| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53326
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
ßTCR heterodimers. Similar experiments with CD4 and CD8 knockout
donor BM suggested that the immunoregulatory
Thy1+ßTCR+ cells consisted of two
subpopulations: a CD4+CD8- subpopulation and a
CD4-CD8- subpopulation. Together, these
results show that thymus-derived,
Thy1+ßTCR+ donor cells generated early
after allogeneic BMT suppress the graft-vs-host reactivity of T cells
given as DLI. These cells may mediate dominant peripheral tolerance
after allogeneic BMT. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Experimental data from our laboratory indicated that the generation of alloreactive Th cells was inhibited following DLI in murine MHC-matched bone marrow (BM) chimeras (4). Mechanisms responsible for decreased GVHD following DLI might include 1) avoidance of the "cytokine storm" induced by pretransplant conditioning (5, 6, 7); 2) presence of fewer host-type APC due to the switch in hematopoiesis from host to donor (8); and/or 3) induction of immunosuppressive regulatory cells in the newly developing immune system (9, 10, 11).
While examining mechanisms for decreased graft-vs-host (GVH) reactivity
following DLI, we serendipitously observed that administration of a
Thy1 allele-specific mAb against donor BM-derived T cells increased the
severity of GVHD in full MHC-mismatched murine recipients given DLI.
Similar results were obtained in a MHC-matched model. The results led
us to test the hypothesis that immunoregulatory
Thy1+ cells of donor origin developed early
posttransplant and suppressed the GVH reactivity of T cells given as
DLI. Using thymectomized hosts as well as marrow from donors lacking
ßTCR+, CD4+, or
CD8+ T cells, we determined that the
immunoregulatory cell population was 1)
ßTCR+CD4+/-CD8-;
2) derived from the donor BM; and 3) educated in the repopulating host
thymus. The origin and regulatory properties of this population suggest
that dominant peripheral tolerance contributes to the suppression of
GVH reactivity after DLI therapy.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
C57BL/6 (H-2b; Thy1.2+), B6.PL-Thy1a (H-2b; Thy1.1+), B10.BR (H-2k; Thy1.2+), AKR (H-2k; Thy1.1+), C57BL/6-Cd4tm1MAK(CD4 knockout (ko)), C57BL/6-Cd8atm1MAK (CD8 ko), and C57BL/6-Tcrbtm1Mom (TCR ß-chain ko) mice (4–6-wk old) were purchased from The Jackson Laboratory (Bar Harbor, ME). B10.BR-Thy1.1 congenic mice were obtained from Bruce Blazar (University of Minnesota, Minneapolis, MN) and bred at the Medical College of Wisconsin (Milwaukee, WI). All mice were housed in the Medical College of Wisconsin’s American Association for the Accreditation of Laboratory Animal Care approved Animal Resource Center.
Bone marrow transplantation and DLI therapy
Normal or surgically thymectomized (Tx) AKR recipient mice were preconditioned with a lethal dose of 1100 cGy of total body irradiation 2–24 h before BMT. BM cells were obtained from healthy C57BL/6, C57BL/6 transgenic (CD4 ko, CD8 ko, or ßTCR ko), or B10.BR donor mice by flushing the femurs and tibias with DMEM (Life Technologies, Grand Island, NY). The irradiated AKR recipients were injected i.v. with either 107 non-T cell-depleted or 107 T cell-depleted (TCD) donor BM cells. For T cell depletion, the BM cells were treated with anti-Thy1.2 mAb (clone 30-H12; obtained from the American Type Culture Collection, Manassas, VA) and Low-Tox-M complement (Accurate Chemical and Scientific, Westbury, CT). Some chimeras were treated with i.p. injections of anti-Thy1.2 mAb before DLI. Anti-Thy1.2 mAb was used in the form of bioreactor-derived culture supernatant or partially purified from bioreactor culture supernatants by ammonium sulfate precipitation. For DLI, 3 x 107 B10.BR, congenic B10.BR-Thy1.1, C57BL/6, or congenic B6.PL-Thy1a spleen cells were injected i.v. at day 21 or 28 after BMT.
Flow cytometric analysis
Spleen cells and purified T cells were stained with various combinations of anti-Thy1.2 mAb (clone 30-H21; FITC-conjugated), anti-H-2Kb mAb (clone AF6-88.5; FITC-conjugated), anti-Thy1.1 mAb (clone OX-7; FITC- or PE-conjugated), anti-CD4 mAb (clone GK1.5; PE-conjugated; PharMingen, San Diego, CA), and anti-CD8 (clone CT-CD8a; PE-conjugated; Caltag, Burlingame, CA). Two-color analysis was performed using a Becton Dickinson FACScan flow cytometer (San Jose, CA).
Limiting dilution analysis assays
Limiting dilution analysis (LDA) assays were used to determine Th cell and CTL precursor frequencies as described previously with minor modifications (4). Briefly, the spleen cells from five or six individual BM chimeras given DLI 7 days previously were isolated and pooled. The cells were first treated with anti-Thy1.2 mAb and complement to eliminate thymus-derived donor T cells. Responder Thy1.1+ T cells (i.e., donor cells from the DLI) were then enriched by positive selection using a MACS cell separator with a combination of anti-CD4-conjugated and anti-CD8-conjugated microbeads. Enrichment of H-2b/Thy1.1+ cells was confirmed by two-color flow cytometric analysis. To assess alloreactive Th cell frequencies, the Thy1.1-enriched responder cells were cocultured at 10 different concentrations in 24-replicate U-bottom microwells with 3 x 104 irradiated (3000 cGy) AKR dendritic cells and 105 irradiated (700 cGy) AKR B cells (200 µl/well total volume). Dendritic cells and B cells were enriched by MACS cell separation using CD11c-conjugated or B220-conjugated microbeads, respectively. After 4 days of culture in a 37°C, 10% CO2 incubator, 150 µl of culture supernatant was removed from each well and transferred to a new microwell plate containing 2500 IL-2-dependent SAC 9.12 (12) indicator cells and 1 µCi of [3H]thymidine. The plates were cultured for an additional 18–24 h, and thymidine uptake was assessed. Spontaneous thymidine uptake was determined from the supernatants of 24 wells that had contained stimulator cells only.
To assess CTL frequencies, various numbers of Thy1.1-enriched responder cells were cocultured in U-bottom microwells (24 wells per responder concentration) with 3 x 104 irradiated (3000 cGy) AKR dendritic cells and 2 x 105 irradiated (700 cGy) AKR B cells. Con A-stimulated rat spleen cell-conditioned medium was added to the wells at a concentration of 50% (v/v) (200 µl/well total volume). The plates were cultured for 8 days. On day 8, 50 µl of culture supernatant was removed from each well and replaced with 50 µl of 51Cr-labeled AKR Con A-stimulated lymphoblast targets (5000/well). 51Cr release was assessed after a 3.5-h incubation. Spontaneous and maximum 51Cr release values were determined from 24 wells containing target cells plus stimulators only or detergent (2.5% 7x detergent; Flow Laboratories, McLean, VA), respectively.
Individual wells in the Th cell and CTL assays were scored as positive
when experimental values (cpm [3H]thymidine
uptake or percent specific 51Cr release) exceeded
the spontaneous control values by at least 3 SDs. The frequencies of
alloreactive Th cells and CTL was calculated by
2 minimization as described by Taswell
(13).
Statistics
Kaplan-Meier survival curves were compared using log-rank statistical analysis. The Student t test was used to analyze the percentages and numbers of donor T cells in the spleens of BMT chimeras given DLI.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
MHC-matched BM chimeras (B10.BR-into-AKR) given DLI at 21 days
after marrow transplantation survived without GVHD (Fig. 1
A). In contrast,
MHC-mismatched (C57BL/6-into-AKR) chimeras developed severe GVHD after
DLI, which resulted in 67% GVH-associated mortality (Fig. 1A). GVHD in the MHC-mismatched chimeras was reflected by a
sharp loss in body weight within the first week after donor cell
infusion (Fig. 1B), followed by continued body weight loss
during the remainder of the experiment. These results confirmed earlier
work from our laboratory (4, 14, 15).
|
1–3%) augmented the
alloreactivity of donor T cells contained in the DLI inoculum, thereby
increasing the severity of DLI-induced GVHD. We used two different
experimental approaches to test this hypothesis. First, we depleted the
donor BM of T cells ex vivo with anti-Thy1 mAb and complement
before BMT. If mature donor T cells in the marrow graft were promoting
GVH reactivity of T cells given as DLI, we speculated that ex vivo
depletion of the donor T cells would result in less severe GVHD after
DLI. AKR recipients were transplanted with untreated or TCD C57BL/6 BM
and then randomized to receive no further treatment (BM controls) or to
be given DLI at 21 days after BMT (Fig. 2). Control mice given T-depleted or
nondepleted BM alone (no DLI) did not develop clinically evident GVHD
and maintained their body weight after an initial loss attributed to
the total body irradiation conditioning. Both groups of mice given DLI
on day 21 developed GVHD as indicated by increased weight loss and
mortality following infusion. Thus, ex vivo T cell depletion of the
marrow graft had no effect on GVHD-related mortality and did not
support the working hypothesis.
|
A, chimeras pretreated with
anti-Thy1.2 mAb in vivo showed accelerated and increased
GVHD-associated mortality after DLI as compared with non-Ab-treated
chimeras. Mice in both experimental groups had a sharp loss in body
weight following DLI (Fig. 3B) and developed clinically
evident signs of GVHD including diarrhea and ruffled fur; however,
clinical symptoms in the anti-Thy1.2-treated chimeras were more
severe. Control mice given MHC-mismatched BM alone (no DLI) survived
without any clinical evidence of GVHD and showed only a transient 10%
body weight loss between 3 and 5 wk posttransplant. All BM-only control
mice treated with anti-Thy1.2 survived >90 days and did not show
any significant body weight loss, indicating that the mAb treatment
alone was not toxic. Taken together, these results contradicted our
original hypothesis and suggested instead that a population of donor
BM-derived Thy1.2+ cells suppressed, rather than
increased, the severity of GVHD after DLI.
|
A, 97%
(30/31) of chimeras treated with anti-Thy1.2 mAb died within 2 wk
after DLI. Death was paralleled by a significant decrease in body
weight (Fig. 4B). Ex vivo T depletion of the BM inoculum had
no impact on the timing of mortality. Untreated BM chimeras had a
significantly higher survival rate than the anti-Thy1.2-treated
chimeras, and body weight loss was decreased. Differences in
GVH-associated mortality between the BM chimeras transplanted with
nondepleted or TCD BM were not significant (Fig. 4A),
confirming the results of Fig. 2
. These data supported the hypothesis
that a donor marrow-derived population of Thy1+
"immunoregulatory" cells suppressed GVHD following DLI in
MHC-mismatched BM chimeras. The suppressive effect of the cells was
more pronounced at 28 days than at 21 days posttransplant, but, in both
instances, their removal resulted in intensified GVHD after
DLI.
|
The presence of Thy1+ regulatory
cells was examined in an established MHC-matched BMT model
(B10.BR-into-AKR) to determine whether the observations made in the
MHC-mismatched combination were model specific. AKR recipients,
transplanted with non-T-depleted B10.BR BM, were treated with
anti-Thy1.2 mAb on days 10, 12, 17, and 19 posttransplant. DLI with
B10.BR-Thy1.1 congenic spleen cells was given at 21 days after BMT.
Control non-Ab-treated BM chimeras given DLI did not develop lethal
GVHD and maintained their body weights after DLI (Fig. 5). In contrast, chimeras treated with
anti-Thy1.2 mAb developed GVHD after DLI, resulting in 75%
mortality (Fig. 5A). GVH reactivity in Ab-treated chimeras
was accompanied by a significant loss of body weight (Fig. 5B). These results indicated that suppression of
DLI-mediated GVH reactivity by donor-derived
Thy1+ immunoregulatory cells was a general
phenomenon and not model dependent.
|
BM chimeras pretreated with anti-Thy1.2 mAb developed
significantly more severe GVHD after DLI, as indicated by increased
mortality and body weight loss. To determine whether the frequencies of
host-reactive CTL and Th cells increased as a result of depletion of
the immunoregulatory Thy1+ cells, spleen cells
were collected from MHC-mismatched BM chimeras 7 days after DLI. Flow
cytometric and LDA assays were performed. Thy1.1+
T cells in the DLI inoculum could be distinguished from residual host T
cells by differential MHC class I expression
(H-2Kb). As shown in Table I, the anti-Thy1.2-treated chimeras
had significantly increased percentages and absolute numbers of splenic
T cells derived from the DLI inoculum as compared with non-mAb-treated
controls. Infused CD8+ T cells accounted for the
majority of this increase (data not shown). Results of LDA assays
performed on splenocyte preparations from anti-Thy1.2-treated
chimeras 7 days after DLI indicated that significantly greater numbers
of both anti-host-reactive CTL and Th cells were present as
compared with the untreated BM chimeras (Table II). Anti-Thy1.2-treated chimeras had
15-fold and 3-fold increases in anti-host-reactive CTL and Th
cells, respectively. Together, the data in Tables I and II provided
further evidence that donor marrow-derived Thy1+
cells down-regulated anti-host (GVHD) alloreactivity after
DLI.
|
|
Because pretransplant depletion of T cells had no effect on
DLI-induced GVHD, but in vivo depletion of Thy1+
cells increased GVHD after DLI, we hypothesized that the BM-derived
immunoregulatory cells were generated de novo in the repopulating host
thymus. Emigration of Thy1.2+ T cells from the
donor-reconstituted host thymus begins 14 days after BMT (B.
Johnson, unpublished data). To prove that the immunoregulatory donor
cells were derived from the repopulated host thymus after BMT, AKR
recipients were thymectomized 2 wk before BMT. Tx or normal euthymic
AKR recipients were transplanted with T-depleted C57BL/6 BM and then
given DLI at day 28 posttransplant. Separate groups of Tx and normal
recipients were treated with anti-Thy1.2 mAb on days 24 and 26
after BMT and then given DLI on day 28. All nonthymectomized chimeras
treated with anti-Thy1.2 mAb died from severe GVHD within 16 days
after DLI (Fig. 6A). The Tx
chimeras with or without anti-Thy1.2 mAb treatment developed severe
GVHD after DLI. The kinetics of body weight loss and mortality
paralleled that of the anti-Thy1.2-treated nonthymectomized group
(Fig. 6). These results demonstrated that an intact thymus was required
for generation of the donor-derived Thy1+
immunoregulatory cells. The nonthymectomized chimeras given DLI had an
overall survival rate of 78% and maintained their average body weight
near pretransplant levels (Fig. 6).
|
ßTCR+CD4+CD8- and
ßTCR+CD4-CD8-
Experiments were designed to further characterize the
donor-derived host-educated Thy1+
immunoregulatory cells. The first set of experiments addressed whether
the immunoregulatory cells coexpressed ß heterodimers of the TCR
by using mice with a ko mutation for the ß-chain of the TCR as BM
donors. These mice do not produce T cells expressing ßTCR
heterodimers (16). AKR recipients were transplanted with
TCD BM from normal C57BL/6 mice or TCD BM from C57BL/6 ßTCR ko mice.
If the immunoregulatory cells were ßTCR+,
the severity of DLI-induced GVHD in chimeras transplanted with ßTCR
ko BM should be comparable to that of chimeras treated with
anti-Thy1.2 mAb. The transplanted chimeras were randomized to be
treated or not treated with anti-Thy1.2 mAb on days 24 and 26
posttransplant. DLI was administered on day 28 posttransplant. Groups
of chimeras given BM alone served as GVH-negative controls.
Non-Ab-treated chimeras transplanted with normal BM developed only mild
GVHD after DLI and had a 70% survival rate (Fig. 7). In contrast, chimeras transplanted
with ßTCR ko BM developed severe GVHD, and the kinetics of mortality
and body weight loss (data not shown) was similar to the groups treated
with anti-Thy1.2 mAb. As described previously, C57BL/6-into-AKR
chimeras pretreated with anti-Thy1.2 mAb rapidly developed severe
and lethal GVHD following DLI. These results indicated that the donor
Thy1+ immunoregulatory cells were
ßTCR+.
|
ßTCR+
immunoregulatory donor cells belonged to either the CD4 or CD8 T cell
subset. For these experiments, mice with ko mutations for CD4 or CD8
were used as BM donors. AKR recipients were transplanted with
T-depleted BM from either normal, CD4 ko, or CD8 ko C57BL/6 mice. The
transplanted recipients were again randomized to be treated or not
treated with anti-Thy1.2 mAb on days 24 and 26 posttransplant,
followed by DLI on day 28 after BMT. A group of recipients given normal
T-depleted BM only was included as a GVH-negative control. Mice in the
experimental groups treated with anti-Thy1.2 mAb (filled symbols in
Fig. 8) developed severe and lethal GVHD
after DLI regardless of the BM source. Recipients of normal BM and DLI
(but no mAb) lost body weight after DLI (data not shown), but there
were no deaths (Fig. 8), indicating that GVH reactivity was relatively
mild when the immunoregulatory cells were not depleted. Chimeras
transplanted with CD8 ko BM also developed only mild GVHD after DLI as
indicated by low mortality (18%) and modest weight loss. Survival of
these chimeras was not significantly different from that of the
GVH-negative controls (p > 0.05). These
results indicate that the
Thy1+ßTCR+
immunoregulatory cells do not belong to the CD8 T subset.
|
). However, although survival of these chimeras was
significantly worse than that of AKR hosts given normal BM and DLI
(p < 0.00008), the kinetics of death was
delayed as compared with the anti-Thy1.2-treated chimeras, and
median survival time was longer by 20 days. Because BMT with CD4 ko
BM did not completely eliminate the suppression of DLI-induced GVHD, we
speculate that there may be two subpopulations of
Thy1+ßTCR+
immunoregulatory cells: one of which is CD4+ and
the other CD4-. |
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
of this paper confirm our previous report
(15) that DLI given 21 days after BMT induced lethal GVHD
in MHC-mismatched recipients but did not induce GVHD in MHC-matched
recipients. Increased immunogenetic disparity in the MHC-mismatched
model (i.e., greater alloreactivity) may contribute to the disparate
results in these two models. We hypothesized that because of the higher
frequency of alloreactive T cells in the MHC-mismatched BMT model, the
small numbers of mature T cells in non-T-depleted donor BM intensified
GVH reactivity after DLI in MHC-mismatched BM chimeras. This hypothesis
was based on our observation that although the number of T cells in the
MHC-mismatched marrow grafts were below the threshold needed to induce
acute GVHD, transient body weight loss (5–15%) often occurred 3–6 wk
after BMT (for examples, see Figs. 1B and 3B). In
contrast, significant body weight loss did not occur in MHC-matched
recipients given BM only (Fig. 1B). The early and transient
body weight loss in MHC-mismatched recipients was eliminated if the
donor BM was depleted of mature T cells, indicating that T cells were
involved. Two different strategies were used to address our hypothesis:
1) ex vivo depletion of donor T cells from the BM graft and 2) in vivo
depletion of BM-derived donor T cells with anti-Thy1 mAb. Ex vivo
depletion of T cells from the BM graft had no effect on the severity of
GVHD after DLI (Fig. 2). To our surprise, when recipient mice were
treated in vivo with anti-Thy1.2 mAb after BM but before DLI,
GVH-associated mortality and body weight loss were significantly more
severe when DLI therapy was given (Figs. 3 and 4). This phenomenon was
not unique to the MHC-mismatched donor-host combination. Similar
results were observed in an MHC-matched BMT model (Fig. 5). These
serendipitous results led us to hypothesize that a population of
Thy1+ donor cells developed early after BMT and
suppressed GVH reactivity of the infused donor cells. Subsequent
studies revealed that the immunoregulatory Thy1+
cells coexpressed ßTCR heterodimers and that an intact host thymus
was required for their development (Figs. 6 and 7). Results from
experiments using CD4 and CD8 ko mice as BM donors established that
ßTCR+CD4+CD8-
and
ßTCR+CD4-CD8-
regulatory cells played key roles in suppressing GVH reactivity after
DLI (Fig. 8). Immunoregulatory CD4+ cells have been shown to be involved in BMT tolerance (17), solid organ allograft tolerance (18), and skin graft tolerance (19, 20). There are numerous reports describing the role of CD4+CD8- immunoregulatory cells in various models of autoimmunity (reviewed in Ref. 21). Typically, these cells have been found to express the CD45RB molecule at low levels, which is a characteristic of memory T cells. Unlike typical memory T cells, these cells fail to proliferate in response to polyclonal activation and have tolerogenic properties (22, 23). They become detectable in peripheral lymphoid tissues shortly after birth, and an intact thymus is required for their development (24, 25, 26, 27). Elimination of the CD4+ regulatory cells in both normal and autoimmune-susceptible animals has resulted in the development and/or acceleration of various autoimmune diseases, suggesting that these cells actively suppress autoreactive T cells that escape thymic selection.
To our knowledge, T cells with a CD4+ phenotype
have not been previously described as playing an important role in
suppressing GVHD after allogeneic BMT. Tutschka et al.
(9, 10, 11) published a series of papers in the early 1980s
describing the involvement of suppressor cells in immune tolerance
after BMT. They reported that histoincompatible rat BM chimeras that
survived acute GVHD demonstrated tolerance to host alloantigens and
possessed T lymphocytes that suppressed donor-anti-host mixed
lymphocyte reactions in vitro (10). Furthermore, chimeric
splenocytes containing the suppressor T cells could adoptively transfer
suppression of GVHD to secondary hosts. Long-term BM chimeras (250 days
after BMT) possessing the suppressor cells did not develop GVHD when
given DLI with small numbers of donor-type cells. However, if the
chimeras were treated with immunosuppressive agents such as
cyclophosphamide or radiation before DLI, tolerance was disturbed and
the mice developed GVHD. Perhaps the immunoregulatory
Thy1+ßTCR+CD4+/-
cells identified by us are similar to the immunosuppressive T cells
described in those earlier studies.
Hess and colleagues (28, 29) have demonstrated that
elimination of a peripheral regulatory mechanism is required for the
development of cyclosporin A (CSA)-induced autologous GVHD. The primary
autoregulatory activity appears to reside within the
CD4+ T subset. Recently, Wu and Goldschneider
(30) demonstrated that the immunoregulatory
CD4+CD8- cells are recent
thymic emigrants that are exported to the peripheral lymphoid organs
within a few days after cessation of CSA treatment. Their results
suggest that the regulatory T cells actively suppress autoeffector T
cells that have escaped intrathymic negative selection during CSA
treatment. Similarly, development of the immunosuppressive regulatory
cells described in our studies required an intact thymus (Fig. 6).
Modigliani et al. (20, 31) have shown that the thymic
epithelium is involved in generating CD4+
regulatory T cells that maintain peripheral tolerance to Ags not
present in the thymus. This form of tolerance has been referred to as
active or dominant peripheral tolerance (21, 32). Perhaps
the
ßTCR+CD4+CD8-
regulatory cells identified from our work emerge from the
reconstituting thymus after BMT to help maintain dominant peripheral
tolerance over anti-host-reactive T cells that have escaped thymic
selection. Donor leukocytes infused into chimeric hosts after BMT may
be seen by the donor-derived, host thymus-selected immunoregulatory T
cells as "autoreactive" since they respond to "host-self" but
express "donor-self" histocompatibility Ags.
Although administration of CD4 ko donor BM significantly reduced the
suppression of DLI-induced GVHD (Fig. 8), the suppressive effect was
not completely eliminated. These results suggest that
ßTCR+CD4-CD8-
cells also are involved in the suppression of GVHD after DLI. Cells
with this phenotype have been previously found to exhibit suppressor
activity, inhibit GVHD, and facilitate tolerance in mice
(33, 34, 35). Cells expressing the NK1 Ag with an
ßTCR+CD4-CD8-
phenotype have been shown by others to exhibit immunoregulatory
properties (36, 37). The NK1+ cells
described by Sykes et al. (36) were able to suppress GVHD.
Experiments are in progress to examine whether
NK1+ßTCR+ cells
contribute to the suppression of GVHD in our DLI models.
It is noteworthy that when the immunoregulatory
Thy1+ßTCR+ cells
were eliminated before DLI, the kinetics of GVHD-related mortality in
MHC-mismatched chimeras was similar to that seen when irradiated hosts
were given the donor spleen cells at the time of BMT (15).
This suggests that, at 3–4 wk after BMT in mice, active suppression
mediated by the immunoregulatory cells described in this report may be
the principal mechanism responsible for suppressing GVHD after DLI. We
speculate that these immunoregulatory cells are particularly important
because they are being actively produced by the newly
donor-reconstituted host thymus to mediate dominant peripheral
tolerance.
In summary, we have identified an active regulatory/suppressor
mechanism in mice which plays an important role in suppressing GVH
reactivity after DLI. The regulatory activity appears to be mediated by
at least two populations of donor BM-derived, host thymus-selected
cells:
Thy1+ßTCR+CD4+CD8-
cells and
Thy1+ßTCR+CD4-CD8-
cells. These immunoregulatory cells may be important for maintaining
dominant peripheral tolerance. If regulatory cells similar to those
described in this report can be identified in humans, their
immunosuppressive properties could be exploited to reduce the incidence
and severity of GVHD following DLI. The possible role of thymic-derived
regulatory T cells raises questions about age-related intensification
of GVHD after BMT (38, 39) and about the more severe level
of GVHD that occurs after DLI in humans (1, 3).
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Bryon D. Johnson, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226. E-mail address:
3 Abbreviations used in this paper: DLI, delayed leukocyte infusion; GVH, graft-vs-host; GVHD, graft-vs-host disease; BM, bone marrow; BMT, bone marrow transplantation; ko, knockout; TCD, T cell depleted; LDA, limiting dilution analysis; Tx, thymectomized; CSA, cyclosporin A.
Received for publication July 26, 1999. Accepted for publication October 6, 1999.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
and ß block thymocyte development at different stages. Nature 360:225.[Medline]
/ß T cell receptor-bearing cells. J. Immunol. 145:4046.[Abstract]
ß+) T cell which promote tolerance induction and regulate autoimmunity. Immunol. Rev. 149:217.[Medline]
This article has been cited by other articles:
|
|
 |
|
  H.-J. Kolb Graft-versus-leukemia effects of transplantation and donor lymphocytes Blood, December 1, 2008; 112(12): 4371 - 4383. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 R. Chakraverty, B. Flutter, F. Fallah-Arani, H.-S. Eom, T. Means, G. Andreola, S. Schwarte, J. Buchli, P. Cotter, G. Zhao, et al. The Host Environment Regulates the Function of CD8+ Graft-versus-Host-Reactive Effector Cells J. Immunol., November 15, 2008; 181(10): 6820 - 6828. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Giorgini and A. Noble Blockade of chronic graft-versus-host disease by alloantigen-induced CD4+CD25+Foxp3+ regulatory T cells in nonlymphopenic hosts J. Leukoc. Biol., November 1, 2007; 82(5): 1053 - 1061. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
R. Chakraverty and M. Sykes The role of antigen-presenting cells in triggering graft-versus-host disease and graft-versus-leukemia Blood, July 1, 2007; 110(1): 9 - 17. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Durakovic, V. Radojcic, M. Skarica, K. B. Bezak, J. D. Powell, E. J. Fuchs, and L. Luznik Factors governing the activation of adoptively transferred donor T cells infused after allogeneic bone marrow transplantation in the mouse Blood, May 15, 2007; 109(10): 4564 - 4574. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Patterson, I. Kotsianidis, A. Almeida, M. Politou, A. Rahemtulla, B. Matthew, R. R. Schmidt, V. Cerundolo, I. A. G. Roberts, and A. Karadimitris Human Invariant NKT Cells Are Required for Effective In Vitro Alloresponses J. Immunol., October 15, 2005; 175(8): 5087 - 5094. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Y. Mapara and M. Sykes Tolerance and Cancer: Mechanisms of Tumor Evasion and Strategies for Breaking Tolerance J. Clin. Oncol., March 15, 2004; 22(6): 1136 - 1151. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. J. Young, L. S. Kay, M. J. Phillips, and L. Zhang Antitumor Activity Mediated by Double-Negative T Cells Cancer Res., November 15, 2003; 63(22): 8014 - 8021. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. W. Soper, M. D. Lessard, C. D. Jude, A. J. T. Schuldt, R. M. Bunte, and J. E. Barker Successful Allogeneic Neonatal Bone Marrow Transplantation Devoid of Myeloablation Requires Costimulatory Blockade J. Immunol., September 15, 2003; 171(6): 3270 - 3277. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. D. Billiau, S. Fevery, O. Rutgeerts, W. Landuyt, and M. Waer Transient expansion of Mac1+Ly6-G+Ly6-C+ early myeloid cells with suppressor activity in spleens of murine radiation marrow chimeras: possible implications for the graft-versus-host and graft-versus-leukemia reactivity of donor lymphocyte infusions Blood, July 15, 2003; 102(2): 740 - 748. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. J. Young, B. DuTemple, M. J. Phillips, and L. Zhang Inhibition of Graft-Versus-Host Disease by Double-Negative Regulatory T Cells J. Immunol., July 1, 2003; 171(1): 134 - 141. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. D. Billiau, S. Fevery, O. Rutgeerts, W. Landuyt, and M. Waer Crucial role of timing of donor lymphocyte infusion in generating dissociated graft-versus-host and graft-versus-leukemia responses in mice receiving allogeneic bone marrow transplants Blood, August 13, 2002; 100(5): 1894 - 1902. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Y. Mapara, Y.-M. Kim, S.-P. Wang, R. Bronson, D. H. Sachs, and M. Sykes Donor lymphocyte infusions mediate superior graft-versus-leukemia effects in mixed compared to fully allogeneic chimeras: a critical role for host antigen-presenting cells Blood, August 13, 2002; 100(5): 1903 - 1909. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Hayashi, W. H. Peranteau, A. F. Shaaban, and A. W. Flake Complete allogeneic hematopoietic chimerism achieved by a combined strategy of in utero hematopoietic stem cell transplantation and postnatal donor lymphocyte infusion Blood, July 18, 2002; 100(3): 804 - 812. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Teshima, C. Liu, K. P. Lowler, G. Dranoff, and J. L. M. Ferrara Donor Leukocyte Infusion from Immunized Donors Increases Tumor Vaccine Efficacy after Allogeneic Bone Marrow Transplantation Cancer Res., February 1, 2002; 62(3): 796 - 800. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Luznik, S. Jalla, L. W. Engstrom, R. Iannone, and E. J. Fuchs Durable engraftment of major histocompatibility complex-incompatible cells after nonmyeloablative conditioning with fludarabine, low-dose total body irradiation, and posttransplantation cyclophosphamide Blood, December 1, 2001; 98(12): 3456 - 3464. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. A. Exley, S. M. A. Tahir, O. Cheng, A. Shaulov, R. Joyce, D. Avigan, R. Sackstein, and S. P. Balk Cutting Edge: A Major Fraction of Human Bone Marrow Lymphocytes Are Th2-Like CD1d-Reactive T Cells That Can Suppress Mixed Lymphocyte Responses J. Immunol., November 15, 2001; 167(10): 5531 - 5534. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. R. Drobyski, H. C. Morse III, W. H. Burns, J. T. Casper, and G. Sandford Protection from lethal murine graft-versus-host disease without compromise of alloengraftment using transgenic donor T cells expressing a thymidine kinase suicide gene Blood, April 15, 2001; 97(8): 2506 - 2513. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Weinberg, B. R. Blazar, J. E. Wagner, E. Agura, B. J. Hill, M. Smogorzewska, R. A. Koup, M. R. Betts, R. H. Collins, and D. C. Douek Factors affecting thymic function after allogeneic hematopoietic stem cell transplantation Blood, March 1, 2001; 97(5): 1458 - 1466. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Blazar, C. J. Lees, P. J. Martin, R. J. Noelle, B. Kwon, W. Murphy, and P. A. Taylor Host T Cells Resist Graft-Versus-Host Disease Mediated by Donor Leukocyte Infusions J. Immunol., November 1, 2000; 165(9): 4901 - 4909. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
W. R. Drobyski, S. Vodanovic-Jankovic, and J. Klein Adoptively Transferred {gamma}{delta} T Cells Indirectly Regulate Murine Graft-Versus-Host Reactivity Following Donor Leukocyte Infusion Therapy in Mice J. Immunol., August 1, 2000; 165(3): 1634 - 1640. [Abstract] [Full Text] [PDF]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
vs
•, p = 0.023; 
vs 
, p =
0.037; • vs 
