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Selective Enhancement of the Expression of Granulocyte Proc. Natl. Acad. Sci. USA Vol. 82, pp. 2503-2507, April 1985 Medical Sciences Selective enhancement of the expression of granulocyte functional antigens 1 and 2 on human neutrophils (surface antigens/N-formyl-Met-Leu-Phe/lipopolysaccharide/132-microglobulin) M. A. VADAS, A. F. L6PEZ, AND D. J. WILLIAMSON Experimental Allergy Laboratory of the Clinical Research Unit, The Walter and Eliza Hall Institute of Medical Research, Post Office, Royal Melbourne Hospital, Victoria 3050, Australia Communicated by J. F. A. P. Miller, December 7, 1984 ABSTRACT The regulation of expression of two human GFA could be increased rapidly and selectively by the che- granulocyte functional antigens (GFA-1 and GFA-2) was ex- motactic peptide N-formylmethionylleucylphenylalanine amined. N-formylmethionylleucylphenylalanine (fMet-Leu- (fMet-Leu-Phe) and that this was accompanied by increased Phe) caused a rapid, dose-dependent enhancement of the stimulation of neutrophil function by MAb against these anti- expression of these antigens, 2- to 4-fold within 30 min, but not gens. Treatment of neutrophils with cytochalasin B and of another surface structure, P2-microglobulin. Pretreatment fMet-Leu-Phe, a "complete secretagogue" (13), further en- of the cells with cytochalasin B at 5 ,ug/ml further enhanced hanced the expression of GFA-2. LPS also increased their the effect of fMet-Leu-Phe on the expression of GFA-2, raising expression, but to a lesser extent than did fMet-Leu-Phe, its surface expression li-fold. Lipopolysaccharide also stimu- and with relatively more effect on GFA-1. lated the expression of GFA-1 and GFA-2. The effect of lipo- polysaccharide was less than that of fMet-Leu-Phe and was more marked on GFA-1 than on GFA-2. Pretreatment of neu- MATERIALS AND METHODS trophils with fMet-Leu-Phe not only stimulated their cytotoxic Medium. Eagle's minimum essential medium (GIBCO) activity against antibody-coated target cells but also increased containing 10% fetal calf serum (Flow), and antibiotics (ben- their capacity to be stimulated by monoclonal antibodies to zylpenicillin at 60 mg/liter and streptomycin at 100 mg/liter; GFA-1 and GFA-2. These findings show that the expression of Glaxo, Boronia, Victoria, Aus.) was used for the separation functional surface structures on human neutrophils is subject of peripheral blood leukocytes, cytotoxicity, and immuno- to rapid and selective regulation. fluorescence assays. Purification of Human Neutrophils. Peripheral blood from We have described recently two granulocyte-specific anti- normal volunteers was sedimented on dextran, followed by gens that appear to be involved in the function of human centrifugation on a hypertonic metrizamide (Nyegaard, neutrophils and eosinophils. The first of these granulocyte Oslo) gradient as described (14). The purity of the neutrophil functional antigens (GFA-1) has a molecular weight of preparations was always >96% with eosinophils as the only 110,000, and an IgM monoclonal antibody (MAb) against it contaminant. strongly enhanced antibody-dependent cytotoxicity of tumor Monoclonal Antibodies. The IgM MAb WEM-G1 (against cells by human neutrophils and eosinophils (1). GFA-1 ap- GFA-1), and the IgG1 MAb WEM-G11 (against GFA-2) pears early in granulocyte maturation, being present on day were developed as described (1, 5). The murine IgG2b MAb 7 colony-forming cells (unpublished results) and seems to to 2-microglobulin (82 m) was a gift from I. F. C. McKenzie possess a similar reactivity to that of other anti-granulocyte (University of Melbourne). Nonbinding control murine MAb IgM MAbs (2-4). were K7 (IgM, anti-trinitrophenyl) and PB10 (IgG1, anti- The second GFA, GFA-2, has a molecular weight of chicken 6 antigen), gifts from M. Kennedy (National Insti- 95,000, with -20,000 cell-surface structures on each neutro- tute of Medical Research, London) and P. Bartlett (Walter phil. An IgG1 MAb against GFA-2 inhibited antibody-depen- and Eliza Hall Institute, Melbourne, Australia), respective- dent cell-mediated cytotoxicity (ADCC) by neutrophils as ly. Ascites containing MAb was precipitated with 40% am- well as eosinophils; however, the F(ab')2 fragment of this monium sulfate before conjugation with fluorescein isothio- MAb was a strong stimulator of these functions (5). Signifi- cyanate (FITC) as described (15). In some experiments cantly, the capacity of neutrophils to phagocytose IgG-coat- WEM-G11 was purified, and F(ab')2 fragments were made ed particles also was inhibited by the whole IgG but stimulat- (16) before conjugation with FITC. ed by its F(ab')2 fragment. Reagents. Escherichia coli LPS (026:B6, Difco) and stock The function of human neutrophils is also influenced by solutions of fMet-Leu-Phe (Sigma; 1 mM in ethanol) and cy- other stimuli, such as chemotactic peptides (6), colony-stim- tochalasin B (Sigma; at 0.5 mg/ml of dimethyl sulfoxide) ulating factors (CSF) (7), and lipopolysaccharide (LPS) (8). were diluted in phosphate-buffered saline prior to use. The The effects of these substances on granulocytes include the human granulocyte-macrophage colony stimulating factor a enhancement of their tumoricidal and microbicidal capaci- (CSF-a) was a gift from N. Nicola, prepared as described ties (9, 10), stimulation of oxidative metabolism (9, 11), and (17, 18) and used at concentrations found to be supramaxi- alteration of their ability to adhere to endothelial cells (12). mal in the colony-forming assay. The mechanisms of action of these regulators are not ADCC Assay. P815 tumor target cells (DBA/2, mastocy- clear, but our demonstration of the functional importance of toma) were labeled with 51Cr and coupled with trinitrophenyl GFA-1 and GFA-2 raised the possibility that such regulators as described (7). P815 cells (4 x 103) were then placed into may exert their effects by modulating these antigens. In this communication we show that the number of cell-surface Abbreviations: GFA, granulocyte functional antigen; fMet-Leu- Phe, N-formylmethionylleucylphenylalanine; 132m, j32-microglob- The publication costs of this article were defrayed in part by page charge ulin; LPS, lipopolysaccharide; MAb, monoclonal antibody; ADCC, payment. This article must therefore be hereby marked "advertisement" antibody-dependent cell-mediated cytotoxicity; CSF, colony-stimu- in accordance with 18 U.S.C. §1734 solely to indicate this fact. lating factor; FITC, fluorescein isothiocyanate. 2503 Downloaded by guest on September 26, 2021 2504 Medical Sciences: Vadas et al. Proc. NatL Acad Sd USA 82 (1985) 96-well Linbro microtiter plates (Flow) containing rabbit anti-dinitrophenyl IgG (Miles-Yeda, Rehovot, Israel), neu- 25 1,100 trophils (1.2 x 105), and MAb or CSF dilutions in a total 23 GFA-2 *°o 1,000 volume of 160 /tl. Anti-dinitrophenyl crossreacts strongly GFA-1 o with the trinitrophenyl determinant on target cells. After in- "21 900 ; cubation for 2.5 hr at 370C, 80 Al of supernatant was re- moved from each well for in a gamma counter. The cU counting 800 C percent cytotoxicity was determined according to the formu- c la: %di 17 700 a,uw 0 C 600 ' Cytotoxicity = 4- 8 13 500 Go Experimental cpm - spoftaneous release cpm 100 maximum cpm - spontaneous release cpm 11 400 a where "spontaneous release" was obtained by incubating 9 Sc 0- 300 target cells in medium alone, and "maximum release" was obtained by incubating them with 5% Triton X-100. NIL 10-10 10-9 1i-8 10-7 10-6 16-5 Direct Immunofluorescence Assay. Granulocytes that had FMLP(M) been treated in different ways were mixed at i07 cells per ml FIG. 1. Effect of incubation with various concentrations of with FITC-MAb in microtiter plates for 45 min at 4°C. The fMet-Leu-Phe (FMLP), for 39 min at 370C on the expression (mean cells were washed three times in medium and fixed (1% fluorescence ofbound FITC-MAb) ofGFA-2 and GFA-1. The effect formaldehyde/5 mM sodium azide/2% glucose in phos- of 0.1 ,uM fMet-Leu-Phe for 30 min at 4°C is also shown (starred symbols), as is the effect of incubation with concentrations of etha- phate-buffered saline) before analysis by flow cytometry. nol found in fMet-Leu-Phe (30 min at 37°C) (open symbols). Flow Cytometry. Fixed granulocytes were analyzed in a fluorescence-activated cell sorter (FACS II, Becton Dickin- son), which was equipped with 3-decade logarithmic amplifi- were incubated for 30 min at 37°C with various doses of ers in the fluorescence detection channel and linked to a fMet-Leu-Phe, then washed at 4°C, and mixed with FITC- PDP11 computer data-handling system. In each sample a MAb WEM-G1 or WEM-G11 or with anti-f32m before analy- minimum of 10,000 cells were analyzed. The fluorescence sis by flow cytometry. fMet-Leu-Phe increased the expres- profiles obtained with most cell preparations were unimodal. sion of GFA-1 and GFA-2 in a dose-dependent fashion (Fig. In a few individuals staining with WEM-G1 yielded a bimo- 1). Ethanol in the concentrations present in the fMet-Leu- dal distribution. After computer transformation to a linear Phe preparations had no effect on the fluorescence. Incuba- scale, the mean and median fluorescence of each sample tion with fMet-Leu-Phe (0.1 ,uM) at 40C was also ineffective. were calculated. The mean was defined as the sum of the In contrast to the changes in GFA-1 and GFA-2 induced by fluorescence intensities of individual cells divided by the fMet-Leu-Phe at 37°C, the amount of 832m did not alter sig- number of cells analyzed, and it is expressed in arbitrary nificantly during the experiment. These data are shown in units. The median is the fluorescence intensity below which Table 1, together with relevant controls. 50% of the cells are found.
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