WO2009007348A2

WO2009007348A2 - Use of antagonists of g protein coupled receptors (gpcrs) for treating diseases caused by agonistic autoantibodies activated gpcrs

Info

Publication number: WO2009007348A2
Application number: PCT/EP2008/058802
Authority: WO
Inventors: Rudolf Kunze; Marion Bimmler; Petra Hempel; Bernd Lemke
Original assignee: E.R.D.E.-Aak-Diagnostik Gmbh
Priority date: 2007-07-06
Filing date: 2008-07-07
Publication date: 2009-01-15
Also published as: EP2011515A1; WO2009007348A3

Abstract

Use of antagonists of G protein coupled receptors (GPCRs) for the preparation of a medicament for treating and preventing diseases caused by or associated with agonistic autoantibodies (agAABs) activated GPCRs.

Description

Use of Antagonists of G Protein Coupled Receptors (GPCRs )

The present invention relates to the use of antagonists of so-called G protein coupled receptors (GPCRs) for the preparation of a medicament.

One of the most important groups of diseases in humans are the so-called autoimmune diseases. These include such diverse diseases as rheumatoid arthritis, multiple sclerosis and diabetes mellitus (type 1 and type 2).

In autoimmune diseases, the immune system attacks endogenous structures, cells and molecules. Their impairment, which is often manifested as a (local) acute or chronic inflammation, causes a restriction or loss of the corresponding cell and organ function.

Both misguided cells (e.g., macrophages) and molecules (e.g., antibodies) of the immune system, but also frequently products of immune cells themselves (e.g., proinflammatory cytokines) can induce and maintain autoimmunological processes.

The diagnostic rating of a clinical entity as an autoimmune disease is associated with a number of scientific requirements. In addition to the diagnostic detection of, for example, autoreactive T cells or autoantibodies against defined target structures, the generation of the clinical picture in an animal experiment is generally demanded, totally along the lines of an extended Koch's postulate.

The therapy of autoimmune diseases is almost a therapy of symptoms with a more or less pronounced anti-inflammatory component. Preferably, so-called immunosuppressives are employed. In addition to non-steroidal anti-inflammatory drugs, substances like corticosteroids or therapeutical monoclonal antibodies directed against proinflammatory cytokines ("biologies") are effective medicaments for autoimmune diseases. For example, they suppress the production of autoreactive antibodies, inhibit the proliferation of leukocytes, or block the activity of proinflammatory cytokines.

From animal-experimental studies, it has been known that autoantibodies can occur long before clinical symptoms are produced. The treatment of such autoimmune diseases has not only the usual indicative aspect, but also a prophylactic component to prevent the occurrence of clinical symptoms of the disease.

One well-known classical example is the treatment of HIV infection. Already before the occurrence of clinical symptoms, a virostatic therapy is started by using laboratory data, such as the number of viruses in the blood or the number of particular lymphocyte populations, which is basically prophylactic in order to prevent or at least delay the onset of the actual disease. Another example is the treatment of severe rheumatoid arthritis with therapeutical monoclonal antibodies against tumor necrosis factor α.

An exceptional position among autoimmune diseases is held by diseases associated with autoantibodies against extracellular loops of G protein coupled receptors (GPCRs) (survey in Wallukat G. et al., in : Brinckmann R and Kunze R, 2002). They include, in particular, the cardio- and nephrovascularly relevant βl-, β2- receptors (βl-R, β2-R), α-receptors (α-R) and type I angiotensin II receptors (ATl-R). They occur in such diverse diseases as dilatative cardiomyopathy (DCM, βl-R), primary open angle glaucoma (POAG, β2-R) and preeclampsia, vascular-necrotic kidney graft rejection (ATl-R), hypertension (α-R, ATl-R) and diabetes 2 (α-R, βl-R, ATl-R).

GPCRs are a wide-spread group of receptors. Their amino acid chain crosses the cell membrane seven times. Intracellular^ coupled to the eponymous G protein, they are essential to cells. Through GPCRs, cells regulate the signal transport, for example, when hormones bind to them extracellularly. Thus, for example, the contraction of smooth muscle, striated muscle and cardiac muscle cells is con- trolled or co-controlled by them. For some time, it has been known that autoantibodies against GPCRs can activate these receptors as well as the physiological agonists can (literature survey in Brinckmann R and Kunze R (edts.), 2002). Transferred to the in vivo situation, the cell activation caused by antibodies results in a permanent load on the organ, for example, the cardiac muscle, with consequential loss of heart performance and so-called remodeling of the cardiac muscle tissue.

For DCM, the causation of the antibodies against βl-R in the pathogenesis and maintenance of this cardiac disease has been shown in an animal experiment (Jahns R et al., 2004; Matsui S et al., 1997; Matsui S et al., 2006). In animals, the antibodies can be induced by immunization with antigenic epitopes from βl- R, and the animals contract cardiac dilatation, which is very similar too human DCM, after about 9-12 months. If the immunoglobulins of the antibody-positive animals are infused in healthy animals, these also develop the disease after about 9-12 months, i.e., this time elapses before the pathophysiological activity of the transferred antibodies results in a clinical picture.

Matsui's working group (2006) has recently shown in an experiment with rabbits that the specific elimination of the antibodies formed against βl-R by means of extracorporeal immunoadsorption results in a regression of the antibody-caused left-ventricular cardiac dilatation. This confirms the clinical improvement achieved in humans by means of specific immunoadsorption in patients afflicted with DCM and agAAB against βl-R (Wallukat G et al., 2002).

The pathophysiological relevance of agAAB against ATl-R has also been demonstrated by animal experiments. In a rat graft model, human agAABs isolated from patients with vascular-necrotic kidney graft rejection are pathologically active on ATl-R and induce a histologically visible vascular necrosis in the transplanted kidney (Dragun D et al., 2005).

The therapeutical effect of the receptor antagonists ("beta blockers", ATI receptor antagonists) in indications such as chronic heart insufficiency, DCM or hypertension is based on an elimination or reduction of the effect of the endoge- nous receptor agonists. In the case of βl-R, the effect of adrenalin/noradrenalin is attenuated, with the result that the cardiac muscle reduces its performance. ATI receptor antagonists lower the blood pressure, inter alia, by blocking the binding sites of angiotensin on the corresponding receptors.

While the physiological agonists in blood have a biological half life of a few minutes, it is significantly longer in immunoglobulins. For IgGl, IgG2 and IgG4 immunoglobulins, it is 21 days, and for IgG3, it is about 7 days. This is probably one of the essential causes of the pathophysiological changes in tissues and organs initiated by agAAB or the long-term receptor activation.

In a cellular test system with neonatal rat cardiomyocytes, for example, antibod- ies against βl-R or ATl-R have a similar effect as that of the corresponding hormones adrenalin and angiotensin, i.e., they increase the spontaneous pulsation rate of the rat cardiomyocytes. Accordingly, they are also referred to as agonistic autoantibodies (agAAB) since they are functionally similar to the agonists.

The pathophysiological importance of the agAABs seems to derive from their property of permanently stimulating the cells through the binding of antibody to receptors. The antibody binding is associated with a loss of receptor desensibili- zation capacity (Wallukat et al., 1991), i.e., the cells can no longer protect themselves against the antibody-mediated overactivation by using their intrinsic control loops.

On a molecular level, the agonistic effect of the autoantibodies is based on their capability of receptor homodimerization, which results in receptor or cell activation. One antigenic binding site of IgG each will bind to one extracellular epitope on the extracellular loops (on loop 1 or loop 2). The antibody binding is very stable and cannot be reversed by washing processes in a physiological medium (Wallukat G, public lecture on February 22, 2007; lecture hall of the ophthalmic hospital of Erlangen University).

It has been described that the in vitro effect from antibody binding to the above mentioned receptors (exception : endothelin receptor A, muscarinic M2 receptor) on neonatal rat cardiomyocytes lasts for several hours (Wallukat et al., 1991). In vitro on spontaneously pulsating neonatal rat cardiomyocytes, receptor-specific antagonists can neutralize the positive chronotropic effect, i.e., the addition of an antagonist corresponding to the antibody/receptor results in deactivation of the receptor. This becomes visible through the reduction of the antibody-induced increase of the pulsation rate of the rat cardiomyocytes. The process is specific, and an antagonist will reduce the pulsation rate only if the previously employed antibody is specific for the same receptor.

It is the object of the present invention to treat subjects suffering from diseases such as type 2 diabetes, a cardiovascular, nephrological, urological, ophthalmologi- cal or neurological disease and simultaneously bearing agAABs against GPCRs, such as angiotensin II receptor 1, alpha receptors or βl/β2 receptors therapeutically to reduce symptoms mediated by autoantibodies or preventively. In the context of individualised medicine and therapy the screening of patient's blood for agAAB is a prerequisition of a specific drug antagonist treatment to reduce agAAB mediated clinical symptoms. P.e., the finding of agAAB directed against the ATl-R indicates the use of a sartan for the treatment of the hypertension associated with that agAAB.

The invention is based on the discovery that receptor antagonists are able to remove agAABs from the attacked GPCRs which reduces the pathophysiological cellular effects.

According to the invention, this object is achieved by the use of antagonists of so- called G protein coupled receptors (GPCRs) for the preparation of a medicament for treating diseases caused by or associated with agonistic autoantibodies (agAABs) activated GPCRs.

The invention makes possible a causal treatment of various disorders. If a therapy, e.g. of hypertension is designed, a diagnosis of presence of agAABs should be performed. In case that agAABs against the αi_A-receptor are detectable then as consequence alpha rezeptor antagonists have to be administered. In case that agAABs against the ATl-R are detectable then as consequence sartans have to be administrated. However, due to the clinical findings the administration of sartans or alpha receptor antagonists is essential to deactivate receptor activation caused by the agAABs which receptor activation is causing the disorder. Thus, the physician is now enabled to design a therapy individually and with a higher probability of success than just by shot-gun method based on the clinically finding of hypertention only without respect to the status of agAABs.

The invention also relates to the use of receptor antagonists not only for attenuating the activity of physiological agonists, but also for reversing the binding of autoantibodies to GPCRs by detaching the agAABs from receptors and blocking the agAAB binding to receptors.

The antagonistic effect of the receptor antagonists on the antagonistic activity of the autoantibodies is surprisingly associated by a detachment of the autoantibodies from their binding to the receptors (see Figure 3).

The present invention extends the therapy of diseases by the use of receptor antagonists for the reversal and prevention of antibody-mediated pathological cell activations. According to the invention, receptor antagonists can be used for therapeutical purposes in patients in whom agAABs have been detected in the blood. It should be considered that the respective receptor antagonist is indicated for the GPCR against which agAABs have been detected. In living cells, it has been found that agAABs specifically bound to receptors will become detached from its binding to the receptor by the addition of corresponding antagonists (for agAABs against βl-adrenoreceptor, it is a so-called beta blocker, for agAABs against αl- adrenoreceptor, it is a so-called alpha blocker, etc.). The detachment is detected in the cell culture supernatant containing the immunoglobulins that are detected in an antigen-specific way in a second test system, a sensitive enzyme immunoassay.

Illustratively, this is shown for an agonistic antibody against human αlA adrenoceptor, its specific antagonist prazosin, using biological assay systems.

The use according to the invention relates to GPCRs which are selected, in particular, from the group consisting of βl-R, β2-R, ATI receptor, αl receptors and endothelin receptor (preferably subtype IA). Prevalences for the agAABs of the autoantibodies against the above mentioned GPCRs, if known, are stated in Table 1. The use according to the invention further relates to diseases such as arteriosclerosis, diabetes 2, patients with terminal renal insufficiency, different forms of dementia, especially Alzheimer's disease, different forms of glaucoma (normal pressure glaucoma, pseudo-exfoliative glaucoma) as well as prostate hyperplasia, erectile dysfunction, tinnitus, migraine, permanent headache, peripheral circulatory disturbances if associated with agAABs against the above mentioned GPCRs.

Table 1 : Agonistic autoantibodies against G protein coupled receptors in various diseases (Table modified from: Brinckmann R and Kunze R edts., 2002; the publications used for presenting the prevalence data are contained in the original publication)

α-R: α-adrenergic receptor; β-R: β-adrenergic receptor; ATl-R: angiotensin II receptor 1; TSH-R: thyroid hormone receptor

In particular, the antagonists that can be employed according to the invention are selected from the group consisting of antagonists against the above mentioned GPCRs. Table 2 gives an exemplary overview.

Table 2: Clinically relevant GPCRs and therapeutically available receptor antagonists

α-R: α-adrenergic receptor; β-R: β-adrenergic receptor; ATl-R: angiotensin II receptor 1

The use of the antagonists according to the invention also includes the combination thereof with other active substances, for example, those used for the treatment of acute myocardial infarction, chronic heart insufficiency, kidney insufficiency and hypertension (see Table 1). Examples thereof include so-called ACE inhibitors, heart glycosides, anti-arrhythmic agents, diuretic agents as well as antiinflammatory or blood flow stimulating agents. In the same way as the cardiomyocytes are stimulated by physiological receptor agonists, they are also stimulated by the agAABs, and in both cases, the stimulation is reversed by the corresponding receptor antagonists. From a clinical point of view, the reduction of the effect of the agAABs can be compared to that of classical immunosuppressives. However, it is not evident what reverses the effect of the agAABs, i.e., it is not known whether the restoring of cellular function is due to a change of the cellular receptor status or has different causes. From an immunological point of view, this is not an immunosuppressive therapy, but a novel pharmacological principle of action which reverses the effect of the agAABs at their target, the corresponding GPCR.

Immunosuppressive drug therapies are performed for diseases involving detected pathological functionally relevant autoantibodies. Their object is to block, neutralize or at least reduce pathological and clinically active autoimmune mechanisms. In the therapy against agAABs, these immunosuppressives are not clinically active. However, according to the invention, this task can be adopted by antagonists against GPCRs that reverse the binding of the agAABs to the receptors and detach the agAABs from their receptors.

The data shown in Figures 2, 3 and 4 illustratively demonstrate the detachment of agAABs directed against human αlA adrenoreceptor. For the experiments, an IgG type model antibody produced in rabbits was employed. The amino acid sequence of the complete extracellular 2nd loop of the mentioned receptor with the amino acid sequence ¹⁶⁸PAPEDETICQINEE¹⁸¹ in which the binding epitope of the human autoantibodies is contained served as the antigen. The model antibody has identical agonistic receptor-activating properties with those of the agonistic autoantibody occurring in humans with hypertension.

After the model antibody has been added, the pulsation rate of the rat cardiomyocytes is increases as expected (Figure 1). The experimental procedure for illustratively demonstrating the property of the receptor antagonists to detach agonistic antibodies from the receptor is described in the legends of Figures 2, 4 and 5. According to these results, the antagonistically mediated deactivation of the a gAAB- induced increase of the pulsation rate is based on dissociation of the agAABs from their binding sites at the GPCR.

Another part of the invention relates to the use of antagonists against GPCRs for preventing antibody binding at the receptor. When neonatal rat cardiomyocytes are pretreated with an antagonist, the stimulating action of later administered agAABs of the corresponding receptor fails to occur. Thus, the antibody added after a delay from the addition of prazosin cannot display its agonistic action towards the cells. Illustratively, this is shown in Figure 2 (columns 3 and 4). This property of the antagonists to prevent the binding of agAABs is surprising since the agAABs will bind in a highly specific manner to defined regions (epitopes) on the extracellular loops 1 or 2 of the corresponding GPCRs, i.e., in regions that are not identical with the binding site of the antagonists.

Thus, the conformational change induced at the receptor by antagonists blocks not only the activity of the corresponding agonists, but also that of the autoantibodies and thus protects the receptor from a pathological, autoimmunologically caused activation.

The surprising results relating to the dissociation of the antibody from the receptor were obtained from neonatal rat cardiomyocytes.

Method and materials for determining agonistic autoantibodies in a bioassay

The determination of agAABs is effected functionally in a bioassay using neonatal rat cardiomyocytes.

The assay can be used as well for the screening on agAAB in plasma of patients as the demonstration of the pathophysiological effects of agAAB against GPCRs and the downmodulating activities of antagonists in respect to the corresponding agAAB. For the determination of the agAABs in patient sera (without anticoagulation), the immunoglobulins are prepared therefrom as described in Wallukat et al. (1991). In a final dilution of from 1 : 20 to 1 : 100, the samples are then added to the spontaneously pulsating rat cardiomyocytes in cell culture flasks.

According to their GPCR status, the identification of agAABs against six different receptor types is possible with the bioassay, namely of αl-R, βl-R, β2-R, ATl-R, endothelin receptor (subtype IA), and muscarinic receptor M2. Due to a very high sequence homology or even identity of these GPCRs in humans and rats, the binding of the human autoantibodies to the extracellular receptor loops of the rat cardiomyocytes is possible. With this functional assay, not only human agAABs can be identified and characterized. Antibodies generated in animals by immunization with receptor peptides are also agonistically active and detectable. Therefore, the invention is illustratively presented by the use of an immunoglobulin (IgG) produced in rabbits and purified by affinity chromatography that also has agonistic activity and recognizes the same epitopes on the receptor loops as its human analogue that is associated with disease.

The preparation of the neonatal rat cardiomyocytes and the creation of the cell culture is effected by analogy with Wallukat G and Wollenberger A (1987) and Wallukat et al. (1991). Spontaneously pulsating neonatal rat heart cells are employed in the bioassay on days 4 to 6 of culturing. The determination of the agAABs is effected in three blocks (interval 20 min) of 5 cell culture flasks each (12.5 cm² surface area, supplied by BD Falcon). To prepare the counting of a run, the culture medium (always 2 ml) is replaced in a maximum of 15 cell culture flasks, and the flasks are cultured stationarily at 37 ⁰C for one hour. At 5 min before the counting, the first 5 flasks are briefly opened and placed onto the heating stage (37 ⁰C) of a microscope.

Successively, the basal pulsation rate of the cells is determined in these five flasks. The flask to be counted is contained in a metal template with counting fields. The pulsation rate of the cells is determined with computer aid in at least 5 selected counting fields of this template. Subsequently, the immunoglobulins (IgG) isolated from patient serum is added at a dilution of from 1.20 to 1 :40. If model antibodies are used, they are employed in a dissolved state in phosphate- buffered physiological saline at a final concentration of 2.5 μg/ml.

After stationary incubation at 37 ⁰C for one hour, the cell culture flasks are again placed on the heating stage (37 ⁰C) of the microscope for 5 min, and the pulsation rate of the cells in the same at least 5 counting fields are again determined with computer aid.

In the rat heart cells, AgAAB-positive samples usually lead to an increase of the pulsation rate by the added immunoglobulins by more than 2 beats per 15 seconds. The subsequent additional incubation of the cell cultures with antagonists and the following decrease of the pulsation rate towards the basal pulsation rate confirms the existence of agAABs in the patient serum.

The specificity of the agAABs for one receptor type is established by adding antagonists to the cell culture. In the same assay system, if needed, the receptor specificity of the autoantibodies can be established without the addition of antago- nists by preincubating the immunoglobulin fraction to be tested (or with the autoantibodies contained therein) with the long-chain extracellular loop peptides (complete amino acid sequence) or with the short chain peptides (about 7 amino acids, may contain antibody binding site = epitope). If the positive chronotropic signal is missing for a particular peptide after preincubation in the bioassay, this is a proof of the presence of an agAAB directed against the GPCR from whose amino acid sequence (preferably extracellular loops 1 or 2) it is derived (Wallukat et al., 1999).

The counting of the pulsation rate is effected with the following technical means:

- Olympus microscope, model IMT-2, with heating stage, Olympus Optical Co., Ltd., Japan

- Zeiss microscope, type TELAVAL3, with heating stage, Carl Zeiss Jena, Germany - metal template with defined counting fields

- program software: Imagoquant Lab View 5.1, Mediquant GmbH, Germany

The chemicals employed were of analytical grade and were supplied by the company Sigma. Cell culture media, cell culture flasks and other materials were purchased from various known manufacturers.

Method and materials for measuring the antibodies in an enzyme immunoassay

The antibody employed can be determined as a molecular mass in a sensitive enzyme immunoassay (Figure 3). For this purpose, a peptide corresponding to the extracellular loop 2 of human αlA adrenoceptor was coupled as an antigen through biotin with a so-called PEG (polyethylene glycol) spacer at the N-terminal end of the amino acid chain.

In order to test whether the addition of the receptor antagonist results in a release of the antibodies bound to the receptors, the cell culture supernatant was removed and subjected to quantitative detection in a specific enzyme immunoassay with the extracellular loop 2 as the antigen.

After co-incubation of the loop peptide (100 ng/ml) with the rabbit antibody in different concentrations for one hour, the immune complex was added to neutra- vidin-coated microtitration plates (Pierce). This causes the biotinylated peptide to be bound to the plate surface via neutravidin. Subsequently, the wells were washed (200 μl each, 3x with 25 mM Tris-buffered 0.15 M saline containing 0.05% Tween 20, pH 7.2, Pierce). After the addition of a secondary antibody (30 min, anti-rabbit IgG, peroxidase-conjugated, 1 : 100,000, Dianova) and the addition of the TMB substrate (15 min, Pierce), the converted enzyme substrate was subse- quently measured by photometry at 450 nm. Legends of the Figures

Figure 1 : Increase of the spontaneous pulsation rate of neonatal rat cardiomyo- cytes by an agonistic antibody (IgG) produced in rabbits and directed against the 2nd extracellular loop of αlA adrenoreceptor.

The model antibody (final concentration 2.5 μg/ml) was added to the cell culture. The pulsation rates of the cells were determined before and after 60 min from the addition of the model antibody. The data from 7 parallel cultures are shown as a difference from the so-called basal rates and per 15 seconds. For each cell culture flask, the pulsation of cells from 5 cell populations was measured (see number in the respective column). The mean value and SEM (standard error of the mean) are shown. For column 3, the error width is extremely narrow and therefore not visible. An increase of the pulsation rate by < 1.7 beats/15 seconds is not yet considered a proof of an agAAB. It is marked as a light gray region between the columns. Figure 1 shows typical examples of an antibody-induced increase of the pulsation rate of different cell cultures.

Figure 2: Influence of the receptor-specific antagonist prazosin on the binding of the antibody to αlA adrenoceptor

To the cell cultures shown in Figure 1, the receptor antagonist prazosin (10-7 M) was added after incubation with the antibody for 1 h and measurement of the pulsation rate (graphic columns 1 and 2 for the repetition). The result, which was expected because it was known from the literature, is a reduction of the pulsation rate of the cells. This is shown in the columns respectively designated as Ia and 2a. The measurement was effected 10 min after the addition of prazosin.

In parallel cell cultures, the reverse method was employed, i.e., the cells were first preincubated with the receptor antagonist prazosin (10 min). Subsequently, the antibody was added and incubated for 1 hour. As can be seen from graphic columns 3 and 4 (repetition of 3), the antagonist prazosin blocks the induction of the antibody-mediated increase of the pulsation rate. The additions are respectively mentioned under the abscissa. Figure 3: Binding of the model antibody against the 2nd extracellular loop of the human αlA adrenoceptor in an enzyme immunoassay (EIA)

The quantitative detection of the antibody directed against the 2nd extracellular loop is successfully performed in an EIA. Figure 3 shows a typical linear calibration curve.

Figure 4: Detachment of the antibody from spontaneously pulsating rat cardiomyo- cytes by the antagonist prazosin

To demonstrate the antibody detachment, the cell cultures from Figure 1 were used. After incubation for one hour, the unbound antibody was washed out. Subsequently, prazosin was added to cultures 3-7, and the cell culture was incubated for 20 min. Thereafter, cell culture supernatants were removed from all cultures, and the antibody level was determined by EIA; column 1 (n = 2) without prazosin, column 2 (n = 5) with prazosin. The data show that prazosin detaches the antibody from the binding, which is manifested by a higher antibody concen- tration in the cell culture supernatants of cultures 3-7 (column 2).

References

1. Brinckmann R and Kunze R (edts.). G-protein coupled receptors and autoantibodies, 2002 Pabst Science Publishers, ISBN 3-936142-93-9.

2. Dragun D, Mϋller DN, Brasen JH, Fritsche L, Nieminen-Kelha M, Dechend R, Kintscher U, Rudolph B, Hoebeke J, Eckert D, Mazak I, Plehm R, Scho- nemann C, linger T, Budde K, Neumayer HH, Luft FC, Wallukat G (2005). Angiotensin II type 1-receptor activating antibodies in renal-allograft rejection. /V Engl J Med., 352(6) : 558-569.

3. Jahns R, Boivin V, Hein L, Triebel S, Angermann CE, Ertl G, Lohse MJ. (2004). Direct evidence for a beta 1-adrenergic receptor-directed autoimmune attack as a cause of idiopathic dilated cardiomyopathy. J Clin Invest. 113(10) : 1419-1429.

4. Matsui S, Fu ML, Katsuda S, Hayase M, Yamaguchi N, Teraoka K, Kurihara T, Takekoshi N, Murakami E, Hoebeke J, Hjalmarson A (1997). Peptides derived from cardiovascular G-protein-coupled receptors induce morphological cardiomyopathic changes in immunized rabbits. J MoI Cell Cardiol. 29(2) : 641-655.

5. Matsui S, Fu M, Hayase M, Katsuda S, Yamaguchi N, Teraoka K, Kurihara T, Murano H, Takekoshi N (2006). Transfer of immune components from rabbit autoimmune cardiomyopathy into severe combined immunodeficiency (SCID) mice induces cardiomyopathic changes. Autoimmunity, 39(2) : 121-128.

6. Wallukat G and Wollenberger A (1987). Involvement of beta2-adrenergic receptors in the potentiation of the chronotropic action of isoprenaline evoked in rocker-cultured neonatal rat heart cells by pyruvate and L( + )- lactate. In: Beamish RE, Panagia V, Dhalla NS; Eds. Pharmacological aspects of heart diseases. Boston : Martinus Nijhoff, p 217-231. 7. Wallukat G, Morwinski M, Kowal K, Forster A, Boewer V, Wollenberger A (1991). Autoantibodies against the beta-adrenergic receptor in human myocarditis and dilated cardiomyopathy: beta-adrenergic agonism without desensitization. Eur Heart J. ) 12 Suppl D: 178-181.

8. Wallukat G, Homuth V, Fischer T, Lindschau C, Horstkamp B, Jupner A, Baur E, Nissen E, Vetter K, Neichel D, Dudenhausen JW, Haller H, Luft FC (1999). Patients with preeclampsia develop agonistic autoantibodies against the angiotensin ATI receptor. J CHn Invest. ; 103(7) : 945-952.

Claims

C L A I M S :

1. Use of antagonists of so-called G protein coupled receptors (GPCRs) for the preparation of a medicament for treating or preventing diseases caused by agonistic autoantibodies (agAABs) activated GPCRs.

2. The use according to claim 1, wherein said GPCRs are selected from the group consisting of βl-R, β2-R, ATI receptor, αl receptor, muscarinic R2, endothelin receptor.

3. The use according to either of claims 1 and/or 2, wherein said βl adrenore- ceptor antagonists are, in particular: atenolol, metoprolol, bisoprolol, pro- pranolol, sotalol, pindolol, nevibolol, carvedilol, nebivolol for the treatment and prevention of chronic heart insufficiency, dilatative cardiomyopathy, hypertension, tachycardias, coronary heart disease, migraine.

4. The use according to either of claims 2 and/or 3, wherein said β2 adrenore- ceptor antagonists are, in particular: carvedilol, timolol for the treatment and prevention of glaucomas and antibody-mediated systemic and local circulatory disturbances.

5. The use according to either of claims 2 and/or 3, wherein said α adrenore- ceptor antagonists are, in particular: phenoxybenzamine, prazosin, terazosin, alfuzosin, tamsulosine for the treatment and prevention of prostate hyperplasia, hypertension or tinnitus.

6. The use according to either of claims 2 and/or 3, wherein said angiotensin 1 receptor antagonists are, in particular: valsartan, losartan, irbesartan, can- desartan, eprosartan, olmesartan, telmisartan for the treatment and prevention of hypertension, acute cardiac infarction, kidney injury.

7. The use according to either of claims 2 and/or 3, wherein said endothelin receptor (ETlA) antagonists are, in particular: bosentan, darusentan for the treatment and prevention of pulmonary arterial hypertension, chronic heart insufficiency.

8. A method of treating a patient suffering from a disorder caused by agAAB activated GPCR comprising the steps of

measuring whether or not agAABs against a GPCR are present in the patient and if yes

administering an antagonist of the GPCR in order to deactivate agAAB mediated receptor activation.