[Effects of anti-idiotypic antibody NP30 on modulation of egg granuloma formation and hepatic fibrosis of schistosomiasis]

OBJECTIVE

To study the effects of the monoclonal anti-idiotypic antibody NP30 active immunization on egg granuloma formation and hepatic fibrosis in Schistosoma japonicum infection.

METHODS

ICR mice were actively immunized with NP30 100 micrograms x 3 i.p. every 10 days while the mice in control group were injected with SP2/0 ascites i.p. simultaneously. After cercariae challenging, the mice were killed at the 4th, 8th, 12th, 16th, 20th and 24th week, respectively. Mouse livers were removed and stained histochemically with VG and subjected to immunohistochemical assay of collagen type I, III and fibronectin(FN). The volume of egg granulomas and the content of collagen type I, III and FN were determined quantitatively by NYD-1000 Image Analysis System.

RESULTS

The volume of egg granulomas in NP30 immunized group was much smaller than that of control group from the 12th week after cercariae challenge. The cellular components of egg granulomas in NP30 immunized group were significantly different from those of the control group, exhibiting two types of atypical egg granulomas were found. VG stain revealed that the average optical density of collagen in hepatic granulomas of experimental group was lower than that of control group. Immunohistochemical assay revealed that the contents of collagen type I, III and fibronectin in egg granulomas of experimental group were lower than those of control group.

CONCLUSION

NP30 vaccination may induce both cellular and humoral protective immunity to modulate egg granulomas and suppress liver fibrosis of schistosomiasis japonica.

[Cloning and sequence analysis of the light chain variable region gene of monoclonal anti-idiotypic antibody NP30 of Schistosoma japonicum]

OBJECTIVE

To amplify and sequence the light chain of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.

METHODS

By comparing the conserved regions at each end of the nucleotide sequences of murine germ-line genes encoding FR1 and FR4 regions of immunoglobulin light chain variable regions, we designed a set of primers for amplification of VL gene. The hybridoma cells secreting anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum were cultured and their genome DNAs were extracted and used as templates for PCR. The PCR product was then cloned into pUC19 vector. The recombinants were sequenced by Sanger's method. The VL gene was compared with GenBank and published mouse VL genes.

RESULTS

The full-length of VL gene was 318 bp. The VL gene was a member of mouse Ig kappa light chain subgroup IV and generated from rearrangement of germ line V and J kappa 4 genes. The VL gene sequence has been registered by GenBank(accession No. AF206720).

CONCLUSION

The obtained VL gene was a potentially functional gene of anti-idiotypic monoclonal antibody NP30 of Schistosoma japonicum.