Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad-500007.
Abstracts of the papers presented at the 16th Annual Convention and International Symposium of Indian Virological Society on “Management of Vector-Borne Viruses” at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru-502324, Hyderabad, India, February 7–10, 2006.
In spite of inherited self-adoptability and survival tactics tribal islanders of Andaman and Nicobar (Onges, Great Andamanese, and Nicobarese) have become ‘the vanishing tribes’ today. Various causes have been suggested for this unfortunate event. Recent reports suggest that human immunodeficiency virus (HIV) makes its way in the island of Andaman and Nicobar and possible threat of intrusion of this virus through illegal sex between tribal women and new settlers in exchange of food, tobacco and alcohol alarms us devastating effect of possible entrance of HIV in these tribes which will lead to increased mortality and their eventual disappearance. As natural genetic makeup is one of the means of protection of any community against acquired immunodeficiency syndrome (AIDS), in this context we have studied various genes viz. CCR5, m303, CCR2, SDF1 and IL-10 in individuals of these tribes, responsible for susceptibility against HIV infection. We have found that CCR5D32, and m303 mutation (in ExU2 region) of CCR5 gene were absent in these tribal populations, which introduces premature stop codon and prevent the expression of a functional coreceptor and hence entry of virus. We have also found mutation in CCR2 gene, named CCR2-V64I which substitute valine by isoleucine in transmembrane domain of CCR2 and delays onset of AIDS two to three years. The SDF1-3’A mutation, residing at the 3’ UTR in the stromal cell derived factor-1 gene was also present, which delays AIDS progression when present as recessive homozygous genotype.
The individuals were also carrying single polymorphic variant in IL10 promoter region known as IL10-5’ – 592A, making them at risk of rapid progression of AIDS. Collectively our study exhibit that wrong structure of chemokine and their receptor genes in population of Andaman and Nicobar tribes makes them vulnerable towards HIV-1 infection, which has emerged as one of the biggest modern day challenge and may act as last nail to coffin of these vanishing tribal populations of Andaman and Nicobar.
