WO2008036747A2 - Composition and method for immunomodulation - Google Patents

Abstract

A pharmaceutical composition and method is provided for modulating an immune response in a warm-blooded vertebrate animal. The method comprises administering to the animal an immunomodulatory composition comprising an anthelmintic benzimidazole compound. More particularly, in one embodiment the animal to be treated is afflicted with a disease state selected from the group consisting of a non-parasitic infection, an autoimmune disorder, an inflammatory disorder, an immunodeficiency-related disorder, and neoplasia. In one embodiment the anthelmintic benzimidazole compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole. In one embodiment a method of enhancing a vaccine's efficacy is provided wherein a vaccine composition and an anthelmintic benzimidazole compound are co-administered to a warm-blooded vertebrate animal.

Description

COMPOSITION AND METHOD FOR IMMUNOMODULATION

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent Application Serial No. 60/846,252 filed on September 21, 2006, the entire disclosure of which is hereby incorporated by reference.

BACKGROUND

The immune system in warm-blooded vertebrates provides a means for the recognition and elimination of invading foreign pathogens. While the immune system normally provides a strong line of defense, there are still many instances where infectious organisms or tumor cells fail to elicit a strong immune response or the host is immunodeficient and the immune system cannot respond to invading pathogens. Thus, therapeutic agents which stimulate the immune system have been developed for treating humans or other warm-blooded vertebrates such as agricultural and domestic animals. For example, interferon has been used to stimulate the immune system in humans afflicted with such diseases as infectious diseases and neoplastic disease, and has been used to treat infectious diseases in bovine, porcine, canine, avian, and feline species (U.S. Patent No. 5,019,382 and U.S. Patent No. 5,215,741). Additionally, interferon has been used to potentiate the immune response to vaccines in humans and bovine species (U.S. Patent No. 4,820,514).

Antimicrobial agents, such as antibiotics, which directly attack infectious organisms, have also been developed for the prevention and treatment of infections in humans and other warm-blooded vertebrates. However, many of the currently available antimicrobial agents have adverse side effects and have limited efficacy in instances where the infectious organism has developed resistance to the antimicrobial agent. Similarly, chemotherapeutic agents have been developed to treat disorders such as neoplastic disease, autoimmune disorders, and inflammatory disorders such as hyperallergenicity. However, most, if not all, of the currently available chemotherapeutic agents have adverse side effects and efficacy can be reduced where host drug resistance is developed. Accordingly, there is a need for improved therapeutic agents with the capacity to modulate the immune response, but which do not induce resistance and which exhibit decreased adverse side effects. Although progress has been made in the development of vaccines for the treatment and prevention of infectious diseases in humans and other warmblooded vertebrates, 100% efficacy has not been achieved, adverse side effects continue to be a problem, and some infectious organisms have not been controlled by vaccination. For example in humans, influenza vaccines are only 40-60% efficacious, cholera vaccines are only 50% efficacious with a short-lived immunity, and typhoid vaccines are only 50-70% efficacious with a short-lived immunity. Furthermore, adverse reactions to vaccines are well-known such as hypersensitivity to tetanus toxoid, local reactions to hepatitis A virus, typhoid, rabies, and pneumococcus vaccines, and systemic responses to typhoid and cholera vaccines such as frequent fever. More problematic are the infectious agents not yet controlled by vaccination such as the human immunodeficiency virus (HIV), herpes simplex virus, and Salmonella, Streptococcus, and Neisseria species. Accordingly, there is a need for improved vaccines which exhibit decreased adverse reaction rates and increased protection.

There is also a need for improved vaccines in warm-blooded vertebrate animals such as agricultural animals and domestic animals. For example, one infectious disease which has not been controlled by vaccination in cattle is bovine respiratory disease complex (BRDC). BRDC is an all-encompassing term describing an acute, contagious infection of cattle characterized by inflammation of the upper respiratory passages and trachea. BRDC leads to pneumonia with clinical signs of dyspnea, anorexia, fever, depression, mucopurlent nasal discharge and mucopurulent ocular discharge, all of which result in high morbidity and mortality. BRDC is a major cause of disease loss in beef cattle. The economic loss to US cattlemen for treatment, weight loss, death loss, and culling is estimated to be $640,000,000 annually (National Cattlemen's Association, July 20001980).

When BRDC symptomology is observed in cattle after transport to feedlots or pastures, it is commonly called "shipping fever." On their way to the feedlot, calves are subjected to the stresses of intensive management techniques, transportation without food or water, and a variety of infectious agents. Upon arrival at the feedlot, processing exposes the calves to the additional stresses of weaning, castration, dehorning, branding, ear tagging, worming, vaccination, and debusing. In many situations, calves are stressed still farther by changes in diet and environmental factors.

The infectious agents to which calves entering the marketing system are exposed include viruses (infectious bovine rhinotracheitis (IBR) virus, non-IBR herpesviruses, parainfluenza type 3 (PI3) virus, bovine viral diarrhea (BVD) virus, respiratory syncytial virus, adenoviruses, enteroviruses, rhinoviruses, parvoviruses, and reoviruses), bacteria {Mannheimia hemolytica, Pasteurella multocida, Hemophilus somnus, and Chlamydia species), and mycoplasma (M dispar, M. bovirhinis, M. bovis, and M. arginini). The IBR, BVD, and Pl 3 viruses are three of the infectious agents that are most commonly isolated by veterinary diagnostic laboratories in cases of BRDC. While some commercial vaccines for IBR, BVD, and Pl 3 are available, they have not been completely satisfactory in the past, partly because vaccination of calves stressed by shipping can exacerbate the clinical signs of the disease. Also, some calves will not develop antibodies after vaccination, leaving them still susceptible to infection. Furthermore, many commercial vaccines are designed to provide protection no sooner than 14 days after vaccination, tracking the U.S. Department of Agriculture, Bureau of Biologies, immunogenicity test. Because of the imperfections of the vaccination treatments used in the past and the enormous economic losses involved, a need exists for improved vaccines for preventing and treating BRDC and diseases of other warmblooded vertebrates.

In general, a need exists for improved methods of vaccinating warmblooded vertebrate animals, including humans, agricultural animals, and domestic animals, because current vaccine preparations can cause adverse side effects, current vaccines are not 100% efficacious, and some infectious microorganisms have not been controlled by vaccination. Furthermore, a more efficacious vaccine would provide the advantages that the number of doses required and the amount of killed or live attenuated microorganisms needed for an effective vaccine could be reduced, in turn reducing the chances of a detrimental vaccine-induced infection and reducing the cost of the vaccine. A more efficacious vaccine would also cause stronger and more rapid immune responses, such as a stronger and more rapid antibody response.

The applicant has made the surprising discovery that administering a composition comprising an anthelmintic benzimidazole compound to a warm-blooded vertebrate results in modulation of the immune response. Furthermore, the simultaneous administration to a warm-blooded vertebrate of a composition comprising an anthelmintic benzimidazole compound and a vaccine enhances vaccine efficacy. Accordingly, as disclosed herein a composition and method are provided for modulating the immune response. More particularly, a method is described for modulating the immune response by administering to a warm-blooded vertebrate animal a composition comprising an anthelmintic benzimidazole compound. In one embodiment a composition comprising an anthelmintic benzimidazole compound and a vaccine are co-administered to a warm-blooded vertebrate to enhance vaccine efficacy. In one embodiment the vaccine and the anthelmintic benzimidazole compound are administered as a single composition.

SUMMARY

As described herein a method is provided for modulating an immune response in a warm-blooded vertebrate animal in need of such a response. The method comprises administering to the vertebrate animal an immunomodulatory composition comprising an anthelmintic benzimidazole compound. More particularly, in one embodiment the vertebrate animal to be treated is afflicted with a disease state selected from the group consisting of a non-parasitic infection, an autoimmune disorder, an inflammatory disorder, an immunodeficiency-related disorder, and neoplasia. In one embodiment the anthelmintic benzimidazole compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole.

In another embodiment a pharmaceutical composition comprising an anthelmintic benzimidazole compound and a vaccine is provided. In one embodiment the anthelmintic benzimidazole compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole.

In yet another embodiment the efficacy of a vaccine is enhanced by modulating the immune response. More particularly, in one embodiment the method of enhancing a vaccine's efficacy comprises the step of co-administering to a warm- blooded vertebrate animal a vaccine composition and an anthelmintic benzimidazole compound. DETAILED DESCRIPTION DEFINITIONS

In describing and claiming the invention, the following terminology will be used in accordance with the definitions set forth below. As used herein, the term "pharmaceutically acceptable carrier" includes any of the standard pharmaceutical carriers, such as a phosphate buffered saline solution, water, emulsions such as an oil/water or water/oil emulsion, and various types of wetting agents. The term also encompasses any of the agents approved by a regulatory agency of the US Federal government or listed in the US Pharmacopeia for use in animals, including humans.

As used herein the term "pharmaceutically acceptable salt" refers to salts of compounds that retain the biological activity of the parent compound, and which are not biologically or otherwise undesirable. Many of the compounds disclosed herein are capable of forming acid and/or base salts by virtue of the presence of amino and/or carboxyl groups or groups similar thereto.

As used herein, the term "treating" includes prophylaxis of the specific disorder or condition, or alleviation of the symptoms associated with a specific disorder or condition and/or preventing or eliminating said symptoms.

As used herein an "effective" amount or a "therapeutically effective amount" of an anthelmintic compound refers to a nontoxic but sufficient amount of the compound to provide the desired immunomodulating effect. For example one desired effect would be an enhanced cytokine response, including an enhanced interferon response. The amount that is "effective" will vary from subject to subject, depending on the age and general condition of the individual, mode of administration, and the like. Thus, it is not always possible to specify an exact "effective amount." However, an appropriate "effective" amount in any individual case may be determined by one of ordinary skill in the art using routine experimentation.

As used herein the term "immunomodulation" or "immune response modulation" as used herein relates to an adjustment of the immune response to a desired level, and includes immunopotentiation, immunosuppression, or induction of immunologic tolerance.

An enhanced cytokine or interferon "response" relates to increasing detectable levels of the relevant cytokine or interferon concentrations in an animal's bodily fluids or tissues or enhancing the cell's responsiveness to the relevant compound.

The term, "parenteral" means not through the alimentary canal but by some other route such as intraperitoneal, intradermal, subcutaneous, intramuscular, intraspinal, or intravenous.

An "anthelmintic benzimidazole compound" as used herein includes compounds of the general structure:

wherein Ri is selected from the group consisting of H, -(Cj-C₄ alkyl), -S(C]-C₄ alkyl),

-CO(C₃-C₅ cycloalkyl), -SR₃, -SOR₃, -0(C₁-C₄ alkyl) and -COR₃, R₂ is selected from the group consisting of H, NHCOOCH₃ and -4-thiazole and R₃ is an optionally substituted phenyl group. In one embodiment the anthelmintic benzimidazole compound has the capability of expelling or destroying parasitic worms, particularly those present in the digestive tract of warm-blooded vertebrate species.

The term "C]-C_n alkyl" wherein n is an integer greater than or equal to

2, as used herein, represents a branched or linear alkyl group having from one to the specified number of carbon atoms. For example, C]-C₆ alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, iso-propyl, butyl, iso-butyl, sec-butyl, tert- butyl, pentyl, hexyl and the like.

The term "C₃ -C₅ cycloalkyl" represents cyclopropyl, cyclobutyl and cyclopentyl. As used herein the general term "interferon" or "IFN" absent further characterization refers to all three major classes of interferons: alpha (α), beta (β), and gamma (γ). EMBODIMENTS

A method is provided for the therapeutic treatment of a host with a non-parasitic infection, an autoimmune disorder, an inflammatory disorder, an immunodeficiency-related disorder, or neoplasia. The method results in potentiation of disease-corrective immune responses in a warm-blooded vertebrate to treat immunodeficiencies and to enhance elimination of non-parasitic pathogenic cell populations, such as infectious microorganisms and cancer cells. The method also results in immune response modulation to treat autoimmune and inflammatory disorders. In accordance with one embodiment the method comprises administering to a warm-blooded vertebrate a pharmaceutical composition comprising an anthelmintic benzimidazole compound in an amount effective to induce an immunomodulating effect.

In accordance with one embodiment the immunomodulating effect is mediated by the anthelmintic benzimidazole's ability to enhance cytokine production in an animal administered the anthelmintic benzimidazole. More particularly, in accordance with one embodiment a method for enhancing the production of interferon in a warm-blooded vertebrate animal is provided. The method comprising the step of administering a pharmaceutical composition comprising an anthelmintic benzimidazole compound of the general structure:

wherein Ri is selected from the group consisting of H, -(Ci-C₄ alkyl), -S(Ci-Gi alkyl), -CO(C₃-C₅ cycloalkyl), -SR₃, -SOR₃, -0(C]-C₄ alkyl) and -COR₃, R₂ is selected from the group consisting of H, NHCOOCH₃ and -4-thiazole; and R₃ is selected from the group consisting of

and wherein R₄ is selected from the group consisting of H, halo and Cj-C₄ alkyl and a pharmaceutically acceptable carrier.

In one embodiment Ri is selected from the group consisting of H, -SCH₂CH₂CH₃, -S-phenyl, -SO-phenyl, -OCH₂CH₂CH₃ and -CO-phenyl, and in a further embodiment R] is selected from the group consisting of H, -SCH₂CH₂CH₃, -S- phenyl, -SO-phenyl, -OCH₂CH₂CH₃ and -CO-phenyl, and R₂ is NHCOOCH₃. In accordance with one embodiment the anthelmintic benzimidazole compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, albendazole, cyclobendazole, parbendazole, oxibendazole, carbendazim and oxfendazole. In one embodiment the anthelmintic benzimidazole compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole, and in one embodiment the compound is fenbendazole. The pharmaceutical composition is administered by a route selected from the group consisting of oral, intramuscular, intradermal, intraperitoneal, intranasal, and intravascular route. In one embodiment the route of administration is oral.

In accordance with one embodiment a method is provided for enhancing the efficacy of a vaccine formulation. The vaccine composition may comprise the standard components such as antigenic compounds, adjuvants, carrier proteins and a pharmaceutically acceptable carrier. Such a vaccine composition can be co-administered with the anthelmintic benzimidazole compounds disclosed herein to further stimulate an endogenous immune response to the vaccine. As used herein, the term "co-administering" means administering the second formulation during the timeframe wherein the first formulation is still inducing a physiological response. In accordance with one embodiment the vaccine composition is administered to the patient either prior to or after the administration of the composition comprising the anthelmintic benzimidazole compound. In one embodiment the two compositions are both administered within 24 hours of each other, and in another embodiment the two compositions are administered within 8 hours, and in one embodiment the two compositions are administered within 1 or 2 hours of each other. In one embodiment the two compositions are administered sequentially, one immediately following the other.

In one embodiment the vaccine and anthelmintic benzimidazole compounds are administered as separate compositions, and optionally in one embodiment the two compositions are formulated for different routes of administration. For example the composition comprising the anthelmintic benzimidazole compounds can be formulated for oral delivery whereas the vaccine formulation is formulated for parenteral administration. In an alternative embodiment the vaccine composition is mixed with the anthelmintic benzimidazole compound to form a single composition that is administered to the warm-blooded vertebrate. The anthelmintic benzimidazole comprising compositions can be administered to the warm-blooded vertebrate in a single dose format or in a multiple dose format. In accordance with one embodiment the anthelmintic benzimidazole compounds for use in modulating the immune response in warm-blooded vertebrates include fenbendazole, thiabendazole, mebendazole, and albendazole. These anthelmintics all contain a benzimidazole ring structure and were discovered based on their potent activity against gastrointestinal parasites which infect humans and other warm-blooded vertebrates. The structures of those four anthelmintic compounds are as follows:

Fenbendazole

Albendazole

Thiabendazole

The present method can be used for potentiating or otherwise modulating the immune response in any warm-blooded vertebrate animal and is applicable to human clinical medicine or to the treatment of agricultural animals, domestic animals, laboratory animals, or wild animals in captivity. Thus, the present compositions and methodology has human clinical and veterinary applications among other applications. The methods can be applied to warm-blooded vertebrate animals including, but not limited to, humans, laboratory animals such rodents (e.g., mice, rats, hamsters, etc.), rabbits, monkeys, chimpanzees, domestic animals such as dogs, cats, and rabbits, agricultural animals such as cows, horses, pigs, sheep, goats, and chickens, and wild animals in captivity such as birds, bears, pandas, lions, tigers, leopards, elephants, zebras, giraffes, gorillas, bison, deer, antelope, marmosets, dolphins, whales, and any endangered warm-blooded animal.

The anthelmintic benzimidazole compounds disclosed herein modulate endogenous immune responses. The endogenous immune response may include a humoral response, a cell-mediated immune response, and any other immune response endogenous to the warm-blooded vertebrate animal. These immune responses include antibody responses, complement-mediated cell lysis, antibody-dependent cell- mediated cytoxicity (ADCC), antibody opsonization leading to phagocytosis, activation of phagocytic cells such as macrophages, clustering of receptors upon antibody binding resulting in signaling of apoptosis, antiproliferation, or differentiation, and direct immune cell recognition of foreign antigens. It is also contemplated that the anthelmintic benzimidazole compounds will modulate the secretion of cytokines, such as interferons and interleukins, that regulate such processes as the multiplication and migration of immune cells. The endogenous immune response modulated may include responses requiring the participation of such immune cell types as B cells, T cells, including helper and cytotoxic T cells, macrophages, natural killer cells, neutrophils, LAK cells and the like.

The method is applicable to such disease states as non-parasitic infections, neoplastic disease, autoimmune disorders, inflammatory disorders, and immunodeficiency-related disorders. The method can be used potentiate the immune response to cancers that are tumorigenic, including benign tumors and malignant tumors, or cancers that are non-tumorigenic. Such cancers may arise spontaneously or by such processes as mutations present in the germline of the host animal or somatic mutations, or may be chemically-, virally-, or radiation-induced. The method can be utilized to enhance the immune response to such cancers as carcinomas, sarcomas, lymphomas, Hodgkin's disease, melanomas, mesotheliomas, Burkitt's lymphoma, nasopharyngeal carcinomas, leukemias, myelomas, and other neoplastic diseases. The cancer cell population can include, but is not limited to, oral, thyroid, endocrine, skin, gastric, esophageal, laryngeal, pancreatic, colon, bladder, bone, ovarian, cervical, uterine, breast, testicular, prostate, rectal, kidney, liver, and lung cancers.

The anthelmintic benzimidazole compounds can also be used to potentiate the immune response to exogenous pathogens or to a cell population harboring exogenous pathogens, e.g., a virus. The present method is applicable for treating such exogenous pathogens as Chlamydia, bacteria, fungi, viruses, and mycoplasma. Infectious agents that may be treated with the present method are any art-recognized infectious microorganisms that cause pathogenesis in warm-blooded vertebrate animals, including such microorganisms as bacteria that are gram-negative or gram-positive cocci or bacilli. Of particular interest are bacteria that are resistant to antibiotics such as antibiotic-resistant Streptococcus species and Staphylococcus species, or bacteria that are susceptible to antibiotics, but cause recurrent infections treated with antibiotics so that resistant organisms eventually develop. Such organisms can be treated with anthelmintic benzimidazole compounds in combination with lower doses of antibiotics than would normally be administered to warm-blooded vertebrates to avoid the development of these antibiotic-resistant bacterial strains.

The anthelmintic benzimidazole compounds disclosed herein may also be used to treat DNA and RNA viruses, including, but not limited to DNA viruses such as papilloma viruses, papovaviruses, parvoviruses, adenoviruses, herpesviruses and vaccinia viruses, and RNA viruses, such as arenaviruses, coronaviruses, rhinoviruses, respiratory syncytial viruses, influenza viruses, picornaviruses, paramyxoviruses, reoviruses, retroviruses such as the human immunodeficiency virus, and rhabdoviruses. The anthelmintic benzimidazole compounds may also be used to enhance the immune response to a cell population harboring endogenous pathogens (e.g., a virus), including pathogens that persist in such a cell population without causing overt signs of infection.

The present compositions and methods are also applicable for use in enhancing the immune response to any fungi, mycoplasma species, or other infectious microorganisms that cause disease in warm-blooded vertebrate animals. Examples of fungi that may be treated with the present method include fungi that grow as molds or are yeast-like, including, for example, fungi that cause diseases such as ringworm, histoplasmosis, blastomycosis, aspergillosis, cryptococcosis, sporotrichosis, coccidioidomycosis, paracoccidio-idomycosis, and candidiasis. The present method is advantageous for enhancing the immune response in dogs having canine parvovirus and canine herpesvirus infections, and in cats with feline leukemia and feline infectious peritonitis. The method is also advantageous for enhancing the immune response in cattle infected with viruses such as infectious bovine rhinotracheitis (IBR) virus, non-IBR herpesviruses, parainfluenza type 3 (P 13) virus, bovine viral diarrhea (BVD) virus, respiratory syncytial virus, adenoviruses, enteroviruses, rhinoviruses, parvoviruses, and reoviruses. Bacterial infections in cattle that can be treated with the anthelmintic benzimidazole compounds include infections by such bacteria as Mannheimiahemolytica, Pasteurella multocida, Hemophilus somnus, and Chlamydia species, and by mycoplasma including M. dispar, M. bovirhinis, M. bovis, and M. arginini.

Other afflictions responding to the anthelmintic benzimidazole compositions are autoimmune disorders, inflammatory disorders, and immunodeficiency disorders. The anthelmintic benzimidazole compounds may be used to modulate the immune response to such autoimmune disorders as rheumatoid arthritis, lupus erythematosus, multiple sclerosis, myasthenia gravis, Guillain-Barre syndrome, Graves disease, Sjogren's syndrome, autoimmune alopecia, scleroderma, psoriasis, and graft-versus-host disease. Inflammatory disorders that respond to the anthelmintic benzimidazole compounds include such as hyperallergenic conditions as asthma, anaphylaxis, eczema, atopic and allergic contact dermatitis, and food, drug, and environmental allergies. Any immunodeficiency-related disorder may also be treated with the anthelmintic benzimidazole compounds including such disorders as acquired immunodeficiency syndrome, xeroderma pigmentosa, severe combined immunodeficiencies, and the like.

In accordance with one embodiment a method of inducing an enhanced immune response in a ruminant species is provided. More particularly, in one embodiment the ruminant species is a bovine species (cattle). The method comprises the steps of administering to the ruminant species a first composition comprising a vaccine and a second composition comprising an anthelmintic benzimidazole compound of the general structure:

wherein Ri is selected from the group consisting of H, -S(C]-C₄ alkyl), -SR₃, -SOR₃, 0(C₁-C₄ alkyl) and -COR₃;

R₂ is selected from the group consisting of H, NHCOOCH₃ and -4- thiazole; and

R₃ is selected from the group consisting of

wherein R₄ is selected from the group consisting of H, halo and Ci-C₄ alkyl. The vaccine and anthelmintic benzimidazole compound are typically administered within 24, 12, 8, 4, 1 or 0.5 hours of each other. In one embodiment the two compositions are administered simultaneously either as two separate formulations (that may or may not be administered by the same route) or as a single composition comprising a mixture of the vaccine and anthelmintic benzimidazole compound. In accordance with one embodiment the vaccine represent a commercially available vaccine formulated for administration to ruminant species such as cattle. In one embodiment the vaccine is directed against a virus selected from the group consisting of infectious bovine rhinotracheitis (IBR) virus, non-IBR herpesviruses, parainfluenza type 3 (PI3) virus, and bovine viral diarrhea (BVD) virus. In one embodiment the anthelmintic compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole, and in one embodiment the anthelmintic compound is of fenbendazole. The anthelmintic benzimidazole compound may be administered to the warm-blooded vertebrate animal parenterally or by other medically recognized routes, such as oral or intranasal administration, and any effective dose and suitable therapeutic dosage form can be used. Oral and parenteral routes may be used for administration of the anthelmintic benzimidazole compounds to humans, but the parenteral route is preferred for administration of the anthelmintic benzimidazole compound to non-human warm-blooded vertebrates such as agricultural and domestic animals. However, it is contemplated that some oral dosage forms may be useful for administration of anthelmintic benzimidazole compounds to non-human warmblooded vertebrates as described below. Parenteral administration is also preferred, for both humans and non-human warm-blooded vertebrates, when the administered composition comprises an anthelmintic benzimidazole and a vaccine.

The anthelmintic benzimidazole compounds can be administered parenterally and such injections can be intraperitoneal, intradermal, subcutaneous, intramuscular, or intravenous injections. Examples of parenteral dosage forms include buffered aqueous solutions of the active agent, in an isotonic saline, 5% glucose or other well-known pharmaceutically acceptable liquid carriers such as liquid alcohols, glycols, esters, and amides. The parenteral dosage forms typically contain a stabilizing amount (1-5% by weight) of blood serums. The parenteral dosage form can be in the form of a reconstitutable lyophilizate comprising the anthelmintic benzimidazole compound and can also contain one or more "protective" proteins such as albumin or blood serum.

Exemplary of a buffered solution suitable as a carrier of the anthelmintic benzimidazole compounds is phosphate buffered saline prepared as follows: A concentrated (2Ox) solution of phosphate buffered saline (PBS) was prepared by dissolving the following reagents in sufficient water to make 1,000 ml of solution: sodium chloride, 160 grams; potassium chloride, 4.0 grams; sodium hydrogen phosphate, 23 grams; potassium dihydrogen phosphate, 4.0 grams; and optionally phenol red powder, 0.4 grams. The solution is sterilized by autoclaving at 15 pounds pressure for 15 minutes and then diluted with additional water to a single strength concentration prior to use.

In one embodiment, the anthelmintic benzimidazole compound is combined with a vaccine formulation and the composition is administered parenterally. Vaccines that may be co-administered with the anthelmintic benzimidazole compounds include commercially available vaccines such as those directed against polio, tetanus, influenza, diphtheria, anthrax, tuberculosis, hepatitis, cholera, typhoid, measles, mumps, and rabies vaccines. Additional commercially available vaccines that may be co-administered with anthelmintic benzimidazole compounds, for treating agricultural animals, include vaccines directed against BRDC, and for treating domestic animals, suitable vaccines include those directed against feline leukemia and rabies virus.

Oral ingestion may be achieved by the use of such dosage forms of anthelmintic benzimidazole compounds as syrups, sprays, or other liquid dosage forms, a gel-seal, or a capsule or caplet. Buccal and sublingual administration comprises contacting the oral and pharyngeal mucosa of the patient with the anthelmintic benzimidazole compound either in a pharmaceutically acceptable liquid dosage form, such as a syrup or a spray, or in a saliva-soluble dosage form which is held in the patient's mouth to form a saliva solution in contact with the oral and pharyngeal mucosa. Exemplary of saliva-soluble dosage forms are lozenges, tablets, and the like.

The anthelmintic benzimidazole compound for buccal/sublingual administration is formulated into a solid dosage form, such as a lozenge or a tablet. This formulation preferably contains the anthelmintic benzimidazole compound and a saliva-soluble carrier and may optionally contain desirable excipients, such as buffers, or tableting aids. The solid dosage form is formulated to dissolve, when held in a patient's mouth, to form a saliva solution of the anthelmintic compound to promote contact of the compounds with the oral and pharyngeal mucosa. In one embodiment, the solid dosage form is in the form of a lozenge adapted to be dissolved upon contact with saliva in the mouth, with or without the assistance of chewing, to form a saliva solution of the anthelmintic benzimidazole compound. Lozenges can be prepared, for example, by art-recognized techniques for forming compressed tablets where the anthelmintic benzimidazole compound is dispersed on a compressible solid carrier, optionally combined with any appropriate tableting aids such as a lubricant (e.g., magnesium-stearate) and is compressed into tablets. The solid carrier component for such tableting formulations can be a saliva- soluble solid, such as a cold water-soluble starch or a monosaccharide or disaccharide, so that the lozenge will readily dissolve in the mouth to release the contained anthelmintic benzimidazole compound in saliva solution for contact with and absorption by the oral/pharyngeal mucosa when the lozenge is held in the mouth. The pH of the above-described formulations can range from about 4 to about 8.5. Lozenges can also be prepared utilizing other art-recognized solid unitary dosage formulation techniques.

Tablets can be prepared in a manner similar to that described for preparation of lozenges or by other art-recognized techniques for forming compressed tablets such as chewable vitamins. Suitable solid carrier components for tableting include mannitol, microcrystalline cellulose, carboxymethyl cellulose, and dibasic calcium phosphate.

Solid dosage forms for oral ingestion administration include such dosage forms as caplets, capsules, and gel-seals. Such solid dosage forms can be prepared using standard tableting protocols and excipients to provide anthelmintic- containing capsules, caplets, or gel-seals. Any of the solid dosage forms may be in a form adapted for sustained release.

Alternatively the anthelmintic benzimidazole compounds can be formulated into flavored or unflavored solutions, sprays, or syrups using a buffered aqueous solution of the compound as a base with added caloric or non-caloric sweeteners, flavor oils and pharmaceutically acceptable surfactant/dispersants. Such dosage forms can be administered buccally, sublingually, or by oral ingestion.

Some oral dosage forms of anthelmintic benzimidazole compounds may be useful for treating non-human warm-blooded vertebrates. For example, oral vaccine formulations comprising an enzymatically degraded antigen in a hydrogel matrix for administration to ruminant species as described in U.S. Patent No. 5,352,448, incorporated herein by reference, may be useful in the methods disclosed herein. Furthermore, microspheres prepared from biodegradable polymers for the targeted delivery of vaccine antigens to the gut-associated lymphoid tissue may be used for administration to non-human warm-blooded vertebrates of vaccine compositions containing anthelmintic, benzimidazole compounds (Eldridge, et al., Jour, of Controlled Release, vol. 11, p .205214 (1990)). Such oral dosage forms may also be useful for administration of anthelmintic benzimidazole compounds, in the absence of a vaccine, to non-human warm-blooded vertebrates. The method disclosed herein may be used in combination with other therapies, such as in the case of treatment of neoplastic disease in combination with surgical removal of a tumor or radiation therapy or chemotherapy, or in combination with antibiotics. Antibiotics that can be administered in combination with the anthelmintic benzimidazole compounds include penicillins, cephalosporins, vancomycin, erythromycin, clindamycin, rifampin, chloramphenicol, aminoglycosides, gentamicin, amphotericin B, acyclovir, trifluridine, ganciclovir, zidovudine, and amantadine.

Any effective regimen for administering the anthelmintic benzimidazole compounds that results in modulation of the immune response can be used. For example, the anthelmintic benzimidazole compound can be administered as a single dose, or the dose can be divided and administered as a multiple-dose daily regimen. Further, a staggered regimen, for example, one to three days per week can be used as an alternative to daily treatment, and such intermittent or staggered daily regimen is considered to be equivalent to every day treatment and within the scope of the present disclosure.

The optimum dosage of the anthelmintic benzimidazole compound varies somewhat from species to species, and probably animal to animal. Also, effects similar to those produced by a given daily dosage administered for a given number of days might be achieved by administering a slightly lower dosage for a slightly greater number of days, or a slightly higher dosage for a slightly smaller number of days. EXAMPLE 1

Broad spectrum anthelmintics are used almost universally to eradicate internal parasites in the livestock industry. Fenbendazole (FBZ) is a broad spectrum product that is a member of the benzimidazole group of anti-parasite medications. The following experiments were conducted to determine FBZ's effect on the bovine immune system, particularly the effect of FBZ on the interferon (IFN) titers in their nasal secretions when given during viral infections. An in vitro study was also conducted to ascertain the effect of various concentrations of FBZ on IFN induction by bluetongue virus in cell culture.

MATERIAL AND METHODS

Cell Cultures - Bovine fetal kidneys (BFK) obtained at an abattoir were used to prepare BFK cell cultures. Growth medium for cells consisted of Eagle's Minimal Essential Medium (MEM) prepared in deionized water with 0.11% NaHCO₃ and 10% Fetal Bovine Serum (FBS). Growth medium for cells used in the bovine viral diarrhea (BVD) study consisted of the aforementioned MEM with 0.11% NaHCO₃ and 10% Horse Serum (HS). Maintenance medium consisted of MEM with 10% FBS and 0.11% NaHCO₃. Maintenance medium consisted of MEM with 10% HS and 0.11% NaHCO₃. Potassium Penicillin G, Streptomyciin Sulfate, and Amphotericin B were included in all media. Cultures were incubated at 37⁰C under CO₂ (1 to 2%).

Neutralization Tests - Serum antibody titers for infectious bovine rhinotraceitis (IBR) and BVD viruses were determined by microtitration in BFK cells, essentially as described by others but with the addition of the microtransfer technique. Four microtiter wells per serum dilution were used, and the titer was recorded as the reciprocal of the highest final dilution of serum completely protecting at least 3 of 4 wells. Serum samples were inactivated by heating at 56⁰C for 30 minutes.

Viruses - The IBR virus used in 2 studies was an avirulent vaccine strain obtained from Dr. Dale Bordt, Beecham Laboratory, Whitehall, Illinois. Vaccine (Resbo IBR-PI3 [Parainfluenza Type 3]) for intramuscular (IM) administration, used in one study, was obtained from Norden Laboratories, Lincoln, Nebraska. The BVD virus was the virulent NY-I strain obtained from Dr. Don Croghan, the National Veterinary Services Laboratory, USDA, Ames, Iowa. Bluetongue Virus (BTV) was obtained from Colorado Serum Company, Denver, CO. Vesicular Stomatitis Virus (VSV), Indiana Strain, was obtained from BD Rosenquist, University of Missouri, Columbia, MO.

Fenbendazole - FBZ was supplied as a 10% suspension (100 mg/ml) and dosed according to label instructions (2.5 cc/100 lbs). FBZ was given orally to cattle at the time of virus inoculation. For the in vitro tests, FBZ was diluted in MEM to concentrations of 1, 10 and 100 mg/ml and 1 and 10 nanograms/ml.

Experimental Design - Ten calves (4 heifers and 6 steers) were purchased from a Tennessee farm and transported to Texas Experimental Station in Bushland, Texas. The average weight for heifers was 499 pounds and 544 pounds for steers. Upon arrival, the calves were given 4-way clostridial bacterin and placed in a pen with a Pinpo inter® device that allowed for individual monitoring of feed consumption. Two separate trials were conducted with these calves. In trial 1 calves were inoculated intranasally with avirulent IBR virus (2 ml dose of 10^{7 2} plaque- forming units (PFU)/ml). Weight and rectal temperatures were recorded, blood samples for complete blood counts (CBC) and serum IFN determinations were collected at 0, 1, 2, 4, 7, 11 and 14 days post- inoculation. Nasal secretions for IFN assay were obtained by inserting a tampon into the nasal passage for 20-30 minutes. Serum samples for antibody determinations were collected before, and at 14 and 21 days after, IBR virus inoculation. Nasal swabs for viral isolation were collected on the same days as the weights and temperatures. The nasal swabs were expressed immediately into vials of transport media (MEM with 2% HS and antibiotics) and stored at -7O⁰C until tested.

Fecal samples were tested for parasite ova before and after each trial by the Texas A&M Veterinary Medical Diagnostic Laboratory (TVMDL), Amarillo, Texas. A flotation technique was used to detect ova.

In trial 2, calves were given virulent BVD virus (10^{7 0} TCID50/ml, 2 ml dose). Weight and rectal temperatures were recorded on day 0, 1, 2, 4, 7, 8, 11 and 13 days after challenge. Nasal samples for BVD virus excretion, nasal secretions for IFN determinations and blood samples for CBC and serum IFN determinations were collected on 0, 2, 4, 7, 11 and 13. Serum samples for antibody determinations were collected before and 13 days after virus inoculation. A third study was conducted to determine the effect of FBZ on the response to a modified, live IBR virus vaccine given at the same time as the dewormer. Cattle were screened to determine serum neutralization antibody titers for IBR virus. Thirty (30) steer calves were also given an intranasal IBR virus modified, live vaccine and 15 of these calves were given the recommended dose of FBZ (5 mg/kg). Cattle were allotted to 6 pens of 5 head each. Variables measured were serum antibody titers at 0 and 21 days, IFN in the nasal secretions at 0, 2 and 7 days after vaccination, and weights at 0 and 28 days. The mean initial weights were 617.3 lbs and 601.2 lbs for controls and FBZ-treated calves, respectively. Fecal samples were taken at 0 and 7 days for detection of parasite ova.

In a fourth study, IFN production was measured in the nasal secretions of cattle given FBZ, thiabendazole (TBZ), morantel tartrate (MOT) or levamisol (LVS). One hundred (100) male calves were purchased from 6 sale barns in Virginia, Tennessee or South Carolina during a three day period and transported to an order buyer barn in Newport, Tennessee. The calves were allotted to treatment groups or a control group by sale barn of origin and by sale weight. Twenty calves each received either FBZ, TBZ, MOT, or LVS at the recommended dosage and route of administration. Twenty calves served as untreated controls. Calves were ear tagged and fecal samples and nasal secretions were collected, and rectal temperatures were recorded.

After co-mingling for another day, the calves were shipped from Tennessee to Texas, a distance of 1,180 miles. After arrival in Texas they were immediately unloaded, weighed, and offered access to feed and water. The shrink calculated from pay weight to arrival was calculated. On the day after arrival, calves were processed with a clostridial bacterin, a spot-on insecticide and a vitamin A injection. Calves were ear tagged with a Pinpointer® tag to allow monitoring of individual feed intake. Calves were bled for serology, and weights and rectal temperatures were recorded.

Two days after arrival, calves were inspected at dawn and scored for clinical illness using a 7-point system (2 points for temperature >104°F or anorexia, i.e. - less than 0.1 Ib consumption for 24 hours and 1 point each for depression or mucopurulent nasal or ocular discharge). Sick calves with > 5 points were treated with antibiotics for 3 consecutive days. If the calf did not respond to treatment, retreatment with a different antibiotic was given for 3 additional days. Nasal secretions were collected at 2 and 6 days after arrival. Body weights were recorded 51 days after arrival. Calves were bled for serology again at 50 days after arrival.

In a fifth study, 15 healthy feedlot steers were assigned to a study of 28 days duration to determine the effect of FBZ on IFN concentrations in the nasal secretions of calves given IM modified live IBR-PI3 vaccine. Body weights were determined at 0 and 28 days. Feed intake was determined by Pinpointer®. IFN concentrations in nasal secretions were determined at 0, 3, and 7 days after vaccination. Antibody to IBR virus was determined before and 28 days after vaccination. Ten calves were given vaccine and 5 of those were also given FBZ. Five control calves received only FBZ at 0 day.

In an in vitro study, samples from cell cultures treated with each dosage of FBZ were screened for IFN at FBZ concentrations of 10 and 100 ng/ml and 1, 10, 100 μg/ml of culture media. Cell cultures were grown until each flask of BFK cells had a confluent monolayer. FBZ dilutions were then made. FBZ was added to the flasks at concentrations of 10 or 100 ng/ml or 1, 10 or 100 μg/ml either 24 hours before, 24 hours after, or both 24 hours before and after inoculation with 105.9 TCID50 of BTV. Control cultures were given MEM only.

After 24 hours flasks were harvested by freezing. Flasks were thawed and combined at respective dilutions. Samples were then dialyzed for 24 hours in a KCl-HCl Buffer of pH 2.0, obtained by dissolving 16.655 grams KCl and 3.33 ml concentrated HCl in sufficient water to make 5,000 ml total buffer. Dialysis for another 24 hours was conducted in phosphate buffered saline (PBS), with a pH approximately 7.4. Dialysis tubing with a molecular weight of 12,000 to 14,000 was used in the dialysis.

Viral Isolation - Nasal excretion of IBR virus was detected and quantified in BFK 6 well culture plates. Serial dilutions were made from the nasal swab transport medium and 0.5 ml of the dilution was incubated on BFK cell cultures at 37⁰C for 1 hour. The viral fluids were aspirated and the overlay medium was added. The plates were stained after 7 days to detect IBR viral activity through plaque formation. Nasal excretion of BVD virus in trial 2 was detected by fluorescent antibody testing performed by Dr. Richard Mock, TAMVMDL, Amarillo, Texas. IFN Assay - Before the IFN assay, nasal secretions were dialyzed overnight in a KCI-HCI pH 2.0 buffer and dialyzed in PBS solution of pH 7.2 for 24 additional hours. The plaque reduction IFN assay method, as modified was used (Rosenquist BD, Loan RW. Am J Vet Res 28:619-628, 1967). Serial dilutions of the prepared sample were made in maintenance medium, and 0.1 ml amounts of these dilutions were applied to microtiter plates of BFK cells and allowed to remain overnight at 37⁰C. Control cultures were treated overnight with 0.1 ml maintenance medium. After the incubation period, fluids were aspirated and washed with 0.05 ml of Hanks' balanced salt solution (BSS). The VSV virus, (calculated to contain 50 PFU) was added to each plate. After absorption at 37⁰C for 1 hour, excess viral fluids were aspirated and the soft agar overlay medium was added. After 24 hours plates were fixed with an alcohol-formaldehyde fixative. The IFN titers were determined by the probit method (Lindenmann J, Gifford GE. Virology 19:302-309, 1963) and were expressed as the reciprocals of the dilutions which produced 50% reduction in the number of VSV plaques, as compared with the number in control cultures.

Statistical Analysis - An analysis of variance system (Barr et al. A user's guide to SAS76. Raleigh, NC, Sparks Press, 1976) was used to compare experimental data, and a P-value of 0.05 was considered significant.

RESULTS In study 1, 7 calves seronegative to IBR virus at the time of virus inoculation, developed antibody to IBR virus by 14 days post-inoculation. The geometric mean titers (GMT) of antibody to IBR virus were not different between treatment groups. Four of the 7 calves had IFN in their nasal secretions at the time of virus IBR inoculation and all calves developed IFN in their nasal secretions after virus inoculation. Calves had nasal secretion IFN from 1-7 days after inoculation but serum IFN was detected in one calf. The nasal secretion GMT IFN titers were higher at 1, 4 and 7 days after IBR virus inoculation in the FBZ-treated group. Virus excretion in the nasal secretions was similar in both groups of calves. The mean daily gain and feed efficiency was better in FBZ treated calves than in control calves, but the differences were not significant. Calves did not develop fever after avirulent IBR virus inoculation. In study 2, seven calves, seronegative to BVD virus at the time of virus inoculation, developed BVD virus neutralizing antibody by 13 days after inoculation. IFN was detected in the nasal secretions of 6 of 7 calves after BVD virus inoculation. The GMT IFN titers of FBZ treated calves was higher at 4, 7, and 11 days after virus inoculation. Serum IFN was detected in one calf at one sampling after BVD virus inoculation. Virus excretion of BVD virus (as evidenced by duration and amount of BVD virus excretion in the nasal secretions) indicated that the most severe BVD infections occurred in control calves at 2, 4, 7 and 11 days after virus inoculation. BVD was detected at 13 of 15 sampling times in control calves, and 9 of 20 sampling times in FBZ-treated calves (PO.01).

Calves given virulent BVD virus inoculation consumed less feed after BVD virus inoculation. Consumption declined to a third or less of normal consumption by 7 days, and generally returned to normal by 11 days after inoculation. The FBZ-treated calves, on average, had a better mean daily gain and better feed efficiency than controls (see Table 1). All calves given BVD virus developed fever by 7 or 8 days after BVD virus inoculation.

aStandard deviation in parenthesis. Four calves given FBZ (but not a virus) did not have IFN detected in their NS at 0, 3 or 7 days after FBZ administration. One calf given FBZ had IFN detected in the serum at 0 and 3, but not 7, days after FBZ administration.

In study 3, the average daily gains favored the FBZ treated cattle (3.92 lbs/day), compared to control cattle (3.51 lbs/day), with significance at P=O.109 (Table 1). Feed intakes were the same for both groups. The serum neutralization test results indicate that 11 of the 15 vaccinated cattle in each group were seronegative to IBR virus at baseline, and after 21 days all calves seroconverted; the antibody GMT was higher in the FBZ-treated calves, but not significantly so (Table 2). Calves given FBZ and IBR virus produced more IFN in their nasal secretions at 2 (P=O.12) and 7 (P=0.065) days after vaccination (Table 3).

M l of 15 in each group were seronegative at baseline.

14 calves, 1 1 calves, ^c 13 calves

In the fourth study, a natural shipping fever outbreak occurred. The overall morbidity rate was 64% and mortality rate was 10%. By 51 days after processing, all groups of calves were gaining at approximately 2.0 lb/day or better, and all treated groups had average daily gains that were equal or better than controls; however, differences were not statistically significant. Weight gain and feed intake were not significantly different between treatment groups.

The 10 deaths were due to shipping fever pneumonia. Mannheimia hemolytica was the major pathogen isolated from 8 of 10 dead calves and

Corynebacterium pyogenes was isolated from the other 2 calves. BVD virus was also isolated from 2 calves. There were deaths from within all 5 treatment groups and no significant difference in morbidity or mortality was observed between treatments. After arrival in Texas, IFN concentrations were higher in control calves and FBZ-treated calves than in other groups. The FBZ-treated calves and controls had significantly more IFN than LVS-treated calves 2 days after arrival. The TBZ-treated calves and the MOT-treated calves had less than half the IFN concentrations of FBZ or control calves, but the difference was not significant (Table 4). At 6 days after arrival, GMT IFN concentrations were < 21 and treatment means were not significantly different.

In the fifth study, 10 calves were given IB R-PB vaccine and 5 of those calves were also given FBZ at the time of vaccination. Interferon was detected in the NS of one of 10 vaccinated calves (vaccine only group) at the time of vaccination. Interferon was not detected in the NS of any of the 10 vaccinated calves 3 days after vaccination but was detected in 3 (one FBZ only and 2 FBZ + vaccine) of 10 calves 7 days after vaccination. Calves given FBZ, on average, gained more weight than control calves (Table 5).

Table 5. Weight gains of calves given FBZ with or without IM IBR-PI3 vaccine

In the in vitro test in which FBZ was added to cell cultures after the virus (MEM/FBZ), all the IFN titers were higher in the FBZ-treated cells than in the control cells. The 10 ng/ml concentration of FBZ resulted in the highest IFN titer. When FBZ was on cell cultures before and after BTV (FBZ/FBZ), the 100 μg/ml concentration had the IFN lowest titer compared to the 10 ng/ml concentration of FBZ which had the highest IFN titer. All of the IFN titers were significantly higher than the control IFN titer, except for the 100 μg/ml concentration.

In the in vitro (FBZ/MEM) study in which the FBZ was added to cell cultures before virus, and then removed when virus was added, the 100 μg/ml concentration was the only concentration of FBZ with an IFN titer higher than the control. The IFN titers in the lower FBZ concentrations were all lower than the control and the IFN titers decreased as the FBZ concentrations decreased.

There was a significant (P<0.05) difference in IFN titers from FBZ/MEM, FBZ/FBZ and MEM/FBZ treatments using total means and logarithmic means. The MEM/FBZ test resulted in the highest IFN titers, compared to the other two tests.

DISCUSSION

In these studies, FBZ treatment resulted in enhancement of the IFN response in controlled studies with IBR virus. In a field trial, FBZ treatment compared to other anthelmintics (but not controls), resulted in an enhanced IFN response during a natural mixed viral infection.

The IFN suppression noted in LVS-, MOT-, and TBZ-treated calves is a surprising result. Very little is known about the immune modulating effects of morantel tartrate, but levamisole and TBZ have been suggested as immune modulators (Blecha F. Immunomodulation: a means of disease prevention in stressed livestock. J Anim Sci 66:2084-2090, 1988). In the studies reported herein, FBZ has shown consistent effects on nasal secretion IFN. The dosage, frequency, and timing of FBZ administration relative to the time and severity of viral infection are factors that can be investigated to optimize the enhancement of the IFN response and provide the greatest benefit to the calf.

Compared to unvaccinated calves given TBZ, MOT or LVS, calves given FBZ produced a higher GMT of IFN 2 days after arrival in the feedlot. The IFN detected was not in response to intranasal vaccination, but was instead the response to viral or other IFN inducers naturally occurring in the shipping fever outbreak. FBZ treated calves performed better than control calves after infection with BVD virus or IBR virus. They gained more weight and used feed more efficiently, but results were not significant. Significantly, less virus was excreted firom FBZ-treated calves after BVD virus inoculation. IFN production persisted longer in FBZ-treated calves after BVD virus inoculation, but BVD virus excretion did not.

Calves given intranasal IBR virus vaccine and FBZ gained more weight than calves only given IBR virus vaccine. Calves given intranasal IBR virus vaccine and FBZ produced significantly more nasal secretion IFN and had a higher mean neutralizing antibody titer (not significant), compared to IBR vaccinated calves not given FBZ. In contrast, FBZ did not enhance the IFN response in the nasal secretions of calves given IM IBR-PI3 vaccine, presumably because the viruses from the IM vaccine did not replicate in the nasal passages.

In the in vitro tests, the 10 ng/ml concentration in the MEM/FBZ and FBZ/FBZ studies induced the highest IFN titers in BFK cells inoculated with BTV. This low dose was the best dosage for enhancing the IFN response induced by BTV in vitro. Interferon has a profound effect on the immune system because interferon activates many immune response genes. Therefore any increase in interferon levels during the course of a non-parasitic disease state should produce a beneficial modification of the immune response.

Claims

WHAT IS CLAIMED IS:

1. A method for enhancing the production of interferon in a warm-blooded vertebrate animal, said method comprising administering a composition comprising an anthelmintic benzimidazole compound of the general structure:

wherein Ri is selected from the group consisting of H, -(C₁-C₄ alkyl), -S(Ci-C₄ alkyl), -CO(C₃-C₅ cycloalkyl), -SR₃, -SOR₃, -0(C₁-C₄ alkyl) and -COR₃; R₂ is selected from the group consisting of H, NHCOOCH₃ and -4- thiazole; and

R₃ is selected from the group consisting of

wherein R₄ is selected from the group consisting of H, halo and Ci-C₄ alkyl.

2. The method of claim 1 wherein R) is selected from the group consisting of H, -SCH₂CH₂CH₃, -S-phenyl, -SO-phenyl, -OCH₂CH₂CH₃ and -CO- phenyl and R₂ is NHCOOCH₃ or -4-thiazole.

3. The method of claim 2 wherein R₂ is NHCOOCH₃.

4. The method of claim 3 wherein the anthelmintic benzimidazole is fenbendazole.

5. The method of claim 1 wherein the anthelmintic benzimidazole composition is administered by a route selected from the group consisting of oral, intramuscular, intradermal, intraperitoneal, intranasal, and intravascular route.

6. A method for modulating an immune response in a warm- blooded vertebrate animal afflicted with a non-parasitic disease state, said method comprising the steps of administering an anthelmintic benzimidazole compound of the general structure:

wherein Ri is selected from the group consisting of H, -(Ci-C₄ alkyl), -S(Ci-C₄ alkyl), -CO(C₃-C₅ cycloalkyl), -SR₃, -SOR₃, -O(C,-C₄ alkyl) and -COR₃;

R₂ is selected from the group consisting of H, NHCOOCH₃ and -4- thiazole; and

R₃ is selected from the group consisting of

wherein R₄ is selected from the group consisting of H, halo and C]-C₄ alkyl.

7. The method of claim 6 wherein the non-parasitic disease state is selected from the group consisting of a non-parasitic infection, an autoimmune disorder, an inflammatory disorder, an immunodeficiency-related disorder, and neoplasia.

8. The method of claim 7 wherein the anthelmintic compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole and albendazole.

9. The method of claim 8 wherein the anthelmintic compound is fenbendazole.

10. The method of claim 6 wherein the vertebrate animal is selected from the group consisting of humans, horses, sheep, cattle, swine, poultry, domestic animals, and wild animals in captivity.

11. The method of claim 6 wherein the immunomodulatory composition is administered by a route selected from the group consisting of oral, intramuscular, intradermal, intraperitoneal, intranasal, and intravascular route.

12. The method of claim 6 wherein the immune response modulated comprises a cytokine response.

13. The method of claim 12 wherein the cytokine response comprises an interferon response.

14. The method of claim 6 wherein the non-parasitic pathogen disease state is a bacterial, fungal, viral or mycoplasmic infection.

15. A pharmaceutical composition comprising an anthelmintic benzimidazole compound of the general structure:

wherein Ri is selected from the group consisting of H, -(C₁-C₄ alkyl), -S(CpC₄ alkyl), -CO(C₃-C₅ cycloalkyl), -SR₃, -SOR₃, -O(C_rC₄ alkyl) and -COR₃;

R₂ is selected from the group consisting of H, NHCOOCH₃ and -A- thiazole; and

R₃ is selected from the group consisting of

wherein R₄ is selected from the group consisting of H, halo and C]-C₄ alkyl; a vaccine; and a pharmaceutically acceptable carrier therefor.

16. The pharmaceutical composition of claim 15 wherein the anthelmintic compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole.

17. The pharmaceutical composition of claim 15 wherein the vaccine is a commercially available vaccine against bovine respiratory disease complex.

18. The pharmaceutical composition of claim 15 wherein the vaccine is directed against a virus selected from the group consisting of infectious bovine rhinotracheitis (IBR) virus, non-IBR herpesviruses, parainfluenza type 3 (PI3) virus, and bovine viral diarrhea (BVD) virus.

19. The pharmaceutical composition of claim 18 wherein the anthelmintic compound is fenbendazole.

20. A method of inducing an enhanced immune response in a ruminant species, said method comprising the steps of administering to said species a composition comprising a vaccine; and an anthelmintic benzimidazole compound of the general structure:

wherein Rj is selected from the group consisting of H, -S(C]-C₄ alkyl), -SR₃, -SOR₃, - 0(C₁-C₄ alkyl) and -COR₃; R₂ is selected from the group consisting of H, NHCOOCH₃ and -4- thiazole; and

R₃ is selected from the group consisting of

wherein R₄ is selected from the group consisting of H, halo and C₁-C₄ alkyl, and a pharmaceutically acceptable carrier, further wherein said vaccine and anthelmintic benzimidazole compound are administered within 24 hours of each other.

21. The method of claim 20 wherein the vaccine is directed against a virus selected from the group consisting of infectious bovine rhinotracheitis (IBR) virus, non-IBR heφesviruses, parainfluenza type 3 (PI3) virus, and bovine viral diarrhea (BVD) virus.

22. The method of claim 21 wherein the anthelmintic compound is selected from the group consisting of fenbendazole, thiabendazole, mebendazole, and albendazole.