By
From the Howard Hughes Medical Institute and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, New York, 10461
Experimental allergic encephalomyelitis (EAE) is an autoimmune disease of the central nervous system (CNS), and the most commonly used experimental model for multiple sclerosis. It is mediated by autoreactive T cell clones exhibiting a T helper cell (Th) 1 cytokine profile. Nonencephalitogenic T lymphocytes specific for self or exogenous antigens have been found to suppress encephalitogenic T cell responses and to protect against autoimmune disease. The mechanisms by which exogenous antigens modulate autoimmunity are not fully understood. In this study, we tested the hypothesis that a Th2-type immune response against an exogenous, nonself antigen, keyhole limpet hemocyanin (KLH), by releasing IL-4 in the microenvironment, could shift the cytokine profile of encephalitogenic T cells from an inflammatory Th1 to a protective Th2 type. SJL/J mice were preimmunized with the KLH in incomplete Freund's adjuvant to induce a population of Th2 memory cells that would be expected to release Th2 cytokines when activated by the specific antigen at the time of EAE induction. Four weeks later, mice received an encephalitogenic challenge containing guinea pig myelin in complete Freund's adjuvant with or without KLH. All KLH primed animals not receiving the exogenous antigen at the time of EAE induction developed a severe clinical disease indistinguishable from control mice not KLH primed. In contrast, animals preimmunized and challenged with the encephalitogenic inoculum containing KLH showed either no, or markedly reduced, clinical signs. Enzyme-linked immunospot analysis demonstrated that KLH-specific T cells in the primed mice were producing IL-4 characteristic of Th2 cells. In the KLH-primed and restimulated mice, the cytokine profile of the autoreactive, myelin basic protein-specific T cells was shifted from an inflammatory Th1 towards a protective Th2 type. We infer that the presence of IL-4 secreted by KLH-specific memory Th2 cells in the lymphoid system microenvironment in which the autoreactive T cells were engaged by the encephalitogenic stimulus were able to bias their cytokine profile towards a protective Th2 phenotype. This interpretation is supported by the observation that the protective effect of preimmunization with KLH was overcome by rm- IL-12, which inhibited the production of IL-4 by the Th1 cells and biased the autoimmune response to a predominantly Th1 type. Since IL-4 mRNA could not be detected by reverse transcriptase PCR in the CNS, the protective effect was inferred to be mediated by Th2 cells in the lymphoid system, and not the target organ. We conclude that exogenous, nonself antigens that can induce Th2 responses, can modify the cytokine environment sufficiently to alter the cytokine phenotype of inflammatory, autoreactive T cell clones, and ultimately, to provide significant protection against EAE and possibly other T cell-mediated autoimmune diseases.
Experimental allergic encephalomyelitis (EAE)1 is an autoimmune disease of the central nervous system (CNS)
mediated by CD4+ T lymphocytes specific for autoantigens
of the myelin sheath, including myelin basic protein (MBP)
and proteolipid protein (1, 2). Encephalitogenic T cell
clones have a classical Th1 cytokine profile, secreting the
cytokines IFN- Infectious agents have often been implicated in the etiology of autoimmune diseases (11), and considerable evidence
has accumulated indicating that immune responses to foreign antigens are able to modulate the activation of autoimmune T cell clones. For example, it has been shown
that the immune response against bacterial antigens can attenuate the outcome of experimental autoimmune diseases
such as adjuvant arthritis, insulin-dependent diabetes mellitus in NOD mice, and EAE in mice and rats (12). In
several studies, administration of mycobacterial proteins
such as heat-shock cognate proteins of 65 and 70 kD, a
12-kD protein, or tuberculin PPD in IFA, induced protection against EAE (19). Understanding the mechanisms
involved in the modulation of experimental autoimmune diseases could provide insights into immunologic strategies for developing useful interventions in human autoimmune diseases.
At present, the mechanisms responsible for protection
against autoimmune diseases induced by microbial antigens
remain unclear. One hypothesis to explain how an immune response against an exogenous antigen may interfere
with autoimmunity holds that the bacterial proteins may
induce a state of tolerance, as suggested by a downregulation of the CD4 coreceptor detected at the time of onset of
the autoimmune disease in mice protected by treatment
with mycobacterial hsp60 (19). In this paper we test an alternative hypothesis, namely, that the immunization against
nonself antigens can inhibit the development of EAE by
modifying the cytokine environment in which autoreactive
T cell clones develop and expand upon autosensitization, such that their cytokine profile is shifted from an inflammatory Th1 towards a protective Th2 type.
Mice.
Female SJL/J mice (8-12-wk old) were purchased from
the Jackson Laboratory (Bar Harbor, ME). Animals were housed
in the animal facility of the Albert Einstein College of Medicine,
maintained on standard laboratory chow and water ad libitum,
and were free of 12 murine pathogens. The experiments were
done in accordance to the animal use guidelines of the National
Institutes of Health.
Antigens.
The guinea pig myelin was purified from guinea
pig spinal cords (Pel-Freeze, Rockland, PA) according to the
method of Norton and Poduslo (22). KLH of Megathura crenulata
was purchased from Calbiochem Corp. (San Diego, CA) and bovine MBP from Sigma Chemical Co. (St. Louis, MO).
Preimmunization with KLH.
SJL/J mice were injected intraperitoneally 4 wk before the induction of EAE with 50 µg of
KLH emulsified in IFA (Difco Labs., Detroit, MI). Control mice
received PBS at the same time.
Induction of EAE.
SJL/J mice were injected in four different
sites in the back with 0.1 ml of inoculum containing 700 µg of
guinea pig myelin in CFA (700 µg/ml of Mycobacterium tuberculosis H37Ra strain in IFA). One group of mice received again the
KLH antigen (50 µg) with the encephalitogenic inoculum. All
groups of mice received 100 ng of pertussigen/mouse intravenously on days 0, 2, and 7.
Clinical Evaluation.
Mice were monitored daily and a clinical
score was assigned using the following scale (23): 0, no clinical
sign; 1, a limp tail; 2, hind limb weakness; 3, complete hind limb
paralysis; 4, tetraplegia; 5, death.
Recombinant Murine IL-12.
The recombinant murine (rm) IL-12
(Genetics Institute, Boston, MA) was administered intraperitoneally at 0.3 µg/mouse on days 0, 1, and 2 p.i. to a group of SJL/J
mice pretreated with the KLH antigen that received a second
KLH immunization at the time of EAE induction (24).
Establishment of KLH- and MBP-specific T Cell Lines.
Axillar and
inguinal lymph nodes were removed 10 d p.i., homogenized,
pooled, and resuspended (4 × 106/ml) in RPMI 1640 (GIBCO
BRL, Gaithersburg, MD) supplemented with 10% FCS, 100 U/ml
penicillin/streptomycin, 2 mM glutamine, 15 mM Hepes, 100 µM
nonessential amino acids, 1 mM Na-pyruvate, and 50 µM 2-mercaptoethanol. Cells were stimulated with KLH or MBP (50 µg/
ml) for 6 d at 37°C in 5% CO2.
Determination of Cytokine Profiles of Specific T Cell Lines by Enzyme-linked Immunospot.
An adaptation of the enzyme-linked
immunospot (ELISPOT) assay (25) was used to enumerate IFN- Determination of Cytokine Profiles in the CNS by Quantitative Reverse Transcriptase-PCR.
The CNS of KLH-protected and control EAE mice were removed 18 d p.i., and the total RNA was
extracted using TRIzol Reagent (GIBCO BRL). RNA samples
were reverse transcribed using random hexamers (GIBCO BRL)
as primers and Superscript reverse transcriptase (GIBCO BRL).
The cDNA was then amplified with the following specific primers: hypoxanthine phosphoribosyl transferase (HPRT), 5 To test the hypothesis that T cells specific for a foreign antigen could alter the course of EAE in SJL/J mice, two groups of mice
were primed intraperitoneally with KLH in IFA. A control group received PBS at the same time. After 4 wk all mice
received an encephalitogenic inoculum containing guinea
pig myelin in CFA, and one of the two groups of mice previously primed with KLH received the KLH antigen at this
time. EAE was fully developed after 10-14 d in the animals
that were not primed, or that received the KLH in IFA 4 wk before but were not given the foreign antigen at the time of the encephalitogenic immunization. In contrast,
when the KLH-specific T cells were reactivated at the time
of EAE induction by a second antigenic challenge, the KLHprimed mice were almost completely protected. In this group
of mice, both the incidence and the mean clinical score were
significantly reduced compared to controls (Fig. 1). These
results indicated that stimulating primed mice with the
nonself antigen at the time of activation of autoimmune T
cell clones could alter the course of the autoimmune disease.
To test the hypothesis that
the protection induced by the KLH was due to a shift in
the cytokine profile of the encephalitogenic clones from a
Th1 to a Th2 type, we attempted to reverse the KLH effect
by modifying the cytokine profiles of the KLH- and MBPspecific T cells in the KLH protected mice. Since previous
studies established that IL-12, the major Th1 "priming" cytokine, is able to inhibit KLH-specific memory Th2 cells in
primed mice (27), we treated the KLH-primed and challenged mice with rmIL-12. SJL/J mice were preimmunized with KLH as before. After 4 wk the exogenous antigen was given again with encephalitogenic inoculum and,
at the same time, a portion of the mice were treated for three
consecutive days with rmIL-12. In these mice, the KLHinduced protection was completely abolished, and, in fact, the
mice receiving IL-12 showed even greater mean clinical
score than the control, non-KLH primed mice (Fig. 2).
To verify our hypothesis that KLH
administered in IFA induces the Th2 response that alters
the nature of autoimmune T cells, we examined the cytokine profiles of both KLH- and MBP-specific T cell lines
in these mice. T cells were isolated from lymph nodes from
the three groups of animals at 10 d p.i. and stimulated in vitro with KLH or MBP, the predominant autoantigen in
EAE. After 6 d, the cytokine profiles of these short-term
lines directly obtained from the animals were determined
by ELISPOT. As expected, the KLH-specific T cells from
animals preimmunized intraperitoneally with KLH in IFA
showed a predominantly Th2 phenotype. In contrast, when
the KLH-primed mice were treated with rmIL-12, both
IFN-
In the Protected, KLH-primed Mice, the Cytokine Profile of the Encephalitogenic T Cells Is Shifted Towards a Th2 Type.
Among the
MBP-specific T cell lines isolated from lymph nodes, the
number of IL-4-secreting T cells was significantly higher in
the KLH-protected mice compared to the controls (Fig. 3
b). The number of IFN- We
sought to address the question whether the protective effect on EAE induced by KLH-specific Th2 cells was mediated centrally or in the CNS target organ. Histopathological analysis of the brain and spinal cords of KLH-protected
and control mice confirmed a lower degree of lymphocyte
infiltration in the CNS of the protected mice, consistent
with the reduced clinical score (data not shown). To determine the cytokine profile phenotype of the T cells found in
the CNS, we performed a reverse transcriptase (RT)-PCR
analysis on the total RNA samples extracted from brains
and spinal cords of both groups of mice. After normalization for HRPT DNA, we evaluated IL-4 and IFN- Autoreactive T lymphocytes are present in the T cell
repertoire of healthy individuals and the mechanisms that
modulate their activation in T cell-mediated autoimmune
diseases remain unclear. Multiple lines of evidence suggest
that simultaneous T cell immune responses against nonself
antigens, for example, during infections, may modulate the
activity of autoreactive T cell clones. Epidemiological studies have clearly shown that environmental factors play a role in the pathogenesis of human autoimmune diseases (28, 29). Experimental studies on transgenic mice expressing the MBP
T cell receptor indicate that the ability of the encephalitogenic clones to induce EAE is modulated by lymphocytes
with different specificity, presumably specific for antigens
present in the environment (9, 10). Most of these studies
have stressed the ability of immune responses to environmental antigens to activate the autoreactive T cells (30)
and induce disease, but in a number of cases, it has been
observed that responses against exogenous antigens can downregulate the encephalitogenic T cell clones (17). Several laboratories have reported that immunization with mycobacterial proteins such as PPD, hsp65, and hsp70 can confer
protection against EAE, but the mechanisms responsible for
this protection have not been elucidated. Another example
of downmodulation of autoimmune T cell clones by an exogenous antigen is the protection against EAE reported
after oral administration of ovalbumin (33). Although a
"bystander suppression" mechanism mediated by Th2 cytokines has been proposed, a shift in the cytokine profile of
the autoreactive T cells was not clearly demonstrated, and
other immunosuppressive cytokines such as TGF- Several attempts have been made to shift the cytokine
profile of autoimmune T cell clones from a Th1 to a Th2
type, for example, by oral administration of the autoantigen
(5), or targeting of the encephalitogenic peptide of MBP
on B cells (34), and recently by modifying of the amino
acid sequence of the encephalitogenic peptide (35). In most
such studies, protection against EAE and clinical disease
was observed, but a shift in cytokine profiles of the autoreactive T clones from an inflammatory Th1 to a protective Th2, IL-4-producing phenotype has not been clearly
shown. At the present time, the mechanisms that regulate
the Th1 or Th2 differentiation remain to be clarified, and
currently only the presence of "priming" cytokines such as
IL-12 or IL-4, in the microenvironment where the naive
T cells receive their primary antigenic stimulus, appears to
be determinative (36). In other systems it has been demonstrated that Th1 and Th2 subsets with different antigen specificities can interact in vivo. In particular, Th2-type immune
responses against parasitic agents can alter Th1 responses to
mycobacterial antigens and viruses by an IL-4-dependent
mechanism (37).
Previous studies have shown that the administration of
an antigen in IFA biases the response towards a Th2 phenotype, while CFA more likely induces a Th1 cytokine
profile in T helper cells (41). In our model, we find that the
production of Th2 cells, defined by the ability to produce
IL-4, induced by an exogenous antigen by administration
in IFA was sufficient to prime for a cytokine microenvironment in which the autoimmune stimulus was modulated to an attenuated or protective one. This finding indicates that the exogeneous antigen need not be a cognate
hsp or cross-reactive with autoantigens to supress EAE.
When the effect of IL-4 was countered by the administration of IL-12, the protection provided by the KLH-specific, Th2 cells was abrogated. However, our findings suggest that the modulation of the response mediated by
exogenous antigen occurs in the lymphoid system rather
than the target organ, since by RT-PCR we were unable to
detect IL-4 mRNA in the CNS, although IFN- In summary, our data suggest a mechanism for modulation of disease-causing autoimmune T cell clones development by Th2 cells specific for nonself antigens. We believe
that a Th2-type immune response against an exogenous antigen modulates the autoimmune disease by modifying the
cytokine environment at the time of primary autoantigenic
stimulation of the autoreactive T cell clones, shifting their
cytokine profile from an inflammatory Th1 to a protective Th2 type. These findings may serve to clarify the role of Th2 immune responses against exogenous antigens, such as those
found to occur during parasitic infections, in modulating
the pathogenesis of Th1-mediated autoimmune diseases. At
the same time, because of obvious risks in immunizing individuals with specific autoantigens to prevent autoimmunity, they provide further support for the possibility of modulating the cytokine profile of encephalitogenic T cell clones
by means of exogenous antigens to induce protection in
experimental autoimmune diseases of CNS, and encourage
the view that it may ultimately be possible to modify the
immune responses of autoreactive T cell clones therapeutically
to prevent or attenuate human T cell-mediated autoimmune
diseases.
and IL-2, and induce local macrophage
activation, inflammation, and demyelination (3, 4). Th2 cell
clones specific for encephalitogenic peptides are unable to
induce the disease and can inhibit Th1 autoimmune clones,
presumably by secreting IL-4, IL-10, and TGF-
(5). In
a transgenic mouse model, the presence of lymphocytes expressing a transgenic TCR specific for MBP was not sufficient to induce the autoimmune disease. Rather, these
transgenic mice developed spontaneous EAE only when
the RAG-1 gene was deleted and the transgenic, MBPspecific T cells were present in a context in which no other lymphocytes expressing different T cell receptors existed
(9, 10). This observation supports the view that the pathogenicity of predetermined autoimmune T cells can be effectively modulated by lymphocytes of other specificities.
and IL-4 secreting T cells among the KLH- and MBP-specific
short-term lines. In brief, 96-well nitrocellulose based plates (Millititer HA; Millipore Corp., Bedford, MA) were coated overnight
with mAb anti-murine IL-4 or IFN-
mAbs (10 µg/ml; PharMingen, San Diego, CA). The plates were washed with PBS, and
the T cell lines were purified on ficoll-hypaque and added to individual wells at serial twofold dilutions (2 × 105-6 × 103). Splenocytes from donor SJL/J mice were negatively selected for
CD3+ T cells using a rat anti-murine CD3 mAb (GIBCO BRL)
and magnetic beads coated with antibodies to rat IgG (DYNAL,
Inc., Great Neck, NY), irradiated, and added to the plate (5 × 104/well) together wth Con A (2.5 µg/ml). After 20 h, the plates were washed with PBS containing 0.05% Tween and incubated
overnight with biotinylated mAbs anti-IL-4 or anti-IFN-
(4 µg/ml). The plates were then washed with PBS-Tween and incubated with avidin-peroxidase (2.5 µg/ml). Spots representing
single IL-4- or IFN-
-secreting T cells were developed with the
substrate 3-amino-9-ethylcarbazole in 0.1 M sodium acetate
buffer + H2O2. The number of spots was enumerated using a dissecting microscope.
-GTTGGATACAGGCCAGACTTTGTTG, 3
-GAGGGTAGGCTGGCCTATGGCT; IFN-
, 5
-TGCATCTTGGCTTTGCAGCTCTTCCTCATGGC, 3
-TGGACCTGTGGGTTGTTGACCTCAAACTTGGC; IL-4, 5
-CATCGGCATTTTGAACGAGGTCA, 3
-CTTATCGATGAATCCAGGCATCG. To normalize the
amount of cDNA, we performed a quantitative PCR analysis of
HPRT mRNA levels using serial dilution of the pQRS polycompetitor (provided by Dr. D.B. Corry, University of California at San Francisco, San Francisco, CA; 26). The amount of
IFN-
-specific RNA in the two cDNA normalized samples was
measured by quantitative PCR using serial dilutions of the mouse
IFN-
PCR MIMIC (Clontech, Palo Alto, CA). Reactions were
performed in a programmable thermal controller (Perkin-Elmer Cetus Instrs., Norwalk, CT) for 35 cycles. Each cycle consisted of
94°C for 40 s, 60°C for 20 s, and 72°C for 40 s. After amplification, 10 µl of PCR product was separated by electrophoresis on
1% agarose gels and visualized by ethidium bromide staining.
Priming and Challenge of Mice with an Exogenous Antigen,
KLH, in IFA Induces Protection from EAE.
Fig. 1.
Effect of the KLH preimmunization and challenge at the
time of EAE induction on the incidence and clinical score of the disease. Two groups of SJL/J mice were injected intraperitoneally with an emulsion of KLH in IFA. One control group was injected with PBS. After
4 wk, EAE was induced by immunizing the animals with guinea pig myelin in CFA. One of the two groups of mice pretreated with KLH received the foreign antigen with the encephalitogenic inoculum. This group
of mice was almost completely protected (filled circles) against EAE. The
control group that was not preimmunized with KLH (open circles) or the
group that was primed, but not challenged a second time with KLH (open
squares) both showed high incidences and clinical scores for the disease.
[View Larger Version of this Image (14K GIF file)]
Fig. 2.
rmIL-12 at the time of immunization overcomes protection
engendered by pretreatment and reticulation with KLH. One group of mice that was pretreated with KLH in IFA received the antigen again
with the encephalitogenic inoculum together with rmIL-12 (0.3 mg/
mouse), given on days 0, 1, and 2 after immunization (filled squares). The
mice receiving the minimal treatment with rmIL-12 were not protected
against EAE and showed a significantly higher mean clinical score compared to the KLH-protected mice (filled circles).
[View Larger Version of this Image (10K GIF file)]
- and IL-4-producing cells were found among the
KLH-specific T cells, but the number of IL-4 secreting T
cells was consistently decreased (Fig. 3 a). In control mice
not primed with KLH, the KLH-specific T cells receiving
the first antigenic stimulus in vitro, expressed a Th1 profile.
This indicated that primary antigenic stimulation of naive
T cells with KLH in vitro leads to a predominantly Th1 phenotype.
Fig. 3.
Determination of cytokine profiles of KLH (a) and MBP (b) specific short-term T cell lines. Two mice of each group were killed at day 10 p.i. and lymph node cells stimulated in vitro with KLH or MBP for 6 d. The number of IL-4 (crosshatched bars) and IFN- (solid bars) was determined by
ELISPOT analysis. The KLH-specific lymph node T cells of mice immunized with the antigen in IFA showed a Th2 cytokine profile. When the mice
were treated with rmIL-12, the number of IL-4-producing cells was decreased. In control mice receiving only PBS, the primary antigenic stimulation in
vitro with KLH induced a Th1 phenotype. The MBP-specific T cells showed a Th1 inflammatory profile in nonprotected controls (not pretreated with,
or not restimulated with KLH) while in KLH-protected mice, the cytokine profile was shifted to a Th2 type. Treatment with rmIL-12 for only 3 d was
sufficient to modify the phenotype of the MBP-specific T cells in the KLH/IFA-treated mice from Th2 from Th1.
[View Larger Versions of these Images (23 + 23K GIF file)]
-producing, inflammatory Th1
cells in these mice is very low, a result consistent with the
protection against EAE that we observed. When the KLHprimed and challenged mice were treated for 3 d with
rmIL-12, the cytokine profile of the MBP-specific T cells was
reversed to a predominantly inflammatory Th1 type (Fig. 3 b).
mRNA expression in the two samples. No IL-4 RNA expression was found in either group of mice. The amount of
IFN-
expression was measured by quantitative PCR. As
expected, the attomoles per microgram of IFN-
mRNA
was significantly lower in the protected mice (5 × 10
2 attomoles) than in the control (1.2 × 10
1 attomoles). Although the failure to detect the IL-4 mRNA expression in
the brain of the protected mice does not allow us formally to exclude the possibility that Th2 cells enter the CNS, the
data support the interpretation that the downregulation of
Th1 inflammatory clones takes place in the lymph nodes at
the time of autoantigenic stimulation, so that a lower number
of Th1 encephalitogenic clones develop and reach the CNS.
and IL-10
were implicated in the protection induced.
mRNA
was readily detectable in the control group that developed
EAE. This observation suggests that Th2 autoreactive cells
either do not reach, or are not retained in the CNS. Our interpretation is that MBP-specific Th2 cells do not induce
inflammation in the CNS and, at the same time, inhibit the
Th1 autoreactive clones at the level of the peripheral
lymph nodes such that fewer are developed or migrate to
the CNS. This is indicated by the lower amount of IFN-
mRNA we found in the CNS of the KLH-protected mice.
Fig. 4.
IFN- and IL-4
mRNA in the CNS of KLHprotected and control mice sensitized to myelin. The RT-PCR
was performed on RNA samples extracted from brain and spinal
cord of the mice at day 16 after immunization using specific primers
for IFN-
and IL-4. The mRNAs for IFN-
and IL-4 were measured by quantitative PCR using
a competitor DNA fragment for
each, and the quantities expressed
as attomoles of cDNA per microgram of total RNA.
[View Larger Version of this Image (7K GIF file)]
Address correspondence to Barry R. Bloom, Howard Hughes Medical Institute and Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY 10461. Dr. Marika Falcone's present address is Department of Neuropharmacology, CVN10, The Scripps Research Institute, 10666 North Torrey Pines Rd., La Jolla, CA 92037.
Received for publication 20 September 1996 and in revised form 26 December 1996.
Dr. M. Falcone was supported by a Fellowship from the Cenci-Bolognetti Foundation, Pasteur Institute of Rome, Italy. This work was supported by the National Multiple Sclerosis Society, National Institutes of Health AI 07118, and the Howard Hughes Medical Institute.We thank Celia Brosnan, Robert Modlin, and Marco Salvetti for review of the manuscript.
1. | Ben-Nun, A., H. Wekerle, and I.R. Cohen. 1981. The rapid isolation of clonable antigen-specific T lymphocytes lines capable of mediating autoimmune encephalomyelitis. Eur. J. Immunol. 11: 195-199 [Medline] . |
2. |
Pettinelli, C.B.,
R.B. Fritz,
C.H.J. Chau, and
D.E. McFarlin.
1982.
Encephalitogenic activity of guinea pig myelin basic
protein in the SJL/J mouse.
J. Immunol.
129:
1209-1211
|
3. | Liblau, R.S., S.M. Singer, and H.O. McDevitt. 1995. Th1 and Th2 CD4+ T cells in the pathogenesis of organ-specific autoimmune diseases. Immunol. Today. 1: 34-38 . |
4. | Miller, S.D., and W.J. Karpus. 1994. The immunopathogenesis and regulation of T-cell-mediated demyelinating diseases. Immunol. Today. 8: 356-361 . |
5. | Chen, Y., V.K. Kuchroo, J. Inobe, D.A. Hafler, and H.L. Weiner. 1994. Regulatory T cell clones induced by oral tolerance: suppression of autoimmune encephalomyelitis. Science (Wash. DC). 265: 1237-1240 [Medline] . |
6. | Racke, M.K., A. Bonomo, D.E. Scott, B. Cannella, A. Levine, C.S. Raine, E.M. Shevach, and M. Rocken. 1994. Cytokine-induced immune deviation as a therapy for inflammatory autoimmune disease. J. Exp. Med. 180: 1961-1966 [Abstract] . |
7. | Van der Veen, R.C., and S.A. Stohlman. 1993. Encephalitogenic Th1 cells are inhibited by Th2 cells with related peptide specificity: relative roles of interleukin (IL)-4 and IL-10. J. Neuroimmunol. 48: 213-220 [Medline] . |
8. |
Miller, A.,
A. Al-Sabbagh,
L.M.B. Santos,
M. Prabhu-Das, and
H.L. Weiner.
1993.
Epitopes of myelin basic protein that
trigger TGF-b release after oral tolerization are distinct from
encephalitogenic epitopes and mediate epitope-driven bystander suppression.
J. Immunol.
151:
7307-7315
|
9. | Lafaille, J.J., K. Nagashima, M. Katsuki, and S. Tonegawa. 1994. High incidence of spontaneous autoimmune encephalomyelitis in immunodeficient anti-myelin basic protein T cell receptor transgenic mice. Cell. 78: 399-408 [Medline] . |
10. | Governman, J., A. Woods, L. Larson, L.P. Weiner, L. Hood, and D.M. Zaller. 1993. Transgenic mice that express a myelin basic protein-specific T cell receptor develop spontaneous autoimmunity. Cell. 72: 551-560 [Medline] . |
11. | Oldstone, M.B.A.. 1989. Overview: Infectious agents as etiologic triggers of autoimmune disease. Curr. Top. Microbiol. Immunol. 145: 1-3 [Medline] . |
12. | Yang, X.-D., and U. Feige. 1992. Heat shock proteins in autoimmune diseases. From causative antigen to specific therapy? Experientia (Basel). 48: 650-656 . |
13. | van den Broek, M.F., E.J.M. Hogervorst, M.C.J. van Bruggen, W. van Eden, R. van der Zee, and W.B. van den Berg. 1989. Protection against streptococcal cell wall-induced arthritis by pretreatment with the 65-kD mycobacterial heat shock proteins. J. Exp. Med. 170: 449-466 [Abstract] . |
14. | Billingham, M.E.J., S. Carney, R. Butler, and M.J. Colston. 1990. A mycobacterial heat shock protein induces antigenspecific suppression of adjuvant arthritis, but is not itself arthritogenic. J. Exp. Med. 171: 339-344 [Abstract] . |
15. | Elias, D., D. Markovits, T. Reshef, R. van der Zee, and I.R. Cohen. 1990. Induction and therapy of autoimmune diabetes in the non-obese diabetic (NOD/Lt) mouse by a 65-kDa heat shock protein. Proc. Natl. Acad. Sci. USA. 87: 1576-1580 [Abstract] . |
16. | Elias, D., T. Reshef, O.S. Birk, R. van der Zee, M.D. Walker, and I.R. Cohen. 1991. Vaccination against autoimmune mouse diabetes with a T cell epitope of the human 65kDa heat-shock protein. Proc. Natl. Acad. Sci. USA. 88: 3088-3091 [Abstract] . |
17. | Hempel, K., A. Freitag, B. Freitag, B. Endres, B. Mai, and G. Liebaldt. 1985. Unresponsiveness to experimental allergic encephalomyelitis in Lewis rats pretreated with complete Freund's adjuvant. Int. Arch. Allerg. Appl. Immunol. 76: 193-199 [Medline] . |
18. | Lehmann, D., and A. Ben-Nun. 1992. Bacterial agents protect against autoimmune disease. I. Mice pre-exposed to Bordetella pertussis or Mycobacterium tuberculosis are highly refractory to induction of experimental autoimmune encephalomyelitis. J. Autoimmun. 5: 675-690 [Medline] . |
19. | Fiori, P., G. Ristori, C. Buttinelli, M. Falcone, A. Cacciani, S. Di Giovanni, C. Pozzilli, and M. Salvetti. 1996. Downregulation of cell-surface CD4 coreceptor expression and modulation of experimental allergic encephalomyelitis. Int. Immunol. In press. |
20. | Ben-Nun, A., S. Yossefi, and D. Lehmann. 1993. Protection against autoimmune disease by bacterial agents. II. PPD and pertussis toxin as proteins active in protecting mice against experimental autoimmune encephalomyelitis. Eur. J. Immunol. 23: 689-696 [Medline] . |
21. |
Ben-Nun, A.,
I. Mendel,
G. Sappler, and
N. Kerlero de
Rosbo.
1995.
A 12-kDa protein of Mycobacterium tuberculosis
protects mice against experimental autoimmune encephalomyelitis.
J. Immunol.
154:
2939-2948
|
22. | Norton, W.T., and S.E. Poduslo. 1973. Myelin in rat brain: method of myelin isolation. J. Neurochem. 21: 749-757 [Medline] . |
23. | Merrill, J.E., D.H. Kono, J. Clayton, D.G. Ando, D.R. Hinton, and F.M. Hofman. 1992. Inflammatory leukocytes and cytokines in the peptide-induced disease of experimental allergic encephalomyelitis in SJL and B10.PL mice. Proc. Natl. Acad. Sci. USA. 89: 574-578 [Abstract] . |
24. | Leonard, J.P., K.E. Waldburger, and S.J. Goldman. 1995. Prevention of experimental autoimmune encephalomyelitis by antibodies against interleukin-12. J. Exp. Med. 181: 381-386 [Abstract] . |
25. |
Taguchi, T.,
J.R. McGhee,
R.L. Coffman,
K.W. Beagley,
J.H. Eldridge,
K. Takatsu, and
H. Kiyono.
1990.
Detection of
individual mouse splenic T cells producing IFN-![]() |
26. | Reiner, S.L., S. Zheng, D.B. Corry, and R.M. Locksley. 1993. Constructing polycompetitor cDNA for quantitative PCR. J. Immunol. Methods. 165: 37-46 [Medline] . |
27. |
deKruyff, R.H.,
Y. Fang,
S.F. Wolf, and
D.T. Umetsu.
1995.
IL-12 inhibits IL-4 synthesis in keyhole limpet hemocyaninprimed CD4+ T cells through an effect on antigen-presenting cells.
J. Immunol.
154:
2578-2587
|
28. | Kurtzke, J.F. 1983. Epidemiology of MS. In Multiple Sclerosis. J.F. Hallpike, C.W.M. Adams, and W.E. Tourtellote, editors. Williams and Wilkins, Baltimore, MD. 49-95. |
29. | Ebers, G.C., D.E. Bulman, A.D. Sadovnick, D.W. Paty, S. Warren, W. Hader, T.J. Murray, T.P. Seland, P. Duquette, T. Grey, et al . 1986. A population based study of MS in twins. N. Engl. J. Med. 315: 1638-1642 [Abstract] . |
30. | Oldstone, M.B.A.. 1987. Molecular mimicry and autoimmune disease. Cell. 50: 819-820 [Medline] . |
31. | Wucherpfennig, K.W., and J.L. Strominger. 1995. Molecular mimicry in T cell-mediated autoimmunity: viral peptides activate human T cell clones specific for myelin basic protein. Cell. 80: 695-705 [Medline] . |
32. | Brocke, S., T. Veromaa, I. Weissman, K. Gijbels, and L. Steinman. 1994. Infections and multiple sclerosis: A possible role for superantigens? Trends Microbiol. 2: 250-254 [Medline] . |
33. | Miller, A., O. Lider, and H.L. Weiner. 1991. Antigen-driven bystander suppression after oral administration of antigens. J. Exp. Med. 174: 791-798 [Abstract] . |
34. | Saoudi, A., S. Simmonds, I. Huitinga, and D. Mason. 1995. Prevention of experimental allergic encephalomyelitis in rats by targeting autoantigen to B cells: evidence that the protective mechanism depends on changes in the cytokine response and migratory properties of the autoantigen-specific T cells. J. Exp. Med. 182: 335-344 [Abstract] . |
35. | Windhagen, A., C. Scholz, P. Hollsberg, H. Fukaura, A. Sette, and D.A. Hafler. 1995. Modulation of cytokine patterns of human autoreactive T cell clones by a single amino acid substitution of their peptide ligand. Immunity. 2: 373-380 [Medline] . |
36. | Seder, R.A., W.E. Paul, M.M. Davis, B. Fazekas de St, and Groth. 1992. The presence of interleukin-4 during in vitro priming determines the lymphokine-producing potential of CD4+ T cells from T cell receptor transgenic mice. J. Exp. Med. 176: 1091-1098 [Abstract] . |
37. |
Pearlman, E.,
J.W. Kazura,
F.E. Hazlett, and
W.H. Boom.
1993.
Modulation of murine cytokine responses to mycobacterial antigens by helminth-induced T helper 2 cell responses.
J. Immunol.
151:
4857-4864
|
38. |
Kullberg, M.C.,
E.J. Pearce,
S.E. Hieny,
A. Sher, and
J.A. Berzofsky.
1992.
Infection with Schistosoma mansoni alters
Th1/Th2 cytokine responses to a non-parasite antigen.
J. Immunol.
148:
3264-3270
|
39. | Actor, J.K., M. Shirai, M.C. Kullberg, R.M.L. Buller, A. Sher, and J.A. Berzofsky. 1993. Helminth infection results in decreased virus-specific CD8+ cytotoxic T-cell and Th1 cytokine responses as well as delayed virus clearance. Proc. Natl. Acad. Sci. USA. 90: 948-952 [Abstract] . |
40. | Curry, A.J., K.J. Else, F. Jones, A. Bancroft, R.K. Grencis, and D.W. Dunne. 1995. Evidence that cytokine-mediated immune interactions induced by Schistosoma mansoni alter disease outcome in mice concurrently infected with Trichuris muris. J. Exp. Med. 181: 769-774 [Abstract] . |
41. | Forsthuber, T., H.C. Yip, and P.V. Lehmann. 1996. Induction of Th1 and Th2 immunity in neonatal mice. Science (Wash. DC). 271: 1728-1730 [Abstract] . |