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Locus Secondary Rearrangement: Role in Tolerance Induction1
,
*
Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, MO 63110;
Laboratoire d’Immunobiologie, Université Denis Diderot, Paris, France; and
Departments of Immunology and Medial Biophysics and Ontario Cancer Institute, University of Toronto, Toronto, Ontario, Canada
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Abstract |
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 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
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knock-in mouse in which the knock-in -chain can be replaced with
endogenous -chain through secondary rearrangement, we show that
immunization of superantigen changes the TCR -chain expression on
peripheral superantigen-specific T cells, induces expression of
recombination-activating genes, and generates DNA double-strand breaks
at the TCR -chain locus. These results suggest that viral
superantigens are capable of inducing peripheral TCR revision. Our
findings thus provide a new perspective on pathogen-immune system
interaction. |
Introduction |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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- and 
-chains and interacts with antigenic peptides
bound to self MHC on the surface of APCs (3). Recent
structural analysis of TCR/MHC/peptide complex demonstrates that both
- and -chains of TCRs interact with the peptide/MHC complex.
Moreover, the complementarity-determining region 3 loops of both chains
generated by the joining of V-J segments for -chain and V-D-J
segments for -chain play a critical role in the specific interaction
with the MHC-bound antigenic peptide (4). These findings
establish the structural basis for the MHC-restricted Ag recognition by
T cells.
A unique set of Ags encoded by virus and bacteria termed
"superantigen" interacts with T cells differently from conventional
Ags. Superantigen binds directly to class II MHC molecules
outside of the peptide-binding groove (5) and
also interacts with TCR -chain (6, 7). In addition, the
specificity of the superantigen-TCR interaction is determined by
the V segments (6). Although TCR -chain has been
shown to influence this interaction (8, 9), its effect
does not involve the complementarity-determining region 3 of the
-chain (9, 10). Thus, superantigens can activate a
large number of T cells that use the same V segment.
In contrast to immunization with conventional Ag that induces immunological memory in vivo, injection of cells bearing superantigen or soluble superantigen into adult mice does not induce immunological memory (11, 12, 13, 14, 15). Rather, administration of superantigen to adult mice induces transient activation and proliferation of superantigen-reactive T cells. However, the number of superantigen-reactive T cells rapidly declines due to activation-induced cell death (AICD)3 in vivo (16). The remaining T cells expressing superantigen-reactive TCR become unresponsive to both in vivo and in vitro stimulation with superantigen (11, 12, 13, 14, 15, 17). Thus, superantigen-T cell interaction has served as a model system for investigating extrathymic tolerance of mature T cells.
In this report, using the 2B4 TCR knock-in (KI) mice in which the
introduced 2B4 TCR -chain gene can be deleted by secondary
rearrangement of the TCR locus (18), we demonstrate that
interaction between mature T cells and viral superantigen in vivo
drastically changes the T cell repertoire. This is due to
recombination-activating gene (RAG) re-expression followed by
re-initiation of TCR locus rearrangements in the
superantigen-activated T cells. Thus, in addition to clonal elimination
and anergy induction, viral superantigens induce T cell tolerance by
altering TCR specificity through the expression of new TCR -chains
on mature T cells.
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Materials and Methods |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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The 2B4 TCR recognizes pigeon cytochrome c
(Cyt/C) epitope presented by I-Ek. The 2B4 KI
mice (18), 2B4 -transgenic mice (19), 2B4
-transgenic (-TG) mice (V3+, reactive to
Mtv-6) (19), 2B4 -KI/-transgenic (KI/-TG) mice
(18), 2B4 double transgenic (-TG) mice
(20), and pigeon Cyt/C-transgenic mice (21)
have been previously described. Due to the class II MHC restriction of
the 2B4 TCR, most experiments focused on CD4 T lymphocytes.
CBA/J (Mtv-6+) and B10.BR
(Mtv-6-) mice were purchased from The Jackson
Laboratory (Bar Harbor, ME). KI/-TG,
RAG-I-/- mice were obtained by crossing
KI/-TG mice with B10.BR, RAG-I-/- mice
(22) (a gift from Dr. E. R. Unanue, Washington
University, St. Louis, MO) and screening for the desired genotype.
Handling of the mice complied with the guidelines of Division of
Comparative Medicine at Washington University.
In vitro T cell stimulation
In vitro T cell stimulation was performed as described (23). In short, 2.5 x 107 splenocytes from responder mice were stimulated with 100 µg/ml moth Cyt/C (Sigma-Aldrich, St. Louis, MO), 2.5 x 107 irradiated CBA/J splenocytes, or 5 µg/ml Con A in 20 ml of DMEM plus 5% FCS. Seven days later, responding cells were recovered and analyzed by flow cytometry. Proliferation assays were performed by culturing 2.5 x 105 responder lymph node cells with 10 µg/ml moth Cyt/C or 2.5 x 105 irradiated CBA/J splenocytes in 200 µl of DMEM plus 5% FCS in 96-well plates. Three days later, the wells were pulsed with 1 µCi [3H]thymidine (Amersham Pharmacia Biotech, Piscataway, NJ) for 6 h, then harvested and counted.
Flow cytometry
Flow cytometry was performed as described (18). In
short, cells were stained with anti-CD4 (GK1.5) and biotinylated
anti-2B4 (A2B4) or anti-V3 (KJ-25), followed by goat
anti-rat FITC (Caltag Laboratories, Burlingame, CA) and
streptavidin-PE (Biomeda, Hayward, CA). Samples were then analyzed on a
FACSCalibur with CellQuest software (BD Biosciences, Franklin
Lakes, NJ).
Immunization
Mice were immunized with 5 x 107 CBA/J splenocytes through the tail vein. Alternatively, mice were immunized with 1 mg/ml moth Cyt/C in CFA (1:1 emulsion; Difco, Detroit, MI) at the base of the tail.
RT-PCR
Total RNA from 107 splenocytes was
collected using an Ultraspec RNA isolation kit (Biotecx, Houston, TX).
Five micrograms of RNA was used to generate cDNA with avian
myeloblastosis virus reverse transcriptase (Roche, Indianapolis,
IN) in a 20-µl reaction, following the manufacturer’s
specifications. RT-PCRs were performed using 0.25 µl of cDNA in a
15-µl reaction with AmpliTaq (Roche), following the manufacturer’s
specifications. For RAG-I, the primers used were
5'-CCAAGCTGCAGACATTCTAGCACTC-3' and 5'-CAACATCTGCCTTCACGTCGATCC-3',
which amplified a 563-bp fragment. The PCR condition used was as
follows: 94°C for 5 min, followed by 35 cycles of 94°C for 30
s, 65°C for 30 s, and 72°C for 30 s. A 7-min incubation
at 72°C was included at the end. For RAG-II PCR, the primers used
were 5'-CACATCCACAAGCAGGAAGTACAC-3' and
5'-GGTTCAGGGACATCTCCTACTAAG-3', which amplified a 472-bp fragment. The
PCR condition was similar to RAG-I PCR, except with the annealing
temperature at 59°C. For -actin PCR, the primers used were
5'-GTGGGCCGCTCTAGGCACCAA-3' and 5'-CTCTTTGATGTCACGCACGATTTC-3', which
amplified a 539-bp fragment. The PCR condition was as follows: 94°C
for 5 min, followed by 30 cycles of 94°C for 45 s, 57°C for
30 s, and 72°C for 1 min, with a 7-min incubation at 72°C at
the end. PCR products were then analyzed on 1% agarose gels.
LM-PCR
DNA from cell lysates (1.5 µg) was ligated to the BW
linker (24) (2 mM) with 2 U T4 ligase (Life Technologies,
Rockville, MD) for 16 h at 16°C and heated to 95°C for 15 min.
The ligated samples were stored at -20°C until use. The first round
of PCR was performed with 300–400 ng of ligated DNA, 15 ng each of
primers BW-1HR (5'-CCGGGAGATCTGAATTCGTG-3') and Igen1
(5'-GTTTAACCGAGGAATGGG-3'), 10 mM Tris-HCl (pH 8.3), 50 mM KCl, 0.5%
Triton X-100, 2 mM MgCl2, and 2.5 U AmpliTaq
(Roche) in a 50-µl reaction. A touch-down and hot-start PCR program
was used: 10 cycles of 30 s denaturation at 94°C, 30 s
annealing at 58°C, and 2 min 30 s elongation at 72°C for
VJ intermediates, then another 10 cycles in which the annealing
temperature was decreased to 57°C and another final 10 cycles at
56°C. The second round of PCR was done under the same conditions with
1 µl of a 1/50 dilution of the first PCR product and 8 ng each of
BW-1HR and the nested primer Igen2 (5'-TTTGAAACACTCTGTCCAGCCC-3'). PCR
products were run on 2% agarose gels. DNA was then transferred to
Hybond-N (Amersham Pharmacia Biotech) by capillary blotting and
cross-linked with standard protocols. Southern blots were probed with
radiolabeled Igen3 (5'-GTCCAGGCTGAGCAAAACACCACCTGGGTAAT-3'), exposed to
PhosphoImager plates (Molecular Dynamics, Sunnyvale, CA) for 4 h,
and analyzed with a Storm PhosphoImager and ImageQuant software
(Molecular Dynamics). Igen1, Igen2, and Igen3 primers all recognize the
Ig H chain intronic enhancer sequence located immediately 3' of the KI
VJ gene that was inserted between the endogenous V and J
locus in the KI mice (18) (see Fig. 5
A).
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Bone marrow cells were obtained from -TG
RAG+ and KI/-TG,
RAG-I-/- mice and depleted of T cells by
anti-Thy1.2 (AT83) and complement treatment. Mixtures of 2 x
106 cells from -TG RAG+
and 8 x 106 cells from KI/-TG,
RAG-I-/- bone marrow were then injected into
each lethally irradiated (950 rad) B10.BR mouse through the tail vein.
Two months later, the reconstituted mice were then immunized and
analyzed as described above.
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Results |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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-TG mice
Lymph node cells from the KI/-TG mice were stimulated in vitro
with either superantigen-bearing CBA/J splenocytes or Cyt/C. The
expression of KI chain on these cells was then examined. Cells from
the KI/-TG mouse exhibited strong in vitro proliferative responses
to both superantigen and Cyt/C (Table I).
Although only 
50% of the naive KI/-TG splenocytes expressed the
KI chain, virtually all cells from Cyt/C-stimulated cultures
expressed the KI chain (Fig. 1). This
enrichment is expected because Cyt/C is the cognate Ag that is
recognized by the KI/-TG TCR. In contrast, only a minor increase in
the percentage of KI+ T cells was observed
after in vitro stimulation with superantigen (Fig. 1). These results
demonstrated that T cells bearing the KI/-TG TCR responded to both
Cyt/C and superantigen, whereas T cells expressing the transgenic TCR
-chain alone responded to superantigen but not to Cyt/C.
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chain expression in KI/-TG mice
KI/-TG mice were immunized with superantigen-bearing CBA/J
splenocytes in vivo. Cells from the immunized mice were tested for
their in vitro Ag-specific responses. As shown in Table I
, cells from
the immunized mice failed to respond to either Cyt/C or superantigen.
However, these cells exhibited normal responses to Con A (Table I).
Furthermore, the Ag-nonresponsive state was also induced in -TG
mice with the same immunization (Table I).
When the expression of KI chain on the
lymph node T cells was examined, nonimmunized KI/-TG mice contained
50% KI+ T cells in the CD4 T cell
population. However, in the immunized KI/-TG mice, the fraction of
the KI+ CD4 T cells decreased gradually after
immunization (22% 2 wk after immunization and 5% 3 wk after
immunization; Fig. 2A, solid line). This decrease persisted
for an extended period of time and reached as low as 2% at 8 wk
postimmunization (Table II). It should be
noted that the expression of TCR -chain on the same cells showed no
significant change, indicating that surface TCR expression was not
down-regulated (Fig. 2A, dotted line). When cells from
similarly tolerized -TG mice were analyzed, there was only a
slight decrease in the percentage of transgenic -chain-expressing T
cells (Fig. 2B). These results thus suggested that
immunization of KI/-TG mice with splenocytes bearing viral
superantigen changed the TCR repertoire significantly, whereas the same
immunization had minimum effect on the TCR repertoire in -TG
mice. However, in both mouse lines, peripheral T cells were rendered
nonresponsive to superantigen as well as to their cognate Ag, Cyt/C
(Table I).
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chain expression
We immunized the KI/-TG mice with Cyt/C to test whether the
tolerance induction and the repertoire change were the results of
strong Ag activation followed by AICD of T cells bearing the
Ag-responsive TCR. KI/-TG mice were immunized with Cyt/C in CFA, a
protocol that induced significant activation of the draining lymph node
cells that was similar to superantigen immunization. Two weeks later, T
cells from the draining lymph nodes were tested for their in vitro
responses to superantigen and Cyt/C. In contrast to mice immunized with
superantigen-bearing splenocytes, T cells from these Cyt/C-immunized
mice exhibited strong proliferative responses to superantigen as well
as to Cyt/C (Table III). Analysis of CD4
T cells from the Cyt/C-immunized mice showed no significant decrease in
the expression of the KI chain (Fig. 3). We also immunized KI/-TG mice with
either splenocytes from Cyt/C-transgenic mice or soluble Cyt/C and
observed no sign of tolerance induction or receptor revision, although
neither immunization induced massive activation of the lymph node
cells. These results demonstrated that activation of KI/-TG T cells
by Cyt/C neither induced a state of Ag nonresponsiveness nor changed
the peripheral TCR repertoire. Thus, the induction of the
Ag-nonresponsive state in both KI/-TG and -TG mice, as well as
the TCR repertoire change in KI/-TG mice, was a unique feature of
the in vivo stimulation with superantigen-bearing splenocytes.
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We previously demonstrated that the KI TCR gene and transgenic
TCR gene differed in their susceptibility to RAG-mediated secondary
rearrangement in the thymus (18). However, after
superantigen immunization, the thymic cellularity of the KI/-TG mice
decreased dramatically from 60 x 106 to
15 x 106 cells and did not recover for
more than 2 wk. Thymic contribution to the peripheral repertoire change
should be minimal. Therefore, we tested whether the decreased
percentage of KI+ CD4 T cells was mediated by
peripheral TCR locus secondary rearrangement. RAG-I/II gene
expression was examined in peripheral T cells from
superantigen-immunized KI/-TG mice by RT-PCR. As shown in Fig. 4A, RAG-I/II transcripts could
be detected in lymph node cells from superantigen-immunized mice, but
not in the nonimmunized controls. When the same lymph node cells were
treated with anti-Thy1.2 Ab and rabbit complement, the RAG-I/II
gene transcripts were no longer detectable (Fig. 4B),
suggesting that the RAG-I/II genes were indeed transcribed in the T
cell compartment of superantigen-immunized KI/-TG mice.
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locus, leaving a blunt-end DNA fragment that
contains the recombination signal sequence at both ends. Presence of
this linear DNA is often used as an indication of recent V(D)J
rearrangements (24). Linker-mediated PCR (LM-PCR) was used
to detect the presence of this linear DNA intermediate in
superantigen-immunized KI/-TG mice. As shown in Fig. 5, secondary rearrangement intermediate
containing the KI TCR gene was readily detected at 2 and 3 wk after
superantigen immunization, indicating the presence of peripheral TCR
rearrangement.
We further examined the relationship between RAG gene expression and
the decrease of KI+ T cells in
superantigen-immunized KI/-TG mice through bone marrow chimera
experiments. Mixed bone marrow chimeric mice were established by
reconstituting lethally irradiated B10.BR mice with a mixture of
T-depleted bone marrow cells from -TG RAG+
mice and KI/-TG RAG-I-/- mice. This
experiment was designed so that the preimmunized peripheral T cells in
the reconstituted recipient would contain both a
KI+RAG-/- population
and a KI-RAG+
population, similar to the preimmunized KI/-TG mice (except for the
RAG gene expression in the KI+ population).
This allowed us to compare the fate between the
KI+RAG+ population in
KI/-TG mice and the
KI+RAG-/- population
in the bone marrow recipient based solely on their difference in RAG
gene expression. The reconstituted chimeric mice were immunized with
superantigen-bearing splenocytes as in previous experiments. KI
chain expression on the peripheral lymph node cells of the immunized
chimeric mice was examined at 2 wk postimmunization. In these chimeric
mice, the percentage of KI+ T cells was lower
than in normal KI/-TG mice before immunization (Fig. 6). However, there was no decrease in
KI+ T cells after immunization (Fig. 6). Thus,
in the absence of RAG gene activity, superantigen was not able to
change the peripheral T cell repertoire through modification of TCR
-chain.
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Discussion |
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TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
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-chains, followed by a
long-lasting superantigen-nonresponsive state (11, 12, 13, 14, 15, 17). This Ag-specific nonresponsiveness has been shown to be
mediated by both the deletion of the majority of superantigen-activated
T cells and the induction of anergy in T cells that still bear the
superantigen-reactive TCR (11, 12, 13, 14, 15, 17). This system has
been extensively studied as a model for the induction of Ag-specific T
cell tolerance (25, 26, 27). However, the precise biochemical
and molecular mechanisms by which superantigen induces T cell tolerance
are still poorly understood. In this report, using the 2B4 TCR
-chain KI mice, we have demonstrated a novel mechanism used by
superantigen to induce T cell tolerance.
We have shown in this study that in vivo immunization of transgenic
mice expressing a Cyt/C-specific,
I-Ek-restricted, and Mtv-1-, -3-, -6-, -13-,
-27-, and -44-reactive TCR (V3+) (28, 29) with Mtv-6+ CBA/J splenocytes resulted
in a drastic decrease of both Cyt/C- and Mtv-6-specific T cell
responses. In -TG mice, this T cell tolerance was induced without
a significant loss of the T cells expressing the Ag-specific TCR,
indicating that T cell anergy is a dominant mechanism for the lack of
Ag responsiveness (11, 14). In contrast, in the KI/-TG
mice, a gradual loss of T cells bearing the KI chain was observed,
suggesting that clonal deletion of the Ag-reactive T cells takes place
after superantigen immunization. However, this decrease of T cells
expressing the Ag-reactive TCR was not mediated by the death of
superantigen-reactive T cells, but rather through a change in TCR
expression.
The phenomenon of TCR expression change through secondary rearrangement
of the TCR -chain has been shown in our previous study using the KI
mouse (18). Fink and coworkers (30, 31) also
demonstrated similar changes in TCR expression on mature peripheral T
cells using TCR -chain transgenic mice. In the current study, we
detected reactivation of RAG gene expression and RAG-mediated TCR
locus DNA double-strand breaks in the lymph node cells from
superantigen-immunized KI/-TG mice. It should be noted that the
presence of RAG-I/II transcripts varied among identically immunized
mice, and in some mice we failed to detect the transcripts (data not
shown), which is similar to the findings of McMahan et al.
(31). Regardless, this combination of results strongly
suggests that immunization of KI/-TG mice with superantigen-bearing
CBA/J splenocytes induces TCR -chain secondary rearrangement in
mature peripheral T cells. Our finding that there was no decreased
expression of the KI chain in T cells lacking functional RAG-I gene
upon superantigen immunization further supports this notion. Thus,
superantigen activation induces TCR -chain rearrangement and leads
to the expression of new -chains. T cells expressing new TCRs
that are not capable of interacting with superantigen can then be
spared from cell death or anergy induction. At this point, we do not
know to what extent this mechanism contributes to tolerance induction,
in addition to the well-characterized mechanism of AICD
(32) and anergy induction (11, 14, 17, 33).
However, our results, together with those published by Fink and
coworkers (30, 31), strongly suggest that changes in TCR
repertoire in mature T cells may be a common feature of the immune
response to various superantigens.
This peripheral receptor revision induced by superantigen is readily
detectable in the KI/-TG mice because the introduced KI gene is
susceptible to secondary rearrangement, and the disappearance of the
KI chain on the T cell surface can be used as a marker for the
presence of secondary rearrangement (18, 34). In contrast,
in -TG mice, although TCR -chain secondary rearrangement may
occur, the persistent presence of transgenic TCR -chain makes it
difficult to detect any change in TCR -chain expression.
Potentially, the newly generated TCR -chain may associate with the
transgenic -chain better than the transgenic TCR -chain and can
be detected as a loss of transgenic -chain expression on the surface
(35, 36, 37). However, this type of competition is likely to
be very inefficient, because we observed little change in the numbers
of T cells expressing the transgenic -chain in
superantigen-immunized -TG mice. Similar inefficient competition
between endogenous and transgenic -chains may also play a role in
the gradual decrease of the transgenic V5-positive T cells, as
reported by Fink and coworkers (30, 31), because the
change in V expression can only occur with competition, but not by
deletion of preexisting TCR -chain, whether endogenous or
transgenic.
In our model system, immunization in vivo with the conventional Ag,
Cyt/C, induces neither detectable receptor revision nor tolerance. It
should be noted that the magnitude of the T cell response to both Cyt/C
and superantigen in vitro is similar, and the frequency of T cells
capable of responding to Cyt/C is 50% of the CD4 T cell population.
Therefore, it is unlikely that the difference in the extent of the T
cell response to these two Ags accounts for the different outcomes.
Thus, our findings, in agreement with previous reports (11, 12, 13, 14, 15, 17), demonstrate that immunization with superantigen and
conventional Ag results in two different biological outcomes from the
same TCR. It has been shown that stimulation of T cells with
superantigen induces qualitatively different biochemical events from
what is induced by conventional Ags (38, 39, 40). However, the
relationship between these biochemical differences and the different
biological outcomes, namely tolerance induction with superantigen and
memory formation with conventional Ag, has not yet been established.
Further studies are required to elucidate the mechanisms by which in
vivo immunization with superantigen and conventional Ag elicit two
different outcomes in the same Ag-reactive T cell population.
The biological significance of superantigen-induced TCR -chain
secondary rearrangement and the change in the peripheral TCR repertoire
is currently difficult to determine. However, in the case of Mtv, it
has been shown that activation of virus-infected B cells by T cells via
superantigen expression is required for successful infectious cycles
and, at the same time, virus infection down-regulates virus-specific
and protective immune responses. This host-pathogen interaction is
proposed to be mediated through the superantigen-induced transient
activation of T and B cells and the subsequent induction of cell death
and anergy (27, 41). However, the demonstration of
receptor revision in this report provides a new dimension in this
interaction. Initial superantigen activation may activate T cells and
induce RAG gene re-expression, leading to the secondary rearrangement
of TCR -chains in the periphery. T cells that lose superantigen
reactivity due to the new TCR -chain can then survive, whereas T
cells that still express the superantigen-reactive TCR may be deleted
by AICD. This selection, although not mutually exclusive with anergy
induction in T cells that express the superantigen-reactive TCR, would
induce a superantigen-nonresponsive state.
This change in TCR expression can also be used to alter the specificity of the T cells and the protective T cell immune responses against conventional viral Ags. It has been shown that various viruses, bacteria, and parasites express superantigen-like activity and induce polyclonal activation of T and B lymphocytes (42, 43, 44, 45). In a majority of cases, this polyclonal activation of lymphocytes was accompanied by the absence of protective and pathogen-specific immune responses. In view of our findings in this report, it is possible that induction of lymphocyte receptor revision by viral superantigens is not a rare phenomenon, but rather a mechanism commonly used by the pathogens to change the specificities of the activated immune cells and evade host protective immune responses. Further analysis of pathogen-T cell interaction in vivo would be necessary to test this notion.
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Acknowledgments |
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Footnotes |
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2 Address correspondence and reprint requests to Dr. Osami Kanagawa, Department of Pathology and Immunology, Campus Box 8118, Washington University School of Medicine, St. Louis, MO 63110. E-mail address: kanagawa{at}pathology.wustl.edu
3 Abbreviations used in this paper: AICD, activation-induced cell death; KI, knock-in; RAG, recombination-activating gene; Cyt/C, cytochrome c; -TG, 2B4 -transgenic; KI/-TG, 2B4 -KI/-transgenic; -TG, 2B4 double transgenic; LM-PCR, linker-mediated PCR.
Received for publication September 17, 2001. Accepted for publication January 25, 2002.
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References |
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region of the T cell receptor: Mls and the bacterial toxic mitogens. Adv. Immunol. 50:1.[Medline]
use predicts reactivity and tolerance to Mlsa-encoded antigens. Nature 332:40.[Medline]
expression on Mlsa superantigen-specific T cell responses. J. Exp. Med. 175:1405.-chain junctional region structural characteristics. J. Immunol. 156:1865.[Abstract]
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6+ T lymphocytes on immunizing Mls-1b mice with Mls-1a expressing cells. Nature 339:541.[Medline]
8+ T cells by staphylococcal enterotoxin B. J. Exp. Med. 172:1091.8+,CD4+ T cells in Staphylococcus enterotoxin B-primed mice. J. Exp. Med. 172:1065.8+ CD4+ T cells in mice tolerant to Staphylococcus aureus enterotoxin B. Nature 349:245.[Medline]
8+ peripheral T cells responding to staphylococcal enterotoxin B in vivo. Eur. J. Immunol. 21:1963.[Medline]
-J segment by secondary rearrangement in the thymus: role of continuous rearrangement of TCR chain gene and positive selection in the T cell repertoire formation. Proc. Natl. Acad. Sci. USA 95:11834.-chain genes in transgenic mice. Mol. Cell. Biol. 8:5459.5 T cell antigen receptor. J. Immunol. 149:9.[Abstract]
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locus: role of secondary rearrangement in thymic selection. J. Immunol. 166:2597. genes but uses one heterodimer for allorecognition and self MHC-restricted antigen recognition. Cell 55:49.[Medline]
-gene rearrangements found in both the A10 and BM 3.3 T cell clones give rise to an chain which can contribute to the constitution of a surface-expressed dimer. Int. Immunol. 3:719. and T cell receptor alleles. Cell 69:529.[Medline]
TCR repertoire of CD8+ T cells in murine Trypanosoma cruzi infection. Int. Immunol. 6:387.This article has been cited by other articles:
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  D. Zehn, M. J. Bevan, and P. J. Fink Cutting Edge: TCR Revision Affects Predominantly Foxp3 Cells and Skews Them toward the Th17 Lineage J. Immunol., November 1, 2007; 179(9): 5653 - 5657. [Abstract] [Full Text] [PDF]
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M. Takase, E. M. Kanagawa, and O. Kanagawa Age-Dependent TCR Revision Mediated by Interaction between {alpha}beta TCR and Self-Antigens J. Immunol., August 15, 2007; 179(4): 2163 - 2169. [Abstract] [Full Text] [PDF]
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C. J. Cooper, G. L. Turk, M. Sun, A. G. Farr, and P. J. Fink Cutting Edge: TCR Revision Occurs in Germinal Centers J. Immunol., December 1, 2004; 173(11): 6532 - 6536. [Abstract] [Full Text] [PDF]
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M. Ali, M. Weinreich, S. Balcaitis, C. J. Cooper, and P. J. Fink Differential Regulation of Peripheral CD4+ T Cell Tolerance Induced by Deletion and TCR Revision J. Immunol., December 1, 2003; 171(11): 6290 - 6296. [Abstract] [Full Text] [PDF]
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C. J. Cooper, M. T. Orr, C. J. McMahan, and P. J. Fink T Cell Receptor Revision Does Not Solely Target Recent Thymic Emigrants J. Immunol., July 1, 2003; 171(1): 226 - 233. [Abstract] [Full Text] [PDF]
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 P. Serra, A. Amrani, B. Han, J. Yamanouchi, S. J. Thiessen, and P. Santamaria RAG-dependent peripheral T cell receptor diversification in CD8+ T lymphocytes PNAS, November 26, 2002; 99(24): 15566 - 15571. [Abstract] [Full Text] [PDF]
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| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
, 2B4 KI V
, Ig H chain
intronic enhancer; 
, recombination signal sequence; 
, endogenous
J
, primers for LM-PCR; 
, probe for Southern
hybridization. B, LM-PCR was performed on lymph node
cells from superantigen-immunized KI/
