JPH09227410A - Organ transplant rejection inhibitor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a suppressant for rejection in organ transportation, comprising a bonding inhibitor for P-selectin as an active ingredient, capable of preventing the accumulation of leukocytes caused at the time of organ transplantation and subsequent activation thereof and effective against rejection in the organ transplantation. SOLUTION: This suppressant for rejection in organ transplantation comprises a bonding inhibitor of P-selectin, preferably an anti-P-selectin antibody, a ligand of the P-selectin or an antibody specific for the ligand of the P-selectin, P- selectin or its fragment, a biosynthetic inhibitor of the ligand of the P-selectin or an inhibitor of the expression of the P-selectin as an active ingredient. Furthermore, the dose of the suppressant is about 0.5mg to about 1g for, e.g. a patient weighing 70kg.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel medical use of a P-selectin binding inhibitor. More specifically, the present invention relates to an organ transplant rejection inhibitor containing a P-selectin binding inhibitor as an active ingredient.

[0002]

2. Description of the Related Art When an organ becomes dysfunctional due to various serious diseases, another human organ is transplanted as a treatment method. Recently, attempts have been made to transplant animal organs into humans. Rejection is the most clinical problem in organ transplantation to humans. This is because the organ to be transplanted (graft) cannot be engrafted on the recipient's body and falls off. The primary cause of the rejection reaction is the allograft immune response. When a substance other than its own components enters the body, the body recognizes the substance as an antigen, and as a part of self-defense, the foreign body is stimulated by lymphocytes and humoral immunity by the produced antibodies. Try to eliminate. In the transplantation immune reaction, it is considered that the recipient recognizes the graft as an antigen, and rejection is performed by a T cell-based immune reaction that shows a series of cascades of T cell activation and proliferation and graft destruction. There is. Therefore, in organ transplantation, a group of drugs called immunosuppressants are used to suppress this reaction. They include corticosteroids (prednisone) and cyclosporin A,
More recently, FK-506 has become widely used. However, the effects of these drugs are not perfect, and side effects have been reported. The second most likely cause is ischemia-reperfusion injury. In organ transplantation, the blood flow of the graft is temporarily interrupted (ischemia) along with its removal, and then the blood is restarted by transplantation to the recipient (reperfusion). By ischemia-reperfusion procedure,
It is well known that tissues at the site of reperfusion are damaged, and it is considered that at least one of the mechanisms of action thereof is activation of neutrophils contained in blood. That is, it has been clarified in an animal experiment that reperfusion injury is significantly reduced in an animal in which neutrophils have been reduced. Therefore, suppressing the activation of leukocytes by some method is considered to be an effective means for preventing ischemia-reperfusion injury and preventing organ injury during organ transplantation.

Leukocytes have a function of treating foreign substances that have entered from the outside of the living body, and usually eliminate foreign substances. When the tissue is damaged, it collects at the damaged site and contributes to the repair of the tissue. In general, a problem in the inflammatory reaction is when the self-defense ability of the white blood cells is excessively exerted, which in turn damages the self-tissue. Leukocytes accumulated in the inflammatory site are activated and release proteolytic enzymes stored in the cells or produce active oxygen to decompose and treat foreign substances. At the site of organ transplantation, significant leukocyte accumulation often occurs in surrounding tissues after transplantation. This means that tissue damage occurs at the leukocyte accumulation site. Various attempts have been made to treat this, but at present there is no effective means.

[0004]

An object of the present invention is to find a drug that prevents organ transplant rejection by preventing leukocyte accumulation and subsequent activation that occur during organ transplantation.

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to improve the rejection reaction that occurs during such organ transplantation. As a result, the interaction between leukocytes and vascular endothelial cells is important for these pathological conditions in animals. I found that I played a different role. Moreover, it was clarified through examination using an antibody that this pathological condition is controlled by P-selectin involved in adhesion of leukocytes to vascular endothelial cells, and the present invention was completed.

That is, the present invention provides (1) an inhibitor of organ transplant rejection, which comprises a P-selectin binding inhibitor as an active ingredient. (2) The binding inhibitor of P-selectin is an anti-P-selectin antibody, a ligand of P-selectin or a derivative thereof, an antibody specific to the ligand of P-selectin, P-selectin or a fragment thereof, a ligand of P-selectin The inhibitor according to (1) above, which is a biosynthesis inhibitor or a P-selectin expression inhibitor. (3) The inhibitor according to (1) above, wherein the P-selectin binding inhibitor is an anti-P-selectin antibody. (4) The inhibitor according to any of (1) to (3) above, wherein the organ transplant is heart transplant.

The present inventor has found that a rat heart is transplanted to another rat, and that the anti-P-selectin antibody markedly suppresses the rejection reaction of the transplanted heart. These facts indicate that P-selectin mediates the interaction between leukocyte vascular endothelial cells, plays an important role in leukocyte activation, and in injury of tissues surrounding ischemia-reperfusion site. It has been shown that selectin binding inhibitors are suitable for ameliorating organ transplant rejection associated with these factors.

The term "P-selectin binding inhibitor" refers to an agent that inhibits the binding between P-selectin on vascular endothelial cells and the ligand on leukocytes. Examples of the P-selectin binding inhibitor in the present invention include the following four types depending on the inhibition mode. Inhibitors that bind to ligands on leukocytes by binding to P-selectin Examples of this type of inhibitor include anti-P-selectin antibodies, P-selectin ligands and their derivatives. Those that inhibit the binding of P-selectin by binding to the ligand on leukocytes Examples of this type of inhibitor include antibodies specific to the ligand of P-selectin, P-selectin and fragments thereof. P-selectin ligand biosynthesis inhibitor P-selectin expression inhibitor Particularly preferred among these are those that inhibit binding to ligands on leukocytes by binding to P-selectin, and P-selectin The expression inhibitor of is mentioned.

[0009] The anti-P-selectin antibody means an immunoglobulin that recognizes P-selectin and selectively binds to P-selectin, thereby suppressing the adhesion between cells. This antibody may be a polyclonal antibody or a monoclonal antibody. Although the origin of the present antibody is not limited, examples thereof include an antibody of mouse or human origin, a chimeric antibody in which both human and mouse antibodies are partially bound, or a humanized antibody. Specifically, WO93 / 2195
PB1.3 described in Japanese Patent No. 6 is cited.

P-selectin ligands and derivatives thereof include glycoproteins and glycolipids on the surface of leukocytes and the like, oligosaccharides which are their terminal structures, and derivatives thereof. Examples of oligosaccharides and their derivatives include sialyl Lewis x and sialyl Lewis x derivatives, Lewis x and Lewis x derivatives, sialyl Lewis a and sialyl Lewis a derivatives, Lewis a and Lewis a derivatives, sulfated sugars, phosphorylated sugars, and sulfatide. (Eg, Varki et al. Proc.
Natl. Acad. Sci. USA 91 , 7390
(1994), WO94 / 26760). Examples of glycoproteins include PSGL-1 (eg, Sako et al Cell
75 , 1179 (1993)) and the like.

The antibody specific to the ligand of P-selectin means an antibody specific to the above-mentioned ligand. This antibody may be a polyclonal antibody or a monoclonal antibody. Although the origin of the present antibody is not limited, examples thereof include an antibody of mouse or human origin, a chimeric antibody in which both human and mouse antibodies are partially bound, or a humanized antibody. Specifically, anti-sialyl Lewis x antibody,
Anti-sialyl Lewis a antibody, anti-Lewis x antibody, anti-Lewis a
An antibody or the like (eg, Fukushima et al. Ca
ncer Res. 44 , 5279 (1984), Sh
Itara et al. Cancer Res. 47 , 1267
(1987), Takada et al. Biochem. Bi
ophys. Res. Commun. 179 and 713
(1991)).

P-selectin and its fragments mean membrane-bound P-selectin, soluble P-selectin, P-selectin partial peptide and the like. P-selectin and its fragments adhere to cells, for example, P-selectin adheres to the above-mentioned ligand or its derivative fixed to a plastic well (or the above-mentioned ligand to a plastic well to which P-selectin is fixed). Or its derivative adheres). Examples of the partial peptide of P-selectin include the peptides described in JP-A-7-501828.

The P-selectin ligand biosynthesis inhibitor means an inhibitor such as a glycosyltransferase used in the biosynthesis of the P-selectin ligand described above. Specifically, an inhibitor against sialyltransferase for transferring sialic acid to an oligosaccharide receptor,
Examples include an inhibitor against fucosyltransferase for transferring fucose. For example, Japanese Patent Application Laid-Open
No. 247078, the sialyltransferase inhibitor described in Chi-Huey Wong et al. A
m. Chem. Soc. 114 , 7321 (1992)
Examples include the fucosyltransferase inhibitors described.

The expression inhibitor of P-selectin refers to an agent that inhibits the expression of P-selectin on the cell surface of vascular endothelial cells and the like, and examples thereof include nitric oxide (NO) donors (Gastroenterology, 107). ，
1199-1201 (1994); Am. J. Phys
iol, 267 , G562-G568 (1994)).
Examples of nitric oxide donors include S-nitrosothiols (Eur. J. Pharm, 144 , 379-38).
3 (1987)), N-nitrosothiols (Table 5
-504760), sidone imine derivative (J. Card
iovascula Pharmacology, 1
8 , 522-527 (1991); Biochem.
J. 281 , 419-424 (1992)), nitroglycerines (J. Pharmacology Expe
marginal Therapeutics, 25
3 , 614-619 (1990)), nitroprussides and the like.

Examples of organ transplants in which the agent for suppressing organ transplant rejection of the present invention is used include allogeneic organ transplants from humans to humans and xenogeneic organs transplants from animals such as baboons and pigs to humans. Examples of organs to be transplanted include heart, lung, liver, kidney, pancreas, skin and the like, and the preferable organ is heart. The inhibitor of the present invention is administered parenterally, topically, orally, or transdermally, and can be administered in various unit dosage forms depending on the administration method.
For example, unit dosage forms suitable for oral administration include powders, tablets, pills, capsules and dragees. Preferably, the inhibitor of the present invention is administered intravenously. For intravenous administration, the drug is dissolved or suspended in a pharmaceutically acceptable carrier, preferably an aqueous carrier. As the aqueous carrier, for example, water, buffered water, physiological saline, and the like can be used. The resulting aqueous solution should be packaged as is, or
Alternatively it can be lyophilized and the lyophilized preparation combined with a sterile aqueous solution prior to administration. The inhibitor of the present invention is a pharmaceutically acceptable auxiliary agent such as pH adjusting agent and buffering agent, tonicity adjusting agent, wetting agent, etc., such as sodium acetate, as required for an approximate physiological condition. Sodium lactate, sodium chloride, potassium chloride,
It may contain calcium chloride, sorbitan monolaurate, triethanolamine oleate and the like.

The inhibitor of the present invention is administered to a patient before or after organ transplantation in an amount sufficient to prevent or at least partially prevent transplant rejection. Dosage of the inhibitor of the present invention, for example, the active ingredient,
Although it varies depending on the administration method, the degree of disease to be treated, and the overall health of the patient, generally, the amount of the inhibitor of the present invention is about 0.5 mg to about 1 g per day for a patient weighing 70 kg.
And preferably about 70 mg to about 500 mg of the active ingredient of the present invention per day for a patient weighing 70 kg.
Use a dose in the range of mg.

[0017]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. The binding inhibitor of P-selectin is
The fact that it is an effective inhibitor of rejection in organ transplantation will be specifically described below by taking heart transplantation as an example. In the experiment, an anti-P-selectin antibody PB1.3 (an antibody described in WO93 / 21956) was used as a P-selectin binding inhibitor.

Experimental Example 1 Effects on heart transplant rejection of rats (Experimental method) F344 male rats were used as donors and Lewis.
Allogeneic abdominal ectopic heart transplantation was performed using male s strain rats as recipients. Under a stereoscopic microscope, a donor rat anesthetized with chloral hydrate was thoracotomy, the heart was isolated, and the pulmonary vein and the upper and lower vena cava of the heart were ligated with silk thread. The excised transplanted heart was stored in ice-cold cardioplegic solution until transplanted to the recipient. Next, the abdomen of the recipient rat anesthetized with chloral hydrate was subjected to a midline incision, and the abdominal aorta and inferior vena cava were separated. After ligating with silk thread and bulldog forceps to block blood flow, both blood vessels were partially dissected, and the abdominal aorta of the recipient and the aorta of the transplanted heart, the inferior vena cava of the recipient and the pulmonary artery of the transplanted heart were 10-0. The ends were anastomosed with nylon thread. After that, the ligature with silk thread was loosened, blood flow to the transplanted heart was restarted, and after confirming the recovery of heartbeat, the abdominal wall was closed. The blood flow blocking time of the transplanted heart was about 20 to 30 minutes, and myocardial necrosis due to ischemia was usually slight. The rejection of the transplanted heart was judged by palpation on the abdominal wall to confirm the heartbeat.
In the anti-P-selectin antibody administration group (n = 5), PB1.
3,400 μg / head was intraperitoneally administered 1 day before, 1 day, 1 day, 3 days, 5 days and 7 days after the operation. In addition, an untreated control group (n = 4) was provided as a control. The statistical significance of the experimental results was tested by the Mann-Whitney U test. (Experimental Results) The engraftment period of transplanted hearts in the untreated control group was 7, 9, 10, and 11 days, respectively. Anti-P-
The engraftment period of the transplanted hearts of the selectin antibody administration group was 10, 14, 16, 17, and 18 days, respectively, and the engraftment period of the rat transplanted hearts was significantly (p <0. It was extended to 05).

[0019]

INDUSTRIAL APPLICABILITY The present invention can provide an effective inhibitor of rejection in organ transplantation.

[Brief description of drawings]

FIG. 1 shows the engraftment curve of rat transplanted hearts after administration of anti-P-selectin antibody.

Claims (4)

[Claims] 1. An inhibitor of organ transplant rejection, which comprises a P-selectin binding inhibitor as an active ingredient. 2. A binding inhibitor of P-selectin is anti-P-
A selectin antibody, a P-selectin ligand or a derivative thereof, an antibody specific to a P-selectin ligand,
The inhibitor according to claim 1, which is a P-selectin or a fragment thereof, a biosynthesis inhibitor of a P-selectin ligand, or a P-selectin expression inhibitor. 3. A P-selectin binding inhibitor is anti-P-
The inhibitor according to claim 1, which is a selectin antibody. 4. The inhibitor according to claim 1, wherein the organ transplant is heart transplant.