion-related functions. 相似文献