WO1986002356A1

WO1986002356A1 - Monoclonal antibodies and their use

Info

Publication number: WO1986002356A1
Application number: PCT/GB1985/000467
Authority: WO
Inventors: Bruce William Wright; Peter John Cox; Alice Margaret Noyes; Danny Widdows
Original assignee: Technology Licence Company Limited
Priority date: 1984-10-19
Filing date: 1985-10-16
Publication date: 1986-04-24
Also published as: GB8426460D0; JPS62500584A; EP0199754A1

Abstract

Monoclonal antibodies to the genus Giardia, the labelled antibodies, compositions and kits containing them, and their use in diagnosis of antigen and treatment.

Description

MONOCLONAL ANTIBODIES AND THEIR USE

BACKGROUND OF THE INVENTION

Of current interest in the fields of analysis and diagnosis is the use of monoclonal antibodies to determine the presence of antigens or species in specimens such as urine, blood, water, milk, and the like.

More particularly, monoclonal antibodies specific for the antigens or species of Giardia are desired which when used will rapidly diagnose the presence of such organisms in specimens.

Parasitic diseases of man, especially those due to the one-celled parasites, such as Amebiasis and Giardiasis, are extremely common throughout the world. Their incidence is thought to include

SUBSTITUTE SHEET over half of mankind. There is a rise in para¬ sitic diseases in the United States as the result of promiscuous behavior, with new parasites and old ones being discovered with greater fre¬ quency in urban areas, despite excellent sani¬ tation systems. The diagnosis of parasitic diseases is time-consuming and often insensitive, with repeated microscopic examinations often required. There is a strong demand, especially in the United States, for rapid, direct, sensitive methods of stool parasite analysis.

Divisions have been made among the Giardia

-OBSTITUTH SHEET spec es. ome o e represen a ve mem ers t include Giardia lamblia and Giardia intestinalis. Giardia will be described with particular refer¬ ence to Giardia lamblia, the organism causing giardiasis. Giardiasis is very widespread in tropical countries but has spread extensively into temperature countries. Thousands of cases have been reported from mountainous areas such as Aspen, Colorado, where outbreaks of the disease involving hundreds of people due to contaminated water supplies have been reported. Travelers to Leningrad in Russia have suffered high percent¬ age attack rates of the disease. The organism appears to produce diarrhea and then a chronic diarrhea which may lead to a severe malfunction of the bowel with weight loss, wasting and compli¬ cations from the malabsorption of food. Treatment is potentially toxic, and diagnosis is time consuming, difficult and often insensitive, requiring skilled technicians to make a positive diagnosis. Travelers to other countries may be exposed to Giardia lamblia from contaminated food, particularly vegetables and fruit, and it is a frequent travelers¹ disease which leads to chronic diarrhea which may be inappropriately treated without a specific diagnosis. The ability to antigens of Giardia can provide many opportuni¬ ties for diagnosis and treatment. Such specifi¬ city is a most important requirement for proper and accurate analysis and/or diagnosis, particu¬ larly in diagnosing the presence of diseases which require prompt treatment. Additionally, the use of Giardia lamblia in a kit system would be of great practicality.

A wide variety of isotopic and nonisotopic immunoassays have been utilized in conjunction with monoclonal antibodies to test for the pres¬ ence of an antigenic substance. At the present time, agglutination, immuno-fluorescent, chemilum- inescent or fluorescent immunoassay, immuno- electron microscopy, radiometric assay systems, radio immunoassays, and enzyme-linked immunoassays are the most common techniques used with the monoclonal antibodies. Other techniques include bioluminescent, fluorescence polarization, and photon-counting immunoassays.

When utilizing the enzyme-linked immunoassay procedure (EIA), it is necessary to bind, or conjugate, the monoclonal antibody with an enzyme capable of functioning in such assay; such as alkaline phosphatase. then be used in the known enzyme-linked immunosor- bent assay procedure to determine the presence of an antigenic substance.

After the specific antigen is identified, the serotype of the infecting organism can be determined, and appropriate treatment can then be initiated to rapidly and efficiently eliminate the disease.

The production of monoclonal antibodies is now a well-known procedure first described by Kohler and Milstein (Eur. J. Immunol. 6_, 292 (1975)). While the general technique of preparing hybridomas and the resultant monoclonal antibodies is understood, it has been found that preparing a specific monoclonal antibody to a specific antigen is difficult, mainly due to the degree of specificity and variations required in producing a particular hybridoma. SUMMARY OF THE INVENTION

The present invention provides novel mono¬ clonal antibodies for use in accurately and rapidly diagnosing samples for the presence of Giardia antigens and/or organisms.

Briefly stated, the present invention com¬ prises monoclonal antibodies specific for an antigen or species of Giardia; in particular, the antigens or species of Giardia lamblia (desig¬ nated as Giardia lamblia I, II, III, IV, V, VI, VII, or VIII), and Giardia intestinalis, as well as a monoclonal antibody broadly cross- reactive with an antigen for each species of the genus Giardia.

The invention also comprises labeled mono¬ clonal antibodies for use in diagnosing the presence of the Giardia antigens, each com¬ prising a monoclonal antibody against one of the above-mentioned antigens to Giardia or to a particular species thereof and linked thereto an appropriate label. The label can be chosen from the group consisting of a radioactive iso¬ tope, enzyme, fluorescent compound, chemilumines- cent compound, bioluminescent compound, ferromag¬ netic atom, or particle, or any other label.

The invention further comprises the process for diagnosing the presence of Giardia anti¬ gens or organisms in a specimen comprising con¬ tacting said specimen with the labeled monoclonal antibody in an appropriate immunoassay procedure.

Additionally, the invention is also directed to a therapeutic composition comprising a mono¬ clonal antibody for an antigen of Giardia and a carrier or diluent, as well as kits contain¬ ing at least one labeled monoclonal antibody to an antigen of a Giardia.

DETAILED DESCRIPTION

The monoclonal antibodies of the present invention are prepared by fusing spleen cells, from a mammal which has been immunized against the particular Giardia antigen, with an appropri¬ ate myeloma cell line, preferably NSO (uncloned), P3NS1-Ag4/1, or Sp2/0 Agl4. The resultant product is then cultured in a standard HAT (hypoxanthine, aminopterin, and thymidine) medium. Screening tests for the specific monoclonal antibodies are employed utilizing immunoassay techniques which will be described below.

The immunized spleen cells may be derived from any mammal, such as primates,^' humans, rodents (i.e., mice, rats, and rabbits), bovine, ovine, canine, or the like, but the present invention will be described in connection with mice. The mouse is first immunized by injection of the particular Giardia antigen chosen generally for a period of approximately eleven weeks. When the mouse shows sufficient antibody produc¬ tion against the antigen, as determined by conven¬ tional assay, it is given a booster injection killed so that the immunized spleen may be remov¬ ed. The fusion can then be carried out utilizing immunized spleen cells and an appropriate myeloma cell line.

The fused cells yielding an antibody which give a positive response to the presence of the particular Giardia antigen are removed and cloned utilizing any of the standard methods. The monoclonal antibodies from the clones are then tested against standard antigens to determine their specificity for the particular Giardia antigen. The monoclonal antibody selected, which is specific for the particular Giardia antigen or species, is then bound to.an appropri¬ ate label.

^• Amounts of antibody sufficient for labeling and subsequent commercial production are produced by the known techniques, such as by batch or continuous tissue culture or culture in vivo in mammals, such as mice.

The monoclonal antibodies may be labeled with a multitude of different labels, such as enzymes, fluorescent compounds, luminescent compounds, radioactive compounds, ferromagnetic labels, and the like. The present invention will be described with reference to the use of an enzyme labeled monoclonal antibody. Some of the enzymes utilized as labels are alkaline phosphatase, glucose oxidase, galactosidase, peroxidase, or urease, and the like.

Such linkage with enzymes can be accomplished by any one of the conventional and known methods, such as the Staphylococcal Protein A method, the glutaraldehyde method, the benzoquinone method, or the periodate method.

Once the labeled monoclonal antibody is formed, testing is carried out employing one of a wide variety of conventional immunoassay methods. The particular method chosen will vary according to the monoclonal antibody and the label chosen. At the present time, enzyme immunoassays are preferred due to their low cost, reagent stability, safety, sensitivity, . and ease of procedure. One example is enzyme- linked immunosorbent assay (EIA). EIA is a solid phase assay system which is similar in design to the radiometric assay, but which util¬ izes an enzyme in place of a radioactive isotope as the immunoglobulin marker.

Fluorescent-immunoassay is based on the labeling of antigen or antibody with fluorescent antibody are combined with identical fluorescently labeled antigen. Both labeled and unlabeled antigen compete for antibody binding sites. The amount of labeled antigen bound to the antibody is dependent upon, and therefore a measurement of, the concentration of nonlabeled antigen. Examples of this particular type of fluorescent- immunoassay would include heterogenous systems such as Enzyme-Linked Fluorescent Immunoassay, or homogeneous systems such as the Substrate Labeled Fluorescent Immunoassay. The most suit¬ able fluorescent probe, and the one most widely used is fluorescein. While fluorescein can be subject to considerable interference from scattering, sensitivity can be increased by the use of a fluorometer optimized for the probe utilized in the particular assay and in which the effect of scattering can be minimized.

In fluorescence polarization, a labeled sample is excited with polarized light and the degree of polarization of the emitted light is measured. As the antigen binds to the antibody its rotation slows down and the degree of polari¬ zation increases. Fluorescence polarization is simple, quick, and precise. However, at to the micromole per liter range and upper nano- mole per liter range with respect to antigens in biological samples.

Luminescence is the emission of light by an atom or molecule as an electron is transferred to the ground state from a higher energy state. In both chemiluminescent and bioluminescent reactions, the free energy of a chemical reaction provides the energy required to produce an inter¬ mediate reaction or product in an electronically excited state. Subsequent decay back to the ground state is accompanied by emission of light. Bioluminescence is the name given to a special form of chemiluminescence found in biological systems, in which a catalytic protein or enzyme, such as luciferase, increases the efficiency of the luminescent reaction. The best known chemilu inescent substance is luminol.

A further aspect of the present invention is a therapeutic composition comprising one or more of the monoclonal antibodies to the particular Giardia antigen or species, as well as a pharmacologically acceptable carrier or diluent. Such compositions can be used to treat humans and/or animals afflicted with some form of Giardia infections and they are used in amounts effective to cure; an amount which will vary widely dependent upon the individual being treated and the severity of the infection.

One or more of the monoclonal antibodies can be assembled into a diagnostic kit for use in diagnosing for the presence of an antigen, antigens, or species of Giardia in various speci¬ mens. It is also possible to use the broadly cross-reactive monoclonal antibody which can identify the genus Giardia alone or as part of a kit containing antibodies that can identify other bacterial genera or species of Giardia and/or other bacteria.

In the past there have been difficulties in developing rapid kits because of undesirable cross-reactions of specimens with antiserum. The use of monoclonal antibodies can eliminate these problems and provide highly specific and rapid tests for diagnosis. A rapid and precise kit could replace or augment existing tests and permit early direct therapy using precise antibiotics. Avoiding multiple antibiotics or more expensive or hazardous antibiotics would represent substantial patient and hospital sav¬ ings. Additionally, a kit can be used on an out-patient basis. At present the lack of a rapid test giving "same day" answers may delay the initiation of treatment until the patient has developed more severe symptoms or may require the initiation of more costly therapy in a sick patient. A test that would return results within an hour or two would be a substantial convenience to patients.

In addition to being sold individually, the kit could be included as a component in a comprehensive line of compatible immunoassay reagents sold to reference laboratories to detect the species and serotypes of Giardia.

One preferred embodiment of the present invention is a diagnostic kit comprising at least one labeled monoclonal antibody against a particular Giardia antigen or species, as well as any appropriate stains, counterstains, or reagents. Further embodiments include kits containing at least one control sample of a Giardia antigen and/or a cross-reactive labeled monoclonal antibody which would detect the pres¬ ence of any of the Giardia organisms in a partic¬ ular sample. Specific antigens to be detected in this kit include the antigens of Giardia lamblia (applicant has further divided this species into eight subgroups: Giardia lamblia I, II, III, IV, V, VI, VII) and/or Giardia intestinalis.

Monoclonal diagnostics which detect the presence of Giardia antigens can also be used in periodic testing of water sources, food supplies and food processing operations. Thus, while the present invention describes the use of the labelled monoclonal antibodies to determine the presence of a standard antigen, the invention can have many applications in diagnosing the presence of antigens by determining whether specimens such as urine, blood, stool, water and milk contain the particular Giardia antigen. More particularly, the invention could be utilised as a public health and safety diagnostic aid, whereby specimens such as water or food could be tested for possible contamination.

The invention will be further illustrated in connection with the following Examples which are set forth for the purposes of illustration only and not by way of limitation. In the Examples:

API = Analytical Profile Index (ref. Ayerst Labs)

DMEM = Dulbecco's Modified Eagles Medium

FCS = Foetal Calf Serum

PBS = phosphate-buffered saline % T refers to vaccine concentration measured in a 1 cm light path

Monoclonal antibodies of the present invention are prepared generally according to the method of Koehler and Milstein, Eur. J. Immunol. , (1975) 292. EXAMPLE 1

A. Animal Immunisation

Balb/c mice are injected with prepared Giardia lamblia antigen. They are given intraperitoneal and/or intravenous injections (0.05 ml 80% T vaccine) of vaccine prepared as above. The mice are bled approximately six days after the last injection and the serum tested for antibodies by assay. A conventional assay used for this serum titer testing is the enzyme-linked immunosorbent assay system. When the mice show antibody production after this regimen, generally a positive titer of at least 10,000, a mouse is selected as a fusion donor and given a booster injection (0.02 ml 80% T vaccine) intravenously, three days prior to splenectomy. B. Cell Fusion

Spleen cells from the immune mice are harvested three days after boosting, by conventional techniques. First, the donor mouse selected is killed and surface-sterilised by immersion in 70% ethyl alcohol. The spleen is then removed and immersed in approximately 2.5 ml DMEM to which has been added 3% FCS. The spleen is then gently homogenised in a LUX homogenising tube until all cells have been released from the membrane, and the cells are washed in 5 ml 3% FCS-DMEM. The cellular debris is then allowed to settle and the spleen cell suspension placed in a 10 ml centrifuge tube. The debris is then rewashed in 5 ml 3% FCS-DMEM. 50 ml suspension are then made in 3% FCS-DMEM.

The myeloma cell line used is NSO (uncloned) , obtained from the MRC Laboratory of Molecular Biology in Cambridge, England. The myeloma cells are in the log growth phase, and rapidly dividing. Each cell line is washed using, as tissue culture medium, DMEM containing 3% FCS.

The spleen cells are then spun down at the same time that a relevant volume of myeloma cells are spun down (room temperature for 7 minutes at 600 g) , and each resultant pellet is then separately resuspended in 10 ml 3% FCS-DMEM. In order to count the myeloma cells, 0.1 ml of the suspension is diluted to 1 ml and a haemacytometer with phase microscope is used. In order to count the spleen cells, 0.1 ml of the suspension is diluted to 1 ml with Methyl Violet-citric acid solution, and a haemacytometer and light microscope are used to count the stained nuclei of the cells. 5 Spleen cells are then mixed with myeloma cells, the mixture washed in serum-free DMEM high in glucose, and centrifuged, and all the liquid removed. The resultant cell pellet is placed in a 37°C water-bath. 1 ml of a 50 w/v solution of polyethylene glycol 1500 (PEG) in saline

10 Hepes, pH approximately 7.5, is added, and the mixture gently stirred for approximately 1.5 minutes. 10 ml serum-free tissue culture medium DMEM are then slowly added, followed by up to 50 ml of such culture medium, centrifugation and removal of all the supernatant, and

15 resuspension of the cell pellet in 10 ml of DMEM containing 18% by weight FCS.

10 μl of the mixture are placed in each of ^'672 wells of standard multiwell tissue culture plates. Each well contains 1.0 ml of the standard HAT medium (hypoxanthine,

20 aminopterin and thymidine) and a feeder layer of Balb/c

4 macrophages at a concentration of 5 x 10 macrophages/well.

The wells are kept undisturbed, and cultured at 37°C in 9% CO_ air at approximately 100% humidity. The wells

" - ~ are analysed for growth, utilising the conventional inverted microscope procedure, after about 5 to 10 days.

In those wells in which growth is present in the inhibiting HAT medium, screening tests for the specific monoclonal antibody are made utilising the conventional

30 enzyme immunoassay screening method described below.

Somewhere around 10 days to 14 days after fusion, sufficient antibody against the antigen may develop in at least one well.

C. Cloning 35 From those wells which yielded antibody against the- antigen, cells are removed and cloned using the standard agar or dilution method.

The clones may be assayed by the enzyme immunoassay method to determine antibody production.

D. Monoclonal Selection

The monoclonal antibodies from the clones are screened by the standard techniques for binding to the antigen, prepared as in the immunisation, and for specificity in a test battery of the class bearing different antigens. Specifically, a grid of microtiter plates containing a representative selective of organisms is prepared, boiled, and utilised as a template to define the specificity of the parent group. The EIA immunoassay noted above may be used.

E. Antibody Production and Purification (2 alternatives)

(1) Six Balb/c mice are primed with pristane and

7 injected intraperitoneally with 10 cells of the monoclonal antibody specific against the antigen. The ascites fluid is harvested after the mice have reached the proper stage; the mice are swollen with fluid .but still alive.

The cells are then centrifuged at 1200 g for approximately 10 minutes, the cells discarded, and the antibody-rich ascites fluid collected. The fluid is titrated, as noted above, to establish presence and level of antibody, and purified.

Purification is accomplished using the protein A -

Sepharose method. More particularly, about 10 ml of the ascites fluid are filtered through glass wool and centrifuged at 30,000 g for 10 minutes. The ascites is then diluted with twice its own volume of cold phosphate buffer (0.1 M sodium phosphate, pH 8.2). The diluted ascites is loaded on to a 2 ml column of protein A - Sepharose which has previously been equilibrated with phosphate buffer. The column is washed with 40 ml phosphate buffer, and the monoclonal antibody is eluted with citrate buffer (0.1 M sodium citrate, pH 3.5) into sufficient 1M tris buffer, pH 9.0, to raise the pH immediately to about 7.5. The eluate is dialysed in 2 x 1000 ml PBS at +4°C.

(2) Cells of the monoclonal antibody-producing line specific to Giardia are grown in batch tissue culture. DMEM, to which has been added 10% FCS, is used to support growth in mid-log phase, to 1 litre volume. The culture is allowed to overgrow, to allow maximum antibody production. The culture is then centrifuged at 1200 g for approximately 10 minutes. The cell/cell debris is discarded and the antibody-rich supernatant collected. The fluid may then be titrated, as noted above, to establish presence and level of antibody, and purified by a combination of.batch ion-exchange chromatography, ammonium sulphate precipitation and column ion-exchange (a possible alternative would be protein A - Sepharose) chromatography.

More particularly, to one litre of culture supernatant is added one litre of 0.05M sodium acetate buffer, pH 4.5, and 40 ml of SP-Sephadex, previously equilibrated in 0.1M sodium acetate buffer, pH 5.0. The suspension is stirred at +4°C for one hour. The

SP-Sephadex is allowed to settle and the supernatant is decanted. The SP-Sephadex is packed in a column, washed with 60 ml of 0.1M acetate buffer, pH 5.0, and eluted with 60 ml of the same buffer plus 1M sodium chloride. The eluate is stirred at +4°C, and an equal volume of saturated ammonium sulphate added slowly. The suspension is stirred for a further 30 minutes. The precipitate is then harvested by centrifugation at 10,000 g for 10 minutes. The precipitate is dissolved in a minimum volume of either cold phosphate/EDTA buffer (20mM sodium phosphate, lOmM EDTA, pH 7.5, + 0.02% sodium azide) for

DEAE-cellulose chromatography, or phosphate buffer (0.1M sodium phosphate, pH 8.2 + 0.02% sodium azide) for protein A-Sepharose chromatography. The dissolved precipitate is dialysed versus 2 x 1000 ml of the dissolution buffer at +4°C, and the appropriate chromatography step carried out as previously described.

F. Enzyme-Monoclonal Linkage

The monoclonal antibody specific against the antigen, prepared as above, is linked to an enzyme, viz. highly-purified alkaline phosphatase. The one-step glutaraldehyde method or benzoquinone conjugation is used.

In the one-step glutaraldehyde method, 3 mg monoclonal antibody (in about 1 ml of solution) are dialysed with 10 mg alkaline phosphatase (Sigma Type ^• VII-T) against 2 x 1000 ml of PBS, pH 7.4, at +4°C. After dialysis, the volume is made up to 2.5 ml with PBS, and 25 μl of a 20% glutaraldehyde -in PBS solution are added. The conjugation mixture is left at room temperature for 1.5 hours. After this time, glutaraldehyde is removed by gel filtration on a Pharmacia PH-10 (Sephadex G-25 M) column, previously equilibrated in PBS. The conjugate is eluted with 3.5 ml PBS and then dialysed against 2 x 2000 ml of TRIS buffer (50 mM TRIS, 1 mM magnesium chloride, pH 8.0, plus 0.02% sodium azide) at +4°C. To the dialysed conjugate is added 1/lOth its own volume of 10% BSA in TRIS buffer. The conjugate is then sterile-filtered through a 0.22 μm membrane filter into a sterile amber vial and stored at +4°C. EXAMPLE 2

The general procedure of Example 1 may be followed to produce a monoclonal antibody broadly cross-reactive with an antigen of all species of the genus Giardia. Tests using the present invention are superior to existing tests, based on the following advantages: (i) greater accuracy; (ii) same day results, within an hour or two; (iii) reduction in amount of skilled labour required to administer laboratory procedures, resulting in reduced labour costs; (iv) reduction in laboratory time and space used in connection with tests, resulting in reduced overhead expenses; and (v) improved therapy based upon early, precise diagnosis. While the invention has been described in connection with certain preferred embodiments, it is not intended to limit the scope of the invention to the particular form set forth but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

Claims

1. A monoclonal antibody specific for an antigen or species of Giardia.

2. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia.

3. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia I.

4. The antibody of Claim 1 specific to the antige -or antigens of Giardia lamblia II.

5. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia III.

6. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia IV.

7. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia V.

8. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia VI.

9. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia VII.

10. The antibody of Claim 1 specific to the antigen or antigens of Giardia lamblia VIII.

11. The antibody of Claim 1 specific to the antigen or antigens of Giardia intestinalis.

12. A monoclonal antibody broadly cross- reactive with an antigen of all species of the genus Giardia.

13. A labeled monoclonal antibody consisting essentially of a monoclonal antibody of Claims 1-12 and an appropriate label.

14. The labeled monoclonal antibody of Claim 13, wherein said label is a member of the group selected from a radioactive isotope, enzyme, fluorescent compound, bioluminescent compound, chemiluminescent compound, or ferro¬ magnetic atom, or particle.

15. The labeled monoclonal antibody of Claim 14, wherein said label is an enzyme capable of conjugating with a monoclonal antibody and of being used n an enzyme- n e mmunoassay procedure.

16. The labeled monoclonal antibody of Claim 15, wherein said enzyme is alkaline phos¬ phatase, glucose oxidase, galactosidase, or peroxidase.

17. The labeled monoclonal antibody of Claim 14, wherein said label is a fluorescent compound or probe capable of being used in an immuno-fluorescent or fluorescent immunoassay procedure, enzyme fluorescent immunoassay, or fluorescence polarization immunoassay, photon counting immunoassay, or the like procedure.

18. The labeled monoclonal antibody of Claim 17, wherein said fluorescent compound or probe is fluorescein.

19. The labeled monoclonal antibody of Claim 14, wherein said label is a chemiluminescent compound capable of being used in a luminescent or enzyme-linked luminescent immunoassay.

20. The labeled monoclonal antibody of , is luminol or a luminol derivative.

21. The labeled monoclonal antibody of Claim 14, wherein said label is a bioluminescent compound capable of being used in an appropriate bioluminescent immunoassay.

22. The labeled monoclonal antibody of Claim 21, wherein such bioluminescent compound is luciferase or a luciferase derivative.

23. A process for diagnosing for the pre¬ sence of an antigen of Giardia in a specimen comprising contacting at least a portion of said specimen with a labeled monoclonal antibody of Claim 13 in an immunoassay procedure appropri¬ ate for said label.

24. The process of Claim 23, wherein the appropriately labeled immunoassay procedure is selected from immuno-fluorescent or fluorescent immunoassay, i muno-electron microscopy, radio- metric assay systems, enzyme-linked immunoassays, fluorescence polarization, photon-counting bio¬ luminescent, or chemiluminescent immunoassay. 25. The process of Claim 24, wherein said label is an enzyme capable of being used in an enzyme-linked immunoassay procedure.

26. The process of Claim 25, wherein said enzyme is selected from alkaline phosphatase, glucose oxidase, galactosidase, or peroxidase.

27. The process of Claim 24, wherein said label is a fluorescent compound or probe capable of being used in an immuno-fluorescent or fluores¬ cent immunoassay procedure, enzyme fluorescent immunoassay, or fluorescence polarization immuno¬ assay, or photon-counting immunoassay, or- the like procedure.

28. The process of Claim 27, wherein said fluorescent compound or probe is fluorescein.

29. The process of Claim 24, wherein said label is a chemiluminescent compound capable of being used in a luminescent or enzyme-linked luminescent immunoassay.

30. The process of Claim 29, wherein said derivative.

31. The process of Claim 24, wherein said label is a bioluminescent compound capable of being used in a bioluminescent or enzyme-linked bioluminescent immunoassay.

32. The process of Claim 31, wherein said bioluminescent compound is luciferase or a lucif- erase derivative.

33. A therapeutic composition comprising one or more of the monoclonal antibodies in Claims 1-12 and a pharmaceutically acceptable carrier or diluent.

34. A therapeutic composition comprising one or more of the labeled monoclonal antibodies in Claim 13 and a pharmaceutically acceptable carrier or diluent.

35. A method of treating Giardia infec¬ tions comprising administering an effective amount of a monoclonal antibody of Claims 1-12. of an antigen or species of Giardia in a diagnos¬ tic specimen comprising at least one monoclonal antibody of Claims 1-12.

37. The kit of Claim 36, wherein said at least one antibody is labeled.

38. The kit of Claim 37, wherein said at least one monoclonal antibody is labeled with a fluorescent compound.

39. The kit as in Claim 37, wherein said at least one monoclonal antibody is labeled with an enzyme.

40. The kit as in Claim 37, wherein said at least one monoclonal antibody is labeled with a member of the group consisting of a radio¬ active isotope, chemiluminescent compound, bio¬ luminescent compound, ferromagnetic atom, or particle.

41. The kit of Claims 37, 38, 39, and 40 additionally containing at least one known Giardia antigen as a control. 42. The kit of Claims 37, 38, 39, 40, and 41 containing each known antigen of Giardia lamblia, and/or Giardia intestinalis.

43. The kit of Claims 37, 38, 39, 40, and 41 containing the antigens of Giardia lamblia.

44. The kit of Claims 37, 38, 39, 40, and 41 containing the antigens of Giardia intes¬ tinalis.

45. A kit for diagnosing for the presence of an antigen or species of Giardia in a diagnos¬ tic specimen comprising at least one monoclonal antibody of Claims 1-12 and. a control.

46. The kit of Claim 45, wherein said at least one antigen is labeled and said control is at least one known antigen of Giardia.

47. A kit for diagnosing for the presence of a Giardia infection comprising at least one monoclonal antibody of Claims 1-12.

48. The kit of Claim 47, wherein said at least one monoclonal antibody is labeled.