Targeted innovative design of Bt Cry toxin insecticidal mimics / 生物工程学报

Bt Cry toxin is the mostly studied and widely used biological insect resistance protein, which plays a leading role in the green control of agricultural pests worldwide. However, with the wide application of its preparations and transgenic insecticidal crops, the resistance to target pests and potential ecological risks induced by the drive are increasingly prominent and attracting much attention. The researchers seek to explore new insecticidal protein materials that can simulate the insecticidal function of Bt Cry toxin. This will help to escort the sustainable and healthy production of crops, and relieve the pressure of target pests' resistance to Bt Cry toxin to a certain extent. In recent years, the author's team has proposed that Ab2β anti-idiotype antibody has the property of mimicking antigen structure and function based on the "Immune network theory" of antibody. With the help of phage display antibody library and specific antibody high-throughput screening and identification technology, Bt Cry toxin antibody was designed as the coating target antigen, and a series of Ab2β anti-idiotype antibodies (namely Bt Cry toxin insecticidal mimics) were screened from the phage antibody library. Among them, the lethality of Bt Cry toxin insecticidal mimics with the strongest activity was close to 80% of the corresponding original Bt Cry toxin, showing great promise for the targeted design of Bt Cry toxin insecticidal mimics. This paper systematically summarized the theoretical basis, technical conditions, research status, and discussed the development trend of relevant technologies and how to promote the application of existing achievements, aiming to facilitate the research and development of green insect-resistant materials.

Expression and activity identification of a human nasopharyngeal carcinoma I50 anti-idiotype antibody / 中南大学学报(医学版)

Objective To obtain I50 anti-idiotype antibody and identify its activity in vitro.Methods I50 anti-idiotype (Id) antibody gene was amplified from the template of fuse 5-I50 by PCR to construct a prokaryotic expression vector pET25b-I50. The expression of pET25b-I50 in E. coli BL21(DE3) was induced by isopropylthio-β-D-galactopyranoside (IPTG) and was confirmed by SDS-PAGE and Western blot with Ab1(FC2) monoclonal antibody and an anti-hexahistidine tag antibody. The method of dialysis refolding was used to restore the activity of I50 anti-Id antibody, which was measured by Dot-ELISA and lymphocyte proliferation assay. Results The recombinant vector was successfully constructed and the recombinant protein was successfully expressed and purified with 90% purity. The relative molecular weight of the expressed protein was 15 kD, which was in accordance with expectation. The activity of I50 anti-Id antibody could be restored and could promote the proliferation of lymphocyte in a dose-dependent manner. Conclusion These results suggested that I50 anti-Id protein vaccine is likely an option in the therapy against nasopharyngeal carcinoma in vivo.

In vitro anti-tumor immune mechanism of nasopharyngeal carcinoma bispecific anti-idiotype antibody / 中南大学学报(医学版)

Objective To compare the in vitro antitumor immune responses induced by bivalent bispecific anti-idiotype antibody G22-I50 and monovalent anti-idiotype antibody G22 and I50, and explore its possible mechanism. Methods Proteins G22-I50, G22, and I50 were induced and identified by Western blot and ELISA. Peripheral blood monoclear cells (PBMC) were isolated and stimulated with G22-I50, G22, and I50 anti-idiotype antibodies, respectively. MTT assay and LDH release test were employed to examine the proliferation and cytotoxicity of the PBMC. The levels of IFN-γ, IL-2, and IL-4 in the supernatant were detected by ELISA and changes of T lymphocyte subsets were determined by flow cytometry. Results Western blot showed that G22-I50, G22, and I50 had specific binding capabilities to FC2 (Ab1). The activities of G22-I50, G22, and I50 had recovered and these proteins could be used in the in vitro study. The proliferation and cytotoxicity of the PBMC stimulated with G22-I50 were significantly higher than those stimulated with G22 or I50, The level of IFN-γ and IL-2 in the culture supernatant of the PBMC stimulated with G22-I50 was higher than that in the G22 or I50 group, but the level of IL-4 did not increase.Compared with the G22 or I50 group, the proportion of CD4+ and CD8+ T cells and CD4+/CD8+ ratio significantly increased, and the proportion of CD4+CD25+ T cells significantly decreased in the PBMC stimulated with G22-I50. Conclusion G22-I50 has more potent immunogenicity and would enhance specific antitumor effect which might relate to improving PBMC proliferation, inducing the secretion of Th1 type cytokines, activating CD8+T cells, and suppressing the expression of CD4+CD25+ T cells.

Effect of Anti - idiotype Antibody on Anti - DNA Antibody Production by Hybridoma Cells / 대한면역학회지

Anti-idiotype antibody (anti-id Ab) which recognizes idiotope in the variable region of immunoglobulin (Ig) can regulate Ab production by B cells in vivo and in vitro. Although it has been reported that anti-id Ab can suppress IgM production by lymphocytes or hybridoma cells without suppression of cell proliferation, the regulatory mechanism of anti-id Ab is not completely understood. We studied the effects of anti-id Ab on the production of IgG class anti-DNA Ab by hybridoma cells, on the proliferation of cells, and on the transcription levels of Ig genes. In contrast to suppressive effect of anti-id Ab on the production of IgM previously reported by others, stimulatory effects of anti-id Ab on the production of IgG by hybridoma cells as well as the proliferation of these .cells were observed. However, little effect of anti-id Ab on the transcription levels of Ig genes was observed. These results suggest that anti-id Ab can increase Ab production by stimulation of cell proliferation. Furthermore, these results suggest that the effect of anti-id Ab on the production of Ab may be determined by the difference in class of Ab produced by hybridoma cells following the treatment with anti-id Ab.

Production and Identification of Rat-Rat Monoclonal Anti-idiotypic Antibody against Anti-HBs / 中国免疫学杂志

Two hybridomas (TD_1, TD_2)secreting monoclonal anti-idiotypic antibodies (anti-ld) againstanti-HBs were established by fusing the myeloma cells, IR983F, with the spleen cells of LOU/Crat which had been immunized with mouse monoclonal anti-HBs to the a determinates and syn-genic rat polyclonal anti-HBs. TD_2(Ab_2)showed the ability to inhibit the binding of horse anti-HBs with HBsAg and was also neutralized by anti-HBs from various origins. Ab_2 can induce an-ti-anti-ld (Ab_3)when injected it into LOU/C rats introperitoneally. Ab_3 can react specifically withHBsAg. These data indicate that TD_2 monoclonal anti-ld against anti-HBs are the anti-ld bearingthe internal image of HBsAg epitope that could mimic HBsAg and possess the immunogenicity ofHBsAg.

Clinical significance the positive idiotype in patients with multiple myeloma / 中国免疫学杂志

This article reported a method of anti idiotype antibodies to idiotype in patientswith multiple myeloma.SmIg and CIg of peripheral blood lymphocytes of patientswith multiple myeloma were examined by using anti idiotype antibodies. The result revealed that(1)the anti idiotype antibody only reacted to M pro-tein and serum of the patient,but not to M proteinemia and normal Ig.(2)SmIg andCIg of some B cell reacted to the antiidiotype antibodies,it has been suggestedthatthe abnormal colon of multiple myeloma formed in B cell