The gut mucosa is an important portal for HIV-1 transmission and infection. Therefore, a vaccine which can prevent virus transmission at mucosal surfaces would be an ideal HIV-1 vaccine candidate. Clostridium perfringens has been used as a vehicle to deliver SIV proteins in large quantity to the terminal ileum. A mucosal immunization strategy using C. perfringens should be able to induce potent mucosal immune responses against HIV-1. A recombinant C. perfringens expressing large amount of HIV-1 Gag protein (Cp-Gag) was constructed. Under in vitro conditions, Cp-Gag was found to induce bone marrow derived dendrite cell (BMDC) to mature and stimulate HIV-1 Gag specific T cell responses. Then in vivo experiments were performed in mice to demonstrate orally delivered Cp-Gag ability to prime gut mucosal T cell responses. Since oral tolerance is a major obstacle for orally delivered immunization approaches, a combination of mutated heat-labile enterotoxin of E. coli (mLT) and CpG containing oligodeoxynucleotides (CpG-ODN) were used as adjuvants for oral administration with Cp-Gag. Orally delivered Cp-Gag was tested for induction of HIV-1 Gag specific T cell responses in a prime-boost model with intranasal inoculation of HIV-1 virus like particles (VLP). HIV-1 specific cellular immune responses in both the effector (Lamina propria) and inductive sites (Peyers patches) of the gastrointestinal (GI) tract were significantly higher in mice immunized using Cp-Gag and VLPs in prime-boost approaches compared to mice immunized with either Cp-Gag or VLPs alone. Such cellular immune response was found to be mediated by both CD8+ and CD4+ T cells. These groups of mice also seemed to have HIV-1 specific multifunctional T cells in PPs and LP of the GI tract. In summary, mucosal immunization of mice with a Cp-Gag and VLPs in a prime-boost mode led to strong HIV-1 Gag specific cellular immune responses in both mucosal and systemic immune compartments. Such strong mucosal immune response could be very important to control HIV-1 infection at mucosal surfaces. The proposed vaccine strategy has great public health significance for developing a practical vaccine against HIV due to its safety, low production cost and easy administration.
| Identifer | oai:union.ndltd.org:PITT/oai:PITTETD:etd-06092009-125701 |
| Date | 28 September 2009 |
| Creators | Poonam, Poonam |
| Contributors | Dr. Russell D. Salter, Dr. Phalguni Gupta, Dr. Ted M. Ross, Todd A. Reinhart, |
| Publisher | University of Pittsburgh |
| Source Sets | University of Pittsburgh |
| Language | English |
| Detected Language | English |
| Type | text |
| Format | application/pdf |
| Source | http://etd.library.pitt.edu/ETD/available/etd-06092009-125701/ |
| Rights | unrestricted, I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to University of Pittsburgh or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
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