Construction and evaluation of three candidate vaccines expressing HIV-1 subtype-C mosaic Gag
Doctoral Thesis
2015
Permanent link to this Item
Authors
Journal Title
Link to Journal
Journal ISSN
Volume Title
Publisher
Publisher
University of Cape Town
Department
Faculty
License
Series
Abstract
Of the 35 million people living with HIV-1 globally, approximately 71.4% are in the resource-limited sub-Saharan Africa. The immense sequence diversity of HIV-1, even within subtypes, makes it challenging to develop effective vaccines that target a wide range of HIV subtypes. Mosaic immunogens have been computationally designed to specifically overcome this hurdle by maximizing the inclusion of common T cell epitopes. When compared to consensus immunogens, polyvalent mosaic immunogens of HIV-1 group M have shown increased breadth and depth of antigen-specific T-cell responses. More than 90% of HIV positive individuals in sub-Saharan Africa are infected with HIV-1 subtype C (HIV-1C). We therefore designed, constructed, and evaluated candidate vaccines expressing HIV-1C mosaic Gag (GagM) in a proof of concept study. Gag was chosen as the most appropriate target for a T cell-based vaccine as there are many studies correlating control of HIV viral load with T cell responses to Gag. The immunogen was designed by Fischer et al., 2007 (1). Three different vaccine platforms were chosen based on their different strengths to be used in prime-boost regimens to determine the immunogenicity of HIV-1C GagM in mice. The first was a pantothenic auxotroph of the tuberculosis vaccine Mycobacterium bovis Bacille Calmette Guérin (BCG). The second was a DNA vaccine vector with enhanced expression of transgenes due to a novel enhancer element from porcine circovirus type 1, which has been demonstrated to increase gene expression. The third vaccine vector selected was the well characterised poxvirus modified vaccinia Ankara (MVA).
Description
Includes bibliographical references
Keywords
Reference:
Jongwe, T. 2015. Construction and evaluation of three candidate vaccines expressing HIV-1 subtype-C mosaic Gag. University of Cape Town.