Chemistry: molecular biology and microbiology – Measuring or testing process involving enzymes or...
Reexamination Certificate
2001-02-05
2003-07-01
Navarro, Mark (Department: 1645)
Chemistry: molecular biology and microbiology
Measuring or testing process involving enzymes or...
Reexamination Certificate
active
06586173
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to parasitic helminth aromatic amino acid decarboxylase (ADC) nucleic acid molecules, proteins encoded by such nucleic acid molecules, antibodies raised against such proteins, compounds capable of inhibiting the function of such proteins and methods to identify such inhibitors. The present invention also includes therapeutic compositions comprising such nucleic acid molecules, proteins, antibodies, and/or inhibitors, as well as their use to protect animals from diseases caused by parasitic helminths. The present invention also includes a method for detecting the presence of amino acid decarboxylases.
BACKGROUND OF THE INVENTION
Parasitic helminth infections in animals, including humans, are typically treated by chemical drugs. One disadvantage with chemical drugs is that they must be administered often. For example, dogs susceptible to heartworm are typically treated monthly. Repeated administration of drugs, however, often leads to the development of resistant helminth strains that no longer respond to treatment. Furthermore, many of the chemical drugs cause harmful side effects in the animals being treated, and as larger doses become required due to the build up of resistance, the side effects become even greater. Moreover, a number of drugs only treat symptoms of a parasitic disease but are unable to prevent infection by the parasitic helminth.
An alternative method to prevent parasitic helminth infection includes administering a vaccine against a parasitic helminth. Although many investigators have tried to develop vaccines based on specific antigens, it is well understood that the ability of an antigen to stimulate antibody production does not necessarily correlate with the ability of the antigen to stimulate an immune response capable of protecting an animal from infection, particularly in the case of parasitic helminths. Although a number of antigens have been identified in several parasitic helminths, including proteases and macromolecules demonstrating protease-like activity, (See, for example, Lustigman, 1995
, Antimicrobial Agents and Chemother.,
39(9): 1913-1919; Mehta, 1992
, Mol. Biochem. Parasitol.,
53:1-16; Richer et al., 1992
, Exper. Parasitol.,
75:213-222; Tripp et al., U.S. Pat. No. 5,569,603) there is yet to be a commercially available vaccine developed for any parasitic helminth.
As an example of the complexity of parasitic helminths, the life cycle of
Dirofilaria immitis
, the filariid nematode that causes heartworm, includes a variety of life forms, each of which presents different targets, and challenges, for immunization. In a mosquito,
D. immitis
microfilariae go through two larval stages (L1 and L2) and become mature third stage larvae (L3), which can then be transmitted back to the dog when the mosquito takes a blood meal. In a dog, the L3 molt to the fourth larval stage (L4), and subsequently to the fifth stage, or immature adults. The immature adults migrate to the heart and pulmonary arteries, where they mature to adult heartworms. Adult heartworms are quite large and preferentially inhabit the heart and pulmonary arteries of an animal. Sexually mature adults, after mating, produce microfilariae which traverse capillary beds and circulate in the vascular system of the dog. In particular, heartworm is a major problem in dogs, which typically do not develop immunity upon infection (i.e., dogs can become reinfected even after being cured by chemotherapy). In addition, heartworm infection has been reported in cats, ferrets, and humans.
The mechanisms and regulatory pathways involved in the development of helminths are not clear. For example, it has been shown in the free living nematode,
Caenorhabditis elegans
(
C. elegans
), that the development of the larvae is regulated by environmental signals through chemosensory neurons. Blockage of signal transmission affects the development of the nematode (Bargmann, et al., 1991
, Science,
251, 1243-1246). Many neuron-related genes have been identified in
C. elegans
. Mutation of the genes which control normal neuron function in
C. elegans
will not only affect the behavior of the nematode, but will also affect the development of the larvae and egg laying of mutated female worms. In parasitic nematodes such as
D. immitis
, very little is known about mechanisms involved in the migration, signal transmission and the developmental regulation of the parasites. However, host and tissue specificities in parasite infections suggest that parasitic nematodes might also need correct environmental signals for development.
There has been no previous report of aromatic amino acid decarboxylases (ADC) in parasitic helminths. Although three genes coding for putative aromatic amino acid decarboxylase-like proteins have been sequenced in the free-living nematode
C. elegans
, neither biochemical properties nor biological functions of these proteins have been described. An unrelated but biochemically similar molecule, dopa-decarboxylase (DOPA-DC), has been shown to be an important enzyme in catecholamine metabolism in animals. In Drosophila, studies of DOPA-DC indicate that the majority of DOPA-DC is localized in the epidermis and that the enzyme is involved in the formation of flexible cuticle during the development of larvae (see Wright, T. R. F., 1996
, Journal of Heredity,
87:175-190). Due to the similarities in biochemical properties and in vivo expression between DOPA-DC and parasitic helminth ADC disclosed herein it is likely that parasitic helminth ADC plays a significant role in cuticle formation during parasitic helminth development and in larval survival in the hostile conditions within the host.
As such, there remains a need to identify efficacious compositions that protect animals against diseases caused by parasitic helminths such as
D. immitis
. Such compositions would preferably also protect animals from infection by such helminths.
SUMMARY OF THE INVENTION
The present invention relates to a novel product and a process to protect animals against parasitic helminth infection (e.g., prevent and/or treat such an infection). According to the present invention there are provided parasitic helminth ADC proteins (e.g. Dirofilaria and Brugia ADC proteins) and mimetopes thereof; parasitic helminth ADC nucleic acid molecules, including those that encode such proteins; antibodies raised against such ADC proteins (i.e., anti-parasitic helminth ADC antibodies); and compounds that inhibit the function of parasitic helminth ADCs (i.e. inhibitory compounds).
The present invention also includes methods to obtain and/or identify such proteins, nucleic acid molecules, antibodies and inhibitory compounds. Also included in the present invention are therapeutic compositions comprising such proteins, nucleic acid molecules, antibodies, and/or inhibitory compounds, as well as use of such therapeutic compositions to protect animals from diseases caused by parasitic helminths.
One embodiment of the present invention is an isolated nucleic acid molecule that includes a parasitic helminth aromatic amino acid decarboxylase nucleic acid molecule. Such nucleic acid molecules are referred to as ADC nucleic acid molecules. A preferred parasitic helminth nucleic acid molecule includes an isolated nucleic acid molecule selected from the group consisting of: (a) a nucleic acid molecule having at least about 50 nucleotides wherein said nucleic acid molecule hybridizes with a nucleic acid molecule selected from the group consisting of SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13, SEQ ID NO:15, SEQ ID NO:16, SEQ ID NO:18, SEQ ID NO:19 and SEQ ID NO:21 under conditions that allow about 20% base pair mismatch between said isolated nucleic acid molecule and said nucleic acid molecule having said nucleic acid sequence, and (b) a nucleic acid molecule having at least about 150 nucleotides wherein said nucleic acid sequence hybridizes with a nucleic acid molecule selected from the group consisting of SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13,
Heska Corporation
Heska Corporation
Navarro Mark
LandOfFree
Methods for the detection of amino acid decarboxylases does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for the detection of amino acid decarboxylases, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for the detection of amino acid decarboxylases will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3028867