Revista de Imunobiologia

Synthesis and Characterization of Gold Nanoparticle Conjugated Recombinant Aprv2 of Dichelobactor nodosus and its Immunogenicity

Abstract

Subhash Verma, Geetanjali Singh , Mandeep Sharma , Pratiksha Srivastava , Richa Salwan and Chayan Nand

The present study involves the synthesis, characterization and immunogenicity of Gold Nanoparticle (GNP) conjugated recombinant AprV2 protein of Dichelobactor nodosus. To achieve this, GNPs of size 20 nm were prepared and characterized. The gold nanoparticles effectively adsorbed 3.3 μg of recombinant AprV2 protein over the surface. TEM studies revealed corona of AprV2 over GNPs (1-2 nm thick) in GNPs-AprV2 conjugate. Further, GNP-AprV2 conjugate revealed a red shift from 523 nm to 532 nm, indicating increased size of GNPs after conjugation with AprV2. To evaluate the immunogenic response, mice were allotted to 5 different groups. Mice in group I injected with GNP-AprV2 conjugate, group II with GNP-AprV2 with MPLA (Monophosphoryl lipid A), group III with AprV2 on its own, group IV with GNPs and group V with Phosphate Buffered Saline (PBS). The highest antibody responses against the AprV2 were recorded in pooled sera from mice of group II compared to group me and III on day 28. Among all groups, the group II mice vaccinated with GNP-AprV2/ MPLA exhibited the highest IgG levels. The third dose of vaccine formulations did not enhance antibody levels. This study is a first report studying the immunogenic effect of conjugation of GNPs with rAprV2 of D. nodosus.