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*
Deutsches Rheumaforschungszentrum, Berlin, Germany;
Institut für Medizinische Immunologie, Universitätsklinikum Charité, Berlin, Germany; and
Universitätsklinikum Charité, Rheumatologie/Klinische Immunologie, Berlin, Germany
| Abstract |
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|
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-). A peptide substitution
analysis was performed in which each residue of the
MBPAc111 peptide was exchanged by all 20 naturally
occurring amino acids. This allowed the definition of the motif
(supertope) that is recognized by the MBPAc111-specific T
cells. The supertope was used to screen protein databases (SwissProt
and TREMBL). By the search, 832 peptides of microbial origin were
identified and synthesized. Of these, 61 peptides induced proliferation
of the MBPAc111-specific transgenic T cells in vitro.
Thus, the definition of a supertope by global amino acid substitution
can identify multiple microbial mimic peptides that activate an
encephalitogenic TCR. Peptides with only two native MBP-residues were
sufficient to activate MBPAc111-specific T cells in
vitro, and experimental autoimmune encephalomyelitis could be induced
by immunizing mice with a mimic peptide with only four native MBP
residues. | Introduction |
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More recently, it was demonstrated that individual TCRs could recognize different peptide/MHC complexes that do not show strong sequence homology (5, 6, 27, 28, 29, 30, 31, 32). Structural analyses have demonstrated that the antigenic peptide contributes little to the TCR-peptide-MHC interface. Furthermore, this interface shows a poor shape complementarity that could accommodate a wide range of different peptides, thus providing a structural base for the degenerate recognition of peptide-MHC complexes by individual TCRs (33). Consequently, two groups have demonstrated cross-reactivity for MBP-specific T cell clones from MS patients with many microbial ligands that were structurally unrelated to the MBP epitope recognized by those T cell clones (5, 6, 34, 35). Thus, it has become evident that simple sequence alignment will not suffice to identify microbial ligands for autoreactive T cells. In the EAE model, an improved method to identify microbial ligands for murine MBP-specific T cells was used: after careful definition of MHC and TCR contact residues within the immunodominant MBP epitope, database searches were performed that were based on these structural characteristics, allowing nonhomologous amino acids at the "non-contact-residues." A number of microbial and viral peptides fulfilling the search criteria were identified, and some of these peptides induced EAE in mice (7, 24). However, this "knowledge-based" approach requires laborious analysis of the contact residues of an individual epitope with MHC and TCR. Therefore, we wished to examine an alternative approach to identifying microbial ligands for autoreactive TCRs. In earlier work, we had used the spot-synthesis technique for peptides (36, 37) to identify multiple ligands for mAbs (38). Here, we have used peptide spot synthesis for global amino acid replacements of the MBPAc111 epitope, which is immunodominant in mice of the H-2u haplotype. We identified 61 microbial mimic peptides that activated MBPAc111-specific T cells. Several of these peptides induced EAE in mice that are transgenic for a MBPAc111-specific TCR (11).
| Materials and Methods |
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|
|---|
Mice transgenic for a TCR that recognizes
MBPAc111 bound to I-Au
(11) were crossed onto TCR
-chain knockout mice
(39), resulting in mice carrying only
ß T cells
specific for MBPAc111
(T+
-) (40, 41), and were obtained from Dr. Juan Lafaille (Skirball
Institute, New York, NY). Mice were bred at our animal facility in
specific pathogen-free conditions and checked for TCR expression by
flow cytometry with anti-Vß8-PE (MR52, PharMingen, San Diego,
CA) and anti-CD4-FITC Abs (GK1.5). All animal experiments were
performed according to institutional and state guidelines.
Peptides
Cellulose-bound peptides were prepared by automated spot synthesis (Abimed, Langenfeld, Germany; Software DIGEN, Jerini Biotools, Berlin, Germany) with the use of Whatman No. 50 cellulose membranes (Whatman, Maidstone, U.K.) as described before (36, 37). Peptides were N-terminally acetylated using acetanhydride and diisopropylethylamine. For synthetic reasons, the peptides contained an additional C-terminal glycine residue. Peptides were cleaved from the solid support by treating the cellulose with ammonia vapor for 5 h. Each spot was eluted in 200 µl double-distilled H2O resulting in an approximately 150200 µM peptide solution. For titration experiments and in vivo analysis, peptides were conventionally synthesized according to standard Fmoc machine protocols with a multiple peptide synthesizer (Abimed). The following peptides were synthesized (given in single letter code, with Ac denoting N-terminal acetylation): MBPAc111 (AcASQKRPSQRSK); pep200 (AcANMQRQAVPTL; Escherichia coli, Salmonella typhimurium, Haemophilus influenzae, Buchnera aphidicola); pep378 (AcASMNRPNLVAL; Mycobacterium tuberculosis); pep383 (AcASMSRPVKQLK; E. coli, S. typhimurium); and pep387 (AcASQARQLADSY, E. coli). Purity of the peptides was determined by HPLC and composition monitored by MALDI-TOF mass spectroscopy.
In vitro T+
- spleen cell assays
Single-cell suspensions were prepared from spleens in RPMI 1640
supplemented with 10% FCS, 2 mM glutamine, 100 U/ml penicillin, 100
µg/ml streptomycin, and 50 µM 2-ME (complete RPMI, Sigma, St.
Louis, MO) as described (14). For proliferation, cells
were cultured in 96-well plates at 1 x
106/ml with 5 µl peptide spots (
0.51.5
µM), with conventionally synthesized peptides at concentrations
indicated, or with complete RPMI alone, at 37°C in 5%
CO2. Proliferation was measured by an 18-h
incorporation of 1 µCi [3H]thymidine on day
3. Stimulation indices (SI) were determined as cpm of peptides divided
by cpm of cells cultured with medium alone (range for background values
14002100 cpm for the various experiments). SIs
15 were considered
positive. For cytokine determination, cells were cultured in complete
medium at 5 x 106/ml with 5 µl peptide
spots, or at 1 x 106/ml for dose-response
analysis with conventionally synthesized peptides as indicated.
Supernatants were collected at 48 h for analysis by sandwich
ELISA. IFN-
, TNF-
, and TGF-ß were determined with commercially
available kits according to manufacturers instructions (Genzyme
Diagnostics, Cambridge, MA). IL-4, IL-5, IL-10, and IL-2 were
determined as described (42). The lower detection limit
for each ELISA was as follows: IFN-
, TNF-
, and IL-4, 50 pg/ml;
IL-2 and TGF-ß, 0.1 ng/ml; IL-5, 10 U/ml; and IL-10, 0.3 ng/ml.
Induction of EAE
Mice were injected s.c. at 2 sites at the base of the tail with 200 µg MBPAc111 or mimic peptides emulsified in CFA in a total volume of 0.2 ml. PT (200 ng; Life Technologies, Gaithersburg, MD) was injected i.v. 24 and 48 h after immunization. Age- and sex-matched control mice received PBS or CFA plus PT. Mice were examined every 12 days for clinical signs of EAE which was scored as follows: level 0, healthy; level 1, limp tail; level 2, partial hind leg paralysis; level 3, complete hind leg paralysis; level 4, front leg weakness; level 5, moribund. Data are represented as mean EAE of each group. Animals were sacrificed when their score reached 45, and their score was kept at 5 for the remainder of the experiment.
| Results |
|---|
|
|
|---|
Peptides prepared by spot synthesis (37) were used
for a substitution analysis of MBPAc111 in
which each position of the peptide was substituted with all 20
naturally occurring amino acids. The resulting 220 peptides and
synthesized spots of MBPAc111 were tested for
induction of proliferation of
T+
- spleen cells in
vitro (Fig. 1
A). SIs
15 were
considered positive. The substitutional analysis identified the amino
acid substitutions tolerated at each position of the peptide. This
revealed the binding motif (supertope) and thus the structural
requirements for T cell recognition for the transgenic TCR (Fig. 1
B). Arginine at position 5 (R5) could not be substituted
with any other amino acid. At each of the other positions of the
peptide, at least one substitution was tolerated (Fig. 1
A).
Alanine at peptide position 1 (A1) could be substituted only by serine
(A1S) and P6 could be replaced only by glutamine. S2, Q3, and S7 could
each be replaced by several other amino acids, and positions 811
could be taken by any of the naturally occurring amino acids (Fig. 1
B). The supertope was used to screen the SwissProt and
TREMBL databases (software ExPasy) (43), and 832 peptides
of microbial origin were identified that contained the supertope.
|
The 832 peptides containing the supertope were prepared by spot
synthesis and assayed for the induction of proliferation in
T+
- spleen cells in
vitro. Of the 832 microbial peptides, 61 induced proliferation of the
T+
- cells (SI
50; SI for MBPAc111 = 80). The microbial mimic
sequences, listed in decreasing order of SI, and the organism(s)
containing the corresponding protein are shown in Table I
. The mimic peptides had anywhere from 5
to 9 amino acid substitutions compared with
MBPAc111. There was no statistically
significant correlation between the number of conserved amino acids and
the SI (correlation coefficient, 0.08; p > 0.05).
Therefore, other factors such as the topology of the peptide-MHC
complex must determine the antigenic strength of the individual mimic
peptides. Six peptides sharing only 2 amino acids with the original
MBPAc111 sequence activated the
T+
- T cells (SI
50). Of the 61 mimics 52 had both R5 and P6 conserved and 45 of the
mimics had A1 conserved. Altogether, A1, S2, Q3, and P5 were more
frequently conserved than expected (p < 0.01)
from the numbers of possible amino acids in the supertope. In contrast,
K4, and SQRSK711, were conserved at the expected random frequencies.
R5 could not be substituted at all (Fig. 1
A).
|
Next, we compared the dose requirements for the activation of
MBPAc111-specific T cells by microbial mimic
peptides. Four peptides were selected for further analysis. On the
basis of the results obtained with the peptides prepared by spot
synthesis, we chose two highly stimulatory peptides (pep378 and pep383,
SI
50; see Table I
), and two peptides with low stimulatory
capacity (pep200 and pep387, SI < 10; not included in Table I
).
These peptides and MBPAc111 were synthesized
conventionally and analyzed for the induction of proliferation and
cytokine production in
T+
- cells in a
dose-response analysis. pep378 and pep383 induced proliferation
comparable to that of MBPAc111 (Fig. 2
A). At concentrations
100
µg/ml, pep200 induced low proliferation of the
T+
- cells, whereas
pep387 did not induce proliferation of the
T+
- cells. Thus, the
results obtained with conventionally synthesized peptides confirmed the
results obtained with these peptides prepared by spot synthesis. pep378
and pep383 induced stronger IL-2 production than
MBPAc111 (Fig. 2
B), and neither
pep200 nor pep387 induced IL-2 production in
T+
- cells (Fig. 2
B). IFN-
was induced by MBPAc111
and pep383 in similar amounts (Fig. 2
C), the dose-response
curve for pep378 was slightly shifted to higher concentrations, whereas
neither pep200 nor pep387 induced IFN-
production. Small amounts of
TNF-
were induced by MBPAc111, pep378, and
pep383 (Fig. 2
D), whereas none of the peptides induced IL-4,
IL-10, or TGF-ß (data not shown).
|
To test whether the microbial mimic peptides that activated T
cells in vitro could also induce EAE, we immunized
T+
- mice with these
peptides. Mice were immunized with 200 µg of
MBPAc111, pep383, pep378, pep200, or pep387.
All mice received PT i.v. at 24 and 48 h after immunization and
were observed for at least 35 days postimmunization for the development
of EAE (Fig. 3
). Mice immunized with
MBPAc111 showed clinical onset of EAE at day 8
(mean value; range, 79 days) and rapidly progressed to final stages
by day 12. Immunization with the mimic peptides pep383 and pep378
induced EAE in 8 of 8 and 6 of 8 mice, respectively (data pooled from
two independent experiments). Both onset and progression of disease
with pep383 were delayed as compared with
MBPAc111 or pep378. Control mice received PBS
in CFA and PT and remained healthy for the duration of the experiments
(50 days). Of the two peptides identified that induced low
proliferation of transgenic T cells in vitro, pep200 and pep387,
neither induced EAE (even when the observation period was extended up
to 60 days; data not shown). Pertussis toxin was necessary to
facilitate EAE and mice that were immunized with
MBPAc111 or mimic peptides without PT did not
develop EAE (data not shown). In agreement with other studies
(11, 41, 44), we observed that all
T+
- mice progressed to
full EAE (score 5) rapidly after displaying clear signs of onset of EAE
(score 2).
|
| Discussion |
|---|
|
|
|---|
-/- T lymphocytes used in
this study (11, 41, 45). The supertope recognized by the
T+
- T cells confirms
and extends previous findings on the recognition of variants of the
MBPAc111 epitope by
I-Au-restricted T cells. Using different T cell
hybridomas, T cell clones, or intact mice, others have identified
lysine at position 4 of the original peptide (K4) and R5 as the MHC
contact sites of MBPAc111 and Q3 and P6 as the
putative TCR contact sites of the
MBPAc111/I-Au complex
(46, 47, 48, 49, 50, 51, 52, 53, 54, 55). Most of this work was performed with alanine
substitutions in the MBPAc111 epitope. Our
systematic analysis in which every residue of
MBPAc111 was replaced by every naturally
occurring amino acid revealed that the MHC contact site R5 could not be
replaced by any other amino acid without destroying recognition by the
T+
- T cells, whereas L4
could be replaced by any of the amino acids. This is in agreement with
earlier studies, which had demonstrated that substitution of L4 with
several different amino acids can dramatically increase MHC binding
(46, 49, 50, 53, 54). However, increased MHC binding was
not always associated with improved T cell activation in vitro, and
several of the peptides with substitutions at position 4 abolished T
cell activation of individual T cell hybridomas or clones (27, 46, 48, 50, 51, 53, 55). Thus, the
T+
- T cells differ from
some of the other T cell clones and hybridomas studied to date in that
all the substitutions for K4 induced strong T cell proliferation (Fig. 1
A search of the SwissProt and TREMBL databases for peptides containing
the supertope shown in Fig. 1
B yielded 832 potentially
cross-reactive peptides of microbial origin. However, only 61 of the
832 peptides induced proliferation of the
T+
- T cells.
Wucherpfennig et al. (5) used structural criteria to
search a protein database for microbial mimics of
MBP8994, the immunodominant epitope in
HLA-DR2+ MS patients. Of 129 peptides fulfilling
the set criteria that were synthesized, only 7 activated at least 1 of
the 5 DR2-restricted human T cell clones tested in that study. Why do
so many peptides that fulfill carefully designed structural criteria
fail to induce T cell activation? One explanation is that some
combinations of amino acid substitutions that are allowed individually
will be "forbidden" when combined in one peptide sequence. This has
been observed in a recent study in which MBP-specific human T cell
clones were tested for reactivity with random peptide libraries
(34). Furthermore, Reay et al. (28) have
shown that changing residues apparently not involved in MHC or TCR
contact can nevertheless have dramatic consequences on T cell
activation. Thus, neither a detailed knowledge about the MHC and TCR
contact sites of an epitope nor a global substitution analysis as
performed in the work described here can exactly predict those peptides
that will activate a cross-reactive TCR. Importantly, either of these
approaches will not only predict T cell reactivity with peptides that
are nonstimulatory but also miss several peptides that are stimulatory
for the TCR in question. Substitutions that are "forbidden" if
considered individually can be compensated for by additional
substitutions at other positions of an antigenic peptide that enhance T
cell activation (28, 34). Thus, it is very likely that our
supertope analysis has missed some microbial peptides capable of
stimulating the T+
- T
cells.
25 of the 61 microbial mimic peptides that activated the
T+
- T cells had four
native MBP residues. Gautam et al. (49) have shown earlier
that a peptide with only 4 native MBP-residues could activate T cell
hybridomas specific for
MBPAc111/I-Au. Extending
these data, we found 18 peptides (see Table I
) that had 3 native MBP
residues and 6 peptides that had only 2 native MBP residues among those
mimics that induced SIs
50 in the
T+
- T cells. Thus, in
addition to viral peptides that have been shown earlier to activate
MBPAc111/I-Au-specific or
MBP8799/I-As-specific T
cells (7, 24), we demonstrate here that bacterial peptides
with as little as 2 or 3 conserved MBP residues can activate
MBPAc111/I-Au-specific
T cells. This is similar to findings obtained with human
MBP8799-specific T cell clones; microbial
mimics with as little as 3 native MBP-residues were shown to activate
such clones (5). In one case, a peptide not sharing a
single residue with the original MBP8799
sequence was found to stimulate human T cell clones raised against MBP
(34).
The animal model EAE permits testing of microbial peptides for
encephalitogenicity. Previous work had shown that some altered peptides
could still induce T cell activation but not EAE when injected into
susceptible mice (46, 47, 49). Previous findings had also
indicated that at least 5 native MBP residues need to be present in a
mimic peptide for the peptide to induce EAE after immunization of
susceptible mice (24, 49). Extending these earlier
reports, we found that a mimic peptide containing only 4 native MBP
residues (pep 378) could induce EAE when injected into susceptible mice
(Fig. 3
). Both of the encephalitogenic peptides examined in our study
had A1, S2, R5, and P6 conserved. Our findings that at least 61
microbial mimic peptides can activate the in
T+
- T cells in vitro
and that a fraction of these mimic peptides can also induce EAE in the
T+
- mice support recent
evidence coming from extensive analyses of Ag recognition by individual
T cells (5, 6, 27, 28, 29, 30, 31, 32), or the structural analyses of
TCR-peptide-MHC complexes (33), demonstrating that TCR
recognition of Ag is degenerate. In fact, it has recently been
suggested that a single TCR might productively interact with as many as
106 different ligands (57). How do
these findings relate to the "molecular mimicry" hypothesis
(8)? Our data presented here (and those of B. Maier and T.
Kamradt, unpublished observations) and those of others (5, 6) indicate that peptide molecular mimicry at the level of T
cell activation is a frequent event. We consider it very likely that T
cell cross-reactivity between a microbial peptide and a self peptide
alone is not sufficient to induce autoimmune disease (9).
In fact, in preliminary experiments we could not induce EAE in
T+
- mice via infection
with S. typhimurium, the bacterium from which the
encephalitogenic mimic pep383 is derived (J. L. Grogan, U. E.
Schaible, and T. Kamradt, unpublished observations). Such preliminary
observations, however, must be interpreted with great caution because
all the peptides used in our studies were N-terminally acetylated.
Earlier work had shown that N-terminal acetylation of
MBP111 is essential for T cell recognition. It
was proposed that the positively charged amino terminus revealed by
removal of the N-terminal acetyl group was responsible for the observed
elimination of the proliferative activity (58). Wraith et
al. (46) found that unacetylated
MBP111 with a K4A substitution (MBP111[4A])
effectively activated T cell hybridoma 1934.4 despite its decreased
binding to I-Au. Therefore, the N-terminal acetyl
group is an important determinant in interactions with
I-Au but not absolutely necessary for interaction
with the TCR. This notion was further supported recently. Lee et al.
reported on an unacetylated but NH2-terminally
extended MBP111 peptide (OVA-MBP). This peptide induced IL-3
production in an MBPAc111-specific T cell clone
yet failed to trigger full T cell proliferation (54).
Finally, acetylated MBP111 variants have been
reported that induce T cell proliferation in vitro but not EAE in vivo
(46, 47, 49). Therefore, it is impossible to predict from
our in vitro and in vivo data that were obtained using N-terminally
acetylated MBP111 whether the nonacetylated or
N-terminally extended natural peptides would have similar effects.
Current work in our laboratory addresses the questions whether the
mimic peptide sequences are processed naturally and whether the
naturally processed peptides are encephalitogenic. In addition to this
aspect which is specific for the MBPAc111
system, a multitude of mechanisms usually prevents the induction of
autoimmunity. For cross-reactive T cells to induce autoimmunity,
neither the microbial peptide nor the self peptide should be a cryptic
epitope (59); the self Ag must be present at high enough
concentrations and the T cells at high enough numbers
(60); the T cells must receive the "right"
costimulatory signals (61), to produce the "right" set
of cytokines (1, 40, 62), to migrate to the site where the
self Ag is expressed (45, 63, 64), and must escape
immunoregulation (41, 44). Nevertheless, molecular mimicry
remains an attractive hypothesis for the pathogenesis of autoimmunity.
It is, for example, conceivable that microbial Ags, even if they do not
trigger disease directly, help maintain the memory T cell pool specific
for a particular autoantigen. Furthermore, recurrent infections
possibly even with different microbes could bring the number of
autoreactive T cells over a critical threshold such that autoimmune
disease will finally become manifest.
We have shown that the definition of a supertope by global amino acid substitution can identify multiple microbial mimic peptides that activate an encephalitogenic TCR. Peptides with only 2 native MBP-residues are sufficient to activate MBPAc111-specific T cells in vitro and EAE can be induced by immunizing mice with a mimic peptide with only 4 native MBP residues. The data show that molecular mimicry at the level of TCR cross-reactivity is a frequent event.
| Acknowledgments |
|---|
-/-
breeders; Dr. A. OGarra for generous gifts of mAbs; Dr. U. E.
Schaible for providing the helpful discussions and advice on the
infection experiments; Dr. O. Liesenfeld for helpful
discussion; and Maja Affeldt, Grit Czerwony, Kristine Hagens, Berit
Hoffmann, and Christiane Landgraf for excellent technical
assistance. | Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Thomas Kamradt, Deutsches Rheumaforschungszentrum, Monbijoustrasse 2, 10117 Berlin, Germany. E-mail address: ![]()
3 Abbreviations used in this paper: EAE, experimental autoimmune encephalitis; MBP, myelin basic protein; MS, multiple sclerosis; pep, peptide; PT, pertussis toxin; SI, stimulation index. ![]()
Received for publication May 3, 1999. Accepted for publication July 26, 1999.
| References |
|---|
|
|
|---|
ß TCR transgenic mice. Infect. Immun. 65:4094.[Abstract]
and ß block thymocyte development at different stages. Nature 360:225.[Medline]
4 integrin by CD4 T cells is required for their entry into brain parenchyma. J. Exp. Med. 177:57.
production by myelin basic protein-specific T cell clones correlates with encephalitogenicity. Int. Immunol. 2:539.This article has been cited by other articles:
![]() |
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||||
![]() |
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||||
![]() |
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||||
![]() |
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A. M. Ercolini and S. D. Miller Mechanisms of Immunopathology in Murine Models of Central Nervous System Demyelinating Disease J. Immunol., March 15, 2006; 176(6): 3293 - 3298. [Abstract] [Full Text] [PDF] |
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||||
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R. E. Jones, D. Bourdette, N. Moes, A. Vandenbark, A. Zamora, and H. Offner Epitope Spreading Is Not Required for Relapses in Experimental Autoimmune Encephalomyelitis J. Immunol., February 15, 2003; 170(4): 1690 - 1698. [Abstract] [Full Text] [PDF] |
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Y. Uemura, S. Senju, K. Maenaka, L. K. Iwai, S. Fujii, H. Tabata, H. Tsukamoto, S. Hirata, Y.-Z. Chen, and Y. Nishimura Systematic Analysis of the Combinatorial Nature of Epitopes Recognized by TCR Leads to Identification of Mimicry Epitopes for Glutamic Acid Decarboxylase 65-Specific TCRs J. Immunol., January 15, 2003; 170(2): 947 - 960. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Artik, K. Haarhuis, X. Wu, J. Begerow, and E. Gleichmann Tolerance to Nickel: Oral Nickel Administration Induces a High Frequency of Anergic T Cells with Persistent Suppressor Activity J. Immunol., December 15, 2001; 167(12): 6794 - 6803. [Abstract] [Full Text] [PDF] |
||||
![]() |
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||||
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