SHIV Challenge in a Rhesus Macaque Model

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Journal of Vaccines & Vaccination recently published an article on the Simian/Human immunodeficiency virus (SHIV). The article is about the SHIV Virus-Like Particles (VLPs) Vaccination Induces Partial Protection from SHIV Challenge in a Rhesus Macaque Model which was submitted by the Dr. Qizhi Yao, who is working as a professor which deals the Molecular Virology & Microbiology, Pathology & Immunology in Baylor College of Medicine.

This research article explains SHIV virus-like particles (VLPs) and human CD40L are whole pseudovirion vaccines capable of eliciting both humoral and cellular immunity. They immunized four rhesus macaques by intranasal prime and four sub-cheek boosts with VLPs adjuvanted with conjugatable adjuvant lipid vesicles containing monophosphoryl lipid A (MPLA), and compared their immune parameters to those in five unimmunized control macaques. Increased plasma antibody titers to SIV Gag were observed in all four immunized macaques and increased sf162 gp140 titers were observed in three of the four with one macaque (10-195) maintaining sustained anti-Env antibody levels. Compared to controls, a significant increase in memory B cells and CD4+ central memory T cells was detected in the immunized group.

Among these, elevated Gagspecific CD107a membrane localization in the CD8+ central memory T cells was detected in one macaque (10-195). All nine macaques were subsequently challenged intrarectally with SHIVsf162.P3. After the challenge, eight of the nine macaques became infected with SHIV, while the macaque 10-195 was protected. Another immunized macaque (10-189) that got infected but consequently generated high Gag-specific IFN-γ and CD107a CD8+ T cells; and Env-specific IL-2 and CD107a CD8+ T cells controlled the virus and had undetectable levels of plasma SIV copy number by the termination of the study. Our VLPs vaccine strategy represents a promising immunogenic conformationally intact HIV vaccine that may lead to possible prevention and control of HIV infection.

In this study, we have demonstrated that vaccination with SHIV/HIV VLPs offers partial protection and efficient viral load control in a non-human primate SHIV challenge model. Four macaques were immunized with our novel route of administration of intranasal prime followed by three sub-cheek boosts with baculovirus expression system produced SIV Gag VLPs presenting sf162 gp120/gp41 and human CD40L on their surface, and a final boost of mammalian expression system produced HIV Gag VLPs presenting BaL gp120/gp41 on their surface also administered via the sub-cheek route. Of the four macaques, 10-195, which exhibited both cellular and humoral immune responses, was not infected after high-dose SHIVsf162.P3 virus challenge, and 6-189, in which we observed robust effector T cell function, had undetectable SIV copy number by the completion of the study. Although only 25% of the vaccine group was protected from virus challenge, an additional 25% of the vaccine group could effectively control viral load within the experimental time frame, a detailed dissection of each immune cell population’s phenotype and functional analysis in each of the individuals could offer valuable information for a future large cohort study.

For more information regarding the article information/queries kindly contact us. We cordially invite the authors to submit their manuscript for publication in our journal.

Thanks & Regards,
John Kimberly
Editorial Manager
Journal of Vaccines & Vaccination
Email: [email protected]