Back to Journals » International Journal of Nanomedicine » Volume 9 » Issue 1

Enhancement of immunogenicity and efficacy of a plasmid DNA rabies vaccine by nanoformulation with a fourth-generation amine-terminated poly(ether imine) dendrimer

Authors Ullas PT, Madhusudana SN, Desai A, Sagar BKC, Jayamurugan G, Rajesh Y, Jayaraman N

Received 22 August 2013

Accepted for publication 11 September 2013

Published 28 January 2014 Volume 2014:9(1) Pages 627—634


Checked for plagiarism Yes

Review by Single-blind

Peer reviewer comments 4

Padinjaremattathil Thankappan Ullas,1 Shampur Narayan Madhusudana,2 Anita Desai,2 Bhadravathi Kenchappa Chandrasekhar Sagar,3 Govindasamy Jayamurugan,4 Yamajala Bhaskara Rama Durga Rajesh,4 Narayanaswami Jayaraman4

1School of Chemical and Biotechnology, Shanmugha Arts, Science, Technology and Research Academy (SASTRA) University, Thanjavur, India; 2Department of Neurovirology, 3Department of Neuropathology, National Institute of Mental Health and Neurosciences, Bangalore, India; 4Department of Organic Chemistry, Indian Institute of Science, Bangalore, India

Purpose: Delayed onset of, and low magnitude of, protective immune responses are major drawbacks limiting the practical utility of plasmid vaccination against rabies. In this study we evaluated whether nanoformulation with the novel poly(ether imine) (PETIM) dendrimer can enhance the immunogenicity and efficacy of a plasmid-based rabies vaccine.
Materials and methods: A plasmid vaccine construct (pIRES-Rgp) was prepared by cloning the full-length rabies virus glycoprotein gene into pIRES vector. Drawing upon the results of our previous study, a dendriplex (dendrimer-DNA complex) of pIRES-Rgp was made with PETIM dendrimer (10:1 w/w, PETIM:pIRES-Rgp). In vitro transfection was done on baby hamster kidney (BHK)-21 cells to evaluate expression of glycoprotein gene from pIRES-Rgp and PETIM-pIRES-Rgp. Subsequently, groups of Swiss albino mice were immunized intramuscularly with pIRES-Rgp or PETIM-pIRES-Rgp. A commercially available cell culture rabies vaccine was included for comparison. Rabies virus neutralizing antibody (RVNA) titers in the immune sera were evaluated on days 14, 28, and 90 by rapid fluorescent focus inhibition test. Finally, an intracerebral challenge study using a challenge virus standard strain of rabies virus was done to evaluate the protective efficacy of the formulations.
Results: Protective levels of RVNA titer (≥0.5 IU/mL) were observed by day 14 in animals immunized with pIRES-Rgp and its dendriplex. Notably, PETIM-pIRES-Rgp produced 4.5-fold higher RVNA titers compared to pIRES-Rgp at this time point. All mice immunized with the PETIM-pIRES-Rgp survived the intracerebral rabies virus challenge, compared with 60% in the group which received pIRES-Rgp.
Conclusion: Our results suggest that nanoformulation with PETIM dendrimer can produce an earlier onset of a high-titered protective antibody response to a plasmid-based rabies vaccine. PETIM dendriplexing appears to be an efficacious nonviral delivery strategy to enhance genetic vaccination.

Keywords: nonviral gene delivery, rabies prophylaxis

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]