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(Journal of Leukocyte Biology. 2001;70:130-134.)
© 2001 by Society for Leukocyte Biology

Mechanism of extracellular release of human neutrophil calprotectin complex

Alexandra Voganatsi^*, Alexander Panyutich, Kenneth T. Miyasaki^* and Rekha K. Murthy

^* Section of Oral Biology, School of Dentistry, and
Division of Infectious Diseases, Cedars-Sinai Medical Center, University of California, Los Angeles, and
Department of Medicine, Division of Hematology, Oncology and Bone Marrow Transplantation, University of Minnesota, Minneapolis

Correspondence: Rekha K. Murthy, M.D., Division of Infectious Diseases, Cedars-Sinai Medical Center, 8700 Beverly Blvd., MOT 1130E, Los Angeles, CA 90048. E-mail: armurthy{at}ucla.edu

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Calprotectin is an abundant cytosolic protein complex of human neutrophils with in vitro extracellular antimicrobial activity. Studies suggest that calprotectin may be actively secreted from intact HL-60 cells and that it can be translocated to polymorphonuclear neutrophil (PMN) cell membranes. To examine whether calprotectin is secreted extracellularly, we incubated soluble and particulate stimuli, including live and heat-inactivated Candida albicans, with whole blood and measured calprotectin levels in the plasma. We compared the release of calprotectin to that of lactoferrin, a protein known to be secreted by PMNs. Extracellular lactoferrin was detected after incubation with any of the particulate stimuli. In contrast, a significant increase in extracellular calprotectin was found only after incubation with live C. albicans. Specifically, the increase in extracellular calprotectin correlated directly with a proportional decrease in PMN viability. Our results indicate that human PMN calprotectin is not secreted extracellularly except as a result of cell disruption or death.

Key Words: MRP8 • MRP14 • granulocytes • L1

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Calprotectin (also known as L1 antigen, calgranulin A and B, and MRP14/MRP8) is a molecular complex that constitutes up to 45% of the cytosolic protein of neutrophils [¹ ]. It is composed of two calcium-binding proteins, MRP8 and MRP14, with respective masses of 10 and 14 kDa. Both components belong to the S-100 protein family, whose other members are involved in cell cycle progression, cell differentiation, and cytoskeleton-membrane interactions [² ]. Calprotectin released from PMNs might contribute to host defense, in view of its ability to inhibit the growth of pathogens such as Candida albicans [³ , ⁴ ] and Capnocytophaga sputigena [⁵ ]. Calprotectin is expressed during terminal cellular differentiation [⁶ ] and is also found in monocytes (1% of the cytosolic protein) and in oral/gingival keratinocytes [⁷ , ⁸ ]. Although both MRP8 and MRP14 lack sequences that would constitute a pathway for the direct secretion of calprotectin outside the cell [⁹ ], its release from phorbol myristate acetate (PMA)-stimulated monocytes has been reported [¹ ]. We undertook the studies herein to determine whether human neutrophils could release calprotectin by a secretory mechanism separate from its holocrine release from heat-inactivated or dying cells [¹⁰ ].

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Blood samples
Fresh, heparinized venous blood (15 mL) was obtained from healthy volunteers. To minimize calprotectin release secondary to cellular handling, the blood was used immediately without further processing. Two milliliters of whole blood were added to a tube containing 200-µL suspensions of each of the stimuli described below and were incubated for up to 120 min at 37°C with end-over-end rotation. One aliquot of whole blood (0.5 mL) was immediately placed on ice after collection for cell count determination as described below and then stored at -70°C for later determination of total blood calprotectin and lactoferrin levels.

Leukocyte determination in whole-blood samples
Red blood cell lysis was performed in aliquots of whole-blood samples using hypertonic saline, and leukocytes [white blood cells (WBCs)] were counted in a hemacytometer to determine their concentration in whole blood.

Reagents
Zymosan was boiled for 15 min, washed twice, and resuspended at a concentration of 20 mg/mL in normal saline. A stock solution of 10 mM formyl-Met-Leu-Phe (fMLP) in dimethyl sulfoxide was diluted with an equal mixture of dimethyl sulfoxide and Hanks’ balanced salt solution to the desired concentration (10^-2 M). Escherichia coli lipopolysaccharide (LPS) was prepared in phosphate-buffered saline (PBS) at a concentration of 1 µg/mL. All reagents were obtained from Sigma (St. Louis, MO).

C. albicans
C. albicans (strain 820, provided by Dr. R.I. Lehrer, University of California, Los Angeles) was maintained on Sabouraud agar (Becton Dickinson, Cockeysville, MD). The cultures we planned to use in our experiments were started by inoculating a single agar colony into Sabouraud broth and then incubating the culture overnight at 37°C in a shaking water bath. The test organisms were washed twice in sodium phosphate buffer (10 mM, pH 7.4) at 2,000 rpm for 10 min, counted in a hemacytometer, and adjusted to the desired concentration (C. albicans/WBC ratio, 5:1). Heat-inactivated (HI) C. albicans cells were prepared by boiling the C. albicans suspension for 15 min.

Stimulation of secretion
Immediately after addition of stimulants (zymosan, fMLP, LPS, and live and HI C. albicans) to whole-blood samples, 300 µL of the samples were removed from each tube for measurement of the baseline (time zero) plasma concentrations of calprotectin and lactoferrin. The tubes were incubated at 37°C with rotation, and after 30, 60, and 120 min, 300 µL of each sample were collected. All samples collected at each time point were centrifuged through 0.4 mL of silicon oil, (1.035 density; Sigma), in a microcentrifuge (Biofuge 15; Baxter, Germany) for 5 min to separate plasma from blood cells. The supernatant (plasma) was collected and frozen (-70°C) for later analysis.

PMN viability
Trypan blue dye exclusion (Sigma) was used to determine PMN viability at baseline and after incubation with C. albicans (live and HI) for 120 min. After the red blood cells were lysed, a WBC suspension was prepared in Hanks’ balanced salt solution, and 0.5 mL of 0.4% trypan blue was mixed with 0.5 mL of the cell suspension and incubated for 15 min. Viable and nonviable cells were counted using a hemacytometer, and the percent viability was calculated.

Total content of lactoferrin and calprotectin in whole-blood samples
For determination of the cellular concentrations of lactoferrin and calprotectin in whole blood, a 0.3-mL sample of whole blood was treated with radioimmunoprecipitation assay buffer (Sigma) to disrupt the cell membrane. The suspension was vigorously vortexed, and cellular debris was removed by high-speed centrifugation (10 min at 15,000 g). Lactoferrin and calprotectin levels were measured in these specimens by using the quantitative enzyme-linked immunosorbent assay (ELISA) described below, yielding total cellular concentrations.

Measurement of calprotectin and lactoferrin
Quantitative measurements of lactoferrin and calprotectin were performed by a sandwich ELISA technique, using microtiter plates (Nunc Immunoplate, Naperville, IL) rabbit anti-human lactoferrin immunoglobulin G (IgG) (Sigma), and rabbit anti-human calprotectin IgG prepared in our laboratory. Each of these antibodies was prepared at a concentration of 10 µg/mL in 0.1 M sodium bicarbonate buffer, pH 9.6. The microtiter wells were coated with either calprotectin or lactoferrin antibody solution (100 µL/well) and incubated for 18 h at 4°C. The plates were washed five times with double-distilled water. Stock solutions of purified human lactoferrin (Sigma) in PBS (2 mg/mL) and calprotectin (prepared in our laboratory at 1 mg/mL) were kept at -70°C and diluted before the experiment in 1% bovine serum albumin (BSA) (Sigma) in PBS. Serial twofold dilutions were prepared as standards (ranging from 100 to 1 g/mL for lactoferrin and from 32 to 0.25 g/mL for calprotectin). The test samples were also prepared in serial twofold dilutions in PBS containing 1% BSA. Standards and test samples (100 µL) were placed in each well in a prearranged pattern. All standard dilutions and test samples were run in triplicate.

Plates were incubated for 1 h at room temperature and then washed five times with washing buffer (20 mM Tris, 0.5 M NaCl, pH 7.4); then 100 µL/well of biotinylated anti-lactoferrin IgG solution (1:6,000) or anti-calprotectin IgG (1:400) were added to each well, and the plates were again incubated for 1 h. The plates were then washed five times with washing buffer, horseradish–peroxidase-conjugated adivin (Cappel, Aurora, OH) (100 µL/well; 1:2,000 dilution in 1% PBS/BSA) was added, and the plates were incubated again for 30 min. After the plates were washed five times with washing buffer, peroxidase substrate was prepared with 10 mL of 20 mM sodium citrate buffer (pH 4.7), 4 mg of o-phenylenediamine dihydrochloride (Sigma), and 3.5 µL of 30% H₂O₂. The substrate was added to the wells (100 µL) and incubated for 15 min. The peroxidase reaction was stopped by adding 100 µL/well of 2.5 M H₂SO₄, and the optical density was determined in a microtiter plate reader (Vmax; Molecular Devices, Sunnyvale, CA) at 490 nm, with PBS/BSA serving as a control. Standard curves were determined, and the results from the test samples were plotted against the standard curves to determine sample concentrations of both proteins.

The plasma levels of lactoferrin and calprotectin in all plasma supernates (samples) were expressed as percentages (P) of the whole blood concentration of each protein. For each time point, the difference in plasma levels of lactoferrin or calprotectin compared with controls (without stimulants) was calculated as follows and expressed as release: release = [(P_sample- P_control)/(100-P_control)] x 100.

Statistical analysis
Data were analyzed using the paired Student’s t-test.

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PMN viability
Leukocyte viability, as assessed by trypan blue dye exclusion after incubation of whole blood for 120 min, was found to be 94% in two experiments. Leukocyte viability was also examined in cell suspensions containing HI and live C. albicans; after incubation for 120 min, leukocyte viability was 91% and 78%, respectively (Fig. 1 ).

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Figure 1. Comparison of increase in calprotectin release and decrease in PMN viability, after 120 min of incubation, between controls and samples incubated with live and HI C. albicans.

Lactoferrin levels
The lactoferrin content of whole blood was determined using the ELISA after cell lysis and was found to be 15 µg/5 x 10⁶ WBC equivalents, which is consistent with previous reports [¹¹ ]. Plasma lactoferrin was measured in whole-blood samples treated with stimulants. Incubation with fMLP and LPS did not cause any appreciable increase in plasma lactoferrin; however, in the presence of zymosan, plasma lactoferrin levels were significantly higher than those of controls. The largest increase in plasma lactoferrin levels was noted in the presence of both live and HI C. albicans, with releases of 14.1% and 13.9%, respectively (Fig. 2 ).

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Figure 2. Lactoferrin release at different time points (30, 60, and 120 min) after incubation with fMLP, LPS, zymosan, C. albicans, and HI C. albicans. Results represent mean values ± SD obtained in three experiments performed in duplicate.

Calprotectin levels
The concentration of calprotectin in whole blood was determined using the ELISA after cell lysis and was found to be 5–15 mg/mL, consistent with previous reports [¹² , ¹³ ]. Plasma calprotectin levels from unstimulated whole blood increased over the 120 min of the experiment, up to a maximum of 3% of the total calprotectin content of the whole-blood samples (data not shown). Incubation of whole blood with all PMN stimulants individually, however, resulted in higher plasma calprotectin levels (Fig. 3 ) to different degrees. In the presence of zymosan, calprotectin release at 120 min was 2.88%, whereas with fMLP and LPS, calprotectin release was only 1.4% and 0.39%, respectively. Incubation of whole blood with live C. albicans resulted in significantly greater release of calprotectin than incubation with any of the soluble stimuli, with a release of 23.6%, whereas incubation with HI C. albicans resulted in a calprotectin release of 4.3%.

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Figure 3. Calprotectin release at different time points (30, 60, and 120 min) after incubation with fMLP, LPS, zymosan, C. albicans, and HI C. albicans. Results represent mean values ± SD obtained in three experiments performed in duplicate.

Calprotectin versus lactoferrin release
Differences between release of lactoferrin and calprotectin were statistically significant (P<0.05) after stimulation with HI C. albicans at all time points and after stimulation with zymosan after 60 and 120 min. The differences in release in the presence of other stimulants were not statistically significant (Table 1 ).

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Table 1. Comparison of Lactoferrin and Calprotectin Release from PMN after Incubation with Various Stimuli

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The hypothesis that calprotectin may be actively secreted from intact cells has been supported by studies in monocytes and in HL-60 cells in the presence of certain soluble stimuli, including fMLP, PMA, and zymosan. We incubated soluble and particulate stimuli with whole blood and measured calprotectin in the plasma of these samples. We compared the release of calprotectin to the release of lactoferrin, a protein of specific granules known to be secreted extracellularly by PMNs [¹⁴ ]. We used whole blood without separating PMNs to avoid any potential stimulatory effect on cells during the separation process (e.g., Ficoll-Hypaque, centrifugation, etc.). We assessed PMN viability (using trypan blue dye exclusion) over the duration of the incubation and found a decrease in PMN viability from 100% at the time of sample collection to 94% after a 120-min incubation under the conditions of the experiments.

We found a time-dependent increase in calprotectin release from unstimulated whole blood over time, with a maximum increase of 3% after 120 min. This change in plasma calprotectin levels corresponded inversely with a proportional decrease in cell viability over the duration of the incubation (100%–94%).

We found that lactoferrin release from whole blood increased by only 3% in the presence of fMLP; however, lactoferrin release from whole blood incubated with opsonized zymosan particles was time dependent, with a maximum of 9% at 120 min. Incubation with both live and HI C. albicans also resulted in a time-dependent increase in lactoferrin release of 6% at 30 min and 14% at 120 min. The relative increase in lactoferrin release in the presence of C. albicans compared with zymosan may be due to the much larger particle size of the yeast cells compared with zymosan particles because particles of larger size have been shown to induce greater release of PMN granule enzymes [¹⁵ ].

Incubation of whole blood with the soluble PMN stimuli fMLP and LPS resulted in only minimal increases of 1.4% and 0.39%, respectively, in calprotectin release. In contrast, incubation of whole blood with particulate stimuli resulted in moderate (with zymosan) to large (with C. albicans) increases in calprotectin release. Samples treated with zymosan resulted in calprotectin release of 2.85% after 120 min of incubation, but samples incubated with live C. albicans yielded a much larger increase (23.6%) in calprotectin release than samples incubated with HI C. albicans (4.3%). The difference in release of calprotectin compared with the release of lactoferrin was statistically significant (P<0.05) only after stimulation with HI C. albicans at all time points and with zymosan at 60 and 120 min. Both of these particulate stimuli resulted in release of lactoferrin and not of calprotectin, unlike live C. albicans, which resulted in calprotectin release, likely because they did not cause PMN cellular disruption under the conditions of these experiments.

The release of lactoferrin, a protein of specific granules of PMN, was similar in both live and HI C. albicans; whereas the release of calprotectin, a cytosolic protein of PMN, during incubation with live C. albicans was quite markedly increased compared with HI C. albicans. The difference between the release of lactoferrin and that of calprotectin from whole blood cells upon exposure to cellular stimuli may be explained by the differences in intracellular localization of these two proteins within PMN. It is known that lactoferrin is released from intact PMN on stimulation with C. albicans (16). Although there was a size-dependent increase in release (more with yeast cells than zymosan particles), the difference in release from exposure to live versus HI C. albicans was insignificant at 120 min.

PMN phagocytosis of C. albicans occurred very rapidly after coincubation of these cells (50% phagocytosis by PMNs after 120 min at 37°C; data not shown). After phagocytosis, HI C. albicans remained internalized and stimulated the PMN antimicrobial response. Live C. albicans, however, might continue to undergo mycelial growth in some cells, but in others the PMN response might result in either destruction or growth inhibition of the yeast cells. The strikingly direct correlation between the magnitudes of decrease in PMN viability and increase in calpotectin release indicates that these two events are related. It is known that calprotectin does not possess any sequences that would permit its transmembrane transport in intact PMN [⁹ ]. Our experiments support the hypothesis that calprotectin can be released only extracellularly after PMN death, although the possibility of another mechanism of potential host defense for this protein (e.g., through transfer of calprotectin to cell membrane surfaces of living cells) has not been excluded. In contrast, although granule proteins such as lactoferrin can be released from living cells (primarily into phagocytic vacuoles and less so extracellularly), cell death does not appear to increase this phenomenon, at least not from passive release from granules of dying or dead cells, as was noted with calprotectin in our experiments.

In conclusion, we found that human neutrophil calprotectin does not appear to be secreted extracellularly, even in the presence of various soluble or particulate stimuli, and that the release of calprotectin is most likely a consequence of cell disruption or cell death. Given the short life span of neutrophils in tissues [¹⁷ ] and the evidence of cell death resulting in calprotectin release, it would be of interest to determine whether tissue levels of calprotectin contribute to host defense. Finally, the role of calprotectin in other cells where it is found, including monocytes, macrophages, and keratinocytes, is unknown, and similar studies of calprotectin release from these cells may offer further insight into the potential role of calprotectin in host defense at the tissue or mucosal level.

 
Support provided by a postdoctoral research exchange grant from the Max Kade Foundation (L931029, A.V.), and the University of California, Universitywide AIDS Research Program (R94-CS-117A, R.M.). We thank Dr. R. I. Lehrer (UCLA) for providing C. albicans strain 820 and for assistance with experimental design.

Received December 9, 1999; revised October 23, 2000; accepted March 19, 2001.

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1
1. Fagerhol, M. K., Andrson, K. B., Naess-Andresen, C.-F., Brandtaeg, P., Dale, I. (1990) Calprotectin (the L1 leucocyte protein) Smith, V. L. Dedman, J. R. eds. Stimulus Response Coupling: the Role of Intracellular Calcium Binding Proteins ,187-210 CRC Press Boca Raton, FL..
2
2. Kligman, D., Hilt, D. C. (1988) The S-100 protein family Trends Biochem. Sci. 13,437-443[Medline]
3
3. Sohnle, P. G., Collins-Lech, C., Wiessner, J. H. (1991) The zinc-reversible antimicrobial activity of neutrophil lysates and abscess fluid supernatants J. Infect. Dis. 164,137-142[Medline]
4
4. Murthy, A. R., Lehrer, I. R., Harwig, S. L. S., Miyasaki, T. K. (1993) In vitro candidastatic properties of the human neutrophil calprotectin complex J. Immunol. 151,6291-6301[Abstract]
5
5. Miyasaki, K. T., Bodeau, A. L., Murthy, A. R. K., Lehrer, R. I. (1993) In vitro antimicrobial activity of the human cytosolic complex, calprotectin, against Capnocytophaga sputigena J. Dent. Res. 72,517-523[Abstract/Free Full Text]
6
6. Murao, S., Collart, F. R., Huberman, E. (1990) A protein complex expressed during terminal differentiation of monomyelocytic cells is an inhibitor of cell growth Cell Growth Differ 1,447-457[Abstract]
7
7. Brandtzaeg, P., Dale, I., Fagerhol, M. K. (1987) Distribution of a formalin-resistant myelomonocytic antigen (L1) in human tissues. II. Normal and aberrant occurrence in various epithelia Am. J. Clin. Pathol. 87,700-707[Medline]
8
8. Eversole, L. R., Miyasaki, K. T., Christensen, R. E. (1992) The distribution of the antimicrobial protein, calprotectin in oral keratinocytes Arch. Oral Biol. 37,963-968[Medline]
9
9. Odink, K., Cerletti, N., Bruggen, J., Clec, R. G., Tarcsay, L., Zwadlo, G., Gerhards, G., Schlegel, R., Sorg, C. (1987) Two calcium binding proteins in infiltrate macrophages of rheumatoid arthritis Nature 330,80-83[Medline]
10
10. Lehrer, R. I. (1993) Holocrine secretion of calprotectin: a neutrophil-mediated defense against C. albicans? J. Lab. Clin. Med. 121,193-194[Medline]
11
11. Scettler, A., Thorn, H., Jockusch, B. M., Tschesce, H. (1991) Release of proteinases from stimulated polymorphonuclear leucocytes: evidence for subclasses of the main granule types and their association with cytoskeletal components Eur. J. Biochem. 197,197-202[Medline]
12
12. Dale, I., Fagerhol, M. K., Naesgaard, I. (1983) Purification and partial characterization of a highly immunogenic human leukocyte protein, the L1 antigen Eur. J. Biochem. 134,1-6[Medline]
13
13. Edgeworth, J., Gorman, M., Bennett, R., Freemont, P., Hogg, N. (1991) Identification of p8,14 as a highly abundant heterodimeric calcium binding protein complex of myeloid cells J. Biol. Chem. 266,7706-7713[Abstract/Free Full Text]
14
14. Pryzwansky, K., MacRae, E., Spitznagel, K. J., Cooney, H. M. (1979) Early degranulation of human neutrophils: immunocytochemical studies of surface and intracellular phagocytic events Cell 18,1025-1033[Medline]
15
15. Henson, M. P. (1971) The immunologic release of constituents from neutrophil leukocytes J. Immun. 107,1547-1557[Abstract/Free Full Text]
16
16. Palma, C., Cassone, A., Serbousek, D., Pearson, A. C., Djeu, J. (1992) Lactoferrin release and interleukin-1, interleukin-6, and tumor necrosis factor production by human polymorphonuclear cells stimulated by various lipopolysaccharides: relationship to growth inhibition of Candida albicans Infect. Immun. 60,4604-4611[Abstract/Free Full Text]
17
17. Fliedner, T. M., Cronkite, E. P., Robertson, J. S. (1964) Granulocytopoiesis. I. Senescence and random loss of neutrophilic leukocytes in human beings Blood 24,402-414[Abstract/Free Full Text]

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