Limits...
Anti-idiotypic antibodies: a new approach in prion research.

Colja Venturini A, Bresjanac M, Vranac T, Koren S, Narat M, Popović M, Curin Serbec V - BMC Immunol. (2009)

Bottom Line: Our results demonstrate that it is possible to induce a strong anti-idiotypic immune response against the V5B2 monoclonal antibody in both xenogeneic and syngeneic experimental systems.From the competition seen between polyclonal and monoclonal anti-idiotypic antibodies and the original immunogen, the P1 peptide, and even more importantly, the ultimate target antigen, PrPSc, we conclude that selected antibodies bind to the antigen-combining site of the V5B2 monoclonal antibody and might even resemble the PrPSc-specific epitope.The results of the present study not only provide an example of the successful production of Ab2 monoclonal antibodies based on a well planned strategy for selection, but should also provide a new experimental approach that is applicable to the field of prion diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia. anja.venturini@ztm.si

ABSTRACT

Background: In certain cases, anti-idiotypic antibodies that recognize an antigen-combining site of an antibody can mimic the structure and/or function of certain nominal antigens. This feature makes them particularly useful if conventional experimental approaches fail to fulfil expectations, especially when the molecule of interest is infectious, toxic or difficult to isolate and purify. We suggest the application of an anti-idiotype concept to the field of prion biology, with the aim of evoking a humoral immune response against the pathological isoform of the prion protein (PrPSc). Different ways to induce anti-idiotypic responses were studied in mice and chickens using various forms of V5B2, a PrPSc-specific monoclonal antibody we have described previously.

Results: The preparation of anti-idiotypic monoclonal antibodies was achieved with well-defined strategies of immunization, selection and subsequent characterization. Our results demonstrate that it is possible to induce a strong anti-idiotypic immune response against the V5B2 monoclonal antibody in both xenogeneic and syngeneic experimental systems. From the competition seen between polyclonal and monoclonal anti-idiotypic antibodies and the original immunogen, the P1 peptide, and even more importantly, the ultimate target antigen, PrPSc, we conclude that selected antibodies bind to the antigen-combining site of the V5B2 monoclonal antibody and might even resemble the PrPSc-specific epitope. The involvement of both antigen-combining sites in the interaction between V5B2 and the most promising monoclonal anti-idiotypic antibody was further supported by molecular docking.

Conclusion: The results of the present study not only provide an example of the successful production of Ab2 monoclonal antibodies based on a well planned strategy for selection, but should also provide a new experimental approach that is applicable to the field of prion diseases.

Show MeSH

Related in: MedlinePlus

Competitive immunohistochemical studies. (A) Representative photomicrographs of immunohistochemically stained sCJD cerebellar cortex sections in the absence and presence of different competitor molecules. The brown precipitate in the Purkinje cells layer and internal granular cell layer indicates specific prion immunoreactivity to a variable degree in all of the images except the negative control. Only photomicrographs of sections stained with the use of following concentrations of competitor molecules are shown: 100 μg/ml for isotype control, 5D12 and 4F8, and 10 μg/ml for Ch5, P1 and Pscr. (B) Bar chart showing the effects of different competitor molecules at varying concentrations on the mean immunohistochemical signal intensity, expressed as percentages of the uncompeted V5B2-HRP immunoreactive signal intensity (positive control). Asterisks indicate statistically significant (p < 0.004) reductions in the mean signals. Competitor molecule concentrations are given in μg/ml in brackets.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC2666643&req=5

Figure 4: Competitive immunohistochemical studies. (A) Representative photomicrographs of immunohistochemically stained sCJD cerebellar cortex sections in the absence and presence of different competitor molecules. The brown precipitate in the Purkinje cells layer and internal granular cell layer indicates specific prion immunoreactivity to a variable degree in all of the images except the negative control. Only photomicrographs of sections stained with the use of following concentrations of competitor molecules are shown: 100 μg/ml for isotype control, 5D12 and 4F8, and 10 μg/ml for Ch5, P1 and Pscr. (B) Bar chart showing the effects of different competitor molecules at varying concentrations on the mean immunohistochemical signal intensity, expressed as percentages of the uncompeted V5B2-HRP immunoreactive signal intensity (positive control). Asterisks indicate statistically significant (p < 0.004) reductions in the mean signals. Competitor molecule concentrations are given in μg/ml in brackets.

Mentions: Since the P1 peptide is only a mimic of the PrPSc-specific epitope on the PrPSc molecule, and since the final target is the PrPSc molecule itself, we wanted to determine whether Ab2 antibodies can inhibit the binding of V5B2 to PrPSc directly in immunohistochemistry of brain slices of a sCJD affected individual. Fig 4 shows the results of immunohistochemical staining in the presence of different competitor molecules through representative photomicrographs of labelled tissue sections (Fig. 4A) and in a graphical form (Fig. 4B).


Anti-idiotypic antibodies: a new approach in prion research.

Colja Venturini A, Bresjanac M, Vranac T, Koren S, Narat M, Popović M, Curin Serbec V - BMC Immunol. (2009)

Competitive immunohistochemical studies. (A) Representative photomicrographs of immunohistochemically stained sCJD cerebellar cortex sections in the absence and presence of different competitor molecules. The brown precipitate in the Purkinje cells layer and internal granular cell layer indicates specific prion immunoreactivity to a variable degree in all of the images except the negative control. Only photomicrographs of sections stained with the use of following concentrations of competitor molecules are shown: 100 μg/ml for isotype control, 5D12 and 4F8, and 10 μg/ml for Ch5, P1 and Pscr. (B) Bar chart showing the effects of different competitor molecules at varying concentrations on the mean immunohistochemical signal intensity, expressed as percentages of the uncompeted V5B2-HRP immunoreactive signal intensity (positive control). Asterisks indicate statistically significant (p < 0.004) reductions in the mean signals. Competitor molecule concentrations are given in μg/ml in brackets.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2666643&req=5

Figure 4: Competitive immunohistochemical studies. (A) Representative photomicrographs of immunohistochemically stained sCJD cerebellar cortex sections in the absence and presence of different competitor molecules. The brown precipitate in the Purkinje cells layer and internal granular cell layer indicates specific prion immunoreactivity to a variable degree in all of the images except the negative control. Only photomicrographs of sections stained with the use of following concentrations of competitor molecules are shown: 100 μg/ml for isotype control, 5D12 and 4F8, and 10 μg/ml for Ch5, P1 and Pscr. (B) Bar chart showing the effects of different competitor molecules at varying concentrations on the mean immunohistochemical signal intensity, expressed as percentages of the uncompeted V5B2-HRP immunoreactive signal intensity (positive control). Asterisks indicate statistically significant (p < 0.004) reductions in the mean signals. Competitor molecule concentrations are given in μg/ml in brackets.
Mentions: Since the P1 peptide is only a mimic of the PrPSc-specific epitope on the PrPSc molecule, and since the final target is the PrPSc molecule itself, we wanted to determine whether Ab2 antibodies can inhibit the binding of V5B2 to PrPSc directly in immunohistochemistry of brain slices of a sCJD affected individual. Fig 4 shows the results of immunohistochemical staining in the presence of different competitor molecules through representative photomicrographs of labelled tissue sections (Fig. 4A) and in a graphical form (Fig. 4B).

Bottom Line: Our results demonstrate that it is possible to induce a strong anti-idiotypic immune response against the V5B2 monoclonal antibody in both xenogeneic and syngeneic experimental systems.From the competition seen between polyclonal and monoclonal anti-idiotypic antibodies and the original immunogen, the P1 peptide, and even more importantly, the ultimate target antigen, PrPSc, we conclude that selected antibodies bind to the antigen-combining site of the V5B2 monoclonal antibody and might even resemble the PrPSc-specific epitope.The results of the present study not only provide an example of the successful production of Ab2 monoclonal antibodies based on a well planned strategy for selection, but should also provide a new experimental approach that is applicable to the field of prion diseases.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department for Production of Diagnostic Reagents and Research, Blood Transfusion Centre of Slovenia, Ljubljana, Slovenia. anja.venturini@ztm.si

ABSTRACT

Background: In certain cases, anti-idiotypic antibodies that recognize an antigen-combining site of an antibody can mimic the structure and/or function of certain nominal antigens. This feature makes them particularly useful if conventional experimental approaches fail to fulfil expectations, especially when the molecule of interest is infectious, toxic or difficult to isolate and purify. We suggest the application of an anti-idiotype concept to the field of prion biology, with the aim of evoking a humoral immune response against the pathological isoform of the prion protein (PrPSc). Different ways to induce anti-idiotypic responses were studied in mice and chickens using various forms of V5B2, a PrPSc-specific monoclonal antibody we have described previously.

Results: The preparation of anti-idiotypic monoclonal antibodies was achieved with well-defined strategies of immunization, selection and subsequent characterization. Our results demonstrate that it is possible to induce a strong anti-idiotypic immune response against the V5B2 monoclonal antibody in both xenogeneic and syngeneic experimental systems. From the competition seen between polyclonal and monoclonal anti-idiotypic antibodies and the original immunogen, the P1 peptide, and even more importantly, the ultimate target antigen, PrPSc, we conclude that selected antibodies bind to the antigen-combining site of the V5B2 monoclonal antibody and might even resemble the PrPSc-specific epitope. The involvement of both antigen-combining sites in the interaction between V5B2 and the most promising monoclonal anti-idiotypic antibody was further supported by molecular docking.

Conclusion: The results of the present study not only provide an example of the successful production of Ab2 monoclonal antibodies based on a well planned strategy for selection, but should also provide a new experimental approach that is applicable to the field of prion diseases.

Show MeSH
Related in: MedlinePlus