Mac-1 (CD11b/CD18) as Accessory Molecule for FcαR (CD89) Binding of IgA

Annemiek B. van Spriel, Jeanette H. W. Leusen, Henriëtte Vilé and Jan G. J. van de Winkel
J Immunol October 1, 2002, 169 (7) 3831-3836; DOI: https://doi.org/10.4049/jimmunol.169.7.3831

Abstract

IgA, the principal ligand for FcαRI, exists in serum as monomeric IgA and at mucosal sites as secretory IgA (SIgA). SIgA consists of dimeric IgA linked by joining chain and secretory components. Human polymorphonuclear leukocytes (PMN) and mouse PMN transgenic for human FcαRI exhibited spreading and elicited respiratory burst activity upon interaction with either serum or SIgA. However, PMN devoid of the β2 integrin Mac-1 (Mac-1−/−) were unable to bind SIgA, despite expression of FcαRI. Consistent with this, serum IgA stimulated Mac-1−/− PMN oxygen radical production, in contrast to SIgA. Binding studies showed the secretory component, by itself, to interact with Mac-1-expressing PMN, but not with Mac-1−/− PMN. These data demonstrate an essential role for Mac-1 in establishing SIgA-FcαRI interactions.

Immunoglobulin A, representing the predominant Ab isotype in humans, is present in the circulation primarily in monomeric form (serum IgA), and in mucosal secretions as dimeric complexes, called secretory IgA (SIgA)3 (1). SIgA exists as dimeric IgA (dIgA) containing an additional joining chain and secretory component (SC), which has been proposed to increase IgA stability. Serum IgA is produced by splenic and bone marrow-derived plasma cells. Mucosal plasma cells in the lamina propria produce joining chain-associated IgA dimers (dIgA), which bind with high affinity to the polymeric IgR (pIgR) present on the basolateral surface of mucosal epithelium (2). Subsequently, dIgA-pIgR complexes are endocytosed and transported to the mucosal lumen. SC, a portion of the pIgR, is cleaved off during this transepithelial transport, leading to local SIgA production (3).

FcαRI (CD89) is the IgA receptor, which is uniquely expressed on polymorphonuclear leukocytes (PMN), monocytes, eosinophils, and select macrophages (4, 5). FcαRI binds serum and SIgA with low affinity (Ka, ∼106 M−1) (6). FcαRI expression and function can be up-regulated by fMLP, GM-CSF, IL-8, IL-1β, TNF-α, and LPS, and down-regulated by TGF-β. The FcαRI ligand-binding chain contains a short cytoplasmic tail and its expression and function are dependent on FcR γ-chains, which contain specialized immunoreceptor tyrosine-based activation motifs (7).

Serum IgA can initiate numerous immune effector functions via FcαRI, which include phagocytosis, cytotoxicity, respiratory burst activity, release of inflammatory mediators, and Ag presentation (4, 5, 8). Moreover, serum IgA-FcαRI interactions on Kupffer cells may provide a “second-line” of defense in mucosal immunity (9).

SIgA is considered crucial for the “first-line” mucosal defense (10, 11, 12), however, its precise in vivo role remains unclear. SIgA has been shown to interact with microorganisms and to block virulence factors, which may prevent microbial invasion. Furthermore, SIgA can trigger phagocyte respiratory burst activity, degranulation, and TNF-α production (13, 14, 15, 16, 17). Another role suggested for SIgA is neutralization of viruses within infected epithelia (18, 19). Significant correlations have been reported between specific titers of SIgA and resistance to infection (20).

PMN and macrophages are the major phagocytic populations at mucosal sites. Upon microbial invasion these phagocytes are recruited, increase receptor levels, and become activated (or “primed”). Fc and complement receptors are essential for the recognition and elimination of foreign targets. Mac-1 (CR3, CD11b/CD18, or αmβ2) is an important PMN complement receptor that binds multiple ligands, including C3bi, ICAM-1, fibrinogen, and β-glucan. Mac-1 is important for leukocyte adhesion, migration, phagocytosis, cytotoxicity, and chemotaxis (21). Furthermore, Mac-1 has been proposed to act as “signaling partner” for other leukocyte receptors, including IgG receptors (22). Although Mac-1 has been implicated in FcR function, this is the first study demonstrating a crucial role for Mac-1 in FcR ligand binding.

Materials and Methods

Antibodies

dIgA was purified from human serum by HPLC on HR200 Superdex size-exclusion columns (Pharmacia, San Diego, CA). Anti-CD11b mAb M1/70 (rat IgG2b) and 44a (mouse IgG1) were purified from supernatants of American Type Culture Collection hybridomas (Manassas, VA). Anti-CD11b mAb Bear-1 (mIgG1) was obtained from Caltag Laboratories (Burlingame, CA). mAb 14.1 (human IgG1, anti-FcαRI) was produced by immunizing mice transgenic (Tg) for human Ig (23) with recombinant soluble FcαRI (24) in Ribi adjuvant (Sigma-Aldrich, St. Louis, MO). Splenic lymphocyte suspensions were fused to P3 × 63-Ag8.653 mouse myeloma cells (American Type Culture Collection), and hybridomas were selected by ELISA and FACS on FcαRI transfectants (7). mAb 14.1 recognizes FcαRI within extracellular domain 2, outside the IgA-binding site. mAb My43 (IgM anti-FcαRI) blocks the FcαRI ligand-binding domain (25).

Mice

CD11b knockout mice (Mac-1−/−) in the C57BL/6 × 129SV background were kindly provided by Dr. T. N. Mayadas (Harvard Medical School, Boston, MA) (26, 27, 28). To study Mac-1 involvement in human FcαRI function, mice were crossed with human FcαRI (CD89) Tg FVB/N mice (27), yielding four different genotypes: nontransgenic (Ntg) Mac-1+/−, Ntg Mac-1−/−, Tg Mac-1+/−, and Tg Mac-1−/−. Mac-1-deficiency does not affect PMN FcR expression levels (27, 28).

PMN isolation

Human PMN were isolated from heparinized venous blood of healthy volunteers by Ficoll-Histopaque (Sigma-Aldrich) density gradient centrifugation. PMN purity determined by cytospin preparations exceeded 95%, and cell viability was >98%.

Before murine PMN isolation, mice were injected s.c. with 15 μg polyethylene-glycol G-CSF (kindly provided by Dr. J. Andresen; Amgen, Thousand Oaks, CA) to increase PMN numbers (29, 30). Blood was collected from the retro-orbital plexus 3 days later. Erythrocytes were removed by hypotonic lysis, followed by washing remaining leukocytes with RPMI 1640 medium (Life Technologies, Grand Island, NY) with 10% FCS. FACS analyses, performed on a FACScan (BD Biosciences, San Jose, CA), revealed leukocytes to consist of ∼60% PMN, ∼35% lymphocytes, ∼3% monocytes, and ∼1% eosinophils. Cell viability determined by trypan blue exclusion was always >95%.

PMN binding and spreading on IgA

To exclude interference with complement, all Ab preparations were heat-inactivated before use (30 min, 56°C). Glass slides (Menzel, Braunschweig, Germany) were coated with 0.5% (w/v) BSA (Boehringer Mannheim, Mannheim, Germany), 100 μg/ml human serum IgA (ICN Pharmaceuticals, Costa Mesa, CA), dIgA (kindly provided by Dr. C. van Kooten, Leiden University Medical Center, Leiden, The Netherlands), SIgA (Sigma-Aldrich), or IgG (CLB, Amsterdam, The Netherlands) for 3 h at 37°C, and rinsed with PBS. Isolated human or mouse PMN (2 × 105 cells) were incubated in RPMI 1640 medium (with 10% FCS) on coated slides for 10 or 30 min at 37°C. Cells were fixed in 3.7% paraformaldehyde, and stained for actin with phalloidin-FITC (1:200; Sigma-Aldrich), or stained for FcαRI and Mac-1 (see Colocalization studies) for 30 min at 20°C. Samples were mounted in Mowiol (with 2.5% 1,4-diazobicyclo-[2.2.2]-octane), and PMN binding and spreading was analyzed by confocal laser scanning microscopy using a Leitz DMIRB fluorescence microscope (Leica, Voorburg, The Netherlands) interfaced with a Leica TCS4D confocal laser microscope (Heidelberg, Germany). Cell morphology was imaged just above (0.2 μm) the coated surfaces. PMN diameters were measured orthogonally, and then averaged. At least 30 PMN from three different experiments were analyzed. In Mac-1 blocking experiments, PMN were preincubated with 10 μg/ml anti-CD11b mAb for 30 min at 4°C before SIgA binding. In additional experiments, PMN were preincubated with 0.1 M N-acetyl-d-glucosamine (NADG; Sigma-Aldrich) for 10 min at 20°C, and plated on SIgA-coated slides in the presence of NADG. Cytochalasin D (Sigma-Aldrich) was used at 10 μg/ml to study the role of actin microfilament polymerization in FcαRI-IgA binding.

Respiratory burst measurements

The luminol-ECL method was used for analysis of real-time respiratory burst activity. Polystyrene tubes were coated with PBS, 100 μg/ml serum IgA, or SIgA for 3 h at 37°C, and blocked with HEPES+ buffer (containing 20 mM HEPES, pH 7.4, 132 mM NaCl, 6 mM KCl, 1 mM MgSO4, 1.2 mM NaH2PO4, 1 mM CaCl2, 5 mM glucose, and 0.5% (w/v) BSA) for 1 h at 37°C. Isolated mouse PMN (4 × 105 cells) in HEPES+ buffer were incubated in these tubes, and placed in a 953 LB Biolumat (Berthold, Wildbad, Germany). Luminol (150 μM) was injected in all tubes and light emission was recorded continuously for 30 min at 37°C. As a positive control, PMN were stimulated with 100 ng/ml PMA (Sigma-Aldrich), and PMN incubated with luminol only served as negative control. In blocking experiments, PMN were incubated with FcαRI mAb My43 supernatant during the assay (25).

SC binding to cells

Purified recombinant human SC (kindly provided by Dr. B. Corthesy, State University Hospital, Lausanne, Switzerland) was incubated at 50 μg/ml with isolated human or mouse PMN (2 × 105 cells) for 60 min at 4°C. PMN were washed with FACS buffer (0.5% (w/v) BSA, 0.05% azide in PBS), incubated with mouse IgG1 anti-human SC (Sigma-Aldrich) (1:50) for 45 min at 4°C, washed, and incubated with FITC-labeled goat anti-mouse IgG F(ab′)2 (Jackson ImmunoResearch Laboratories, West Grove, PA) (1:100) for 30 min at 4°C. Controls included PMN incubated with both mouse anti-human SC, and FITC-labeled goat anti-mouse IgG F(ab′)2. FITC fluorescence of PMN was determined by flow cytometry.

Colocalization studies

Human or mouse PMN were incubated on BSA or IgA-coated glass slides for 15 min at 37°C, washed with PBS, and incubated with 20 μg/ml of mAb 14.1 and mAb M1/70 in PBS containing 0.2% (w/v) BSA and 5% rabbit serum (Jackson ImmunoResearch Laboratories) for 30 min at 4°C. PMN were then fixed in 3.7% paraformaldehyde (30 min, 20°C), quenched with 20 mM NH4Cl in PBS (5 min, 20°C), washed, and incubated with F(ab′)2 of FITC-labeled rabbit anti-human IgG (DAKO, Glostrup, Denmark) (1:50) and F(ab′)2 of TRITC-labeled donkey anti-rat IgG (Jackson ImmunoResearch Laboratories) (1:125) in PBS with 0.2% BSA for 45 min at 20°C. Slides were washed, mounted, and analyzed by confocal microscopy (see above). As a control, colocalization between FcαRI and the β2 integrin LFA-1 (CD11a/CD18) was analyzed using mAb M17/4 (rat IgG2a anti-mouse CD11a), which was a kind gift from Dr. G. Kraal (Vrije Universiteit, Amsterdam, The Netherlands).

Statistical analyses

Data are expressed as means ± SD. Statistical significance was determined by two-tailed unpaired Student’s t tests. Values of p < 0.05 were considered significant.

Results

Role of Mac-1 in FcαRI-IgA binding

To assess Mac-1 involvement in FcαRI-ligand binding, we studied PMN from human FcαRI-Tg mice crossed with CD11b knock-out mice (Mac-1−/−). Because FcαRI represents a low affinity IgAR, we analyzed PMN binding to IgA-coated surfaces. Tg Mac-1-expressing PMN efficiently bound and spread onto serum IgA (IgA), dIgA, and SIgA-coated slides within 10 min (Fig. 1⇓, upper panels). PMN spreading capacity on IgA-coated surfaces varied among different IgA forms, and was quantified by measuring PMN diameters (18 ± 4.2 μm on serum IgA, 15 ± 3.3 μm on dIgA, and 14.6 ± 3.7 μm on SIgA). Tg Mac-1−/− PMN bound properly to serum IgA and dIgA, but did not interact with SIgA (Fig. 1⇓, lower panels). Furthermore, Mac-1−/− PMN, exhibited impaired spreading on slides coated with serum IgA (12.1 ± 2.5 μm) or dIgA (11.9 ± 4.2 μm). PMN of Ntg Mac-1+/− littermates, expressing Mac-1, but not FcαRI, served as controls and did not bind human IgA. These data were supported by studies with human PMN. Binding and spreading capacity of human PMN on serum IgA, dIgA, and SIgA was similar to that of Tg Mac-1+/− PMN. However, F(ab′)2 of α-Mac-1 mAb inhibited spreading of human PMN on SIgA, but not on serum IgA slides (data not shown). In addition, all phagocytes bound IgG- or BSA-coated surfaces (Fig. 1⇓), irrespective of FcαRI/Mac-1 expression. Binding of both human and Tg mouse PMN to SIgA was abolished in the presence of cytochalasin D. These results indicate Mac-1 to be required for phagocyte-FcαRI binding of SIgA.

FIGURE 1.
FIGURE 1.

Mac-1 is crucial for FcαRI-SIgA interaction. Isolated Tg Mac-1+/− (upper panels) and Tg Mac-1−/− (lower panels) PMN were incubated on BSA (control), serum IgA- (IgA), dIgA-, or SIgA-coated slides for 10 min at 37°C, and stained for actin. Cell morphology was imaged in x/y direction in the FITC (upper panel) and transmission (lower panel) channel by confocal microscopy. Experiments were repeated four times yielding comparable results. Cell diameters (mean micrometers ± SD) of Tg Mac-1+/− (upper panels) were 7.6 ± 1.0 (control), 18.0 ± 4.2 (serum IgA), 15 ± 3.3 (dIgA), 14.6 ± 3.7 (SIgA), and of Tg Mac-1−/− (lower panels) were 7.7 ± 1.6 (control), 12.1 ± 2.5 (serum IgA), and 11.9 ± 2.1 (dIgA). Bar represents 15 μm.

Respiratory burst activity

To study the significance of PMN interaction with immobilized IgA, we investigated respiratory burst activity of mouse (Ntg Mac-1+/−, Tg Mac-1+/−, Tg Mac-1−/−) and human PMN. Both serum IgA and SIgA induced comparable oxygen radical production in Tg Mac-1+/− PMN (Fig. 2⇓, left graph). However, Tg Mac-1−/− PMN were stimulated by serum IgA, but not by SIgA (Fig. 2⇓, middle graph). Importantly, Mac-1-expressing and Mac-1-deficient PMN exhibited similar respiratory burst activity in response to PMA. Ntg Mac-1-expressing PMN did not initiate respiratory activity in response to serum IgA or SIgA (Fig. 2⇓, right graph). Human PMN exhibited comparable oxygen radical production upon interaction with serum IgA or SIgA, albeit that serum IgA-induced respiratory burst activity was significantly faster (data not shown). Blocking studies with My43, an IgM recognizing the FcαRI ligand-binding domain (25), decreased oxygen radical production close to background levels (data not shown), showing IgA-induced respiratory burst to depend on interaction with FcαRI. These data demonstrate requirement of both FcαRI and Mac-1 for SIgA-induced respiratory burst activity.

FIGURE 2.
FIGURE 2.

IgA-induced respiratory burst activity. Isolated PMN of Tg Mac-1+/−, Tg Mac-1−/− (left and middle graph) and Ntg Mac-1+/− mice (right graph) were incubated in HEPES (control, ▴)-, serum IgA (IgA, •)-, or SIgA (○)-coated tubes. As positive control, PMN were stimulated with PMA (×). Oxygen radical production of PMN was measured in time by chemiluminescence detection. Experiments were performed four times yielding essentially identical results. Statistical analyses of areas below the curve verified Tg Mac-1+/− PMN to bind SIgA significantly better (p = 0.001) than Tg Mac-1−/− PMN.

Colocalization of Mac-1 and FcαRI

Because our data pointed to an essential role for Mac-1 in FcαRI-IgA interactions, we next studied the distribution of Mac-1 and FcαRI in PMN membranes. Isolated Tg Mac-1+/− PMN were incubated on surfaces coated with BSA, serum IgA, or SIgA, whereupon FcαRI and Mac-1 were stained with FITC (green), and TRITC (red), respectively. Tg Mac-1+/− PMN mediated spreading on both serum IgA (Fig. 3⇓A, upper panel) and SIgA (Fig. 3⇓A, middle panel). FcαRI was expressed on the plasma membrane of PMN, but also in filipodia-like outgrowth of cells. A similar staining was found for Mac-1, and colocalization was indicated in yellow (Fig. 3⇓; merged pictures). Tg Mac-1+/− PMN did not spread on BSA-coated slides, and exhibited overall membrane staining of FcαRI and Mac-1 (Fig. 3⇓A, lower panel). As a control, FcαRI and β2 integrin LFA-1 membrane staining was examined, which revealed no colocalization (Fig. 3⇓B). Importantly, experiments performed with human PMN revealed FcαRI and Mac-1 expression to colocalize as well (see below).

FIGURE 3.
FIGURE 3.

Colocalization of FcαRI and Mac-1 in PMN membranes. A, Tg Mac-1+/− PMN were incubated on immobilized serum IgA (upper panel), SIgA (middle panel), or BSA (lower panel) for 15 min at 37°C, stained for FcαRI (green) and Mac-1 (red), and analyzed by confocal microscopy. Right panels show merges of the two signals (indicating receptor colocalization). B, FcαRI (green) and β2 integrin LFA-1 (red) localization in Tg Mac-1+/− PMN bound to IgA. Experiments were repeated four times yielding similar results. Bars represent 15 μm.

Mac-1 binds SC

Our results demonstrated only Mac-1-expressing PMN capable of binding SIgA-coated surfaces. Next, we evaluated the capacity of Mac-1+/− and Mac-1−/− PMN to bind aggregated IgA by flow cytometry. Ntg Mac-1+/− PMN were ineffective in binding serum IgA-complexes, but interacted well with SIgA complexes. On the contrary, Ntg Mac-1-deficient PMN were unable to bind SIgA complexes (data not shown). These observations pointed to a role for the SC in PMN-SIgA binding. Therefore, we examined the capacity of recombinant SC to interact with isolated human and mouse PMN. As shown in Fig. 4⇓A, Mac-1-expressing PMN readily bound SC, irrespective of the presence of FcαRI. However, binding of SC to Mac-1-deficient Tg and Ntg PMN, was abrogated. SC interacted with human PMN as well (Fig. 4⇓B). These data show SC, either recombinant or present in its normal configuration (i.e., complexed with dIgA), to be capable of interacting with Mac-1.

FIGURE 4.
FIGURE 4.

PMN binding of SC is dependent on Mac-1. Binding of recombinant SC to mouse (Tg Mac-1+/−, Tg Mac-1−/−, Ntg Mac-1+/−, and Ntg Mac-1−/−) PMN (A) and to human PMN (B) was assayed by flow cytometry. PMN were incubated with SC, mouse IgG1 anti-SC, and were stained with FITC-conjugated anti-mouse IgG (thick lines). Controls were incubated with mouse IgG1 anti-SC and FITC-conjugated anti-mouse IgG (thin lines). Representative histograms of one of three experiments are shown.

Involvement of Mac-1 lectin-binding site in SIgA binding

We next evaluated the region of Mac-1 involved in SIgA-FcαRI binding. Human PMN were plated on immobilized serum IgA or SIgA in the absence (control) or presence of NADG, which interacts with the Mac-1 lectin-binding domain (31), and were stained for both FcαRI and Mac-1 (Fig. 5⇓). Human PMN exhibited spreading on both serum IgA and SIgA, like Tg Mac-1+/− PMN. Incubation of PMN with NADG resulted in a blockade of PMN binding to SIgA-coated surfaces, whereas binding to serum IgA was barely affected by NADG (Fig. 5⇓, lower panel). The partial colocalization of FcαRI and Mac-1 observed in control PMN bound to serum IgA-coated slides was decreased in the presence of NADG. PMN incubated on BSA-coated surfaces in the presence of NADG exhibited no change in binding. Furthermore, NADG impaired binding of Tg Mac-1+/− to SIgA, but not to serum IgA (data not shown). In contrast, Abs directed against the I-domain of Mac-1, although partly inhibiting PMN spreading, did not inhibit binding of human PMN to serum and SIgA (data not shown). These results implicate the Mac-1 lectin-binding domain to be involved in FcαRI-SIgA interaction.

FIGURE 5.
FIGURE 5.

Mac-1 lectin-binding site involved in FcαRI-IgA interaction. Purified human PMN were plated on serum IgA- (left panels) or SIgA- (right panels) coated surfaces in the absence (upper panels) or presence (lower panels) of NADG for 15 min at 37°C. PMN were stained for membrane FcαRI (green) and Mac-1 (red) expression, and analyzed by confocal microscopy. Pictures show overlays of the staining, and bars indicate 15 μm.

Discussion

The significance of IgA in immune defense is well-recognized, but incompletely understood (32). Although a number of studies focused on the molecular characterization of FcαRI and IgA, relatively little is known about the biology of FcαRI-IgA interactions. The present study documents a new role for Mac-1, a β2 integrin, in ligand binding of FcαRI. Mac-1 was found to be crucial for interaction of PMN FcαRI with SIgA, and subsequent PMN activation. Our data support Mac-1 binding to SC to underlie this phenomenon, and implicate the Mac-1 lectin-binding domain to be involved.

Modulation of receptor-ligand interactions by accessory molecules is well-documented for a number of immune receptors, including cytokine receptors, integrins, and FcR (28, 33, 34, 35, 36). IgG binding to FcγRI (CD64) and FcγRIII (CD16a) is dependent on association with the FcR γ-chain (36, 37, 38). In this study, Mac-1 is identified as a novel accessory protein, crucial for FcαRI-SIgA interaction. In SIgA, SC is covalently ligated to the Cα2 and Cα3 domains within the dIgA Fc region (39), which may interfere with the affinity of FcαRI for SIgA (40, 41, 42). The present study demonstrates SC binding to PMN in a Mac-1-dependent manner. When one appreciates the structure of SC, Mac-1 interaction with SC seems rational. SC represents a heavily glycosylated protein belonging to the Ig superfamily (3). Moreover, we observed Mac-1 lectin-binding domain, bearing carbohydrate-binding specificity (31), involved in PMN binding of SIgA.

Physical association between leukocyte membrane proteins (such as FcR-FcR γ-chain, and FcγRIIIb-Mac-1) has been documented before (22, 37, 38). Despite clear colocalization of FcαRI and Mac-1, a direct FcαRI-Mac-1 interaction was not apparent from immunoprecipitation experiments (our unpublished data).

Importantly, Mac-1 modulates PMN function upon IgA binding, as indicated by stimulation of a potent respiratory burst. Our data show requirement of both FcαRI and Mac-1 for SIgA-induced respiratory burst activity, because Mac-1-deficient Tg PMN and Ntg PMN were unable to elicit oxygen radical production in response to SIgA. A role for Mac-1 in FcγR functions, including respiratory burst has been shown before (28, 43, 44, 45). CD18 interactions with the actin cytoskeleton and associated proteins may enable Mac-1 signaling (46, 47). Furthermore, the present work is consistent with earlier studies documenting a role for β2 integrins in superoxide production of eosinophils mediated by SIgA, and not serum IgA (48). SC by itself was described to activate eosinophil functions, but not PMN functions, which was proposed to relate to an additional (15 kDa) “SC receptor” on eosinophils (49). Indeed, we observed Mac-1-deficient eosinophils capable of interacting with both SC and SIgA (our unpublished data).

In conclusion, this study provides evidence for a crucial role of Mac-1 in phagocyte SIgA binding. Enhanced IgA responses upon incubation of PMN with GM-CSF, TNF-α, or IL-8 have been reported (50, 51, 52), although the underlying mechanisms remain to be addressed. We propose Mac-1 involvement in these phenomena to be likely, because of the well-recognized ability of these cytokines and chemokines to activate Mac-1 (53, 54, 55). Requirement of two molecules interacting with one ligand may provide immune effector cells with an extra way to regulate their activity. When “first-line” defense fails, mucosal inflammation leads to PMN recruitment and priming, accompanied by up-regulation of Mac-1, which may trigger more potent FcαRI-mediated responses. We hypothesize Mac-1 to increase affinity of FcαRI-SIgA interaction via binding of SC.

Acknowledgments

We thank Tanya Mayadas for providing CD11b-deficient mice, Jacques Duijs and Cees van Kooten for human dIgA, and Bruce Wines and Jos van Strijp for critically reading the manuscript. Furthermore, we thank Arnout Gerritsen and Marc van Dijk for assistance in generating mAb 14.1, and Toon Hesp, Herma Boersma, and Sabine Versteeg for excellent animal care.

Footnotes

  • ↵1 This work was supported by the Netherlands Organization for Scientific Research (Fellow Grant No. 901-07-229, to J.H.W.L.).

  • ↵2 Address correspondence and reprint requests to Dr. Jan G. J. van de Winkel, Immunotherapy Laboratory, Department of Immunology, University Medical Center, Room KC02.085.2, Lundlaan 6, 3584 EA, Utrecht, The Netherlands. E-mail address: JanvandeWinkel{at}aol.com

  • 3 Abbreviations used in this paper: SIgA, secretory IgA; dIgA, dimeric IgA; SC, secretory component; pIgR, polymeric IgR; PMN, polymorphonuclear leukocyte; Tg transgenic; Ntg, nontransgenic; NADG, N-acetyl-d-glucosamine.

  • Received December 7, 2001.
  • Accepted July 26, 2002.

References

  1. ↵
    Kerr, M. A.. 1990. The structure and function of human IgA. Biochem. J. 271: 285
    OpenUrlFREE Full Text
  2. ↵
    Deitcher, D. L., M. R. Neutra, K. E. Mostov. 1986. Functional expression of the polymeric immunoglobulin receptor from cloned cDNA in fibroblasts. J. Cell Biol. 102: 911
    OpenUrlAbstract/FREE Full Text
  3. ↵
    Mostov, K. E., M. Friedlander, G. Blobel. 1984. The receptor for transepithelial transport of IgA and IgM contains multiple immunoglobulin-like domains. Nature 308: 37
    OpenUrlCrossRefPubMed
  4. ↵
    Morton, H. C., M. van Egmond, J. G. J. van de Winkel. 1996. Structure and function of human IgA Fc receptors (FcαR). Crit. Rev. Immunol. 16: 423
    OpenUrlPubMed
  5. ↵
    Van Spriel, A. B., J. G. J. van de Winkel. 2001. CD89 (FcαRI) review. Encyclopedia of Molecular Medicine Wiley, New York.
  6. ↵
    Wines, B. D., M. D. Hulett, G. P. Jamieson, H. M. Trist, J. M. Spratt, P. M. Hogarth. 1999. Identification of residues in the first domain of human Fcα receptor essential for interaction with IgA. J. Immunol. 162: 2146
    OpenUrlAbstract/FREE Full Text
  7. ↵
    Morton, H. C., I. E. van den Herik-Oudijk, P. Vossebeld, A. Snijders, A. J. Verhoeven, P. J. Capel, J. G. J. van de Winkel. 1995. Functional association between the human myeloid immunoglobulin A Fc receptor (CD89) and FcR γ chain: molecular basis for CD89/FcR γ chain association. J. Biol. Chem. 270: 29781
    OpenUrlAbstract/FREE Full Text
  8. ↵
    Shen, L., M. van Egmond, K. Siemasko, M. L. Lang, H. Gao, T. Wade, M. Clark, J. G. J. van de Winkel, W. F. Wade. 2001. Presentation of ovalbumin internalised via the IgA Fc receptor (CD89) is enhanced through FcR γ chain signalling. Blood 97: 205
    OpenUrlAbstract/FREE Full Text
  9. ↵
    Van Egmond, M., E. van Garderen, A. B. van Spriel, C. A. Damen, E. S. van Amersfoort, G. van Zandbergen, J. van Hattum, J. Kuiper, J. G. J. van de Winkel. 2000. FcαRI-positive liver Kupffer cells: reappraisal of the function of immunoglobulin A in immunity. Nat. Med. 6: 680
    OpenUrlCrossRefPubMed
  10. ↵
    Childers, N. K., M. G. Bruce, J. R. McGhee. 1989. Molecular mechanisms of immunoglobulin A defense. Annu. Rev. Microbiol. 43: 503
    OpenUrlCrossRefPubMed
  11. ↵
    Mazanec, M. B., J. G. Nedrud, C. S. Kaetzel, M. E. Lamm. 1993. A three-tiered view of the role of IgA in mucosal defense. Immunol. Today 14: 430
    OpenUrlCrossRefPubMed
  12. ↵
    Corthesy, B.. 1997. Recombinant secretory IgA for immune intervention against mucosal pathogens. Biochem. Soc. Trans. 25: 471
    OpenUrlPubMed
  13. ↵
    Shen, L., M. W. Fanger. 1981. Secretory IgA antibodies synergize with IgG in promoting ADCC by human polymorphonuclear cells, monocytes, and lymphocytes. Cell. Immunol. 59: 75
    OpenUrlCrossRefPubMed
  14. ↵
    Shen, L., J. Collins. 1989. Monocyte superoxide secretion triggered by human IgA. Immunology 68: 491
    OpenUrlPubMed
  15. ↵
    Stewart, W. W., M. A. Kerr. 1990. The specificity of the human neutrophil IgA receptor (FcαR) determined by measurement of chemiluminescence induced by serum or secretory IgA1 or IgA2. Immunology 71: 328
    OpenUrlPubMed
  16. ↵
    Furrie, E., B. C. Bonner, A. Hutchings, M. L. Lang, M. A. Kerr. 1997. Differential activation of peripheral blood monocytes using various forms of human IgA. Biochem. Soc. Trans. 25: 332.S.
    OpenUrlFREE Full Text
  17. ↵
    Honorio-Franca, A. C., M. P. Carvalho, L. Isaac, L. R. Trabulsi, M. M. Carneiro-Sampaio. 1997. Colostral mononuclear phagocytes are able to kill enteropathogenic Escherichia coli opsonized with colostral IgA. Scand. J. Immunol. 46: 59
    OpenUrlCrossRefPubMed
  18. ↵
    Mazanec, M. B., C. S. Kaetzel, M. E. Lamm, D. Fletcher, J. G. Nedrud. 1992. Intracellular neutralization of virus by immunoglobulin A antibodies. Proc. Natl. Acad. Sci. USA 89: 6901
    OpenUrlAbstract/FREE Full Text
  19. ↵
    Renegar, K. B., G. D. Jackson, J. Mestecky. 1998. In vitro comparison of the biologic activities of monoclonal monomeric IgA, polymeric IgA, and secretory IgA. J. Immunol. 160: 1219
    OpenUrlAbstract/FREE Full Text
  20. ↵
    Russell, M. W., M. Kilian, M. E. Lamm. 1999. Biological activities of IgA. P. L. Ogra, ed. Mucosal Immunology 225 Academic Press, San Diego, CA.
  21. ↵
    Arnaout, M. A.. 1990. Structure and function of the leukocyte adhesion molecules CD11/CD18. Blood 75: 1037
    OpenUrlFREE Full Text
  22. ↵
    Petty, H. R., R. F. Todd, III. 1993. Receptor-receptor interactions of complement receptor type 3 in neutrophil membranes. J. Leukocyte Biol. 54: 492
    OpenUrlAbstract
  23. ↵
    Lonberg, N., L. D. Taylor, F. A. Harding, M. Trounstine, K. M. Higgins, S. R. Schramm, C. C. Kuo, R. Mashayekh, K. Wymore, J. G. McCabe, et al 1994. Antigen-specific human antibodies from mice comprising four distinct genetic modifications. Nature 368: 856
    OpenUrlCrossRefPubMed
  24. ↵
    Van Zandbergen, G., R. Westerhuis, N. K. Mohamad, J. G. J. van de Winkel, M. R. Daha, C. van Kooten. 1999. Crosslinking of the human Fc receptor for IgA (FcaRI/CD89) triggers FcR γ chain-dependent shedding of soluble CD89. J. Immunol. 163: 5806
    OpenUrlAbstract/FREE Full Text
  25. ↵
    Shen, L., R. Lasser, M. W. Fanger. 1989. My43, a monoclonal antibody that reacts with human myeloid cells inhibits monocyte IgA binding and triggers function. J. Immunol. 143: 4117
    OpenUrlAbstract
  26. ↵
    Coxon, A., P. Rieu, F. J. Barkalow, S. Askari, A. H. Sharpe, U. H. von Andrian, M. A. Arnaout, T. N. Mayadas. 1996. A novel role for the β2 integrin CD11b/CD18 in neutrophil apoptosis: a homeostatic mechanism in inflammation. Immunity 5: 653
    OpenUrlCrossRefPubMed
  27. ↵
    Van Egmond, M., A. J. van Vuuren, H. C. Morton, A. B. van Spriel, L. Shen, F. M. Hofhuis, T. Saito, T. N. Mayadas, J. S. Verbeek, J. G. J. van de Winkel. 1999. Human immunoglobulin A receptor (FcαRI, CD89) function in transgenic mice requires both FcR γ chain and CR3 (CD11b/CD18). Blood 93: 4387
    OpenUrlAbstract/FREE Full Text
  28. ↵
    Van Spriel, A. B., J. H. W. Leusen, M. van Egmond, H. B. P. M. Dijkman, K. J. M. Assman, T. N. Mayadas, J. G. J. van de Winkel. 2001. Mac-1 (CD11b/CD18) is essential for Fc receptor-mediated neutrophil cytotoxicity and immunological synapse formation. Blood 97: 2478
    OpenUrlAbstract/FREE Full Text
  29. ↵
    Tanaka, H., R. Satake-Ishikawa, M. Ishikawa, S. Matsuki, K. Asano. 1991. Pharmacokinetics of recombinant human granulocyte colony-stimulating factor conjugated to polyethylene glycol in rats. Cancer Res. 51: 3710
    OpenUrlAbstract/FREE Full Text
  30. ↵
    Van Spriel, A. B., I. E. van den Herik-Oudijk, J. G. J. van de Winkel. 2000. A single injection of polyethylene-glycol granulocyte colony-stimulating factor strongly prolongs survival of mice with systemic candidiasis. Cytokine 12: 666
    OpenUrlCrossRefPubMed
  31. ↵
    Thornton, B. P., V. Vetvicka, M. Pitman, R. C. Goldman, G. D. Ross. 1996. Analysis of the sugar specificity and molecular location of the β-glucan-binding lectin site of complement receptor type 3 (CD11b/CD18). J. Immunol. 156: 1235
    OpenUrlAbstract
  32. ↵
    van Egmond, M., C. A. Damen, A. B. van Spriel, G. Vidarsson, E. van Garderen, J. G. J. van de Winkel. 2001. IgA and the IgA Fc receptor. Trends Immunol. 22: 205
    OpenUrlCrossRefPubMed
  33. ↵
    Nicola, N. A., D. Metcalf. 1991. Subunit promiscuity among hemopoietic growth factor receptors. Cell 67: 1
    OpenUrlCrossRefPubMed
  34. ↵
    Noguchi, M., Y. Nakamura, S. M. Russell, S. F. Ziegler, M. Tsang, X. Cao, W. J. Leonard. 1993. Interleukin-2 receptor γ chain: a functional component of the interleukin-7 receptor. Science 262: 1877
    OpenUrlAbstract/FREE Full Text
  35. ↵
    Hermanowski-Vosatka, A., J. A. G. van Strijp, W. J. Swiggard, S. D. Wright. 1992. Integrin modulating factor-1: a lipid that alters the function of leukocyte integrins. Cell 68: 341
    OpenUrlCrossRefPubMed
  36. ↵
    Miller, K. L., A. M. Duchemin, C. L. Anderson. 1996. A novel role for the Fc receptor γ subunit: enhancement of FcγR ligand affinity. J. Exp. Med. 183: 2227
    OpenUrlAbstract/FREE Full Text
  37. ↵
    Ra, C., M. H. Jouvin, U. Blank, J. P. Kinet. 1989. A macrophage Fcγ receptor and the mast cell receptor for IgE share an identical subunit. Nature 341: 752
    OpenUrlCrossRefPubMed
  38. ↵
    Ernst, L. K., A. M. Duchemin, C. L. Anderson. 1993. Association of the high-affinity receptor for IgG (FcγRI) with the γ subunit of the IgE receptor. Proc. Natl. Acad. Sci. USA 90: 6023
    OpenUrlAbstract/FREE Full Text
  39. ↵
    Crottet, P., B. Corthesy. 1999. Mapping the interaction between murine IgA and murine secretory component carrying epitope substitutions reveals a role of domains II and III in covalent binding to IgA. J. Biol. Chem. 274: 31456
    OpenUrlAbstract/FREE Full Text
  40. ↵
    Carayannopoulos, L., J. M. Hexham, J. D. Capra. 1996. Localization of the binding site for the monocyte immunoglobulin (Ig) A-Fc receptor (CD89) to the domain boundary between Cα2 and Cα3 in human IgA1. J. Exp. Med. 183: 1579
    OpenUrlAbstract/FREE Full Text
  41. ↵
    Pleass, R. J., J. I. Dunlop, C. M. Anderson, J. M. Woof. 1999. Identification of residues in the CH2/CH3 domain interface of IgA essential for interaction with the human Fcα receptor (FcαR) CD89. J. Biol. Chem. 274: 23508
    OpenUrlAbstract/FREE Full Text
  42. ↵
    Kerr, M. A., J. M. Woof. 1999. Fcα receptors. P. L. Ogra, III, ed. Mucosal Immunology 213 Academic Press, San Diego, CA.
  43. ↵
    Krauss, J. C., H. Poo, W. Xue, L. Mayo-Bond, R. F. Todd, III, H. R. Petty. 1994. Reconstitution of antibody-dependent phagocytosis in fibroblasts expressing Fcγ receptor IIIB and the complement receptor type 3. J. Immunol. 153: 1769
    OpenUrlAbstract/FREE Full Text
  44. ↵
    Zhou, M. J., E. J. Brown. 1994. CR3 (Mac-1, αMβ2, CD11b/CD18) and FcγRIII cooperate in generation of a neutrophil respiratory burst: requirement for FcγRIII and tyrosine phosphorylation. J. Cell Biol. 125: 1407
    OpenUrlAbstract/FREE Full Text
  45. ↵
    Todd, R. F., III, H. R. Petty. 1997. β2 (CD11/CD18) integrins can serve as signaling partners for other leukocyte receptors. J. Lab. Clin. Med. 129: 492
    OpenUrlCrossRefPubMed
  46. ↵
    Pavalko, F. M., S. M. LaRoche. 1993. Activation of human neutrophils induces an interaction between the integrin β2-subunit (CD18) and the actin binding protein α-actinin. J. Immunol. 151: 3795
    OpenUrlAbstract
  47. ↵
    Clark, E. A., J. S. Brugge. 1995. Integrins and signal transduction pathways: the road taken. Science 268: 233
    OpenUrlAbstract/FREE Full Text
  48. ↵
    Motegi, Y., H. Kita. 1998. Interaction with secretory component stimulates effector functions of human eosinophils but not of neutrophils. J. Immunol. 161: 4340
    OpenUrlAbstract/FREE Full Text
  49. ↵
    Lamkhioued, B., A. S. Gounni, V. Gruart, A. Pierce, A. Capron, M. Capron. 1995. Human eosinophils express a receptor for secretory component: role in secretory IgA-dependent activation. Eur. J. Immunol. 25: 117
    OpenUrlCrossRefPubMed
  50. ↵
    Weisbart, R. H., A. Kacena, A. Schuh, D. W. Golde. 1988. GM-CSF induces human neutrophil IgA-mediated phagocytosis by an IgA Fc receptor activation mechanism. Nature 332: 647
    OpenUrlCrossRefPubMed
  51. ↵
    Hostoffer, R. W., I. Krukovets, M. Berger. 1994. Enhancement by tumor necrosis factor-α of Fcα receptor expression and IgA-mediated superoxide generation and killing of Pseudomonas aeruginosa by polymorphonuclear leukocytes. J. Infect. Dis. 170: 82
    OpenUrlAbstract/FREE Full Text
  52. ↵
    Nikolova, E. B., M. W. Russell. 1995. Dual function of human IgA antibodies: inhibition of phagocytosis in circulating neutrophils and enhancement of responses in IL-8-stimulated cells. J. Leukocyte Biol. 57: 875
    OpenUrlAbstract
  53. ↵
    Berger, M., E. M. Wetzler, R. S. Wallis. 1988. Tumor necrosis factor is the major monocyte product that increases complement receptor expression on mature human neutrophils. Blood 71: 151
    OpenUrlAbstract/FREE Full Text
  54. ↵
    Sengelov, H., L. Kjeldsen, M. S. Diamond, T. A. Springer, N. Borregaard. 1993. Subcellular localization and dynamics of Mac-1 (αMβ2) in human neutrophils. J. Clin. Invest. 92: 1467
    OpenUrlCrossRefPubMed
  55. ↵
    van Pelt, L. J., M. V. Huisman, R. S. Weening, A. E. von dem Borne, D. Roos, R. H. van Oers. 1996. A single dose of granulocyte-macrophage colony-stimulating factor induces systemic interleukin-8 release and neutrophil activation in healthy volunteers. Blood 87: 5305
    OpenUrlAbstract/FREE Full Text
Back to top

In this issue

Print
Download PDF
Article Alerts
Email Article
Citation Tools

Jump to section