The present study was conducted to identify new target immunogenic molecules from the larval stage of the cattle tick, Boophilus annulatus (Acari: Ixodidae). Two specific larval glycoproteins (GLPs) were isolated by two-step affinity chromatography. The larval immunogens were first purified with CNBr-Sepharose coupled to rabbit anti-larval immunoglobulins, and the glycoproteins were then purified with Con-A Sepharose. These glycoproteins have molecular weights of approximately 32 and 15 kDa with isoelectric points between 6.8 and 7.2. Antibodies against the two GLPs, labeled I and II, were detected in the anti-whole tick, -whole larval, and -gut antigens through immunoblot analysis. These results suggest that these GLPs are good immunogens and can be useful in the vaccination of cattle against tick infestation.
Amino Acid Sequence ; Animals ; Cattle ; Cattle Diseases/immunology/*parasitology/prevention & control ; Chromatography, Affinity ; Electrophoresis, Polyacrylamide Gel ; Glycoproteins/immunology/*isolation & purification ; Immunoblotting ; Isoelectric Focusing ; Ixodidae/chemistry/*immunology ; Male ; Molecular Weight ; Rabbits ; Sequence Analysis, Protein ; Tick Infestations/immunology/parasitology/prevention & control/*veterinary

The present study observed the resistance to reinfection with Clonorchis sinensis in various experimental animals including mice, guinea pigs, rabbits, and dogs, as well as rats and hamsters. The resistance rates to reinfection in rats, mice, hamsters, guinea pigs, rabbits, and dogs were 79.7%, 58.0%, -12.6%, 54.8%, 62.6%, and 6.0%, respectively. Worms recovered from reinfected rats and mice were immature, and significantly smaller than those from the primarily infected (P < 0.01), whereas those from other animals were fully matured to adults. These findings indicate that the protective response against reinfection with C. sinensis is prominent in rats and mice, and that they may be a good animal model to investigate the mechanism of resistance to reinfection with C. sinensis.
Rats ; Rabbits ; Praziquantel/therapeutic use ; Mice ; Guinea Pigs ; Dogs ; Cricetinae ; Clonorchis sinensis/immunology/*physiology ; Clonorchiasis/drug therapy/immunology ; Anthelmintics/therapeutic use ; Animals, Laboratory/immunology/*parasitology ; Animals

The breeding of domestic rabbits (Oryctolagus cuniculus) for human consumption has a long tradition in China. Infections that can affect the production of meat or even be transmitted from animals to humans are important to monitor, especially for public health reasons as well as for their impact on animal health. Thus, a total of 1,132 domestic rabbit sera from 4 regions in China were collected for serological screening for Encephalitozoon cuniculi and for Toxoplasma gondii by ELISA and modified agglutination test (MAT), respectively. Antibodies to E. cuniculi were detected in 248/1,132 (21.9%) sera tested while antibodies against T. gondii revealed a seroprevalence of 51/1,132 (4.5%). We believe that the present results are of epidemiological implications and public health importance due to the acknowledged susceptibility of humans to E. cuniculi and T. gondii infections. Therefore, routine screening tests of domestic rabbits are proposed considering the zoonotic potential of these parasites.
Animals ; Animals, Domestic/blood/microbiology/parasitology ; Antibodies, Fungal/*blood ; Antibodies, Protozoan/*blood ; China/epidemiology ; Encephalitozoon cuniculi/*immunology/isolation & purification ; Encephalitozoonosis/blood/microbiology/*veterinary ; Female ; Male ; Rabbits/blood/microbiology/parasitology ; Seroepidemiologic Studies ; Toxoplasma/*immunology/isolation & purification ; Toxoplasmosis, Animal/*blood/parasitology

BACKGROUNDRecently congenital infection with Schistosoma japonicum (S. japonicum) has been demonstrated in pigs, rabbits, mice and dogs. We explored the rabbit as an animal model for the congenital infection of schistosomiasis japonica and assessed the effect of a congenital S. japonicum infection on the resistance of rabbit kittens to a postnatal challenge infection.

METHODSSixteen pregnant New Zealand white rabbits were infected with a single dose of S. japonicum cercariae. The exposed animals were divided into three groups according to the gestation age at the time of infection. Diagnosis of prenatally acquired S. japonicum infection in the rabbit kittens was primarily based on serological tests in combination with parasitological and histopathological findings. Congenitally infected kittens were challenged percutaneously with 100 S. japonicum cercariae to assess the effect of a congenital S. japonicum infection on kitten resistance to a postnatal challenge infection.

RESULTSThe overall prevalence of congenital infection in offspring of infected mothers was 20% (12/60). The congenital infection rate in group L (late gestation) was much higher than in group E (early gestation) and group M (mid-gestation) (P <0.05). After a postnatal challenge infection, prenatally infected kittens had a 54.66% worm reduction rate, 41.45% egg reduction rate, and 51.76% granuloma size reduction rate compared to naïve kittens.

CONCLUSIONSThis study demonstrates the possibility of congenital infection of S. japonicum in rabbits and the resistance of congenitally infected kittens to a postnatal challenge infection. These results have important implications not only for epidemiological investigations, but also in designing government control programs for schistosomiasis.

Animals ; Antibodies, Helminth ; blood ; Female ; Immunoglobulin M ; blood ; Infectious Disease Transmission, Vertical ; Male ; Pregnancy ; Rabbits ; Schistosomiasis japonica ; congenital ; immunology ; parasitology

The sodium hydrogen exchanger 1 (NHE1), which functions in maintaining the ratio of Na+ and H+ ions, is widely distributed in cell plasma membranes. It plays a prominent role in pH balancing, cell proliferation, differentiation, adhesion, and migration. However, its exact subcellular location and biological functions in Toxoplasma gondii are largely unclear. In this study, we cloned the C-terminal sequence of T. gondii NHE1 (TgNHE1) incorporating the C-terminal peptide of NHE1 (C-NHE1) into the pGEX4T-1 expression plasmid. The peptide sequence was predicted to have good antigenicity based on the information obtained from an immune epitope database. After induction of heterologous gene expression with isopropyl-b-D-thiogalactoside, the recombinant C-NHE1 protein successfully expressed in a soluble form was purified by glutathione sepharose beads as an immunogen for production of a rabbit polyclonal antiserum. The specificity of this antiserum was confirmed by western blotting and immunofluorescence. The antiserum could reduce T. gondii invasion into host cells, indicated by the decreased TgNHE1 expression in T. gondii parasites that were pre-incubated with antiserum in the process of cell entry. Furthermore, the antiserum reduced the virulence of T. gondii parasites to host cells in vitro, possibly by blocking the release of Ca2+. In this regard, this antiserum has potential to be a valuable tool for further studies of TgNHE1.
Animals ; Cell Line ; Immune Sera/genetics/immunology/*metabolism ; Male ; Mice ; Protozoan Proteins/genetics/*metabolism ; Rabbits ; Recombinant Proteins/immunology ; Sheep ; Sodium-Hydrogen Antiporter/genetics/immunology/*metabolism ; Toxoplasma/genetics/immunology/*metabolism ; Toxoplasmosis/parasitology/prevention & control

In this experiment, the correlation between antigenemia and specific antibody responses in Toxoplasma gondii-infected rabbits was assessed. We injected 1,000 T. gondii tachyzoites (RH) subcutaneously into 5 rabbits. Parasitemia, circulating antigens, and IgM and IgG antibody titers in blood were tested by ELISA and immunoblot. For detection of parasitemia, mice were injected with blood from rabbits infected with T. gondii and mice died between days 2 and 10 post-infection (PI). Circulating antigens were detected early on day 2 PI, and the titers increased from day 4 PI and peaked on day 12 PI. Anti-Toxoplasma IgM antibody titers increased on day 6 PI and peaked on days 14-16 PI. IgG was detected from day 10 PI, and the titers increased continuously during the experiment. The antigenic protein patterns differed during the infection period, and the number of bands increased with ongoing infection by the immunoblot analysis. These result indicated that Toxoplasma circulating antigens during acute toxoplasmosis are closely related to the presence of parasites in blood. Also, the circulating antigen levels were closely correlated with IgM titers, but not with IgG titers. Therefore, co-detection of circulating antigens with IgM antibodies may improve the reliability of the diagnosis of acute toxoplasmosis.
Animals ; Antibodies, Protozoan/*blood ; Antigens, Protozoan/*blood ; Enzyme-Linked Immunosorbent Assay/methods ; Immunoblotting/methods ; Immunoglobulin G/*blood ; Immunoglobulin M/*blood ; Mice ; Parasitemia ; Rabbits ; Time Factors ; Toxoplasma/*immunology ; Toxoplasmosis, Animal/*immunology/parasitology

Phosphoglycerate mutase (PGAM) is a key enzyme in glycolytic pathways. With PCR technique based on an EST identified in our lab, a novel gene named SjPGAM (GenBank Accession No. EU374631) was cloned. Sequence analysis revealed that the ORF of SjPGAM gene contained 753 nucleotides, encoding 250 amino acids, and the molecular weight was about 28.26 kD. Real-time PCR analysis showed that the mRNA level of SjPGAM was much higher in the 14 days and 19 days schistosomula than other stages, suggesting that the gene was a schistosomula stage differential expression gene. The SjPGAM cDNA fragment was subcloned into an expression vector pET-28a (+) and transformed into Escherichia coli BL21 cells. In the presence of IPTG, the 31 kD fusion protein was expressed in included bodies. Western blotting revealed that the fusion protein could be recognized by the rabbit serum anti-Schistosoma japonicum adult worm antigen preparation. The study provides important basis for investigating the mechanism of the PGAM in the glycolytic pathways of Schistosoma japonnicum.
Animals ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Male ; Phosphoglycerate Mutase ; genetics ; immunology ; RNA, Messenger ; genetics ; metabolism ; Rabbits ; Recombinant Proteins ; genetics ; metabolism ; Schistosoma japonicum ; enzymology ; genetics ; Schistosomiasis japonica ; immunology ; parasitology

In order to identify antigens that can help prevent camel tick infestations, three major glycoproteins (GLPs) about 97, 66 and 40 kDa in size were purified from adult and larval Egyptian ticks, Hyalomma (H.) dromedarii, using a single-step purification method with Con-A sepharose. The purified GLPs were evaluated as vaccines against camel tick infestation in rabbits. The rabbits received three intramuscular inoculations of GLPs (20 microg/animal) on days 0, 14, and 28. In the immunoblot analysis, Sera from the immunized rabbits recognized the native GLPs and other proteins from larval and adult H. dromedarii ticks along with those from other tick species such as Rhipicephalus sanguineus but not Ornithodoros moubata. The effects of immunity induced by these GLPs were determined by exposing rabbits to adult H. dromedarii ticks. These results demonstrated that GLP immunization led to a slightly decreased reproductive index and significantly reduced rates of egg hatchability. These results demonstrated that immunization with the purified GLPs can provide protection against infestation by H. dromedarii and some other tick species. Further studies are needed to confirm the effectiveness of immunization with GLPs against other tick species.
Animals ; Antigens/immunology/isolation & purification ; Argasidae/immunology ; Chromatography, Affinity/veterinary ; Electrophoresis, Polyacrylamide Gel/veterinary ; Female ; Glycoproteins/*immunology/isolation & purification ; Immunoblotting/veterinary ; Injections, Intramuscular/veterinary ; Ixodidae/growth & development/*immunology ; Life Cycle Stages ; Male ; Rabbits/*immunology/parasitology ; Reproduction ; Species Specificity ; Tick Infestations/immunology/prevention & control/*veterinary

The 26S proteasome is a proteolytic complex responsible for the degradation of the vast majority of eukaryotic proteins. Regulated proteolysis by the proteasome is thought to influence cell cycle progression, transcriptional control, and other critical cellular processes. A novel Schistosoma japonicum gene (GenBank Accession No. AY813725) proteasome alpha2 subunit (SjPSMA2) was cloned. Sequence analysis revealed that the ORF of SjPSMA2 gene contains 708 nucleotides encoding 235 amino acids, and the molecular weight was estimated to be 25.84 kDa. Real-time PCR analysis showed that this gene expressed in 7 d, 13 d, 18 d, 23 d, 32 d and 42 d schistosoma. The mRNA level of SjPSMA2 was lower in 7 d and 23 d schistosomulum than that in other stages. The SjPSMA2 cDNA fragment was subcloned into an expression vector pET28a(+) and transformed into E. coli BL21 (DE3) cells. After induction with IPTCQ the 30 kDa fusion protein was produced as included bodies. Western-blotting revealed that the fusion protein could be recognized by the rabbit serum anti-Schistosoma japonicum adult worm antigen preparation, and the protein in native could be detected. After immunization of BALB/c mice with the fusion protein, the reduction rates of worm counts and liver egg counts were 12.33% and 35.23%. ELISA results revealed that the vaccinated group showed a significant increase in the level of IgG antibody. This study provided an important basis for investigating the regulation mechanism of the proteasome during the development of Schistosoma japonicum.
Animals ; Antibodies, Helminth ; blood ; Base Sequence ; Cloning, Molecular ; Escherichia coli ; genetics ; metabolism ; Genes, Helminth ; Helminth Proteins ; genetics ; metabolism ; Immunization ; Liver ; parasitology ; Male ; Mice ; Mice, Inbred BALB C ; Molecular Sequence Data ; Parasite Egg Count ; Proteasome Endopeptidase Complex ; biosynthesis ; genetics ; immunology ; Rabbits ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Schistosoma japonicum ; genetics ; metabolism ; Vaccines, Synthetic ; immunology