The aim of the present study was to confirm observations on the vertical transmission of Schistosoma japonicum in the rabbit. S. japonicum-infected pregnant rabbits were used in this study. Perfusion of mother rabbits was done 9 weeks after infection in order to obtain worm burdens in relation to their initial cercarial dose. Anti-schistosoma specific IgM antibodies in serum samples collected from rabbit kittens were detected by ELISA. Our results showed that gestation period lasted the normal 29-31 days. All the exposed mother rabbits became infected with S. japonicum. Positive IgM antibody OD values were detected in 12 out of the 60 kittens examined (20.0%). In group C and A, 40.0% and 17.9% of the kitten were congenitally infected, respectively. 18.1% of the kittens born to mothers infected with a single dose of 200 cercariae per rabbit were positives; this is not significantly different from that obtained for the 600 dose group (22.2%). Three randomly selected IgM+ kittens harbored between one and two adult worms. The livers of these kittens displayed granulomatous lesions. It is concluded that congenital S. japonicum infection does occur in the rabbit and is affected by the mother stage of pregnancy and to a lesser extent by its infection load.
Antibodies, Helminth/blood ; *Disease Transmission, Vertical ; Immunoglobulin M/blood ; Schistosoma japonicum/immunology ; Schistosoma japonicum/isolation & purification ; Schistosomiasis japonica/*transmission

OBJECTIVETo identify the egg antigens related to the formation of hepatic granulomas and fibrosis of Schistosomiasis japonica.

METHODSThe egg cDNA library of Schistosoma japonicum (S. japonicum) was constructed and screened by immunological methods with the pooled sera of advanced schistosomiasis patients. The inserted foreign DNA fragments of positive clones were sequenced. The sequence data were analyzed using Wdnasis 2.5 and compared with Genebank data using blast software.

RESULTSEighty-one clones containing recombinant DNA fragments were obtained from the egg cDNA library of S. japonicum by immunological screening. The DNA sequences of all clones belonged to the miracidial antigen family. The longest cDNA fragment was 1604 bp, which contained an open reading frame of 351 bp, which encoded a protein of 1 2913.35 daltons.

CONCLUSIONThe cDNA sequence of the miracidial antigen of S. japonicum (Chinese strain) was obtained for the first time.

Animals ; Antigens, Helminth ; genetics ; Base Sequence ; China ; DNA, Complementary ; analysis ; Ovum ; Schistosoma japonicum ; genetics ; immunology

OBJECTIVETo obtain peptide mimicking epitopes of Schistosoma japonicum (S. japonicum) through screening of a phage peptide library and to test their potential for induction of protection.

METHODSS. japonicum infected sera from Microtus fortis (IMFS) and normal sera from Microtus fortis (NMFS) were used respectively to screen a 12-mers random peptide library by testing the reactivity of anti-S. japonicum serum with the phagotopes. After three rounds of biopanning, the pooled phages were used to immunize mice, after which challenge infection was performed.

RESULTSOf 12 randomly picked clones, 10 clones selected using IMFS and 7 clones selected using NMFS were shown to be antigenic. Significant reduction in adult worms (22.6%) and a high reduction (68.9%) in liver eggs were achieved following immunization with phages screened with IMFS. However, no protection was elicited by those selected with NMFS.

CONCLUSIONThe results show that the phagotopes are both antigenic and immunogenic, suggesting a potential use of phage displayed peptide as novel vaccines against S. japonicum.

Animals ; Arvicolinae ; parasitology ; Epitopes ; Helminth Proteins ; immunology ; Peptide Library ; Schistosoma japonicum ; immunology ; Schistosomiasis japonica ; prevention & control ; Vaccines ; immunology

OBJECTIVE: To obtain the coding genes related to Schistosoma japonicum (Sj) cercariae 66 to approximately 68 kD antigens,and to provide antigens for diagnosis and vaccine of schistosomiasis. METHODS: Sj cercariae cDNA library was screened using the monospecific anti-sera of rabbit against soluble cercariae 66 to approximately 68 kD antigens as probes.The inserted cDNA fragments of the positive clones were amplified with PCR and identified by agarose gel electrophoresis. Four strong positive clones were further sequenced and analyzed through the internet NCBI/BLAST software. RESULTS: Twenty-one positive clones were obtained, 10 of which revealed a single band (0.5 to approximately 3.0 kb).The 4 strong positive clones showed high identity to SJCHGC05187,SJCHGC05173,SJCHGC06989, and SJCHGC01894 at the nucleotide level. CONCLUSION Four coding genes related with Sj antigens are obtained.
Animals ; Antibodies, Helminth ; immunology ; Antigens, Helminth ; immunology ; Cercaria ; genetics ; immunology ; DNA, Complementary ; genetics ; Gene Library ; Immune Sera ; immunology ; Schistosoma japonicum ; genetics ; immunology

OBJECTIVETo assess the feasibility of using saliva for Schistosomiasis japonica diagnosis.

METHODSSchistosoma japonicum infected animal model was established. Pairs of saliva and serum samples from rabbits and chronic schistosomiasis patients were collected. Anti-schistosoma specific antibodies in saliva and serum were detected by indirect ELISA.

RESULTSThe specificities of antibody detection of rabbit saliva and serum were 93% (28/30) and 97% (29/30), respectively, and the sensitivities of antibody detection of rabbit serum and saliva were 100% (24/24) and 88% (21/24), respectively. A significant correlation (r = 0.5307, P = 0.0038 < 0.05) existed between anti-SEA IgG levels in serum and saliva. As with those in serum, anti-SEA IgG levels in saliva could reflect the state of infection and treatment. The sensitivity of antibody detection was 91% (29/32) for patient saliva samples and 100% (32/32) for their sera. 8 samples were positive in 140 normal saliva samples (i.e. 6% false positive rate) and 6 samples were positive in 156 normal serum samples (4% false positive rate). There was a significant correlation (r = 0.4227, P = 0.008 < 0.05) between specific antibodies in saliva and serum.

CONCLUSIONThe detection of specific antibodies in saliva can be used as a non-invasive immunodiagnosis method of Schistosomiasis japonica.

Adolescent ; Adult ; Animals ; Antibodies, Helminth ; analysis ; Child ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Immunoglobulin G ; analysis ; Male ; Middle Aged ; Rabbits ; Saliva ; immunology ; Schistosoma japonicum ; immunology ; Schistosomiasis japonica ; diagnosis

The aim of the present study was to confirm observations on the vertical transmission of Schistosoma japonicum in the rabbit. S. japonicum-infected pregnant rabbits were used in this study. Perfusion of mother rabbits was done 9 weeks after infection in order to obtain worm burdens in relation to their initial cercarial dose. Anti-schistosoma specific IgM antibodies in serum samples collected from rabbit kittens were detected by ELISA. Our results showed that gestation period lasted the normal 29-31 days. All the exposed mother rabbits became infected with S. japonicum. Positive IgM antibody OD values were detected in 12 out of the 60 kittens examined (20.0%). In group C and A, 40.0% and 17.9% of the kitten were congenitally infected, respectively. 18.1% of the kittens born to mothers infected with a single dose of 200 cercariae per rabbit were positives; this is not significantly different from that obtained for the 600 dose group (22.2%). Three randomly selected IgM+ kittens harbored between one and two adult worms. The livers of these kittens displayed granulomatous lesions. It is concluded that congenital S. japonicum infection does occur in the rabbit and is affected by the mother stage of pregnancy and to a lesser extent by its infection load.
Animals ; Antibodies, Helminth ; blood ; Female ; Immunoglobulin M ; blood ; Infectious Disease Transmission, Vertical ; Pregnancy ; Rabbits ; Schistosoma japonicum ; immunology ; isolation & purification ; Schistosomiasis japonica ; transmission

OBJECTIVE: To develop a rapid and simple immunoassay to detect antibodies in the sera of patients infect Schistosoma japonicum (S. japonicum). METHODS: Soluble egg antigen (SEA) of S. japonicum conjugated with colloidal carbon in advance was used to react with the antibodies in the sera of patients with schistosomiasis. Then the carbon-antigen-antibody complex would be captured by SEA which had been absorbed on the nitrocellulose membrane and a gray band was shown. RESULTS: A total of 137 sera samples from S. japonicum epidemic area were tested, and the consistency, sensitivity, and specificity of colloidal carbon dipstick assay were 98.54%, 98.99%, and 97.37%, respectively, compared with the IHA method. The gray scale of bands on the dipstick was curvilinear to serum titer which revealed that the assay could be used semi-quantitatively in serum analysis. CONCLUSION Colloidal carbon dipstick assay is not only rapid and simple, but also sensitive and specific for the detection of serum antibodies of schistosomiasis japonica. It will be a practical immunological assay for the diagnosis of schistosomiasis in the field testing.
Animals ; Antibodies, Helminth ; blood ; Carbon ; chemistry ; Colloids ; chemistry ; Humans ; Immunoassay ; methods ; Schistosoma japonicum ; immunology ; isolation & purification ; Schistosomiasis japonica ; blood ; diagnosis ; Sensitivity and Specificity

To obtain peptides mimicking epitope of a protective McAb SSjl4 specific to Schistosoma japonicum and investigate their immuno-protection effects. A phage random 12 peptide library was screened using purified McAb SSj14, 33 clones were picked up for specificity identification by ELISA. The epitope of each positive clones were detected by the sequencing analysis technique. The antigenicity of three positive clones (P1, P2 and P11) and their mixture cock-tail were further confirmed by Western-blotting, and their protective efficiency were evaluated by mice vaccination experiment. IL-12 level between the vaccinated mice and control mice were compared. 30 positive phage clones were obtained, which represented 11 different epitopes respectively, there were a similar sequence "H-N/Q-X-S-P/F-X-X-L-A-T" among all of the epitopes. Western-blotting showed that all of the three tested clones were recognized by McAb SSj14. Significant adult worm reduction (13.84% to approximately 52.83%), liver tissue egg reduction (34.17% to approximately 65.47%) as well as fecal egg reduction (28.89% to approximately 73.78%) were observed in mice vaccinated with phages of P1, P2, P11 and mixture of three clones when compared with those of the blank control group, among them, the mice vaccinated with the mixture of phage clones got higher protection than any of the mice injected with only one kind of clone phages. At the same time, the IL-12 level in serum of vaccinated mice was found higher than those of the blank control one, this suggest that IL-12 may correlate with the protective efficiency induced by the clone phages. The study provides a new way for developing an effective vaccine against S. japonicum.
Animals ; Antibodies, Helminth ; immunology ; Antibodies, Monoclonal ; immunology ; Antigens, Helminth ; immunology ; Epitopes ; immunology ; Interleukin-12 ; blood ; Male ; Mice ; Mice, Inbred BALB C ; Molecular Mimicry ; Peptide Library ; Schistosoma japonicum ; immunology ; Schistosomiasis japonica ; immunology ; prevention & control ; Vaccination

Schistosomiasis japonica is an endemic, zoonotic disease of major public health importance in China. Vaccination is needed as a complementary approach to the ongoing control programs. In the present study, we determined if the efficacies of DNA vaccine encoding the SjGST and Sj32 asparaginyl endopeptidase protein could be enhanced by boosting with SjGST-32 protein vaccines. Mice were inoculated with a VR1012-SjGST-32 DNA vaccine followed by boosting with rSjGST-32 at 0, 14 and 28 d. Two weeks after the final boost, mice were challenged percutaneously with cercariae. On day 45 following the challenge, all mice were sacrificed and the numbers of recovered worms and hepatic eggs were counted. Moreover, we analyzed the immune response among various vaccination groups. The results showed that DNA vaccine efficacy was enhanced when mice were boosted with protein vaccine. Adult worm and liver egg burdens were reduced 42.3% and 59.6%, respectively. We further found that DNA vaccine followed by boosting with protein significantly increased the IgG titer and T cell proliferation over those seen in mice vaccinated solely with DNA vaccines. Furthermore, the higher level of IFN-gamma expression in the splenetic CD4+ T cell showed that DNA prime-Protein boosting vaccine induced CD4+ Th1-type responses. Thus, DNA vaccine efficacy was significantly enhanced via boosting protein vaccine which might provide a basis for rational application of the Schistosoma vaccine.
Animals ; Antigens, Helminth ; immunology ; Female ; Glutathione Transferase ; administration & dosage ; immunology ; Helminth Proteins ; immunology ; Immunization, Secondary ; methods ; Mice ; Mice, Inbred C57BL ; Recombinant Fusion Proteins ; administration & dosage ; immunology ; Schistosoma japonicum ; Schistosomiasis japonica ; prevention & control ; Vaccination ; methods ; Vaccines, DNA ; administration & dosage ; immunology

The cDNA fragments of interest were amplified using Sj lambda ZipLox library as the templates by PCR and then cloned into a eukaryotic expression vector p-CMV-GH; A small number of DNA fragments inserted in the recombinants was identified by restriction cleavage, EST sequencing and bioinformatical analysis; mice were injected intramuscularly with the expression library (L-CMV-SjR) or sublibraries(L-CMV-SjR1, L-CMV-SjR2 and L-CMV-SjR3), immunized mice were challenged with Schistosoma japonicum cercariae on day 35, the levels of IgG antibodies in sera from the immunized mice were detected by ELISA. The results demonstrated that a partial cDNA expression library of S.j, with approximately 10(5) transformants, was constructed, most of the recombinants contained the insert DNA fragments of interest, and these fragments had the features of protein-coding sequences for Schistosome. There were no significant differences for the levels of IgG antibodies in sera from all of the immunized groups. Mice immunized with L-CMV-SjR, L-CMV-SjR1 and L-CMV-SjR2 developed significant protective effect against Sj infection compared to control mice injected with the empty plasmid, the rate of worm reduction was about 30%.
Animals ; Antibodies, Helminth ; blood ; immunology ; Antigens, Helminth ; genetics ; immunology ; DNA, Complementary ; Disease Models, Animal ; Gene Expression ; Gene Library ; Mice ; Schistosoma japonicum ; genetics ; immunology ; Schistosomiasis japonica ; prevention & control ; Vaccination ; methods ; Vaccines, DNA ; genetics ; immunology