The microbicide cyanovirin-N expressed on the surface of commensal bacterium Streptococcus gordonii captures HIV-1

Barrientos,L.G.; Louis,J.M.; Botos,I.; Mori,T.; Han,Z.Z.; O'Keefe,B.R.; Boyd,M.R.; Gronenborn,A.M.: Structure 10: 673-686, 2002.

Abstract:

Objective: To explore the feasibility of expressing the potent HIV-inactivating protein, cyanovirin-N (CV-N), in the human commensal bacterium Streptococcus gordonii as a possible approach for local delivery of CV-N to prevent sexual transmission of HIV-1.
Design and methods:
To express CV-N in S. gordonii, we used the host-vector system we had previously developed. CV-N was expressed as a fusion protein both attached to the bacterial surface and secreted in soluble form in the supernatant of liquid cultures. The soluble form of recombinant CV-N was tested for gp120-binding activity in an ELISA experiment, whereas S. gordonii strain expressing CV-N on the surface was analyzed in an in vitro HIV capturing assay. Results: Two recombinant S. gordonii strains secreting or displaying CV-N on the bacterial surface were constructed and the expression of CV-N was confirmed by immunoblot and cytofluorimetric analysis. The secreted form of recombinant CV-N exhibited a concentration-dependent binding to envelope glycoprotein gp120 of HIV-1, although with low affinity, whereas CV-N displayed on the bacterial surface was able to capture HIV virions efficiently.
Conclusion: We expressed the anti-HIV protein CV-N in S. gordonii in a biologically active form. This represents a first step in the development of a system to deliver and maintain an effective concentration of a microbicide in the vaginal mucosa.

Up to MTDP References

Up to MTDP Home Page