|
|||||||||
|
|
|
|
|
|
|
|
|
|
|
IMMUNOBIOLOGY
From the Department of Molecular Immunology, Research
Institute for Microbial Diseases, Osaka University, Japan.
CD100/Sema4D is a 150-kd transmembrane protein that belongs to the
semaphorin family. The interaction of CD100 with CD72 is critical for
the immune system. In CD100-deficient mice, the production of specific
antibodies against T-cell-dependent antigens is severely impaired, but
not against T-cell-independent antigens. Here, a functional soluble
CD100 protein (sCD100) released from activated lymphocytes is reported.
sCD100 was detected in culture supernatants of activated lymphocytes.
Either affinity-purified from supernatants of activated T-cells, or
produced as a recombinant sCD100 protein consisting of the
extracellular region of the mouse CD100 fused to the human IgG1 Fc
(CD100-Fc), sCD100 significantly enhanced CD40-induced B-cell
responses. Furthermore, sCD100 was detected either in sera of mice
immunized with T-cell-dependent antigens, or in sera of MRL/lpr mice,
but not in sera of mice immunized with T-cell-independent antigens. A
significant correlation was observed between the level of sCD100 and
the titer of autoantibodies in the serum of MRL/lpr mice. This
study's findings suggest a potential role for sCD100 in immune
responses, including production of antibody, and autoimmune diseases.
(Blood. 2001;97:3498-3504) The semaphorin family consists of a large number of
phylogenetically conserved proteins, carrying a large "Sema domain"
(approximately 500 amino acid residues) in their extracellular
regions.1,2 Many members of the semaphorin family are
known to be critically involved in axon pathfinding, acting as
chemorepulsion factors during neuronal development.2-6
Although the function of semaphorins has been initially addressed with
respect to neuronal guidance as mentioned, it is becoming clear that
semaphorins play important roles in organogenesis, vascularization,
angiogenesis, and progression of cancers.7-10
The semaphorin family is divided into 8 groups which are defined based
on structural properties.1 CD100, which belongs to group
IV, is the first semaphorin member expressed physiologically in
lymphocytes to be identified.11-13 CD100 is expressed
abundantly by T cells but weakly by B cells.11,12,14 Its
expression is significantly enhanced in both T and B cells, following
their respective activation.15 Human CD100-expressing
transfectants have been reported to promote aggregation and survival of
B cells in vitro.12 A recombinant soluble mouse CD100
protein, consisting of the extracellular region of CD100 and the Fc
portion of human IgG1 (CD100-Fc), exerts an effect on the production of
antibodies in vivo, as well as B-cell responses in
vitro.15 Collectively, these findings indicate that CD100,
like other semaphorin proteins, can function through a receptor on the
surface of lymphocytes.
Two types of receptors with distinct binding affinities have been
identified for CD100. Plexin-B1, which is widely expressed at prominent
levels in the fetal brain and kidney, is a receptor which has been
shown to have a high affinity for CD100.16,17 In addition,
we have recently identified CD72, a receptor found on the surface of
lymphocytes.15 Our recent study has shown that
CD100-deficient mice have multiple defects in lymphoid tissues, but not
in other tissues where plexin-B1 is abundantly expressed, suggesting
that the interaction of CD100 with CD72, but not with plexin-B1, is
rather important in the immune system.18 CD72 has been
shown to recruit the protein tyrosine phosphatase SHP-1, via its
immunoreceptor tyrosine-based inhibitory motifs (ITIM) of its
cytoplasmic region.19 B cells from CD72-deficient mice have been reported to be hyperproliferative in response to various stimuli.20 CD72 thus appears to be a negative regulator of
B-cell response. Recently, we have shown that CD100-binding induces the dephosphorylation of tyrosines on CD72 and the dissociation of SHP1
from the latter.15 Therefore, CD100 appears to turn off the negative signaling effects of CD72, resulting in an enhancement of
B-cell activation. Indeed, CD100-deficient mice displayed
hyporesponsiveness of B cells. This is almost symmetric in
CD72-deficient mice, whose B cells were hyperreactive to various
stimuli.18,20
Soluble forms of various transmembrane-type factors and receptors such
as CD21, CD23, CD27, CD44, CD106, and Fas have been reported.21-26 For instance, CD27, which is a member of
the tumor necrosis factor (TNF) receptor superfamily and expressed on
the surface of lymphocytes as a 55-kd protein, is cleaved
proteolytically into a 32-kd soluble form after activation of the
lymphocyte.23 The quantity of soluble CD27 has been shown
to be elevated in the sera from patients of infectious and autoimmune
diseases.23 Similarly, soluble CD23 is generated by
proteolytic cleavage, and has been shown to be biologically
active.22 On the other hand, a soluble form of Fas (sFas)
has been shown to be generated by alternative splicing after the
activation of peripheral blood mononuclear cells
(PBMCs).26 sFas has been reported to be elevated in sera
from patients of system lupus erythematosus (SLE),27 suggesting its involvement in the progression of autoimmunity. Also, in
the case of human CD100, Herold et al28,29 reported the
presence of a soluble form of CD100 (sCD100) in culture supernatants of
PBMCs treated with anti-CD100 or anti-CD45 monoclonal antibodies (mAbs). However, the physiologic and pathologic significance of the
activity of sCD100 in immune response has not been elucidated.
Here, we demonstrate the presence, the activities, and the elevation of
the levels of sCD100 protein, either in culture supernatants of
activated lymphocytes, or in the sera of immunized mice and of mice
with autoimmune disease. The physiologic and pathologic roles of sCD100
in the regulation of immune responses are also discussed.
Mice and antibodies
Flow cytometric analysis
Enzyme-linked immunosorbent assay sCD100. Sandwich enzyme-linked immunosorbent assay (ELISA) for detecting sCD100 was performed as follows: 96-well microplates (Maxisorp Nunc-Immuno plate, Rochester, NY) were coated with BMA-12 (100 µL of 5 µg/mL in 0.1 mM NaHCO3, pH 9) at 4°C for 15 hours. The wells were incubated in blocking solution (200 µL of 50 mM Tris-HCl, pH 8.1; 1 mM MgCl2; 0.15 M NaCl; 1% BSA; 0.05% Tween-20) for 1 hour at room temperature. Samples or the standards (a recombinant sCD100 protein consisting of the extracellular region of mouse CD100 fused with FLAG peptide15) diluted in blocking solution were added to the wells (100 µL/well) and incubated for 2 hours at room temperature. The wells were washed 3 times with phosphate buffered saline (PBS) containing 0.05% Tween-20 and incubated with biotinylated BMA-8 for 1 hour at room temperature. The bound Abs were incubated with AP-conjugated streptavidin and subsequently developed by phosphatase substrate (Sigma-104; Sigma). Absorbance values were obtained at 405 nm (correction wavelength set at 620 nm). Anti-single-stranded DNA Ab. Calf thymus DNA (Sigma) was purified with a Sepa Gene kit (Nippon Gene, Tokyo, Japan). Single-stranded DNA (ssDNA) was prepared by boiling the DNA solution for 15 minutes followed by immediate immersion on ice. Serially diluted serum samples were incubated in the ssDNA-coated (5 µg/mL) plates, followed by the addition of AP-labeled antimouse IgG antibodies. We defined serum titers of MRL/lpr mice at 7 months of age as 1000 U/mL. Immunoprecipitation sCD100 in culture supernatants. Primary T (Thy1.2+) or B (B220+) cells were purified from the spleen of C57BL/6 mice (6-8 weeks of age) by Magnetic Cell Sorting (MACS) (Miltenyi Biotech, Bergisch Gladbach, Germany). The resulting primary T cells, B cells, or T-cell hybridoma 2B4 cells were biotinylated by a Cellular Labeling and Immunoprecipitation kit (Boehringer Mannheim) and stimulated with concanavalin A (ConA) (4 µg/mL). The cells were then harvested, washed, and solubilized in 1% NP40. The culture supernatants and the cell lysates were further centrifuged at 100 000g for 1 hour to remove membrane debris. The contents of the supernatants and cell lysates were immunoprecipitated with anti-CD100 mAb (BMA-12), subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and electrophoretically transferred to nitrocellulose membranes. The membranes were blotted with streptavidin-POD conjugates, and developed by enhanced chemiluminescence (ECL) reagent (Amersham Pharmacia Biotech, Uppsala, Sweden) following the manufacturer's protocol. Affinity purification of sCD100 protein 2B4 cells were stimulated with ConA (4 µg/mL) for 20 hours in serum-free culture medium, GIT (Wako, Tokyo, Japan). sCD100 in the culture supernatants was affinity-purified by using a column made of CNBr-activated Sepharose 4 Fast Flow resin (Amersham Pharmacia Biotech) conjugated with anti-CD100 mAb (BMA-12). The CNBr-activated Sepharose 4 Fast Flow gel was conjugated with BMA-12 according to the manufacturer's protocol. The supernatants were applied to the column. After extensive washing with PBS, the bound protein was eluted using glycine-Cl buffer (pH 2.5).B-cell proliferation assays Nonadherent splenic B cells were isolated using a combination of anti-Thy1.2 (F7D5; Serotec, Oxford, United Kingdom) and rabbit complement (Wako) to remove T cells. The remaining B cells were further fractionated through a 50%, 60%, 66%, and 70% step-gradient of percoll, and cells at the interface between 66% and 70% were collected. The resulting small splenic B cells (1 × 105 cells/mL) were stimulated with or without anti-CD40 mAb (1 µg/mL), interleukin 4 (IL-4) (10 U/mL), CD100-Fc (20 µg/mL) or sCD100 (5 µg/mL) in flat-bottomed 96-well microtiter plates for 3 days. Cells were pulsed with 2 µCi of [3H]-thymidine for the last 16 hours.Immunization and serum antibody assays To induce antibody responses to T-cell-dependent antigen (TD Ag), 8-week-old mice were immunized intraperitoneally with 100 µg of 4-hydroxy-3-nitrophenylacetyl-chicken- -globulin (NP-CGG) as an
alum-precipitated complex at day 0 and boosted at day 21. Animals were
bled before and 7, 14, 21, and 28 days after the first immunization.
NP-specific antibodies were detected with NP12-BSA-coated
plates as described.18 To induce antibody responses to
T-cell-independent antigen (TI Ag), 8-week-old mice were immunized intraperitoneally with 50 µg of 2, 4, 6-trinitrophenyl (TNP)
conjugated-LPS (Sigma) in PBS and were bled before and 7 and 14 days
after immunization. The anti-TNP-specific antibodies were detected
using 2,4-dinitrophenylated bovine serum albumin
(DNP-BSA)-coated ELISA plates and quantified by isotype-specific
ELISA.18
Activated T and B lymphocytes release sCD100 Cross-linking of CD100 on the surface of human PBMCs using antihuman CD100 mAb has been shown to induce the release of a 120-kd isoform of CD100.29 We thus tested whether sCD100 is also generated after lymphocyte activation. Mouse T-cell hybridoma 2B4 cells were biotinylated. The fate of the biotinylated CD100 on the cell surface was chased over a time course after ConA stimulation. Immunoprecipitates with an anti-CD100 mAb, BMA-12 from supernatants, or cell lysates after various periods of stimulation were analyzed on SDS-PAGE under reducing or nonreducing conditions (Figure 1). From the culture supernatants of ConA-stimulated 2B4 cells, a single band of 120 kd was detected with BMA-12 under reducing conditions. This was 30 kd smaller than the molecular weight of full-length membrane-bound CD100. The intensity of this band increased with longer culture times with ConA, while unstimulated cells released only trace amounts of sCD100, even after 20 hours culture. Under nonreducing conditions, sCD100 was detected as 2 bands of 240 kd and 120 kd in the culture supernatant of ConA-stimulated cells. The larger is probably a homodimer of sCD100 since CD100 has been shown to form a homodimer via an intermolecular disulfide bond in the extracellular domain.13-15,28,29 In cell lysates of ConA-stimulated 2B4 cells, 2 species of CD100 with molecular weights of about 150 kd and 120 kd were observed in reducing conditions. The intensity of the 150-kd band corresponding to the full-length membrane-bound CD100 decreased gradually, whereas the 120-kd band emerged after stimulation with ConA, suggesting that the 120-kd protein in lysates of stimulated cells may be an intermediate form: sCD100 may be cleaved but remains membrane-associated and not released in the extracellular milieu. The expression of CD100 has been previously shown to be upregulated in activated primary T and B cells.15 We next examined whether sCD100 is also expressed in primary T and B cells after activation. As shown in Figure 2, the single band of 120 kd appeared in the culture supernatants of either ConA-stimulated T cells or CD40-stimulated B cells in reducing conditions, whereas the release of sCD100 was hardly detected for unstimulated T or B cells even after 20 hours culture. These results indicate that sCD100 is also generated from activated primary T and B cells.
Both CD100-expressing transfectants and recombinant soluble CD100 have
been shown to have a synergistic effect on CD40-stimulated B
cells.12,15 To determine whether sCD100 released from
activated lymphocytes retains such a biologic activity, we purified
sCD100 from culture supernatants of ConA-stimulated 2B4 cells, using an
anti-CD100 mAb-conjugated affinity column. Analysis of SDS-PAGE revealed the single band of 120 kd (Figure
3A), indicating that sCD100 was purified near
homogeneity. Then we examined in vitro the effect of sCD100 on B-cell
responses mediated by CD40. As shown in Figure 3B, sCD100 as well as
CD100-Fc synergistically augmented B-cell proliferation induced by
optimal doses of anti-CD40 mAb and IL-4. This activity was not due to
contamination by 2B4-derived cytokines, by particularly IL-2 in the
sCD100 preparation, because sCD100 did not induce any proliferation in
an IL-2-dependent CTLL2 cell line (data not shown). These results thus
demonstrate that purified natural sCD100 released from activated
lymphocytes also has a costimulatory activity on lymphocytes.
Elevation of the amount of sCD100 in sera of immunized mice We have previously shown that administration of recombinant sCD100-Fc enhanced the production of specific antibodies in vivo,15 and the deficiency of CD100 resulted in impaired production of specific antibodies against TD Ag but not against TI Ag.18 To explore the physiologic relevance of natural sCD100 in the antibody response in vivo, we measured the levels of sCD100 in the serum after immunization with a TD Ag, NP-CGG. As shown in Figure 4, although sCD100 was not detected before immunization, significant amounts of sCD100 were detected in the sera of immunized mice. Furthermore, the kinetics of the appearance of sCD100 in the serum is very similar to the kinetics of the production of specific antibodies. The results suggest the involvement of sCD100 released from activated lymphocytes in antibody responses in vivo. However, we could not detect sCD100 in sera of mice immunized with a TI Ag, TNP-LPS (Figure 5). These results suggest a possible involvement of sCD100 in antibody responses against TD Ag but not against TI Ag.
Enhanced expression of membrane-bound CD100 in MRL/lpr mice The MRL/lpr mouse is an autoimmune model that produces various autoantibodies and develops autoimmune diseases including nephritis, arthritis, sialodenitis, and skin lesions.30-33 To examine the pathologic relevance of CD100 in the development of autoimmune diseases, we analyzed the cell surface expression of CD100 and the serum sCD100 levels in these mice. Figure 6 shows that T-cell surface expression of CD100 is significantly increased for either B or T cells of MRL/lpr mice compared with 16-week-old MRL/n mice, although there was no difference before 8 weeks of age. Among the subpopulations of lymphocytes in MRL/lpr mice, there was no difference in CD100 expression between the B220 Thy1.2+ and
B220+Thy1.2+ cell-subpopulations of MRL/lpr
mice (data not shown).
Correlation between the levels of sCD100 and autoantibodies in the serum of MRL/lpr mice We then measured the levels of sCD100 in the serum of MRL/lpr mice (Table 1). The concentrations of sCD100 in the serum were significantly elevated for MRL/lpr mice, whereas C57BL/6, BALB/c, and MRL/n mice did not have detectable levels of sCD100 in the serum. Collectively, these findings demonstrate the existence of sCD100 in sera of MRL/lpr mice with an autoimmune disease. From 8 weeks of age, an increase in the amount of autoantibodies such as anti-ssDNA is observed in MRL/lpr mice.31 We analyzed the levels of sCD100 and anti-ssDNA antibody in each MRL/lpr mice at various weeks of age. Although neither sCD100 nor anti-ssDNA autoantibodies were detected in MRL/lpr mice younger than 8 weeks (data not shown), the levels of sCD100 as well as anti-ssDNA autoantibodies became detectable after 8 weeks (Figure 7A,B). The level of sCD100 gradually increased with age and peaked to 196.6 ± 157.2 ng/mL at 16 weeks. The levels of sCD100 and anti-ssDNA in the serum for each MRL/lpr mouse at 16 weeks of age seemed to be well correlated with ssDNA levels (r = 0.767, P < .01), showing a potential utility of sCD100 as an indicator for the development of autoimmunity.
In this study, we have demonstrated the existence of naturally produced sCD100, not only in the culture supernatants of activated lymphocytes, but also in the sera of immunized mice or of mice with an autoimmune disease. Although the semaphorin family consists of secreted-type and transmembrane-type proteins, most of their functions have been reported on secreted-type members acting as soluble factors.2,4 On the other hand, accumulating evidence suggests that transmembrane-type semaphorins may also function as factors,12 although it is not clear whether transmembrane-type semaphorins can retain their activities when converted into a soluble form. We have recently demonstrated that administration in vivo of recombinant soluble CD100-Fc protein had an effect on humoral and cellular immune responses, suggesting a function of CD100 as a soluble ligand. However, the existence and functions of naturally produced sCD100 in vivo have not been well clarified. In the present study, we provide direct evidence that, like recombinant CD100-Fc, naturally produced sCD100 after lymphocyte activation has a potent costimulatory function to induce proliferation of CD40-stimulated B cells. Our previous study with CD100-deficient mice exhibited reduced production of specific antibodies against TD Ag but not against TI Ag, implying a role of CD100 especially in T-cell-mediated humoral immune responses.18 Here, we observed significant levels of sCD100 in the serum of immunized mice and a good correlation between the levels of sCD100 and titers of specific antibodies produced against a TD Ag. Thus, sCD100 generated in vivo after immunization seems to play a role in humoral immune responses against TD Ag. In contrast, sCD100 was not detectable in the sera of mice immunized with a TI Ag, although the expression of membrane-bound CD100 and the release of sCD100 were upregulated on B cells after LPS-stimulation (data not shown).18 The abundant expression of CD100 by T cells may explain why sCD100 could be detected in the sera of mice immunized with TD Ag but not with TI Ag. Alternatively, CD100 on the surface of T cells may be more easily cleaved into sCD100 after activation, compared with B cells. Human sCD100 is thought to be generated by proteolytic cleavage, not by
alternative splicing.14 Our surface biotinylation-chase experiment demonstrates that mouse sCD100 is a product of proteolytic cleavage. Biotinylated sCD100 was immediately released into the culture
supernatants after activation of 2B4 cells (Figure 1). The release of
sCD100 from activated lymphocytes seems to parallel a decrease in the
expression of the full-length membrane-bound CD100. This kinetic
strongly suggests that sCD100 is generated by a cleavage and a release
from the cell surface. The molecular weight of sCD100 identified here
in vitro and in vivo was almost the same as the human
sCD100.29 Recently, Adams et al34 have demonstrated that Sema3A is converted from proSema into active Sema via
proteolytic cleavage by a furin-like protease. Their findings imply
that activation of proteases is involved in the regulation of
semaphorin functions. Proteases including metalloproteases are known to
be involved in the shedding from the surface of lymphocytes of many
receptors such as CD62L, IL-6 receptor, and TNF This is the first report showing the elevations of the level of serum sCD100 in antibody responses in vivo and in an autoimmune disease. Although it is not clear whether the elevations of the level of serum sCD100 might be a cause or a consequence of the progression of autoimmunity, sCD100 should not only be a good indicator for monitoring the production of antibodies in vivo, but also for following the development of autoimmune diseases. Moreover, sCD100 might be relevant to the progression of autoimmunity in MRL/lpr mice, for several reasons. First, a large amount of sCD100 was detected in the sera of MRL/lpr mice producing autoantibodies, whose levels exhibited a good correlation with the titers of the autoantibodies. Second, sCD100 displays synergistic effects on CD40-induced B-cell responses, which might promote abnormal B-cell proliferation, resulting in the production of autoantibodies in MRL/lpr mice. B cells also play a significant role in the development of autoimmunity, through the production of pathogenic autoantibodies and costimulation of autoreactive T cells.38 Also, in MRL/lpr mice, autoantibodies have been shown to be involved in the progression of autoimmunity, since anti-DNA antibodies derived from the mice are shown to bind to glomerular basal membrane, resulting in exacerbation of kidney damage.39-41 Because neutralizing antibodies against mouse CD100 have not yet been established, further analysis using CD100-deficient mice in MRL background will be required for dissecting the pathogenic role of CD100. In conclusion, we have shown that a soluble isoform of a transmembrane-type semaphorin, sCD100, can be generated from activated lymphocytes. The levels of sCD100 are increased either in the sera of immunized mice or in the sera of mice with an autoimmune disease, suggesting the implication of sCD100 in physiologic and pathologic immune responses.
We gratefully acknowledge Ms Kubota for excellent secretarial assistance.
Submitted November 2, 2000; accepted January 31, 2001.
Supported by research grants from the Ministry of Education, Science and Culture, Japan, to H.K. and A.K.
X.W. and A.K. contributed equally to this work.
The publication costs of this article were defrayed in part by page charge payment. Therefore, and solely to indicate this fact, this article is hereby marked "advertisement" in accordance with 18 U.S.C. section 1734.
Reprints: Hitoshi Kikutani, Department of Molecular Immunology, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan; e-mail: kikutani{at}ragtime.biken.osaka-u.ac.jp
1. Semaphorin Nomenclature Committee. Unified nomenclature for the semaphorins/collapsins. Cell. 1999;97:551-552[CrossRef][Medline] [Order article via Infotrieve]. 2. Yu H-H, Kolodkin AL. Semaphorin signaling: a little less per-plexin. Neuron. 1999;22:11-14[CrossRef][Medline] [Order article via Infotrieve]. 3. Kolodkin AL, Matthes DJ, O'Connor TP, Patel NH, Bentley D, Goodman CS. Fascilin IV: sequence, expression, and function during growth cone guidance in the grasshopper embryo. Neuron. 1992;9:831-845[CrossRef][Medline] [Order article via Infotrieve]. 4. Kolodkin AL, Matthes DJ, Goodman CS. The semaphorin genes encode a family of transmembrane and secreted growth cone guidance molecules. Cell. 1993;75:1389-1399[CrossRef][Medline] [Order article via Infotrieve]. 5. Luo Y, Raible D, Raper JA. Collapsin: a protein in brain that induces the collapse and paralysis of neuronal growth cones. Cell. 1993;75:217-227[CrossRef][Medline] [Order article via Infotrieve]. 6. Dodd J, Schuchardt A. Axon guidance: a compelling case for repelling growth cones. Cell. 1995;81:471-474[CrossRef][Medline] [Order article via Infotrieve]. 7. Kitsukawa T, Shimono A, Kawakami A, Kondoh H, Fujisawa H. Overexpression of a membrane protein, neuropilin, in chimeric mice causes anomalies in the cardiovascular system, nervous system and limbs. Development. 1995;121:4309-4318[Abstract]. 8. Behar O, Golden JA, Mashimo H, Schoen FJ, Fishman MC. Semaphorin III is needed for normal patterning and growth of nerves, bones and heart. Nature. 1996;383:525-528[CrossRef][Medline] [Order article via Infotrieve]. 9. Roche J, Boldog F, Robinson M, et al. Distinct 3p21.3 deletions in lung cancer and identification of a new human semaphorin. Oncogene. 1996;12:1289-1297[Medline] [Order article via Infotrieve].
10.
Sekido Y, Bader S, Latif F, et al.
Human semaphorins A(V) and IV reside in the 3p21.3 small cell lung cancer deletion region and demonstrate distinct expression patterns.
Proc Natl Acad Sci U S A.
1996;93:4120-4125
11.
Furuyama T, Inagaki S, Kosugi A, et al.
Identification of a novel transmembrane semaphorin expressed on lymphocytes.
J Biol Chem.
1996;271:33376-33381
12.
Hall KT, Boumsell L, Schultze JL, et al.
Human CD100, a novel leukocyte semaphorin that promotes B-cell aggregation and differentiation.
Proc Natl Acad Sci U S A.
1996;93:11780-11785 13. Bougeret C, Mansur IG, Dastot H, et al. Increased surface expression of a newly identified 150-kDa dimer early after human T lymphocyte activation. J Immunol. 1992;148:318-323[Abstract]. 14. Delaire S, Elhabazi A, Bensussan A, Boumsell L. CD100 is a leukocyte semaphorin. Cell Mol Life Sci. 1998;54:1265-1276[CrossRef][Medline] [Order article via Infotrieve]. 15. Kumanogoh A, Watanabe C, Lee I, et al. Identification of CD72 as a lymphocyte receptor for the class IV Semaphorin CD100: a novel mechanism for regulating B-cell signaling. Immunity. 2000;13:621-631[CrossRef][Medline] [Order article via Infotrieve]. 16. Tamagnone L, Artigiani S, Chen H, et al. Plexins are a large family of receptors for transmembrane, secreted, and GPI-anchored semaphorins in vertebrates. Cell. 1999;99:71-80[CrossRef][Medline] [Order article via Infotrieve].
17.
Maestrini E, Tamagnone L, Longati P, et al.
A family of transmembrane proteins with homology to the MET-hepatocyte growth factor receptor.
Proc Natl Acad Sci U S A.
1996;93:674-678 18. Shi W, Kumanogoh A, Watanabe C, et al. The class IV semaphorin CD100 plays a nonredundant role in the immune response: Defective B and T-cell activation in CD100-deficient mice. Immunity. 2000;13:633-642[CrossRef][Medline] [Order article via Infotrieve].
19.
Adachi T, Flaswinkel H, Yakura H, Reth M, Tsubata T.
The B-cell surface protein CD72 recruits the tyrosine phosphatase SHP-1 upon tyrosine phosphorylation.
J Immunol.
1998;160:4662-4665 20. Pan C, Baumgarth N, Parnes JR. CD72-deficient mice reveal nonredundant roles of CD72 in B-cell development and activation. Immunity. 1999;11:495-506[CrossRef][Medline] [Order article via Infotrieve]. 21. Fremeaux-Bacchi V, Aubry JP, Bonnefoy JY, Kazatchkine MD, Kolb JP, Fischer EM. Soluble CD21 induces activation and differentiation of human monocytes through binding to membrane CD23. Eur J Immunol. 1998;28:4268-4274[CrossRef][Medline] [Order article via Infotrieve]. 22. Delespesse G, Suter U, Mossalayi D, et al. Expression, structure, and function of the CD23 antigen. Adv Immunol. 1991;49:149-191[Medline] [Order article via Infotrieve]. 23. Hintzen RQ, de Jong R, Lens SM, van Lier RA. CD27: marker and mediator of T-cell activation? Immunol Today. 1994;15:307-311[CrossRef][Medline] [Order article via Infotrieve]. 24. Bazil V, Horejsi V. Shedding of CD44 adhesion molecule from leucocytes induced by anti-CD44 monoclonal antibody simulating the effect of a natural receptor ligand. J Immunol. 1992;149:747-753[Abstract]. 25. Leca G, Mansur SE, Bensussan A. Expression of VCAM-1 (CD106) by a subset of TCR gamma delta-bearing lymphocyte clones. J Immunol. 1995;154:1069-1077[Abstract].
26.
Hughes DPM, Crispe IN.
A naturally occurring soluble iosform of murine Fas generated by alternative splicing.
J Exp Med.
1995;182:1395-1401
27.
Cheng J, Zhou T, Liu C, et al.
Protection from Fas-mediated apoptosis by a soluble form of the Fas molecule.
Science.
1994;263:1759-1762
28.
Herold C, Bismuth G, Bensussan A, Boumsell L.
Activation signals are delivered through two distinct epitopes of CD100, a unique 150 kDa human lymphocyte surface structure previously defined by BB18 mAb.
Int Immunol.
1995;7:1-8 29. Herold C, Elhabazi A, Bismuth G, Bensussan A, Boumsell L. CD100 is associated with CD45 at the surface of human T lymphocytes. J Immunol. 1996;157:5262-5268[Abstract].
30.
Jabs DA, Prendergast RA.
Reactive lymphocytes in lacrimal gland and vasculitic renal lesions of autoimmune MRL/lpr mice express L3T4.
J Exp Med.
1987;166:1198-1203 31. Theofilopoulos AN, Dixon FJ. Murine models of systemic lupus erythematosus. Adv Immunol. 1985;37:269-390[Medline] [Order article via Infotrieve]. 32. Hoffman RW, Alspaugh MA, Waggie KS, Durham JB, Walker SE. Sjogren's syndrome in MRL/l and MRL/n mice. Arthritis Rheum. 1984;27:157-165[Medline] [Order article via Infotrieve].
33.
Andrews BS, Eisenberg RA, Theofilopoulos AN, et al.
Spontaneous murine lupus-like sydromes: clinical and immunopathological manifestations in several strains.
J Exp Med.
1978;148:1198-1215 34. Adams RH, Lohrum M, Klostermann A, Betz H, Puschel AW. The chemorepulsive activity of secreted semaphorins is regulated by furin-dependent proteolytic processing. EMBO J. 1997;16:6077-6086[CrossRef][Medline] [Order article via Infotrieve].
35.
Arribas J, Coodly L, Vollmer P, Kishimoto TK, Rose-Jhon S, Massague J.
Diverse cell surface protein ectodomains are shed by a system sensitive to metalloprotease inhibitors.
J Biol Chem.
1996;271:11376-11382 36. Robache-Gallea S, Bruneau JM, Robbe H, Morand V, Capdevila C, Bhatmagar N. Partial purification and characterization of a tumor necrosis factor-alpha converting activity. Eur J Immunol. 1997;27:1275-1282[Medline] [Order article via Infotrieve]. 37. Blobel CP. Metalloprotease-disintegrins: links to cell adhesion and cleavage of TNFalpha and notch. Cell. 1997;90:589-592[CrossRef][Medline] [Order article via Infotrieve]. 38. Korganow AS, Ji H, Mangialaio S, et al. From systemic T-cell self-reactivity to organ-specific autoimmune disease via immunoglobulins. Immunity. 1999;10:451-461[CrossRef][Medline] [Order article via Infotrieve]. 39. Madaio MP, Carlson J, Cataldo J, Ucci A, Migliorini P, Pankewycz O. Murine monoclonal anti-DNA antibodies bind directly to glomerular antigens and form immune deposits. J Immunol. 1987;138:2883-2889[Abstract]. 40. Sabbaga J, Line SR, Potocnjak P, Madaio MP. A murine nephritogenic monoclonal anti-DNA autoantibody binds directly to mouse laminin, the major non-collagenous protein component of the glomerular basement membrane. Eur J Immunol. 1989;19:137-142[Medline] [Order article via Infotrieve]. 41. Lake RA, Staines NA. A monoclonal DNA-binding autoantibody causes a deterioration in renal function in MRL mice with lupus disease. Clin Exp Immunol. 1988;73:103-110[Medline] [Order article via Infotrieve].
© 2001 by The American Society of Hematology.
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
|
 |
|
  J. R. Basile, J. Gavard, and J. S. Gutkind Plexin-B1 Utilizes RhoA and Rho Kinase to Promote the Integrin-dependent Activation of Akt and ERK and Endothelial Cell Motility J. Biol. Chem., November 30, 2007; 282(48): 34888 - 34895. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Zhu, W. Bergmeier, J. Wu, H. Jiang, T. J. Stalker, M. Cieslak, R. Fan, L. Boumsell, A. Kumanogoh, H. Kikutani, et al. Regulated surface expression and shedding support a dual role for semaphorin 4D in platelet responses to vascular injury PNAS, January 30, 2007; 104(5): 1621 - 1626. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. R. Basile, R. M. Castilho, V. P. Williams, and J. S. Gutkind Semaphorin 4D provides a link between axon guidance processes and tumor-induced angiogenesis PNAS, June 13, 2006; 103(24): 9017 - 9022. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Gautier, B. de Saint-Vis, B. Senechal, J.-J. Pin, E. E.M. Bates, C. Caux, F. Geissmann, and P. Garrone The Class 6 Semaphorin SEMA6A Is Induced by Interferon-{gamma} and Defines an Activation Status of Langerhans Cells Observed in Pathological Situations Am. J. Pathol., February 1, 2006; 168(2): 453 - 465. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Takegahara, A. Kumanogoh, and H. Kikutani Semaphorins: a new class of immunoregulatory molecules Phil Trans R Soc B, September 29, 2005; 360(1461): 1673 - 1680. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Asano, M. Fujimoto, N. Yazawa, S. Shirasawa, M. Hasegawa, H. Okochi, K. Tamaki, T. F. Tedder, and S. Sato B Lymphocyte Signaling Established by the CD19/CD22 Loop Regulates Autoimmunity in the Tight-Skin Mouse Am. J. Pathol., August 1, 2004; 165(2): 641 - 650. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. Giraudon, P. Vincent, C. Vuaillat, O. Verlaeten, L. Cartier, A. Marie-Cardine, M. Mutin, A. Bensussan, M.-F. Belin, and L. Boumsell Semaphorin CD100 from Activated T Lymphocytes Induces Process Extension Collapse in Oligodendrocytes and Death of Immature Neural Cells J. Immunol., January 15, 2004; 172(2): 1246 - 1255. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kumanogoh and H. Kikutani Immune semaphorins: a new area of semaphorin research J. Cell Sci., September 1, 2003; 116(17): 3463 - 3470. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Ishida, A. Kumanogoh, K. Suzuki, S. Akahani, K. Noda, and H. Kikutani Involvement of CD100, a lymphocyte semaphorin, in the activation of the human immune system via CD72: implications for the regulation of immune and inflammatory responses Int. Immunol., August 1, 2003; 15(8): 1027 - 1034. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Kumanogoh, K. Suzuki, E. Ch'ng, C. Watanabe, S. Marukawa, N. Takegahara, I. Ishida, T. Sato, S. Habu, K. Yoshida, et al. Requirement for the Lymphocyte Semaphorin, CD100, in the Induction of Antigen-Specific T Cells and the Maturation of Dendritic Cells J. Immunol., August 1, 2002; 169(3): 1175 - 1181. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Bismuth and L. Boumsell Controlling the Immune System Through Semaphorins Sci. Signal., April 16, 2002; 2002(128): re4 - re4. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Watanabe, A. Kumanogoh, W. Shi, K. Suzuki, S. Yamada, M. Okabe, K. Yoshida, and H. Kikutani Enhanced Immune Responses in Transgenic Mice Expressing a Truncated Form of the Lymphocyte Semaphorin CD100 J. Immunol., October 15, 2001; 167(8): 4321 - 4328. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
 |
 |
 |
|||||||
 |
 |
 |
 |
 |
 |
 |
 |
||
| Copyright © 2001 by American Society of Hematology Online ISSN: 1528-0020 | |||||||||
Top
Abstract
Introduction
]) conditions, electrophoretically transferred
to nitrocellulose membranes, and blotted with streptavidin-POD.
Molecular weight markers (Mr) are indicated on the right.
.