Researchers in India studied the HIV-1 subtype C tat gene found in their country. They found it was most similar to other subtype C tat genes. They created a consensus sequence from Indian samples and optimized it for use in a vaccine. Mice immunized with the tat DNA vaccine alone developed cross-clade immune responses. Those given both DNA and MVA vaccines saw their immune responses increase 3-fold. Key immunogenic regions on the Indian subtype C Tat protein were identified as amino acids 1-20, 16-35, 31-50, and 67-86, with the 31-50 region found to be most immunodominant. The study suggests the Indian subtype C tat gene is a good candidate for inclusion

1. BioMed Central
Page 1 of 1
(page number not for citation purposes)
Retrovirology
Open AccessPoster presentation
Homology of HIV-1 Indian subtype C tat gene with other subtypes
correlates with the induction of potent cross clade immune
responses following immunization with HIV-1 Indian subtype C
mutated and codon optimized tat DNA/MVA vaccine in mice
Huma Qureshi*, VVSP Prasad, Bimal K Das and Pradeep Seth
Address: Department of Microbiology, All India Institute of Medical Sciences, New Delhi, India
* Corresponding author
Presence of anti-Tat immune responses in HIV infected
individual's correlates inversely with the progression of
disease. Thus, we focused on the phylogeny & immuno-
genicity of Indian subtype C tat gene. In this study full
length HIV-1 tat gene was amplified and sequenced. Based
on sequencing data HIV-1 Indian subtype Ctat gene con-
sensus sequence was derived, mutated & codon opti-
mized. This modified tat gene consensus was used to
construct tat DNA/MVA vaccine. Immunogenicity of tat
DNA/MVA vaccine was studied in mice and immune
responses were evaluated by IFNg ELISpot assay and
ELISA. Our tat study sequences depicted maximum hom-
ology with HIV-1 subtype C. DNA distances of tat study
sequences with consensus sequences of subtype M, C,
B&A were 8–10%, 4–6%, 19–21% & 11–18% respec-
tively. Mice immunized with tat DNA construct alone
developed potent cross clade T cell & antibodyresponses.
Magnitude of these immune responses was increased 3
folds in mice immunized with tat DNA/MVA prime boost
regimen. Immunogenic regions of Indian subtype CTat
protein localize at amino acid (aa)1–20, aa 16–35, aa 31–
50, aa 67–86. Core region(aa 31–50) of Indian subtype
CTat protein was found to be immunodominant. In this
scenario HIV-1 Indiansubtype Ctat gene appears to be a
suitable candidate for future multigene HIV vaccine.
from 2006 International Meeting of The Institute of Human Virology
Baltimore, USA. 17–21 November, 2006
Published: 21 December 2006
Retrovirology 2006, 3(Suppl 1):P51 doi:10.1186/1742-4690-3-S1-P51
<supplement> <title> <p>2006 International Meeting of The Institute of Human Virology</p> </title> <note>Meeting abstracts. A single PDF containing all abstracts in this Supplement is available <a href=" http://www.biomedcentral.com/content/files/pdf/1742-4690-3-S1-full.pdf ">here</a></note> <url>http://www.biomedcentral.com/content/pdf/1742-4690-3-S1-info.pdf</url></supplement>
© 2006 Qureshi et al; licensee BioMed Central Ltd.