THE USE OF ESTROGEN RECEPTOR ALPHA
MODULATORS FOR THE TREATMENT OF MULTIPLE SCLEROSIS
FIELD OF THE INVENTION
This invention relates generally to therapies for treating autoimmune diseases
and, more specifically, to the use of compounds having estrogen receptor a
(ERa) agonist activity for the treatment of autoimmune diseases. In particular,
the invention relates to the use of selective estrogen receptor modulators
(SERMS) for the treatment of autoimmune diseases. Furthermore, the present
invention relates to methods of selecting compounds useful for the treatment of
autoimmune diseases.
BACKGROUND OF THE INVENTION
Multiple sclerosis (MS) is an autoimmune disease of the central nervous system
(CNS) in which the immune system makes an inappropriate immune response to
components of myelin. It is characterized by inflammation of the CNS and myelin
damage. CD4+ T-helper-1 (TH-1) cells and their products (e.g., Tumor Necrosis
Factor-α (TNF-α), Interferon-y (IFN-v); and metalloproteinases) mediate much of
the immunopathoJogy.
As with a number of autoimmune diseases, the incidence of multiple sclerosis is
higher (2 to 3 times) in females compared to males1. Immunomodulatory effects
of estrogens in MS have been shown. For example, clinical disease is
ameliorated during pregnancy, when estrogen levels are high, and worsens
during the post-partum period24. Further, improvement in symptoms have been
reported in-MS; patients-given estradiol5. Estrogens appear to directly affect the
function of T cells and modulation of cytokine production by T cell clones from MS
patients has been shown6-8. Jn addition, inhibition of the transcription factor NFkB
by estriol was demonstrated in these cells8.
Estrogens also have been shown to modulate disease activity in murine
experimental autoimmune encephaiomyelitis (EAE), a well-defined model for
multiple sclerosis9-13. This model was used to test treatment with SERMS/Tissue-
Selective Estrogens (TSEs) and estrogen receptor a selective agonists.
SERMS are a class of drugs which bind to the estrogen receptor and show
tissue-selective effects. The SERM raloxifene, for example, has estrogenagonistic
effects on bone, lipids and clotting factors, and estrogen-antagonistic
effects on the breast and uterus.19 SERMS may include 1) agents previously
known as antiestrogens, such as 16-epiestriol, ethamoxytriphetol, clomiphene,
and tamoxifen; 2) a 19-nortestosterone derivative, tibolone; 3) raloxifene and its
analogues; and 4) newer triphenylethylene derivatives, such as droloxifene,
toremifene, idoxifene, and levormeloxifene.19 SERMS compete with
endrogenous estrogens for binding to the receptor and may either activate or
block estrogen action.19
An object of the present invention is to provide novel methods to treat
autoimmune pathologies by the administration of agents having estrogen receptor
a activity, particularly SERMS.
SUMMARY OF THE INVENTION
The present invention provides a method of treating an autoimmune pathology in
a mammal, comprising administering at least one agent having estrogen receptor
a agonist activity to the mammal in an amount sufficient to decrease production of
TH-1 and/or TH-2 cytokines. ,
The present invention also provides a method of treating an autoimmune
pathology in a mammal, comprising administering a selective estrogen receptor
modulator to the mammal in an amount sufficient to decrease production of TH-1
and/or TH-2 cytoKihes.
The present invention further provides a method of selecting compounds useful
for the treatment of multiple sclerosis, comprising selecting a compound which
has estrogen receptor a agonist activity.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention can be more fully understood from the detailed description and the
accompanying drawings that form a part of this application.
Rgure 1A shows the effect of the ER antagonist ICI on estrogen-mediated
suppression of disease.
Figure 1B shows the effect of Raloxifene vs. Compound A on EAE.
Figure 2 shows the effect of ER-selective ligands on EAE.
Figure 3A shows the effect of in vivo administration of ER-selective ligands on
TNF-ct production by splenocytes from mice with EAE.
Rgure 3B shows the effect of in vivo administration of ER-selective ligands on IL-
4 production by splenocytes from mice with EAE.
Figure 3C shows the effect of in vivo administration of ER-selective ligands on
IFN-y production by splenocytes from mice with EAE.
Figure 3D shows the effect of in vivo administration of ER-selective ligands on IL-
5 production by splenocytes from mice with EAE.
Figure 3E shows the effect of in vivo administration of ER-selective ligands on IL-
2 production by splenocytes from mice with EAE.
Figure 3F shows the effect of in vivo administration of ER-selective ligands on 1L-
10 production by splenocytes from mice with EAE.
Rgure 4A shows the effect of compounds on proliferation of CD4- cells upon
antigen stimulation.
Figure 4B shows the effect of compounds on proliferation of CD4+ cells upon
antigen stimulation.
Figure 5A shows the effect of compounds on TNF-a production by effector T cells
upon antigen stimulation.
Figure 5B shows the effect of compounds on IFN-y production by effector T cells
upon antigen stimulation.
Figure 5C shows the effect of compounds on IL-4 production by effector T cells
upon antigen stimulation.
Figure 5D shows the effect of compounds on IL-2 production by effector T cells
upon antigen stimulation.
DETAILED DESCRIPTION OF THE INVENTION
As disclosed herein, administration of an agent having estrogen receptor a
agonist activity to a mammal reduces the severity of autoimmune pathologies.
These effects appear to be due, in part, to the effect of such agonists on reducing
the production of TH-1 and/or TH-2 cytokines by T-cells in the periphery and at
the site of pathology.
Therefore, the present invention provides a method of treating an autoimmune
pathology in a mammal, comprising administering an agent having estrogen
receptor a agonist activity to the mammal in an amount sufficient to decrease
production of TH-1 and/or TH-2 cytokines. The present invention also provides a
method of treating an autoimmune pathology in a mammal, comprising
administering a selective estrogen receptor modulator to the mammal in an
amount sufficient to decrease production of TH-1 and/or TH-2 cytokines.
The methods of the invention can be practiced with respect to a variety of
autoimmune pathologies. Such pathologies are known in the art and include but
are not limited to multiple sclerosis, rheumatoid arthritis, psoriasis, autoimmune
thyrokJitis, uvetis, myesthenia gravis, inflammatory bowel disease and Sjogren's
syndrome. In preferred embodiments of the invention, the mammal may be
female, male, human or non-human.
In an embodiment of the invention, the agent having estrogen receptor a agonist
activity is administered by a route selected from oral, transdermal, respiratory,
subcutaneous and intravenous routes.
In preferred embodiments of the invention, the TH-1 cytokine is selected from the
group consisting of TNF-a, IFN-y and IL-2, and the TH-2 cytokine is selected from
the group consisting of IL-4, IL-5 and IL-10. Those skilled in the art recognize
that a TH-1 mediated immune response is characterized by secretion of proinflammatory
cytokines, which includes TNF-a, IFN-y, IL-2. A TH-2 mediated
response is characterized by secretion of anti-inflammatory cytokines such as IL-
4, IL-5 and IL-10. In one preferred embodiment of the invention, the production
of TH-1 cytokines is suppressed by administration of the agent. In another
preferred embodiment of the invention, the production of both TH-1 and TH-2
cytokines is suppressed. In a further embodiment of the invention, the production
of TH-1 cytokines is suppressed and the production of TH-2 cytokines is
increased.
As a preferred embodiment, the ERα agonist exhibits an anti-inflammatory
activity, e.g. a reduction in NF-kB activity. In another preferred embodiment, the
ERa agonist is non-steroidal.
In a further embodiment of the invention, the SERM is selected from the group
comprising raloxifene, tamoxifen, lasofoxifene, idoxifene, droloxifene,
bazedoxifene, toremifene and their derivatives and analogs. In another
embodiment of the invention the selective estrogen receptor modulator exerts a
biological effect on the brain or central nervous system.
The present invention also provides a method of selecting compounds useful for
the treatment of multiple sclerosis, comprising selecting a compound which has
estrogen receptor a agonist activity. Conventional assays for assaying in vitro
agonist activity, using receptors such as luciferase, are well known in the art.
Illustrative of agonist assays are the following publications which are incorporated
by reference "for their ERα agonfet assays: Lyttle CR, Damian-Jvlatsiimura P.,
Juul H., Butt TR, Human estrogen receptor regulation in a yeast model system
and studies on receptor agonists and antagonists, J. Steroid Biochem Mol Biol
42:677-685 (1992); Katzenellenbogen BS, Bhardwaj B, Fang H, Ince BA, Pakdel
F, Reese JC, Schodin D, Wrenn CK, Hormone binding and transcription
activation by estrogen receptors: analyses using mammalian and yeast systems,
J Steroid Biochem Mol Biol 47:39-48 (1993); PCT International Publication No.
WO 00/37681; Webb P, Lopez GN, Greene GL, Baxter JD, Kushner PJ, 1992,
The limits of the cellular capacity to mediate an estrogen response, Mol
Endocrinology, 6(2):157-67. Preferably, in such assays, an "estrogen receptor a
agonist" is defined as a compound that substantially .mimics ER-a activity of 17-p
estradiol as measured in the selected assay for estrogenic activity.
In a preferred embodiment of the invention, the compound is a SERM. In a
further embodiment of the invention, the compound decreases TNFa production
by at least about 20%-100%, as described in Example II herein. In alternative
embodiments, the decrease may be at least 30,40, 50, 60 or 80%.
Definitions of abbreviations and terms:
The following definitions are provided for the full understanding of terms and
abbreviations used in this specification.
As used herein and in the appended claims, the singular forms "a", "an" and "the"
include the plural reference unless the context clearly indicates otherwise. Thus,
for example, a reference to "an estrogen receptor a agonist" includes a plurality of
such agonists.
The abbreviations in the specification correspond to units of measure,
techniques, properties or compounds as follows: "μg" means microgram(s), "ml"
means milliliter(s), "μM" means micromble(s), "mM" means millimole(s), "s.c."
means subcutaneous, "i.p." means intraperitoneal, and "p.o" means per oral.
"Multiple sclerosis" is abbreviated MS.
"Central nervous system" is abbreviated CNS.
T-helper-1" and T-helper-2" are abbreviated TH-1 and TH-2, respectively.
"Tumor Necrosis Factor-α" is abbreviated TNF-α.
"Interferon-y" is abbreviated IFN-y.
"Nuclear Factbr-kB" is abbreviated NF-KB.
"Experimental Autoimmune Encephalomyelitis" is abbreviated EAE.
"Selective Estrogen Receptor Modulators" is abbreviated SERMS.
Tissue Selective Estrogens" is abbreviated TSEs.
"Estrogen receptor" is abbreviated ER.>
"Interleukin" is abbreviated IL
"Proteolipid protein peptide" is abbreviated PLP.
"Complete Freund's adjuvant" is abbreviated CFA.
"Post transfer" is abbreviated PT.
As used herein, the term "autoimmune pathology" refers to a pathology mediated
by a detrimental autoimmune response. In most autoimmune pathologies, T cells
recognize a host component in one or more tissues as foreign and attack that
tissue.
The term "treatment" as used herein includes preventative (e.g. prophylactic),
curative, or palliative treatment and "treating" as used herein also includes
preventative, curative and palliative treatment Treating", with reference to
autoimmune pathology, refers to any observable effect of the treatment. The
beneficial effect can be evidenced by delayed onset of clinical symptoms in a
susceptible mammal, a reduction in severity of some or all clinical symptoms of
the disease, a slower progression of the disease, a reduction in the number of
relapses of the disease, a reduction in the number or activity (e.g. cytokine
secretion) of pathogenic T cells at the site of pathology or in the circulation, an
improvement in the overall health or well-being of the individual, or by other
parameters well known in the art that are specific to the particular disease.
As disclosed herein, the term "agent having estrogen receptor a activity" is an
agent that exhibits ERa activity and includes but is not limited to selective
estrogen receptor modulators and tissue-selective estrogens. The term-may*also
include partial agonists, peptides, polypeptides, genes, gene fragments, nonpeptide
small molecules, natural products, antisense DMA and mRNA.
As used herein, the term "mammal" refers to a human, a non-human primate,
canine, feline, bovine, ovine, porcine, murine or other veterinary or laboratory
mammal. Those skilled in the art recognize that a therapy which reduces the
severity of an immune pathology in one species of mammal is predictive of the
effect of the therapy on another species of mammal. The skilled person also
appreciates that credible animal models of human immune pathologies are
known, including EAE, which is a credible animal model of multiple sclerosis.
An "amount effective to decrease production of TH-1 and/or TH-2 cytokines"
refers to an amount effective, at dosages and for periods of time necessary, to
achieve the desired result of treating autoimmune pathology. It will be
appreciated that the amount of estrogen receptor a agonist effective to decrease
production of TH-1 and/or TH-2 cytokines in the methods of the present invention
will vary from individual to individual not only with the particular agonist selected,
the route of administration, and the ability of the agonist to elicit a desired
response in the individual, but also with factors such as the disease state or
severity of the condition to be alleviated, age, sex, weight of the individual, the
state of being of the patient, and the severity of the pathological condition being
treated, concurrent medication orspecial diets then being followed by the
particular individual, and other factors which those skilled in the art will recognize,
with the appropriate dosage ultimately being at the discretion of the attendant
physician. Dosage regimens may be adjusted to provide the improved
therapeutic response. An "amount effective to decrease production of TH-1
and/or TH-2 cytokines" is also one in which any toxic or detrimental effects of the
agonist is outweighed by the therapeutically beneficial effects.
Preferably, the estrogen receptor a agonists are administered in the methods of
the present invention at a dosage and for a time such that the production of TH-1
and/or TH-2 cytokines is decreased as compared to production of these
cytokines at the start of treatment Such treatment can also be beneficial to
reduce the overalC severity of symptoms of autoimmune disease, as compared to
the severity of symptoms prior to the start of the treatment In a preferred
embodiment, dosages range from .5mg/kg/day to 500 mg/kg/day, and,
alternatively, at least about 10,50,100 or 150 mg/kg/day.
EXAMPLES
The present invention is further defined in the following Examples. It should be
understood that these Examples, while indicating preferred embodiments of the
invention, are given by way of illustration only. From the above discussion and
these Examples, one skilled in the art can ascertain the essential characteristics
of this invention, and without departing from the spirit and scope thereof, can
make various changes and modifications of the invention to adapt it to various
usages and conditions.
Example 1 - Effect of In Vivo Administration of
Compounds in Animal Model of Multiple Sclerosis
This Example shows that, in an animal model of multiple sclerosis, in vivo
administration of estrogen receptor a selective agonists results in delayed onset
and decreased incidence and severity of disease.
Materials and Methods-
Animals. Twenty-five intact female (6-8 weeks old) SJL mice (Jackson
Laboratories, Bar Harbor, ME) were used as donor mice in the adoptive transfer
model of EAE.
Induction of Experimental Autoimmune Encephalomyelitis (EAE). EAE was
induced by the adoptive transfer of PLP sensitized spleen cells using a
modification of methods previously described.20 Mice were immunized with
proteolipid protein peptide 139-151 (PLP) emulsified in complete Freund's
adjuvant (CFA). Each animal received 150 pg of PLP in a volume of 0.2 ml CFA
that contained 4 mg/ml heat killed and dried Mycobacterium tuberculosis (H37RA
strain). ThePLP/CFAemulsion wasinjecteds.c.in1wosites«ndat
the base of the tail). 0.1 ml was injected at each site. Ten days later, the mice
were euthanized and the spleens were collected. Single cell suspensions were
made from the spleens. After lysis of red blood cells, the cells were cultured at a
concentration of 5x106 cells/ml for 3 days in 75 cm2 tissue culture flasks in RPMI-
10 (RPMI medium containing 10% heat-inactivated fetal bovine serum, 100 U/ml
penicillin, 100 pg/ml streptomycin, 2mM glutamine, 50 pM 2-mercaptoethanol).
PLP was added at a final concentration of 5 pg/ml. The cells were incubated at
37 °C in 5% CO2. After the incubation, PLP-stimulated effector cells were
harvested, washed with phosphate-buffered saline and injected i.p. into
ovariectomized female (6-8 weeks old) SJL mice (1.5x107 cells/mouse). Onset
of disease typically occurs 7-14 days post-transfer (PT) of cells.
The degree of disease severity was monitored daily using the scale shown in
Table 1.
Table 1: Scale of Disease Severity ;_
(Table Removed)
To evaluate the effect of compounds on disease, recipient mice were
administered compounds daily (s.c. or p.ti.) at the doses indicated, using a 10%
ethanol/90% com oil vehicle. Control animals received vehicle only. Mice were
dosed beginning 5-7 days prior to the adoptive transfer of donor cells.
Histological Analysis. At peak disease (14 days PT). mice were euthanized with
CO2. Brains and spinal cords were removed at necropsy and fixed in 10%
buffered formalin. Brains, were cut into three segments (roughly, anterior
cerebrum, midbrain and cerebellum) and embedded as a single block. The spinal
cord was decalcified in 10% HCI and cut into cervical, thoracic and lumber
segments embedded as a single block. A standard H&E (hematoxylin and eosin)
glass slide was prepared from each tissue block (brain and spinal cord) from
each mouse submitted with two resulting H&E slides per mouse evaluated.
Slides were evaluated and lesions seen were graded subjectively for presence
(P=present) and/or severity. Severity grades are 0 =• WNL (within normal limits),
1 = slight or minimal, 2 = mild, 3• = moderate, 4 = marked, and 5 = severe. The
location of findings, relative to the organ, was denoted as perivascular,
periventricular, ependymal or meningeal, and also as focal (in small areas or not
throughout the section), or diffuse (throughout the section examined). Focal was
defined as very localized and not affecting every structure. Findings not defined
as focal were diffuse or affecting every structure (e.g. all vessels). Leukocytes
seen were primarily lymphocytes and macrophages with occasional neutrophils.
Demyelination was observed as distinct open holes in white matter tracts in the
spinal cord.
Typical murine models of EAE have scattered foci of slight to moderate-sized
aggregates of leukocytes and rarely have diffuse infiltrates in the affected tissues.
Analysis of PLP-specffic Recall Responses: Cytokine Production. To
examine the effect of compounds administered in vivo on cytokine production by
splenocytes from mice with EAE, mice were euthanized with CO2 at peak disease
(14 days PT), and spleens were collected. Spleens were individually processed
into single ceil suspensions. After lysis of red blood cells, the cells were
resuspended in RPMI-10 and were cultured in 24-well tissue culture plates at a
concentration of 5x106 cells/ml. Cells were stimulated with 5 ug/ml PLP.
Supernatants were collected after 3 days and frozen until use at -20 °C.
Cytokines (TNF-a, IFN-y, IL-5, IL-4, IL-2) were measured in the supernatants
using a commercially available flow cytometry kit (Cytometric Bead Array, Becton
Dickinson BioSciences, San Diego, CA). IL-10 was measured using an TL-10-
specific ELISA kit (Becton Dickinson BioSciences).
To examine in vitro the effect of compounds on cytokine production by PLPprimed
effector cells, SJL mice were immunized with PLP emulsified in CFA
After 10 days, spleens were collected and single cell suspensions were made.
After lysis of red btood cells, splenocvtes were stimulated with 5 pg/m) PLP in the
presence of compound for 3 days at 37 °C, 5% CO2. Control samples were not
stimulated and cultured in medium only ("medium"). Compounds were added at
a final concentration of 1 uM. After the 3-day incubation, supernatants were
collected and stored at -20 °C. Cytokines (TNF-a, IFN-y, IL-5, IL-4, IL-2) were
measured in the supernatants using a Cytometric Bead Array kiL
Effect of compounds on proliferation of effector T cells upon antigen
stimulation To examine the effect of proliferation of effector T cells in vitro in
response to PLP stimulation, T-cell proliferation was examined by flow cytometry
using the following assay* SJL mice were immunized with PLP emulsified In
CFA. After 10 days, spleens were collected and single cell suspensions were
made. After lysis of red blood cells, splenocytes were labeled with carboxy
fluorescein succinimidyl ester (CFSE). CFSE-Iabeled cells were then incubated
with PLP for 3 days at 37 °C, 5% CO2. Compounds were added at a final
concentration of 1 uM. To determine the percentage of CD4* cells that divided,
the CFSE^abeled cells were stained with antibodies specific for the CD4 marker
prior to flow cytometric analysis.
Results
I. Effect of SERMs/Tissue-Selective Estrogens on EAE induced by
the adoptive transfer of PLP-primed effector cells
As shown previously, treatment with 17p-estradiol (E2) resulted in a delay in
onset as well as decreased incidence and severity of disease (Figure 1A; refs, 9,
11-13). To determine whether the protective effects of estrogen in this model
were estrogen receptor-mediated, mice were treated with both E2 and the
estrogen receptor antagonist tCI 182,780. ICI abolished the effect of E2 on
disease (Figure 1A).
Treatment with E2 or with the SERMs raloxifene or Compound A [2-
(hydroxyphenyl)-3-methyl-1 -[4-(2-piperidin-1 -yl-ethoxy)benzyl]-1 W-indof-5-ol
hydrochloride monohydrate] resulted in a delay in onset as well as decreased
incidence and severity of disease (Figure 1B and Table II). Consistent with the
effects of these compounds on the clinical signs of disease, there was a reduction
in the amount of inflammatory cells infiltrating the spinal cords and brains from
mice treated with Compound A compared to mice from other treatment groups.
In addition, no demyetination was detected in spinal cords from Compound Atreated
mice.
Table II. Histological Findings
(Table Removed)
II. Effect of Estrogen Receptor-Selective Agonists on EAE induced
by the adoptive transfer of PLP-pn'med effector cells
Treatment with E2 or the ERa-selective agonist PPT (propylpyrazole triol)
resulted in a delay in onset as well as decreased incidence and severity of
disease (Figure 2). In addition, mice treated with PPT had reduced inflammation
in the brain and spinal cords compared with mice treated vehicle, or with an ERfJsetective
agonist (Table tlf}. Histologfc examination reveated that mice which
were administered PPT had the most normal tissues compared to the vehicle
control mice. All four had slight leukocyte infiltrates in the mentnges but only at
the base of the brain. (around the hfndbrain/cerebellum/pons/rnedulfa on the
ventral surfaces only). None of these mice had spinal cord tesions; the spinal
cords of these mice were all within normal limits.
Table III.
(Table Removed)

Consistent with the effect of the ERq-setec^ agonist PPT on disease, treatment
of mice with PPT resulted in decreased cytokine production upon stimulation of
sptenocytes with PLP in vitro (Figure 3). Both Th1/pro- (TNF-a, IFN-y, IL-2) and
Th2/anti-inflammatory (1L-4, IL-5, fL-10> cytokines were suppressed by in vivo
treatment with PPT, indicating that PPT may suppress disease by inhibiting T cell
activation, rather than by immune deviation from a pathogenic Th1 response to a
protective Th2 response. In contrast, the ERa-selective agonist had no effect on
cytokine production {*, p<0.05 compared to vehicle group).
Example II - Effect of Compounds on Antiqen'Speciffc Immune Responses
in Vitro
The effect of tissue selective estrogens (Compound A) and ERa-selective ligands
(PPT) on antigen-specific immune responses was examined in vitro.
A. Effect of compounds on proliferation of effector T celts upon
antigen stimulation
Treatment of PLP-primed effector cells with the tissue^setective estrogen
Compound A or with ERa-selective agonist PPT resulted in decreased
proliferation of antigen-specific T ceils (Rgure 4). Proliferation of both CD4* and
CD4- cell populations was suppressed. These results suggest that each of these
compounds may potentially act in part by limrting the donal expansion of antfgenspecjficT
cells.
8. Effect of compounds on cvtokine production by effector cells
upon antigen
Treatment of PLP-primed effector cells with the tissue-selective estrogen
Compound A or with a-setective agonist (PPT) resulted in decreased cytokine
production upon antigen stimulation (Figure 5). Both compounds inhibited the
production of the pro-inflammatory (TH-1) cytokine TNF-a. Both Compound A
and the ERa-selective agonists PPT also suppressed IFN-y production.
Incubation of these cells with the tissue-setectwe- estrogen Compound A also
resulted in a concomitant increase in the anti-inflammatory cytokine ft-4, whereas
the other compounds had no effect These results suggest that ERo-seiective
agonists (PPT) may have different effects than tissue-selective estrogens oh
antigen-specific cytokine production. Whereas the former may suppress EAE by
inhibiting the production of pro-inflammatory (TH-1) eytokines, tissue-selective
estrogens may in addition promote immune deviation to a protective antiinflammatory/
TH-2 immune response.
Conclusions
Treatment with the SERMs/TSEs raloxifene and Compound A, as well as the
ERcr-setective agonist PPT, suppressed EAE, resulting in delayed onset of
disease, as well as decreased incidence and severity. The suppression of the
clinical signs of disease in mice treated with these compounds was associated
with reduced pathology and leukocyte infiltration in the brains and spinal cords.
This suggests that these compounds may reduce disease by limiting trafficking of
pathogenic cells into the brains and spinal cords, for example, by decreasing
adhesion molecule expression and/or by affecting chemokine/chemokine receptor
expression. Suppression of disease induced by the adoptive transfer of PLPprimed
effector cells with SERMs/TSEs and ERa-selective agonists suggests that
these compounds have the capacity to alter the activity of encephalitogenic
effector cells. These findings are in contrast to the notion that differentiated
effector cells are more refractory to the effects of estrogens compared with naive
cells13.
In vitro data presented herein suggests that ERa-selective agonists, preferentially
SERMS or ER-anti-inflammatory ligands, may have direct effects on antigenspecific
T eel! proliferation and cytokine production, thereby limiting the expansion
and differentiation of pathogenic T cells. All three types of ligands are effective in
suppressing the production of the pro-inflammatory (TH-1) cytokines. Tissueselective
estrogens, however, may in addition promote the production of
protective anti-inflammatory (TH-2) cytokines, which suggests that these
molecules may have differential effects on PLPrSpecific immune responses.
The observation that SERMs/TSEs are capable of altering the course of disease
in this model is somewhat surprising, given the known effects of SERMs and
estrogen antagonists in murine systemic lupus ervthematosus, the mouse model
for Jupus. SERMs have been shown to have beneficial therapeutic effects in
lupus, an autoimmune disease in which the disease is exacerbated by
estrogens14"18. Since SERMs appear to act in an antagonist fashion in lupus, it
was anticipated that SERMs would have similar antagonist activity in EAE.
Therefore, the prediction would be that SERMs would either have no effect, or
would exacerbate EAE. Instead, SERMs demonstrated disease-suppressing
activity.
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What is claimed is:
1. A method of treating an autoimmune pathology in a mammal, comprising
administering at least one agent having estrogen receptor a agonist activity to
the mammal in an amount sufficient to decrease production of TH-1 and/or
TH-2 cytokines.
2. The method of claim 1, wherein the autoimmune pathology is selected from
the group consisting of multiple sclerosis, rheumatoid arthritis, psoriasis,
autoimmune thyroiditfs, uvetis, inflammatory bowel disease and Sjogren's
syndrome.
3. The method of claim 1, wherein the mammal is female.
4. The method of claim 1, wherein the mammal is male.
5. The method of claim 1, wherein the mammal is human.
6. The method of claim 1, wherein the mammal is non-human.
7. The method of claim 1, wherein the agent is administered by a route selected
from oral, transdermal, respiratory, subcutaneous and intravenous routes.
8. The method of claim 1, wherein the TH-1 cytokine is selected from the group
consisting of TNF-α, IFN-y and IL-2.
9. The method of claim 1, wherein the TH-2 cytokine is selected from the group
consisting of IL-4, IL-5 and IL-10.

10. The method of claim 1, wherein the agent decreases Nuclear Factor-kB
activity.
11. The method of claim 1, wherein the agent is non-steroidal.
12. a selective estrogen receptor
modulator administered in an amount sufficient to decrease production of TH-
1 and TH-2 cytokines.
13. The method of claim 12, wherein the autoimmune pathology is selected from
the group consisting of multiple sclerosis, rheumatoid arthritis, psoriasis,
autoimmune thyroiditis, uvetis, inflammatory bowel disease and Sjogren's
syndrome.
14. The method of claim 12, wherein the mammal is female.
15. The method of claim 12, wherein the mammal is male.
16. The method of claim 12, wherein the mammal is human.
17. The method of claim 12, wherein the mammal is non-human.
18. The method of daim 12, wherein the selective estrogen receptor modulator is
administered by a route selected from oral, transdermal, respiratory,
subcutaneous and intravenous routes.
19. The method of claim 12, wherein the TH-1 cytokine is selected from the group
consisting of TNF-α, IFN-y and IL-2.
20. The method of daim 12, wherein the TH-2 cytokine is selected from the group
consisting of IL-4, IL-5 and IL-10.
21. The method of daim 12, wherein the selective estrogen receptor modulator
decreases Nuclear Factor-kB activity.
22. The method of claim 12, wherein the selective estrogen receptor modulator is
selected from the group consisting of ratoxifene, tamoxifen, laspfoxifene,
idoxifene, drolqxifene, bazedoxifene, and toremifene.
23. A method of selecting compounds useful for the treatment of multfpie
sclerosis, comprising selecting a compound which has estrogen receptor a
agonist activity.
24. The method of claim 23, wherein the compound is a selective estrogen
receptor modulator.
25. The method of claim 23, wherein the compound decreases TNFa production
by at least about 20%.