Molecular characterization of a Dirofilaria immitis cDNA encoding a highly immunoreactive antigen.

Dirofilaria immitis, a filarial nematode, is the causative agent of canine and feline heartworm disease. Previous research has demonstrated that immunity to D. immitis can be induced in dogs by repeated chemical abbreviation of infections while the parasite is a fourth-stage larva.

Identification of Dirofilaria immitis larval antigens with immunoprophylactic potential using sera from immune dogs.

Previous research has demonstrated that dogs that received chemically abbreviated Dirofilaria immitis larval infections were significantly immune to challenge infections. Sera from those immune animals have been effective in passively transferring larval killing and stunting. In the present study, sera from immune and control animals were used to screen various Ag subsets for unique Ag.

Development and dynamics of regional specialization within the syncytial epidermis of the rat tapeworm, Hymenolepis diminuta.

The epidermis of the tapeworm Hymenolepis diminuta is a highly organized syncytium, composed of an outer layer of continuous cytoplasm, or ectocytoplasm, and an inner layer of nucleated cell bodies, or perikarya. The perikarya are in direct cytoplasmic continuity with the ectocytoplasm via narrow plasmalemma-bound bridges called internuncial process. Although distinct structural and functional differences are apparent between ectocytoplasm and perikarya, all of the perikarya along the body of the cestode are morphologically similar, as are all regions of ectocytoplasm.

Parasite excretory-secretory antigen and antibody to excretory-secretory antigen in body fluids and kidney tissue of Dirofilaria immitis infected dogs.

Excretory-secretory (ES) antigens of adult Dirofilaria immitis were detected by enzyme-linked immunosorbent assay (ELISA) in serum and urine from each of 12 experimentally infected dogs. Excretory-secretory antigens in serum were first detected 154 days postinfection. Serum antibodies directed against parasite ES antigens were detected by ELISA in all dogs.

Induction of protective immunity in dogs to infection with Dirofilaria immitis using chemically-abbreviated infections.

Four dogs were immunized against Dirofilaria immitis infection by a series of 3 larval infections which were each subsequently terminated by ivermectin treatment. Two control dogs received ivermectin treatment alone. Following the final ivermectin treatment, dogs were challenged with infective larvae by subcutaneous inoculation, both free and contained within diffusion chambers.