| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
and IL-10 in the Regulation of Experimental Colitis
*
Mucosal Immunity Section, Laboratory of Clinical Investigation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892; and
Laboratory of Immunology, Istituto Superiore di Sanita’, Rome, Italy
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
and
IL-10 in the regulation of the Th1-mediated inflammation occurring in
trinitrobenzene sulfonic acid (TNBS)-colitis. In initial studies, we
showed that the feeding of trinitrophenol-haptenated colonic
protein to SJL/J mice induces CD4+ regulatory T cells that
transfer protection from induction of TNBS-colitis, and that such
protection correlates with cells producing TGF-, not IL-10. Further
studies in which SJL/J mice were fed haptenated colonic protein, and
then administered either anti-TGF- or anti-IL-10 at the time
of subsequent TNBS administration per rectum, showed that while both
Abs abolished protection, anti-TGF- administration prevented
TGF- secretion, but left IL-10 secretion intact; whereas
anti-IL-10 administration prevented both TGF- secretion and
IL-10 secretion. Thus, it appeared that the protective effect of IL-10
was an indirect consequence of its effect on TGF- secretion. To
establish this point further, we conducted adoptive transfer studies
and showed that anti-IL-10 administration had no effect on
induction of TGF- producing T cells in donor mice. However, it did
inhibit their subsequent expansion in recipient mice, probably by
regulating the magnitude of the Th1 T cell response which would
otherwise inhibit the TGF- response. Therefore, these studies
suggest that TGF- production is a primary mechanism of
counter-regulation of Th1 T cell-mediated mucosal inflammation, and
that IL-10 is necessary as a secondary factor that facilitates TGF-
production. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
-producing T
cell, was demonstrated in studies of trinitrobenzene sulfonic acid
(TNBS)3-colitis, a Th1
T cell-mediated inflammation induced by intrarectal administration of
the haptenating agent, TNBS. Here it was shown that the feeding of
trinitrophenol (TNP)-haptenated colonic protein (HCP) prevented
development of colitis and induced T cells in the lamina propria of the
colon producing TGF-. Furthermore, administration of
anti-TGF- to the fed mice abolished the protective effect of the
feeding (3). TGF--producing T cells were also
demonstrated in the SCID-transfer model of colitis, which is another
Th1 T cell-mediated colitis, with studies showing that
prevention of colitis in SCID mice given
CD45RBhigh T cells by cotransfer of
CD45RBlow T cells is abolished by concomitant
administration of anti-TGF- (4). This observation
has been supported by the recent observation that a
CD25+ T cell subpopulation in the
CD45RBlow T cells is responsible for the
prevention of colitis, and that such prevention is again abolished in
mice by co-administration of anti-TGF- (5).
A second type of regulatory T cell implicated in experimental colitis
is a T cell-producing IL-10. The evidence supporting the existence of
this regulatory T cell comes from studies showing that the ability of
CD45RBlow cells to inhibit the development of
colitis in the SCID transfer model (referred to above) is abrogated by
the administration of Abs to the IL-10 receptor. In addition,
protection from colitis is not observed when
CD45RBlow T cells from IL-10-deficient mice are
cotransferred with CD45RBhigh T cells from
wild-type mice (6). Finally, it has been shown that
Ag-specific clones producing IL-10 (and perhaps TGF-), namely Tr1 T
cells, prevents colitis in the SCID transfer model when cotransferred
with CD45RBhigh T cells (7).
In the above studies, the neutralization of suppressive cytokines from
regulatory T cells producing either TGF- or IL-10 led to the onset
of colitis. This suggests that TGF- and IL-10 do not act
independently in the prevention of colitis, but rather TGF- and
IL-10 regulatory functions are interrelated. To examine this
possibility, we conducted a series of studies focusing on the
conditions necessary for the induction and subsequent effector function
of regulatory T cells arising in mice fed HCP, either in fed mice with
TNBS-colitis, or in mice with TNBS-colitis to which the regulatory
cells were transferred. We found that regulatory T cells preventing
colitis must produce TGF- to do so, but that such production
requires the presence of IL-10 to down-regulate the level of Th1
cytokine production, which would otherwise inhibit TGF--producing
cells.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Colitis studies were performed in specific pathogen-free, 5- to 6-wk-old male SJL/J mice obtained from the National Cancer Institute (National Institutes of Health, Bethesda, MD), and maintained in a specific pathogen-free animal facility at the National Institute of Allergy and Infectious Diseases (National Institutes of Health). Experiments were performed after 3 days of the arrival of the animals. Animals were treated in accordance with the National Institutes of Health guidelines. For induction of colitis, 2.5 mg TNBS (pH 1.5–2.0; Sigma Aldrich, St. Louis, MO) in 50% ethanol was administered per rectum to lightly anesthetized mice through a 3.5 F catheter inserted into the rectum. The catheter tip was inserted 4 cm proximal to the anal verge, 100 ml of fluid (TNBS/ethanol) was slowly instilled into the colon, and the mouse was held in a vertical position for 30 s.
Histologic assessment of colitis
Tissues removed from mice at indicated times of death were fixed in 10% neutral buffered formalin solution (Sigma Aldrich), embedded in paraffin, cut into tissue sections, and stained with H&E. Stained sections were examined for evidence of colitis using the following criteria: the presence of lymphocyte infiltration, elongation, and/or distortion of crypts, frank ulceration, and thickening of the bowel wall. The degree of inflammation on microscopic cross-sections of the colon was graded semi-quantitatively from 0 to 4 (0: no evidence of inflammation; 1: low level of lymphocyte infiltration with infiltration seen in a <10% high-power field (hpf), no structural changes observed; 2: moderate lymphocyte infiltration with infiltration seen in 10–25% hpf, crypt elongation, bowel wall thickening which does not extend beyond mucosal layer, no evidence of ulceration; 3: high level of lymphocyte infiltration with infiltration seen in 25–50% hpf, high vascular density, thickening of bowel wall which extends beyond mucosal layer; 4: marked degree of lymphocyte infiltration with infiltration seen in >50% hpf, high vascular density, crypt elongation with distortion, transmural bowel wall-thickening with ulceration).
Generation of and feeding of HCP
HCP was generated as previously described (3). SJL/J mice were then fed 100 µg of HCP using an 18-gauge feeding needle every other day over an 8-day period.
Treatment of mice with anti-TGF- or anti-IL-10 Abs
Anti-mouse TGF- and anti-IL-10 Abs were obtained from
ascites fluid generated in nude mice by hybridomas producing these Abs.
For this purpose, nude mice were injected i.p. with hybridoma cell
lines, and then maintained until ascites developed using standard
procedures (8). Abs were purified from the ascites fluid
using E-Z-SEP purification kits (Middlesex Sciences, Foxborough, MA).
The hybridoma cell line 2G75A9 (neutralizing
anti-TGF-1, 2, 3 was kindly donated by Dr.
J. Leterio, Lab of Cancer Immunopathogenesis, National Cancer
Institute, National Institutes of Health). The hybridoma cell lines
(SXC-1 and SXC-2) producing neutralizing rat anti-mouse IL-10 Ab
was a gift of Dr. B. Segal (Laboratory of Immunoregulation, National
Institutes of Allergy and Infectious Diseases, National Institutes of
Health). Mice were administered 1 mg of each Ab at indicated times.
Isolation and purification of lamina propria (LP) mononuclear cells and T cell subsets
LP lymphocytes were isolated from freshly obtained colonic specimens, as previously described (3). Enriched LP T cell and CD4+ T cell populations were obtained from these lymphocyte populations by positive selection, using mouse T cell and CD4+ T cell isolation columns (Isocell; Pierce, Rockford, IL). Information on the selecting Abs bound to the column and the use of the column is available from the manufacturer. The resulting cell population, when analyzed by flow cytometry (FACScan; BD Biosciences, Mountain View, CA) contained >90% LP T cells or LP CD4+ T cells (RM4-4 (CD4 stain); BD PharMingen, San Diego, CA). In some experiments, purified LP CD4+ T cells were subjected to a further negative selection isolation process. In brief, LP CD4+ T cells were suspended at 1x 106/ml in calcium-free PBS with 1% FCS (coating media), to which anti-CXCR3 Ab was added. Ab to CXCR3 was a gift from Dr. J. Farber (Laboratory of Clinical Investigation, National Institutes of Health), and prepared as follows. Rabbit anti-murine CXCR3 at a concentration of 0.3 mg/ml was incubated with 2 µl of ultra-pure H2O and 1.2 µl of 1 M HEPES buffer for 30 min at room temperature. Purified LP CD4+ T cells were then added to this preparation and incubated for an additional 40 min at 4°C, washed 3 times with cold 1x PBS and resuspended in coating media at a concentration of 2x 107 cells/ml. The Ab-coated cell population were then removed by incubation with immunomagnetic beads coated with sheep anti-rabbit IgG obtained from Dynal (New York, NY).
Adoptive transfer of LP CD4+ T cells
LP cells were isolated from HCP-fed mice 5 days after completion of the last feeding, or from TNBS-induced colitis mice 4 or 5 days after intrarectal administration. Enriched CD4+ T cells were obtained from these lymphocytes by positive selection using CD4+ T cell isolation columns (Isocell; Pierce). Purified CD4+ T cells (3.0 x 105) were then injected i.v. into the tail vein of normal SJL/J mice.
Cell culture of LP mononuclear cells (LPMC) and CD4+ T cells
Cell culture of LPMC or CD4+ T cell subset
were performed in complete medium consisting of RPMI 1640 (Whittaker,
Walkersville, MD) supplemented with 3 mM L-glutamine, 10 mM
HEPES buffer, 10 mg/ml gentamicin (Whittaker), 100 U/ml each of
penicillin and streptomycin (Whittaker), 0.05 mM 2-ME (Sigma Aldrich),
and 10% FCS (Sigma Aldrich). Cultures of LPMC for evaluation of
TGF- production were performed in serum-free media supplemented with
1% nutridoma-SP (Roche Diagnostics, Indianapolis, IN).
Stimulation and measurement of cytokine production by LPMC
To measure the capacity of isolated LPMC to produce cytokines,
the LPMC populations were cultured in complete medium (or serum-free
media in the case of TGF-) at 106 cells/ml in
24-well plates (Falcon; BD Biosciences) coated or uncoated with
anti-CD3
Ab (clone 145-2C11; BD PharMingen). Coating was
accomplished by pre-exposure of individual wells to 10 µg/ml
murine-anti-CD3 Ab in carbonate buffer (pH 9.6) overnight at
4°C. Culture fluid for cell populations in coated wells also
contained 1 µg/ml soluble CD28 Ab (clone 37.51; PharMingen). After
48 h of culture under these conditions (or 72 h for TGF-),
culture supernatants were removed and assayed for the presence of
cytokines (IFN-
, IL-10, and TGF-) by ELISA. To measure IL-12 and
TNF-
production, LPMC cells were preincubated for 18 h with
1000 U/ml recombinant murine IFN- (Genzyme; R&D Systems,
Minneapolis, MN), followed by stimulation with 0.03%
Staphylococcus aureus, Cowan’s strain I (Calbiochem, La
Jolla, CA). Culture supernatants were harvested after an additional
24 h.
ELISAs
Cytokine concentrations (except for TGF-) were determined by
commercially available specific ELISAs using paired murine cytokines
per the manufacturer’s recommendations (Endogen, Woburn, MA). TGF-
concentrations were determined using the commercially available TGF-
Quantikine kit (R&D Systems). Optical densities were measured on a
Dynatech MR 5000 ELISA reader at a wavelength of 490 nm. Data was
analyzed against the linear portion of the generated standard
curve.
Statistical analysis
Assessment of statistical differences was determined by
Student’s t test and 
2 test as
indicated.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
In previous studies, we showed that the Th1 T cell-mediated
transmural colitis induced in SJL/J mice by the administration of TNBS
per rectum can be suppressed by prior induction of "oral tolerance"
to TNBS, which is accomplished by feeding TNBS-HCP (3).
This protective effect of feeding HCP was accompanied by the induction
of CD4+ T cells producing TGF-, and could be
abrogated by the co-administration of anti-TGF- Ab. In initial
studies to further define this regulatory effect in the present study,
we used an adoptive transfer model of TNBS-colitis, in which primed
CD4+ T cells obtained from mice with TNBS-colitis
or LP CD4+ T cells from HCP-fed mice were
transferred to naive mice. Accordingly, we isolated LP
CD4+ T cells from mice with TNBS-colitis or LP
CD4+ T cells obtained from HCP-fed mice, and then
administered these cells (i.v.) to naive recipient mice. The recipient
mice were then administered TNBS per rectum at a dosage of TNBS known
to cause colitis (2.5 mg) (see Materials and Methods). As
shown in Fig. 1
, we found that whereas
mice administered TNBS per rectum which had been adoptively transferred
LP CD4+ T cells from TNBS-colitis mice alone
experienced severe and persistent weight loss, mice that had been
administered LP CD4+ T cells from HCP-fed mice
did not experience weight loss.
|
, recipient
mice that were administered LP CD4+ T cells from
TNBS-colitis mice showed evidence of severe inflammation, manifested by
shortened, thickened, and erythematous colons; whereas mice that were
administered LP CD4+ T cells from HCP-fed mice
showed no evidence of macroscopic colonic inflammation.
|
A, LP
CD4+ T cells isolated from the colons of mice
that had been administered LP CD4+ T cells from
TNBS-colitis mice (LP CD4+ effector cells)
produced large amounts of IFN-, whereas CD4+ T
cells isolated from recipients that were administered LP
CD4+ T cells from HCP-fed mice (LP
CD4+ regulatory cells) produced strikingly lower
amounts of IFN- (p < 0.002). In addition,
the LP CD4+ T cells isolated from recipients of
LP CD4+ regulatory cells produced greatly
increased amounts of TGF-, in contrast to CD4+
T cells from recipients of LP CD4+ effector
cells, which produced low amounts of TGF- (p
< 0.002), as shown in Fig. 3B. Finally, we measured
IL-10 production by the isolated LP CD4+ T cells.
In this case, we found no marked differences in the production of IL-10
by LP CD4+ T cells from recipient mice who had
received LP CD4+ T cells from mice with colitis
as compared with mice that were administered LP
CD4+ T cells from HCP-fed mice (308 vs 587 pg/ml,
respectively). These findings were replicated and further explored in
the subsequent studies described below.
|
in the recipient colons. Finally, they
suggest that increased production of TGF-, rather than IL-10, may
correlate with protection from colitis.
Treatment with either anti-TGF- or anti-IL-10 mAb at the
time of TNBS administration abolishes the protective effect of feeding
HCP
To further explore the relative roles of TGF- and IL-10 in the
suppression of TNBS-colitis, we determined the effect of
anti-TGF- and anti-IL-10 Ab administration on the protective
effect of feeding HCP. In these studies, mice were fed HCP every other
day for 8 days. After an additional 5 days, the mice were administered
TNBS per rectum. In addition, certain groups of mice also received
anti-TGF- or anti-IL-10 (1 mg/mouse) i.p. at the time of
TNBS administration per rectum (see Materials and
Methods).
As shown by the weight curves in Fig. 4, we found that whereas mice fed HCP alone did not develop colitis
following administration of TNBS per rectum, mice fed HCP and
administered anti-TGF- or anti-IL-10 Ab (at the time of
intrarectal TNBS administration) both developed colitis which did not
differ from that of mice given TNBS per rectum which had not been fed
HCP. However, as shown in the microscopic analysis of colonic tissue
depicted in Fig. 5, while mice
administered either anti-TGF- or anti-IL-10 developed
histologic evidence of colitis, those administered anti-TGF-
displayed a more severe inflammation than mice administered
anti-IL-10. Thus, when colons from these mouse groups were
subjected to histologic scoring (see Materials and Methods),
a statistical difference in histologic scores was observed with a score
of 3.6 + 0.3 for the anti-TGF- treated mice, and a score of 2.7
+ 0.4 for the anti-IL-10 treated mice (p <
0.05). This disparity was also evident in the mortality of the
anti-TGF- and anti-IL-10 treated mice at day 4 after TNBS
administration. Mice administered anti-TGF- displayed a high
mortality rate (70%) as compared with mice given TNBS per rectum alone
or in combination with anti-IL-10 Abs (18 and 22% respectively)
(p < 0.01 mortality anti-TGF- treated
mice as compared with anti-IL-10 treated mice). Finally,
recognizing that these differences in the effects of anti-IL-10 and
anti-TGF- could have been due to differences in the potencies of
the Abs used, we also performed comparative studies in which the dose
of anti-IL-10 was increased to 2 mg i.p. Again we noted that
reversal of protection by anti-TGF- was more complete, both in
terms of microscopic appearance of the colon and mortality (data not
shown). It should be noted that normal SJL mice which were
administered anti-IL-10 and anti-TGF- mAbs, and not
given TNBS per rectum did not display evidence of weight loss or
intestinal inflammation. In addition, these mice did not manifest any
change in IFN- or TGF- secretion as compared with normal SJL mice
which were not administered these Abs (data not shown).
|
|
in response
to SAC plus IFN- stimulation in vitro (see Materials and
Methods). As shown in Fig. 6, A and B, LPMC from mice given TNBS per rectum
(and who manifested TNBS-colitis) secreted large amounts of IL-12 and
IFN-, whereas those from mice fed HCP produced only small amounts of
these cytokines. However, cells from mice fed HCP that had been
concomitantly treated with anti-TGF- produced even greater
amounts of Th1 cytokines than mice given TNBS per rectum alone.
Finally, cells from mice fed HCP that had been concomitantly treated
with anti-IL-10 also produced increased amounts of IL-12 and
IFN-, although such production was lower than that of mice treated
with anti-TGF- or those given TNBS per rectum alone. It should
also be noted that mice treated with anti-IL-10 produced
substantial amounts of TNF- (617 pg/ml) as compared with mice
treated with anti-TGF- (951 pg/ml), or administered TNBS alone
(1086 pg/ml); perhaps explaining the fact that these mice displayed a
weight loss equal to that of mice given TNBS per rectum alone or in
conjunction with anti-TGF-.
|
and IL-10 production by LPMC
extracted from the various mouse groups. As shown in Fig. 6
C, LPMC from mice given TNBS per rectum that had been fed
HCP and which did not have colitis produced large amounts of TGF-,
compared with LPMC from mice given TNBS alone
(p < 0.01). In addition, LPMC from mice
treated with either anti-TGF- or anti-IL-10 and which also
had colitis produced only small amounts of TGF- which did not differ
from those produced by mice given TNBS per rectum alone
(p > 0.05). However, a somewhat different
picture was obtained for IL-10 production (Fig. 6D).
In this case, cells from mice treated with TNBS per rectum alone
produced a moderate amount of IL-10, while cells from mice that had
been fed HCP produced large amounts of IL-10 (p
< 0.01). Furthermore, whereas cells from mice given TNBS per rectum
and treated with anti-IL-10 produced low amounts of IL-10
(p < 0.01, HCP-fed and anti-IL-10 vs
HCP-fed alone), cells from mice given TNBS per rectum and treated with
anti-TGF- produced high levels of IL-10, i.e., levels equal to
those produced by cells of mice that had been fed HCP and not
administered an Ab (p > 0.05). It should be
noted that such IL-10 production most likely represents IL-10 produced
by both T cells and APCs in the LPMC population, because anti-CD3
stimulation of T cells results in indirect stimulation of APCs via
CD40L expression (9).
Taken together, these studies demonstrate that the effectiveness of
feeding HCP and preventing a Th1 T cell-mediated inflammation
correlates best with the presence of cells producing TGF-. In
addition, while administration of anti-IL-10 also prevents the
protective effect of HCP prefeeding, such prevention correlates with
the presence of decreased TGF- production. Severe colitis following
anti-TGF- administration occurs despite high levels of IL-10
production. These results are compatible with the view that while
counter-regulation by TGF- occurs as a direct effect of suppression
by this cytokine, counter-regulation by IL-10 occurs as an indirect
effect on TGF- production, and IL-10 has no significant suppressor
effect in the absence of an effect through TGF- production.
The effect of IL-10 on the induction of TGF--producing T cells
To further clarify the role of IL-10 in the counter-regulation of
TNBS-colitis, we conducted a series of studies in which anti-IL-10
was given to mice either during the induction phase of
TGF--producing T cells (i.e., at the time of HCP-feeding), or at the
time these cells are stimulated to produce large (suppressive) amounts
of TGF- (i.e, at the "effector phase" of TGF- producing cell
activity).
In a first series of such studies addressing the induction of
TGF--producing T cells, LP T cells were isolated from the colons of
either HCP-fed mice (given HCP orally every other day for 8 days) or
HCP-fed mice which were administered anti-IL-10 on days in between
feedings (0.5 mg/dose/mouse each day during feedings for total 2 mg
mAb/mouse). The LP cells from the animals treated were then pooled and
adoptively transferred to naive SJL/J mice who were subsequently
administered TNBS per rectum 5 days later. As shown in Fig. 7, the recipient of the cells from the
mice fed HCP or fed HCP and administered anti-IL-10 did not display
significant weight loss following administration of TNBS per rectum,
whereas the mice given TNBS per rectum alone experienced considerable
weight loss. This result was verified by an additional experiment in
which the amount of anti-IL-10 mAb administered to mice during
feedings was doubled to 4 mg/mouse. In this case as well, mice which
were administered anti-IL-10 still did not manifest significant
weight loss more than mice fed HCP alone (p >
0.05). However, it should be noted that in both experiments that
all of the recipients of cells from mice fed HCP alone manifested no
weight loss or macroscopic evidence of colitis, whereas the recipients
of cells from mice fed HCP and administered anti-IL-10 displayed a
mixed picture. Two-thirds developed no macroscopic evidence of colitis,
whereas one-third displayed evidence of macroscopic colitis; despite
the fact that all of the mice were recipients of aliquots of the same
pooled cell population in any given experiment. We return to an
explanation of this incomplete effect below.
|
, A and B, the
recipients of LP T cells from HCP-fed mice or the two-thirds of the
recipients of LP T cells from HCP-fed and anti-IL-10-treated mice
manifesting no colitis yielded LPMC cells that displayed minimal IL-12
and IFN- production, whereas LPMC cells from mice that were
administered TNBS per rectum alone displayed high IL-12 and IFN-
production. Similarly, as shown in Fig. 8C, recipients of LP
CD4+ T cells from HCP-fed mice, or the two-thirds
of the recipients of LP T cells from HCP-fed and administered
anti-IL-10 mice that did not manifest colitis yielded LPMC cells
that exhibited high TGF- production; whereas the cells from mice
that were administered TNBS per rectum alone produced low TGF-
production. In contrast, the one-third of the recipients of LP T cells
from HCP-fed and anti-IL-10-treated mice that manifests colitis
yield LPMC cells, which displayed high IL-12 and IFN- production,
and low TGF- production.
|
-producing T cells, and
were protected from colitis) strongly suggest that the negative effect
of anti-IL-10 on protection from colitis observed in the studies
above was not due to the fact that IL-10 is necessary during the
induction of TGF- producing T cells. On the contrary, they suggest
that the latter induction is independent of IL-10. One caveat to this
conclusion relates to the finding that one-third of the recipient mice
that were administered cells from HCP-fed mice, administered
anti-IL-10 at the same time, and were not protected from colitis
(despite the fact that they were recipient of the same pool of cells as
the protected mice) in any given experiment. However, this can be
explained by the fact that in feeding mice in the presence of
anti-IL-10 (as in these studies), one is also inducing Th1 effector
cells capable of mediating colitis, as well as regulatory T cells
capable of suppressing colitis. Therefore, in some recipients, the
transferred cells led to colitis rather than to protection. This
possibility is strongly supported by the observation that when the LP T
cells from fed animals that were being adoptively transferred were
placed into culture before transfer and stimulated with
anti-CD3/anti-CD28, we observed that cells from mice that were
fed HCP alone produced low amounts of IFN- (27 ± 24 U/ml) as
compared with cells from mice fed HCP and administered anti-IL-10
(196 ± 31 U/ml). Perhaps more importantly, we observed that cells
from mice that were fed HCP and administered anti-IL-10 still
produced comparable amounts of TGF- as compared to mice fed HCP
alone (831 pg/ml vs 1122 pg/ml, respectively). Thus, whether or not the
transferred cells suppressed the development of colitis, anti-IL-10
treatment did not adversely affect the induction of TGF- producing
regulatory cells.
In a related experiment to further explore this possibility, we
subjected LP CD4+ T cells obtained from HCP-fed
mice administered anti-IL-10 to a negative selection process using
an Ab to CXCR3 (a chemokine receptor found on mainly Th1 T cells (see
Materials and Methods) (10, 11, 12). We found that
in this case that >95% of recipient mice administered TNBS per rectum
not only did not display significant weight loss, they also did not
display evidence of macroscopic or microscopic colitis. These findings
correlated with the fact that when LP CD4+ T
cells obtained from HCP-fed mice administered anti-IL-10 and
subjected to anti-CXCR3 negative selection process were placed into
culture before transfer and stimulated with anti-CD3/anti-CD28,
the cells produced lower amounts of IFN- (76 U/ml), as compared with
HCP-fed mice administered anti-IL-10 alone, yet still produced
amounts of TGF- secretion (996 pg/ml) that were comparable to that
produced by LP CD4+ T cells obtained from HCP-fed
mice. Finally, cytokine secretion by LPMC cell populations
obtained from recipient mice of these LP CD4+ T
cells after transfer and TNBS administration per rectum displayed no
significant IFN- secretion (6 U/ml), but did display increased
TGF- secretion (1110 pg/ml). On this basis, we would conclude that
protection from colitis in recipients of LP T cells from HCP fed mice
also administered anti-IL-10 depends on the delicate balance
between the rate of expansion of TGF--producing suppressor cells,
and the rate of expansion of Th1 T cells, which can oppose
TGF--producing cell development (see further data below).
The effect of IL-10 on the effector phase of TGF--producing T
cell activity
In a second type of adoptive transfer experiment designed to
determine the relation of IL-10 to regulate TNBS-colitis,
anti-IL-10 was administered to recipient mice rather than donor
mice to determine its effect on the effector phase of suppressor T cell
activity. In these studies, mice were fed HCP as in previous studies.
Five days after completion of the feeding, LP
CD4+ T cells were harvested and adoptively
transferred to recipient mice. Five days later, the recipient mice were
administered TNBS per rectum alone or in combination with
anti-IL-10 or anti-TGF-.
As shown in Fig. 9, all of the recipient
mice administered anti-IL-10 or anti-TGF- manifested marked
weight loss similar to mice given TNBS per rectum alone, whereas the
recipient mice not given these Abs did not. However, as in prior
studies, mice administered anti-IL-10 exhibited a colitis which was
histologically milder than those given anti-TGF-, i.e., they
manifest less bowel wall thickening and lymphoid infiltration (data not
shown). Similarly, as shown in Fig. 10, A and B, the
weight loss in the anti-IL-10 and anti-TGF- treated mice was
accompanied by the presence of LP CD4+ T cells
that secreted large amounts of IFN- and small amounts of TGF- as
compared with mice not administered Abs, with the mice administered
anti-TGF- showing more marked differences than the mice
administered anti-IL-10. These data thus show that whereas the
IL-10 does not affect the induction of TGF- producing
CD4+ T cells, it does affect the subsequent
effector phase of these cells.
|
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
. In addition, we define the role of IL-10 in such protection
with studies showing that while TGF--producing regulatory T cells
can be induced in the absence of IL-10, the latter cytokine is
necessary for the production of TGF-, because it down-regulates the
ambient levels of Th1 cytokine, which would otherwise inhibit the
expansion of TGF--producing T cells. Before we discuss these
findings, it is important to mention that many of our studies were
based on the in vivo administration of anti-IL-10 Abs to
investigate IL-10 effects during Th1-mediated inflammation. This was
justified by the fact that we used a combination of murine monoclonal
IgM Abs (SXC-1 and SXC-2), that have been shown to neutralize 95–100%
of the IL-10 responses in vitro (13, 14) and to
efficiently block a variety of IL-10-mediated phenomena in vivo at the
concentrations used here (15, 16, 17). In fact, in most of our
studies, the use of these Abs did inhibit potential IL-10 suppressive
effects at a dose of 1 mg/mouse. In the study in which they did not
inhibit such effects even when given at a total dose of 2 mg/mouse
(studies in which anti-IL-10 was given during HCP feedings before
transfer of cells with regulatory activity), we verified the finding
with an additional study in which the mice were given a total dose of 4
mg/mouse. In addition, in the study in which anti-IL-10 had an
effect on the development of regulatory cells, albeit a somewhat less
robust effect than did TGF-, we again verified the result with an
additional experiment in which the dose of anti-IL-10 was increased
from 1 to 2 mg/mouse. Finally, it should be noted that in a previous
study in which the in vivo inhibitory effect of the anti-IL-10 Ab
was shown to be suboptimally effective, this Ab was a IgG monoclonal
anti-IL-10 not used here (4).
The role of TGF- as a key mediator of suppression of experimental
mucosal inflammation has previously been shown both in the SCID
transfer model of colitis and in the hapten-induced model studied here
(TNBS-colitis) (3, 4). In the former case, it was shown
that the protective effect of transferring mature
CD45RBlow T cells (along with naive
CD45RBhigh T cells) can be reversed by the
administration of anti-TGF-. Similarly, in the latter case, it
was shown that the protective effect of feeding hapten (in the form of
TNP-HCP) is accompanied by the production of TGF- by LP T cells, and
that this protective effect is again reversed by the administration of
anti-TGF-, either during the period of feeding HCP or later when
TNBS was administered per rectum (3). In the present
study, this TGF- effect was initially examined with adoptive
transfer studies in which it was shown that CD4+
T cells are the source of the TGF-. In addition, these studies
showed that while transferred CD4+ T cells confer
the ability to produce high amounts of TGF-, it does not confer the
ability to produce high amount of IL-10. They thereby presaged the
conclusion that it is TGF- rather than IL-10 that is primarily
responsible for suppression of the experimental mucosal
inflammation.
A more direct demonstration of TGF- as the major protective element
induced by feeding comes from additional studies in which mice fed HCP
and later treated with TNBS per rectum to induce inflammation are
concomitantly administered anti-TGF- or anti-IL-10 mAbs at
the time of TNBS administration. This type of experiment showed that
while anti-TGF- administration abolishes TGF- production and
protection, it leaves IL-10 production intact, thereby establishing
that IL-10 does not itself act as protective cytokine in this context.
This finding correlates with previous studies in which inflammation
induced by TNBS per rectum is prevented or treated with a DNA
plasmid-encoding TGF-, which leads to TGF- producing T cells that
prevent inflammation even in the absence of IL-10 production (see
further discussion below) (18).
In the same experiments in which protection was abolished by
anti-TGF- Abs, it was also abolished by administration of
anti-IL-10 Abs. However, since anti-IL-10 administration was
associated with inhibition of TGF- secretion, and anti-TGF-
treatment was not associated with inhibition of IL-10 secretion, we
assumed that the reversal of protection brought about by anti-IL-10
administration was due to an indirect effect on TGF- secretion. To
prove this point, we conducted two kinds of adoptive transfer studies
in which anti-IL-10 was administered either during the period of
induction of T cells producing TGF- (i.e., at the time of HCP
feeding) or after transfer of such cells to recipients. The former
study provided evidence compatible with the conclusion that IL-10 had
no effect on the induction of TGF- producing T cells, in which
two-thirds of recipient mice were subsequently protected from
TNBS-colitis. The fact that not all mice were protected (even
though they received cells from same pooled cell population as the
protected mice) can be explained by the fact that mice administered
anti-IL-10 during feeding were also developing Th1 T cells in the
LP, albeit at a relatively low level. Thus, the transferred cells in
some mice evoked a Th1 response which pre-empted the further expansion
of T cells potentially able to produce TGF-. This explanation is
favored by the finding that the T cells being transferred, when
stimulated in vitro by anti-CD3/anti-CD28, did in fact produce
increased amounts of IFN- as compared with T cells from HCP-fed mice
not administered anti-IL-10. In an additional study, we showed the
depletion of such IFN--producing cells from the transferred cell
inoculum led to protection from colitis in almost all recipients, not
just a large subset. Finally, this explanation is also consonant with
data from the study of mice in which anti-IL-10 is administered to
recipient mice of LP CD4+ T cells from HCP-fed
mice. In this case, the anti-IL-10 abolished protection, and at the
same time shifted the response of the recipient mice to a large Th1
cytokine response and a small TGF- response. Overall, the picture
that emerges is that at least in the present context, while IL-10 is an
important and indeed essential regulatory cytokine, its effects are
indirect and are related to its capacity to facilitate the regulatory
role of TGF-.
Accepting the latter conclusion, the question arises as to the
mechanism by which IL-10 facilitates TGF- regulatory effects. As
reported here, IL-10 is important for the expansion of induced
TGF--producing regulatory cells and the secretion of TGF- from
those cells. Thus, one possibility is that IL-10 regulates the level of
Th1 cytokine production, which if unchecked would inhibit expansion of
TGF- cells or TGF- secretion. Several previous in vitro and in
vivo studies support this possibility. Thus, in studies by Seder et al.
(19) in which in vitro generation of TGF--producing
cells from naive T cells were studied, it was shown that IL-12/IFN-
inhibits TGF- production, whereas IL-10 enhances such production via
an indirect effect on IL-12 secretion. Similarly, in in vivo studies of
oral tolerance in OVA-TCR transgenic mice by Marth et al.
(20), it was shown that induction of TGF--producing
cells by intermittent high dose feeding of OVA was greatly enhanced by
coadministration of anti-IL-12. In a more recent study by these
authors, it was shown that continuous feeding of OVA to OVA-TCR
transgenic mice resulted in the cytokine response gradually shifting
from IFN--production to TGF- and IL-10 production
(21). Taken together, these previous data provide evidence
that high level TGF- production occurs within a cytokine environment
in which Th1 cytokine production is relatively low, and that IL-10
supports TGF- production by regulating Th1 cytokine production. A
second possibility is that IL-10 is necessary for responsiveness to
TGF- regulatory effects. This view is supported by recent data from
Cottrez et al. (22) who have recently reported that
activated cells manifest reduced TGF-R2 expression and this effect
is reversed by IL-10. In addition, it is supported by studies showing
that IFN- can induce intracellular production of SMAD-7 in
fibroblasts and thus interfere with intracellular TGF- signaling
(23). Therefore, if IFN- is down-regulated by IL-10,
TGF- signaling is better maintained. Finally, it is important to
note that these possibilities are not mutually exclusive, and that
IL-10 may act through several different ways to support TGF-
regulation.
One study superficially in disagreement with the view that IL-10 acts
through TGF- as a regulatory cytokine is that of Powrie et
al.(6), in which it was shown that transfer of
CD45RBlow T cells, normally a population that
protects recipients from colitis, is ineffective in doing so if the
CD45RBlow T cells are derived from IL-10
deficient mice. However, it is reasonable to suggest that the T cells
capable of producing IL-10 are necessary to control the level of the
Th1 response and thus the level of TGF- production. This latter
interpretation, of course, is consonant with the observation in
that the SCID-transfer model of colitis administration of
anti-TGF- also abolishes protection from colitis mediated by
CD45RBlow T cells, as mentioned above. Other
studies seemingly at odds with the indirect role of IL-10 are those
showing the existence of Tr1 T cells, i.e., T cells capable of
producing high levels of IL-10 plus or minus relatively low levels
TGF- and shown in vivo to inhibit SCID-transfer colitis
(7). It is possible that these cells have
counter-regulatory effects by virtue of their capability to control Th1
responses as in the scenario defined for IL-10 above. Alternatively, it
is possible that direct delivery of high amounts of IL-10 by these
cells can down-regulate Th1 mediated inflammation in the absence of
TGF-. Evidence that this may be so comes from studies of Cua et al.
(24), which show that IL-10 delivered directly into the
CNS by recombinant adenovirus can ameliorate experimental autoimmune
encephalomyelitis (EAE).
To conclude, the results reported in this study have an important
bearing on the possible treatment of human disease characterized by Th1
T cell-mediated inflammation, such as Crohn’s disease. First, they
suggest that it may be difficult to stimulate an endogenous TGF-
response in the face of an active Th1 response, since the latter may
down-regulate a nascent TGF- response before it can gain the upper
hand. TGF--centered therapy must instead come from cells programmed
to produce TGF-, such as those containing a TGF--encoding gene
which is not subject to down-regulation, such as that recently
described by Kitani et al. (18). Second, they show that
the production of substantial amounts of IL-10 does not necessarily
turn off the Th1 response, and is again more effective in the
prevention of a Th1 response than in its reversal, as when Tr1 T cells
are administered to prevent SCID-transfer colitis (7).
This may arise from the fact that the amounts of IL-10 necessary to
suppress IL-12 production after a full-blown Th1 T cell response has
been established may be very difficult to achieve. Evidence for this
comes from the study of mice that overproduce IL-10 because they bear
an IL-10 transgene (9, 24). Here it was shown that
increased IL-10 production by APCs does not affect the Th1 response
induced by infection with intracellular pathogens (e.g.,
Leishmania), or by administration of myelin basic protein to
induce EAE. Nevertheless, in these same studies IL-10 overproduction
did prevent EAE development, most likely through its direct effect on
macrophage function. As already mentioned, delivery of IL-10 directly
to Th1 lesions by a recombinant adenovirus ameliorates inflammation
(24). Thus, cells bearing IL-10-encoding plasmids that are
not subject to down-regulation may also be a useful therapeutic
option.
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Ivan J. Fuss, Mucosal Immunity Section, Laboratory of Clinical Investigation, National Institutes of Health, 10 Center Drive, Building 10, Room 11N238, Bethesda, MD, 20892-1890. E-mail address: ifuss{at}niaid.nih.gov
3 Abbreviations used in this paper: TBNS, trinitrobenzene sulfonic acid; HCP, haptenated colonic protein; hpf, high-power field; LP, lamina propria; LPMC, LP mononuclear cells; TNP, trinitrophenol; EAE, experimental autoimmune encephalomyelitis.
Received for publication August 15, 2001. Accepted for publication November 8, 2001.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
and TGF- responses regulate the occurrence of mucosa inflammation. Immunol. Today 18:61.[Medline]
-mediated oral tolerance. J. Exp. Med. 183:2605. but not interleukin-4 in the suppression of T helper type 1-mediated colitis by CD45RBlow CD4+ T cells. J. Exp. Med. 183:2669.1 plasmid: TGF-1-mediated suppression of T helper cell type 1 response occurs by interleukin (IL)-10 induction and IL-12 receptor 2 chain downregulation. J. Exp. Med. 192:41.-producing cells from naive CD4+ T cells: IL-4 and IFN- have opposing effects, while TGF- positively regulates its own production. J. Immunol. 160:5719. production by interleukin-12. Eur. J. Immunol. 27:1213.[Medline]
response during T cell activation is modulated by IL-10. J. Immunol. 167:773./SMAD signalling by the interferon-/STAT pathway. Nature 397:710.[Medline]
This article has been cited by other articles:
|
|
 |
|
  I. L. Huibregtse, E. V. Marietta, S. Rashtak, F. Koning, P. Rottiers, C. S. David, S. J. H. van Deventer, and J. A. Murray Induction of Antigen-Specific Tolerance by Oral Administration of Lactococcus lactis Delivered Immunodominant DQ8-Restricted Gliadin Peptide in Sensitized Nonobese Diabetic Ab{degrees} Dq8 Transgenic Mice J. Immunol., August 15, 2009; 183(4): 2390 - 2396. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. TOKUNO, S. HAZAMA, S. YOSHINO, S. YOSHIDA, and M. OKA Increased Prevalence of Regulatory T-Cells in the Peripheral Blood of Patients with Gastrointestinal Cancer Anticancer Res, May 1, 2009; 29(5): 1527 - 1532. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. R. Herbert, T. Orekov, C. Perkins, and F. D. Finkelman IL-10 and TGF-{beta} Redundantly Protect against Severe Liver Injury and Mortality during Acute Schistosomiasis J. Immunol., November 15, 2008; 181(10): 7214 - 7220. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
F. Yasui, C. Kai, M. Kitabatake, S. Inoue, M. Yoneda, S. Yokochi, R. Kase, S. Sekiguchi, K. Morita, T. Hishima, et al. Prior Immunization with Severe Acute Respiratory Syndrome (SARS)-Associated Coronavirus (SARS-CoV) Nucleocapsid Protein Causes Severe Pneumonia in Mice Infected with SARS-CoV J. Immunol., November 1, 2008; 181(9): 6337 - 6348. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. M. Dittrich, A. Erbacher, S. Specht, F. Diesner, M. Krokowski, A. Avagyan, P. Stock, B. Ahrens, W. H. Hoffmann, A. Hoerauf, et al. Helminth Infection with Litomosoides sigmodontis Induces Regulatory T Cells and Inhibits Allergic Sensitization, Airway Inflammation, and Hyperreactivity in a Murine Asthma Model J. Immunol., February 1, 2008; 180(3): 1792 - 1799. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. L. Molitor-Dart, J. Andrassy, J. Kwun, H. A. Kayaoglu, D. A. Roenneburg, L. D. Haynes, J. R. Torrealba, J. L. Bobadilla, H. W. Sollinger, S. J. Knechtle, et al. Developmental Exposure to Noninherited Maternal Antigens Induces CD4+ T Regulatory Cells: Relevance to Mechanism of Heart Allograft Tolerance J. Immunol., November 15, 2007; 179(10): 6749 - 6761. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Setiawan, A. Metwali, A. M. Blum, M. N. Ince, J. F. Urban Jr., D. E. Elliott, and J. V. Weinstock Heligmosomoides polygyrus Promotes Regulatory T-Cell Cytokine Production in the Murine Normal Distal Intestine Infect. Immun., September 1, 2007; 75(9): 4655 - 4663. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I L Huibregtse, A U van Lent, and S J H van Deventer Immunopathogenesis of IBD: insufficient suppressor function in the gut? Gut, April 1, 2007; 56(4): 584 - 592. [Full Text] [PDF]
|
|
|
|
|
|
Q. Xu, J. Lee, E. Jankowska-Gan, J. Schultz, D. A. Roennburg, L. D. Haynes, S. Kusaka, H. W. Sollinger, S. J. Knechtle, A. M. VanBuskirk, et al. Human CD4+CD25low Adaptive T Regulatory Cells Suppress Delayed-Type Hypersensitivity during Transplant Tolerance J. Immunol., March 15, 2007; 178(6): 3983 - 3995. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Daniel, N. Sartory, N. Zahn, G. Geisslinger, H. H. Radeke, and J. M. Stein FTY720 Ameliorates Th1-Mediated Colitis in Mice by Directly Affecting the Functional Activity of CD4+CD25+ Regulatory T Cells J. Immunol., February 15, 2007; 178(4): 2458 - 2468. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. Joetham, K. Takada, C. Taube, N. Miyahara, S. Matsubara, T. Koya, Y.-H. Rha, A. Dakhama, and E. W. Gelfand Naturally Occurring Lung CD4+CD25+ T Cell Regulation of Airway Allergic Responses Depends on IL-10 Induction of TGF-beta J. Immunol., February 1, 2007; 178(3): 1433 - 1442. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 I. Sinuani, Z. Averbukh, I. Gitelman, M. J. Rapoport, J. Sandbank, M. Albeck, B. Sredni, and J. Weissgarten Mesangial cells initiate compensatory renal tubular hypertrophy via IL-10-induced TGF-beta secretion: effect of the immunomodulator AS101 on this process Am J Physiol Renal Physiol, August 1, 2006; 291(2): F384 - F394. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 L. Maggio-Price, P. Treuting, W. Zeng, M. Tsang, H. Bielefeldt-Ohmann, and B. M. Iritani Helicobacter Infection Is Required for Inflammation and Colon Cancer in Smad3-Deficient Mice Cancer Res., January 15, 2006; 66(2): 828 - 838. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Bamias, M. R. Nyce, S. A. De La Rue, and F. Cominelli New Concepts in the Pathophysiology of Inflammatory Bowel Disease Ann Intern Med, December 20, 2005; 143(12): 895 - 904. [Full Text] [PDF]
|
|
|
|
 |
|
 M. L. Drakes, T. G. Blanchard, and S. J. Czinn Colon lamina propria dendritic cells induce a proinflammatory cytokine response in lamina propria T cells in the SCID mouse model of colitis J. Leukoc. Biol., December 1, 2005; 78(6): 1291 - 1300. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Favre, F. Spertini, and B. Corthesy Secretory IgA Possesses Intrinsic Modulatory Properties Stimulating Mucosal and Systemic Immune Responses J. Immunol., September 1, 2005; 175(5): 2793 - 2800. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Nakamura, A. Terajewicz, and J. Stein-Streilein Mechanisms of Peripheral Tolerance following Intracameral Inoculation Are Independent of IL-13 or STAT6 J. Immunol., August 15, 2005; 175(4): 2643 - 2646. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. J. Schiffrin, M. E. Yousfi, M. Faure, L. Combaret, A. Donnet, S. Blum, C. Obled, and D. Breuille Milk Casein-Based Diet Containing TGF-{beta} Controls the Inflammatory Reaction in the HLA-B27 Transgenic Rat Model JPEN J Parenter Enteral Nutr, July 1, 2005; 29(4_suppl): S141 - S150. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. M. Hunter, A. Wang, C. L. Hirota, and D. M. McKay Neutralizing Anti-IL-10 Antibody Blocks the Protective Effect of Tapeworm Infection in a Murine Model of Chemically Induced Colitis J. Immunol., June 1, 2005; 174(11): 7368 - 7375. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Y. Wu, Y. Jin, R. A. Edwards, Y. Zhang, M. J. Finegold, and M. X. Wu Impaired TGF-{beta} Responses in Peripheral T Cells of G{alpha}i2-/- Mice J. Immunol., May 15, 2005; 174(10): 6122 - 6128. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W. Wang, X. R. Huang, A. G. Li, F. Liu, J.-H. Li, L. D. Truong, X. J. Wang, and H. Y. Lan Signaling Mechanism of TGF-{beta}1 in Prevention of Renal Inflammation: Role of Smad7 J. Am. Soc. Nephrol., May 1, 2005; 16(5): 1371 - 1383. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Di Giacinto, M. Marinaro, M. Sanchez, W. Strober, and M. Boirivant Probiotics Ameliorate Recurrent Th1-Mediated Murine Colitis by Inducing IL-10 and IL-10-Dependent TGF-{beta}-Bearing Regulatory Cells J. Immunol., March 15, 2005; 174(6): 3237 - 3246. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. A. Ruiz, A. Shkoda, S. C. Kim, R. B. Sartor, and D. Haller IL-10 Gene-Deficient Mice Lack TGF-{beta}/Smad Signaling and Fail to Inhibit Proinflammatory Gene Expression in Intestinal Epithelial Cells after the Colonization with Colitogenic Enterococcus faecalis J. Immunol., March 1, 2005; 174(5): 2990 - 2999. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B Eksteen, L S K Walker, and D H Adams Immune regulation and colitis: suppression of acute inflammation allows the development of chronic inflammatory bowel disease Gut, January 1, 2005; 54(1): 4 - 6. [Full Text] [PDF]
|
|
|
|
 |
|
 C. Francoeur, F. Escaffit, P. H. Vachon, and J.-F. Beaulieu Proinflammatory cytokines TNF-{alpha} and IFN-{gamma} alter laminin expression under an apoptosis-independent mechanism in human intestinal epithelial cells Am J Physiol Gastrointest Liver Physiol, September 1, 2004; 287(3): G592 - G598. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. P. Gobert, Y. Cheng, M. Akhtar, B. D. Mersey, D. R. Blumberg, R. K. Cross, R. Chaturvedi, C. B. Drachenberg, J.-L. Boucher, A. Hacker, et al. Protective Role of Arginase in a Mouse Model of Colitis J. Immunol., August 1, 2004; 173(3): 2109 - 2117. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H.-B. Park, D.-J. Paik, E. Jang, S. Hong, and J. Youn Acquisition of anergic and suppressive activities in transforming growth factor-{beta}-costimulated CD4+CD25- T cells Int. Immunol., August 1, 2004; 16(8): 1203 - 1213. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. P. Beiting, S. K. Bliss, D. H. Schlafer, V. L. Roberts, and J. A. Appleton Interleukin-10 Limits Local and Body Cavity Inflammation during Infection with Muscle-Stage Trichinella spiralis Infect. Immun., June 1, 2004; 72(6): 3129 - 3137. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. S. Oz, M. Ray, T. S. Chen, and C. J. McClain Efficacy of a Transforming Growth Factor {beta}2 Containing Nutritional Support Formula in a Murine Model of Inflammatory Bowel Disease J. Am. Coll. Nutr., June 1, 2004; 23(3): 220 - 226. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
L. Saurer, I. Seibold, S. Rihs, C. Vallan, T. Dumrese, and C. Mueller Virus-Induced Activation of Self-Specific TCR{alpha}{beta} CD8{alpha}{alpha} Intraepithelial Lymphocytes Does Not Abolish Their Self-Tolerance in the Intestine J. Immunol., April 1, 2004; 172(7): 4176 - 4183. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Jonuleit and E. Schmitt The Regulatory T Cell Family: Distinct Subsets and their Interrelations J. Immunol., December 15, 2003; 171(12): 6323 - 6327. [Full Text] [PDF]
|
|
|
|
 |
|
 A. Kitani, I. Fuss, K. Nakamura, F. Kumaki, T. Usui, and W. Strober Transforming Growth Factor (TGF)-{beta}1-producing Regulatory T Cells Induce Smad-mediated Interleukin 10 Secretion That Facilitates Coordinated Immunoregulatory Activity and Amelioration of TGF-{beta}1-mediated Fibrosis J. Exp. Med., October 20, 2003; 198(8): 1179 - 1188. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. A. Green, L. Gorelik, C. M. McGregor, E. H. Tran, and R. A. Flavell CD4+CD25+ T regulatory cells control anti-islet CD8+ T cells through TGF-{beta}-TGF-{beta} receptor interactions in type 1 diabetes PNAS, September 16, 2003; 100(19): 10878 - 10883. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. Bliss, A. Alcaraz, and J. A. Appleton IL-10 Prevents Liver Necrosis During Murine Infection with Trichinella spiralis J. Immunol., September 15, 2003; 171(6): 3142 - 3147. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. L. Denning, H. Qi, R. Konig, K. G. Scott, M. Naganuma, and P. B. Ernst CD4+ Th Cells Resembling Regulatory T Cells That Inhibit Chronic Colitis Differentiate in the Absence of Interactions Between CD4 and Class II MHC J. Immunol., September 1, 2003; 171(5): 2279 - 2286. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. Asseman, S. Read, and F. Powrie Colitogenic Th1 Cells Are Present in the Antigen-Experienced T Cell Pool in Normal Mice: Control by CD4+ Regulatory T Cells and IL-10 J. Immunol., July 15, 2003; 171(2): 971 - 978. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 Z.-m. Chen, M. J. O'Shaughnessy, I. Gramaglia, A. Panoskaltsis-Mortari, W. J. Murphy, S. Narula, M. G. Roncarolo, and B. R. Blazar IL-10 and TGF-{beta} induce alloreactive CD4+CD25- T cells to acquire regulatory cell function Blood, June 15, 2003; 101(12): 5076 - 5083. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 D A Carter and A D Dick Lipopolysaccharide/interferon-{gamma} and not transforming growth factor {beta} inhibits retinal microglial migration from retinal explant Br J Ophthalmol, April 1, 2003; 87(4): 481 - 487. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. Oida, X. Zhang, M. Goto, S. Hachimura, M. Totsuka, S. Kaminogawa, and H. L. Weiner CD4+CD25- T Cells That Express Latency-Associated Peptide on the Surface Suppress CD4+CD45RBhigh-Induced Colitis by a TGF-{beta}-Dependent Mechanism J. Immunol., March 1, 2003; 170(5): 2516 - 2522. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. E. H. Bashir, P. Andersen, I. J. Fuss, H. N. Shi, and C. Nagler-Anderson An Enteric Helminth Infection Protects Against an Allergic Response to Dietary Antigen J. Immunol., September 15, 2002; 169(6): 3284 - 3292. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. C. Kullberg, D. Jankovic, P. L. Gorelick, P. Caspar, J. J. Letterio, A. W. Cheever, and A. Sher Bacteria-triggered CD4+ T Regulatory Cells Suppress Helicobacter hepaticus-induced Colitis J. Exp. Med., August 19, 2002; 196(4): 505 - 515. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
H. Jonuleit, E. Schmitt, H. Kakirman, M. Stassen, J. Knop, and A. H. Enk Infectious Tolerance: Human CD25+ Regulatory T Cells Convey Suppressor Activity to Conventional CD4+ T Helper Cells J. Exp. Med., July 15, 2002; 196(2): 255 - 260. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
). Recipient mice received TNBS per
rectum 5 days after adoptive transfer of LP CD4+ T cells
(see Materials and Methods). Data shown are from one
representative experiment of three similar experiments. Each point
represents the average weight of five mice and bars SD
), TNBS per
rectum and anti-IL-10 IP after HCP feeding (
), or TNBS per
rectum without any previous treatment (
