| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
/IL-4R
Chimeric Cytokine Receptor Transgene1
*
Division of Rheumatology, Departments of Medicine, Cell Biology,
Pathology, and
Microbiology and Immunology, Vanderbilt University Medical School, Nashville, TN 37232; and
Department of Internal Medicine, University of Tennessee, and The Research Service of the Veterans Administration Medical Center, Memphis, TN 38104
 |
Abstract |
|---|
 Top Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
/IL-4R
chimeric cytokine
receptor transgene specifically in T cells. In response to IL-2
binding, this chimeric receptor transduces IL-4-specific signals and
dramatically enhances type 2 responses. In contrast to published
reports of Th2-mediated protection, CIA was exacerbated in
IL-2R/IL-4R chimeric receptor transgenic mice, with increased
disease incidence, severity, and earlier disease onset. The aggravated
disease in transgenic mice was associated with an increase in type 2
cytokines (IL-4, IL-5, IL-10) and an increase in collagen-specific IgG1
levels. However, IFN-
production is not affected significantly in
the induction phase of the disease. There is also an extensive
eosinophilic infiltration in the arthritic joints of the transgenic
animal, suggesting a direct contribution of type 2 response to joint
inflammation. Taken together, our findings provide novel evidence that
enhancement of a polyclonal type 2 response in immunocompetent hosts
may exacerbate an autoimmune disease such as CIA, rather than serving a
protective role. This finding raises significant caution with regard to
the potential use of therapeutic approaches based on immune deviation
toward type 2 responses. |
Introduction |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
, TNF-, IL-2, and low levels of IL-10,
whereas type 2 cells produce IL-4, IL-5, IL-13, and high levels of
IL-10. Type 1 cells are critical for cell-mediated immunity and
inflammatory responses such as diabetes and experimental autoimmune
encephalomyelitis
(EAE).3 In contrast,
type 2 cells mediate humoral and mucosal immunity and allergy,
including the activation of eosinophils and mast cells and the
production of IgE. Collagen-induced arthritis (CIA) is an animal model
of autoimmune disease that has been extensively used to elucidate
pathogenic mechanisms relevant to human rheumatoid arthritis (3, 4). The contribution of type 1/type 2 responses in CIA is not
completely understood, because both humoral and cell-mediated immune
mechanisms are required for the development of full-blown disease.
Mauri et al. reported that a type 1 cytokine profile predominates in
the induction and acute phases of the disease, while type 2 responses
are associated with the remission phase of disease (5).
However, there is a transient increase in IL-10 during the induction
phase of the disease. Doncarli et al. analyzed the frequency of Th1- or
Th2-like type II collagen (CII)-specific T cell clones (6)
isolated from different stages of CIA. Among lines generated 8 days
after immunization, 60% were Th0-like, 25% were Th1-like, and 15%
were Th2-like compared with 33% Th0-like, 11% Th1, and 56% Th2 by
day 25 after immunization before clinical arthritis. Although these
data are consistent with a pathogenic role of Th1 cells in CIA, they do
not explain the role or potential contribution of Th2 cells and related
cytokines to the development of CIA.
Altering the balance of cytokines produced by effector subsets of T
cells has been under investigation as a therapeutic approach to alter
the outcome of arthritis. For example, the administration of both IL-4
and IL-10 to arthritic animals ameliorates arthritis, whereas
IL-10-neutralizing Abs accelerate disease onset and increase disease
severity (7, 8, 9). In contrast, the incidence and severity
of arthritis are decreased in IL-12 and IFN regulatory
factor-1-deficient mutant mice (10, 11). Although these
data support CIA as a type 1 disease, this straightforward model is
complicated by the contradictory roles of IFN- and IL-12: disease
promoting as well as disease limiting (12, 13, 14, 15, 16, 17). Some of
these differences may arise because the experimental and genetic
manipulations used typically have affected APCs, costimulatory
function, and nonhemopoietic cells in addition to the T cell
compartment.
To investigate the in vivo regulation of the balance of type 1 and type
2 cells, we generated a transgenic mouse line in which an
IL-2R/IL-4R (IL-2R/IL-4R) chimeric cytokine receptor is expressed
specifically in the T lineage but not in APCs or other tissue
(18). This chimeric receptor transduces signals
characteristic of IL-4 in response to IL-2 binding. Although the
transgenic mice exhibit normal development of the T lineage, peripheral
T cells from these transgenic mice exhibited enhanced type 2 responses.
This influence on the development of effector T cells was sufficient to
overcome the resistance of C57BL/6 mice to OVA-induced allergic airway
disease, a disease mediated by type 2 T cells. Thus, in chimeric
receptor transgenic mice, the presence of IL-2 upon antigenic challenge
appears to favor differentiation of naive T cells into type 2 effector
cells.
Because type 2 cytokines are considered to be beneficial in CIA, we
hypothesized that expression of IL-2R/IL-4R chimeric receptor in T
cells in our transgenic mice should protect animals from disease.
Unexpectedly, CIA was exacerbated in chimeric receptor transgenic mice.
Here we report that disease exacerbation is associated with selective
enhancement of type 2 response without significantly affecting IFN-
level at the induction phase of the disease. Moreover, an extensive
eosinophil infiltration was present in the arthritic joints. Taken
together, these results suggest that augmentation of type 2 response in
IL-2R/IL-4R transgenic mice can be pathogenic, a result with
significant implications with regard to the potential use of immune
deviation as a therapeutic approach.
|
Materials and Methods |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
DBA/1 mice were purchased from The Jackson Laboratory (Bar
Harbor, ME) and used at 6–7 wk of age. IL-2R/IL-4R transgenic
mice were derived from C57BL/6 and DBA/2 background. To introduce CIA
susceptibility genes (the H-2q haplotype and
other background genes), IL-2R/IL-4R transgenic mice were crossed
with DBA/1 for two generations
(F1N1). Mice were then
screened for IL-2R/IL-4R transgene by Southern blot analysis and
PCR. The primer set 5'-GAGCCAGCCCCTGACCTTTC-3' and
5'-GGGAAGTCTGTCTTCTTCTT-3' was used to amplify 350 bp of product of the
IL-2R /IL-4R gene. The H-2 haplotype was also identified by PCR.
The primer set 5'-ACCAACGGGACGCAGCGCAT-3' and
5'-CCTCGTAGTTGTGTCTGCAC-3' was used to amplify the 200 bp of product of
the I-A gene. The PCR products were then probed with
oligonucleotides specific for H-2q,
H-2b, or H-2d genes
(5'-ATACGATCTGTGAACAGATA-3', 5'-ATACGATATGTGACCAGATA-3', and
5'-ATACGGCTCGTGACCAGATA-3' were specific for
H-2q, H-2b, and
H-2d genes, respectively). IL-2R/IL-4R
transgenic mice homozygous for H-2q were then
further backcrossed to DBA/1 for four or five additional generations
(F1N5-F1N6).
Collagen-specific DBA1 V8.3 tg mice were developed by Ed Rosloniec
(19). Primer set 5'-CTCTTCTAGAACACATGGAGG-3' and
5'-GACAGACAGCTTGGTTCCATG-3' was used to amplify 346 bp of the product
of the V8.3 gene.
Induction and assessment of CIA
Native bovine CII (Chondrex, Seattle, WA) was dissolved at 2
mg/ml in 0.01 M acetic acid at 4°C overnight and emulsified with an
equal volume of CFA (Difco, Detroit, MI). CIA was induced by
intradermal injection at the base of the tail with 100 µl of emulsion
containing 50 µg of CII. Starting 21 days after immunization, mice
were analyzed every other day and monitored for signs of arthritis and
date of disease onset in a blind fashion by two independent examiners.
Clinical arthritis was assessed by using a scoring system as follows:
grade 0, no swelling; grade 1, paws with swelling in single digit;
grade 2, paws with swelling in multiple digits; grade 3, severe
swelling and joint rigidity. Each limb was graded, giving a maximum
possible score of 12/mouse. Data were analyzed using the Macintosh
InStat software program. Group comparisons were performed using the
2 test for disease incidence and unpaired,
two-tailed Student’s t test for arthritic scores.
Histology
Paws were removed postmortem, fixed in 4% paraformaldehyde, and decalcified in Immunocal solutions (Decal Chemical, Congers, NY). The paws were then embedded in paraffin and sectioned. Eosinophil-specific Luna staining was used to demonstrate tissue eosinophilia. To compare quantitative measures of the tissue eosinophilia in transgenic mice (n = 8) and nontransgenic control littermates (n = 8), eosinophils were counted in 10 fields/cross-section of each joint in a blind fashion.
Proliferation assay
Mice were sacrificed on day 10 after immunization. Draining lymph nodes (inguinal and para-aortic) were excised, and single-cell suspensions were resuspended in serum-free HL-1 medium (BioWhittaker, Walkersville, MD) supplemented with L-glutamine, 2-ME, and antibiotics. Lymph node cells (4 x 105/well) were plated in triplicate in 96-well flat-bottom microtiter plates in medium alone or in the presence of denatured bovine CII at 5 and 50 µg/ml, or CII peptides at 3.3 and 33 µg/ml. Bovine CII synthetic peptide (ATGPLGPKGQTGEBGIAGFKGEQGPK) was a gift from D. D. Brand (University of Tennessee, Memphis, TN). Cells were incubated at 37°C in 5% CO2 for 4 days, and 1 µCi/well of [3H]TdR was added in culture for the last 18 h. Cells were harvested, and [3H]TdR incorporation per well was measured using a beta scintillation counter.
Cytokine assays
Draining lymph nodes were removed 2 and 7 wk after immunization.
Single-cell suspensions were prepared and cultured in RPMI 1640
containing 10% FBS. The cells were cultured in 96-well round-bottom
plates for 72 h at 2 x 106 cells/ml
(200 µl/well) for 72 h in medium alone or with 5 or 50 µg/ml
of heat-denatured bovine CII. Supernatants were harvested and analyzed
for IL-4, IL-5, IL-10, and IFN- by sandwich ELISA using Ab pairs
(PharMingen, Sorrentino, CA), according to the manufacturer’s
recommended procedures.
Measurement of serum anti-CII Ab levels
Serum samples were collected before immunization and 2, 4, and 6
wk after immunization for the detection of CII-specific IgG, IgG1, and
IgG2a levels. The levels of serum anti-CII Abs were measured by
ELISA as previously described (20). In brief, ELISA plates
(Dynex, Chantilly, VA) were coated overnight at 4°C with 10 µg/ml
native bovine CII in 0.1 M NaHCO3 (pH 9.6). After
washing with PBS containing 0.05% Tween 20, nonspecific binding was
blocked by PBS containing 1% BSA for 1 h at room temperature. All
serum samples were tested in serial dilutions from 1/100 to
1/105. After overnight incubation at 4°C, the
samples were washed with PBS containing 0.05% Tween 20; incubated with
alkaline phosphatase-conjugated goat anti-mouse IgG, IgG1, and
IgG2a (Southern Biotechnology Associates, Birmingham, AL) at room
temperature for 1 h, followed by six washes; and plates were
developed using p-nitrophenyl phosphate (Sigma, St. Louis,
MO) as substrate. The OD was measured at 420 nm using a microplate
reader and 
3 software. A standard serum, i.e., mixture of sera from
wild-type arthritic mice, was added at each plate in serial dilutions,
and a standard curve was generated to design arbitrary units of total
IgG, IgG1, and IgG2a anti-CII Abs.
|
Results |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
To study CIA in IL-2R/4R chimeric receptor mice, transgenic mice
were backcrossed to the disease-susceptible DBA/1
(H-2q) background. After the first two crosses,
the pups were genotyped for both the transgene and the
H-2q gene. H-2q/q
homozygous transgenic mice were then selected for four additional
backcrosses to DBA/1. Because our original hypothesis was that T
cell-specific expression of IL-2R/IL-4R chimeric receptor would serve a
protective role in CIA, we initially induced disease by immunizing
transgenic mice and control littermates with 100 µg of bovine CII in
CFA and boosted with 100 µg of bovine CII in IFA 3 wk later. To our
surprise, transgenic mice exhibited accelerated disease onset, although
disease incidence and severity were not altered under this immunization
protocol. Disease developed on day 21 after primary immunization in
transgenic mice compared with day 31 in control littermates (data not
shown). Under this immunization protocol DBA/1 mice develop severe
arthritis with an incidence approaching 100%, thus making it difficult
to assess the potentially increased severity of disease in the
transgenic mice as suggested by the earlier onset. Therefore, we
altered our immunization protocol to a single injection of 50 µg of
CII in CFA. The results of three separate experiments using this less
intensive induction regimen are summarized in Table I
. The incidence and arthritis index of
animals in each group were calculated from pooled data of these
experiments (Fig. 1). Under this new
immunization protocol, it was clear that CIA is exacerbated in
transgenic mice, as indicated by an increase in disease incidence and
severity and earlier disease onset. As shown in Table I and Fig. 1, the
incidence in transgenic mice (50%, 8 of 16 mice) was significantly
increased compared with that in nontransgenic littermates (25%, 5 of
20 mice; p < 0.05). The severity of the disease was
measured as an arthritis index (total clinical scores per group/numbers
of arthritic animals in each group). The arthritis index was also
significantly increased in IL-2R/4 R transgenic mice (9.9 ± 0.9;
p = 0.05), compared with wild-type littermates
(6.4 ± 1.3). In addition, there was an acceleration in disease
onset in transgenic mice, because the median day of onset among
diseased mice was day 24 for IL-2R/4R transgenic mice but day 42 for
arthritic wild-type mice. Taken together, these results clearly
demonstrate that expression of IL-2R/4R chimeric receptor in T cells in
transgenic mice exacerbated arthritis.
|
|
To investigate the mechanism by which altered T cell function in
these transgenic mice leads to exacerbation of the disease, we first
tested Ag-specific proliferative responses of lymph node cells from
transgenic mice and their nontransgenic littermates. Transgenic and
control mice were immunized with bovine CII, and draining lymph node
cells were isolated and rechallenged with 50 µg/ml of CII or
synthetic peptide in culture. As shown in Fig. 2A, there was no significant
difference between proliferation of IL-2R/4R transgenic lymph node
cells and control cells from nontransgenic littermates (at 50 µg/ml
of CII). We also measured the proliferative response of T cells
expressing a CII-specific V8.3-TCR transgene (19) when
the chimeric receptor was present or absent. The results (Fig. 2B) showed that lymph node cells from both control and
chimeric receptor transgenic mice responded strongly to CII peptide in
a dose-dependent manner, but there was no significant difference
between transgenic mice and control littermates. These data suggest
that the exacerbation of arthritis in IL-2R/4R transgenic mice was not
due to enhanced T cell proliferation in response to CII challenge in
IL-2R/4R transgenic mice.
|
Given that the chimeric receptor amplified IL-4-signaling events
during in vitro differentiation (18), we determined the
effect of the chimeric receptor on the production of IL-4, IL-5, and
IL-10 in response to collagen stimulation in vivo. As shown in Fig. 3, both IL-5 and IL-10 levels were
drastically increased in the IL-2R/4R transgenic mice compared with
nontransgenic littermates (Fig. 3, A–D). Production of IL-4
was below the limit of detection at 2 wk postimmunization, but the
level of IL-4 was significantly increased at 7 wk postimmunization
(Fig. 3E). On a CII-specific V8.3 TCR transgenic
background, a dramatic increase in IL-4 level in chimeric receptor
transgenic animals was detected as early as 10 days postimmunization
(Fig. 5B). Although these
results demonstrate that T cell-specific
expression of chimeric receptor enhances type 2 help, IFN-
production was not significantly affected in the induction phase of the
disease in the transgenic mice (Figs. 4A and
5A).
|
|
|
Because development of CII-specific Abs requires T cell help, we
measured the effect of the transgene on type 2 help in vivo by
measuring CII-specific IgG, IgG1, and IgG2a production. Mice were
immunized with CII in CFA, CII-specific Ab levels were determined in
preimmune sera, and samples were collected at 2, 4, and 6 wk after
immunization. CII-specific IgG, IgG1, and IgG2a were undetectable
before immunization, and there was no significant difference in the
IgG2a level between transgenic and control mice after immunization. In
contrast, the CII-specific IgG1 and IgG levels were significantly
increased in chimeric receptor transgenic mice compared with their
nontransgenic littermate controls (Fig. 6) 2 and 4 wk after immunization. This
elevated IgG1 production persisted 6 wk after immunization (Fig. 6),
consistent with our cytokine data, which suggest that T cell-specific
expression of the transgene enhances type 2 help in vivo in CIA. Taken
together, we conclude from these studies that the accelerated arthritis
of chimeric receptor transgenic mice is not attributable to type 1 T
cells. Instead, type 2 help was increased along with a significant
increase in total CII-specific IgG.
|
A hallmark of inflammatory arthritis such as RA and CIA is the
presence of pannus, proliferating synovial membranes that form
interdigitating folds. The formation of active inflamed pannus results
in the destruction of cartilage and bone. Recent reports showed that
local IL-4 gene therapy could protect cartilage and bone from erosion
despite severe inflammation (21). To determine the effect
of enhanced type 2 response in our transgenic mice on cartilage and
bone, we examined joint histology in arthritic mice. When paws with
equivalent degrees of clinical inflammation were examined, there were
no significant differences in cellular infiltration, pannus formation,
and cartilage and bone erosion between transgenic mice and
nontransgenic littermates (data not shown). However, there was
extensive accumulation of eosinophils in IL-2R/4R transgenic mice,
while eosinophils were rarely detected in the joints of nontransgenic
littermates with the same clinical score (Fig. 7, A and B). The
majority of the eosinophils accumulated in areas adjacent
to blood vessels in the dermis. When the degree of eosinophilia was
quantitated (Fig. 7C), there was an increase in the numbers
of eosinophils with the increase in disease severity, with most
abundant eosinophils found in the joints of transgenic mice with grade
3 disease. In contrast, eosinophils were barely detectable in
nontransgenic littermates regardless of the severity of the disease.
These data are consistent with high level IL-4 and IL-5 production in
transgenic mice 7 wk postimmunization (Fig. 3
, E and
B). Taken together, our results suggest that increased
production of IL-4 and IL-5 by type 2 T cells leads to eosinophil
recruitment and activation in the joint, exacerbating inflammation in
chimeric receptor transgenic mice.
|
|
Discussion |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
One interpretation of our results might have been that elevated IL-4
production somehow also promotes a type 1 response in vivo in
transgenic mice. A recent report showed that IL-4 enhances IL-12
production by dendritic cells and thereby promotes a Th1 response
(25). Moreover, IL-4 has been shown to enhance Th1 cell
development in vitro in the presence of TGF- (26).
However, this hypothesis is rendered unlikely by the finding that
IFN- production induced by collagen in transgenic mice either was
not significantly altered during the induction phase of the disease or
was diminished in later phases of the disease. Our data suggest that T
cell-specific expression of chimeric receptor leads to selective
enhancement of Th2 cell development in vivo. An alternative
interpretation is that the more severe disease phenotype of transgenic
mice is directly caused by increased type 2 responses in vivo. This
hypothesis is supported by our observation that the levels of IL-4,
IL-5, and IL-10 were markedly elevated. Furthermore, CII-specific IgG1
(whose production is enhanced by IL-4 and is therefore indicative of
Th2 response) is also significantly increased in transgenic mice 2 wk
after immunization, and the high level of IgG1 persists to the late
stage of the disease (6 wk postimmunization). Finally, there is a
massive eosinophil infiltration in the arthritic joint of transgenic
mice, suggesting the contribution of type 2 response to the disease in
transgenic mice. Considering that type 2 cells and cytokines were found
in CIA before the onset of clinical arthritis (5, 6), we
favor the hypothesis that both type 1 and type 2 cells play roles in
the pathogenesis of the disease. In this view, accentuation of either
subset can aggravate disease as long as the other subset is able to
develop during early phases of the Ag response.
An important question from these findings is how an increased type 2
response exacerbated the disease. Based on several lines of evidence
from other autoimmune disease models, it is likely that the IL-10
produced by infiltrating T cells in the joint plays a role in the
disease pathogenesis. Results with IL-10 transgenic mice provide
evidence supporting this hypothesis. Expression of an IL-10 transgene
specifically in the pancreatic cells of NOD mice promoted the
development of diabetes (27, 28). Moreover, Th2
cell-induced diabetes in immune-compromised NOD mice is mediated by
local IL-10 production, indicating that IL-10 is able to induce local
pathology directly (29). It is likely that a second
contributory mechanism is the elevated level of IL-4 and IL-5. High
levels of IL-4 secreted by type 2 T cells in the joint stimulate the
expression of adhesion molecules such as VCAM-1 on endothelial cells as
well as the production of chemokines such as (MCP-1) from endothelial
cells, resulting in the recruitment of eosinophils and monocytes to the
joints. Type 2 cells also secret IL-5, which stimulates the growth and
differentiation of eosinophils and activates mature eosinophils.
Consistent with this mechanism, an extensive eosinophil infiltration
was observed in the arthritic joint of chimeric receptor transgenic
mice. Finally, high levels of IL-4 may promote CII-specific Ab
production, thus leading to more severe disease. For instance,
expression of an IL-4 transgene under the control of a MHC class I
promoter led to increased levels of total IgG, IgG1, and IgE, and
spontaneous autoimmune-type disease (22). The expression
of our chimeric receptor was restricted to T cells, and T cell and B
cell number and ratio appeared normal in both spleen and lymph node
(data not shown). However, CII-specific IgG and IgG1 levels are
significantly increased, which may partially account for the more
severe disease in transgenic mice.
A prior study demonstrated that local IL-4 gene therapy could protect
cartilage and bone from erosion despite severe inflammation
(21). However, despite enhanced levels of IL-4 and IL-5
and a marked increase in eosinophils in the joint, there is no
significant change in cartilage and bone erosion between chimeric
receptor transgenic mice and control littermates when paws with
equivalent clinical severity were compared. This observation is
consistent with our data that the Th1 response is not significantly
suppressed (Fig. 4A) in the early stage of the immune
response in transgenic mice. Our finding suggests that despite the
enhanced Th2 response and the presence of eosinophils, an initially
normal Th1 response in chimeric receptor transgenic mice can trigger a
cytokine cascade to activate macrophages/monocytes, which, in turn,
stimulates synoviocyte proliferation, pannus formation, and destruction
of cartilage and bone.
Contributions of the type 2 response to autoimmune disease do not appear to be limited to CIA. Recent work in both diabetes and EAE models has found that adoptive transfer of Ag-specific Th2 cells into immunodeficient mice not only failed to protect against Th1 cell-induced disease, but also caused Th2-related disease. Specifically, infiltration of eosinophils in the islets and infiltration of mast cells in the spinal cord were observed for insulin-dependent diabetes mellitus and EAE, respectively (29, 30). Moreover, adoptive transfer of long term T cell clones with a fixed Th2 cytokine profile caused diabetes in immunocompetent mice (31). Our results demonstrate that even in the absence of adoptive transfer and without an expanded population of Ag-specific T cells, sustained elevation of type 2 responses may not be benign and has the potential to cause clinical disease in animal models.
|
Acknowledgments |
|---|
|
Footnotes |
|---|
2 Address correspondence and reprint requests to Dr. Jin Chen, A-4323, Medical Center North, Vanderbilt University Medical School, Nashville, TN 37232.
3 Abbreviations used in this paper: EAE, experimental autoimmune encephalomyelitis; CIA, collagen-induced arthritis; CII, type II collagen.
Received for publication October 4, 2000. Accepted for publication January 16, 2001.
|
References |
|---|
|
TopAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
in murine collagen-induced arthritis. Eur. J. Immunol. 25:1184.[Medline]
receptors. J. Immunol. 158:5501.[Abstract]
-interferon triggers the onset of collagen arthritis in mice. Arthritis Rheum. 31:1297.[Medline]
receptor-deficient mice. J. Immunol. 158:5507.[Abstract]
chain (IL-2 R)/IL-4 R cytokine receptor chimera potentiates allergic airway disease. J. Exp. Med. 188:1803.
B activation in collagen-induced arthritis. J. Immunol. 163:1577. favors an alternative pathway of Th1 development independent of IL-12. J. Immunol. 161:4709. cells in nonobese diabetic mice. J. Exp. Med. 179:1379.This article has been cited by other articles:
|
|
 |
|
  L. Pace, S. Rizzo, C. Palombi, F. Brombacher, and G. Doria Cutting Edge: IL-4-Induced Protection of CD4+CD25- Th Cells from CD4+CD25+ Regulatory T Cell-Mediated Suppression J. Immunol., April 1, 2006; 176(7): 3900 - 3904. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Young, N. Mikhalkevich, Y. Yan, D. Chen, and W.-p. Zheng Differential Regulation of Osteoblast Activity by Th Cell Subsets Mediated by Parathyroid Hormone and IFN-{gamma} J. Immunol., December 15, 2005; 175(12): 8287 - 8295. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. Takasawa, Y. Munakata, K. K. Ishii, Y. Takahashi, M. Takahashi, Y. Fu, T. Ishii, H. Fujii, T. Saito, H. Takano, et al. Human Parvovirus B19 Transgenic Mice Become Susceptible to Polyarthritis J. Immunol., October 1, 2004; 173(7): 4675 - 4683. [Abstract] [Full Text] [PDF]
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
)
after immunization with bovine CII as described in Table I
