According to the study, researchers identifying second gene mutation linking to HIV resistance. A rare genetic mutation that causes a form of muscular dystrophy affecting the limbs also protects against HIV infection. The newly-discovered mutation concerns the Transportin 3 gene (TNPO3) and is far more rare. It was identified several years ago among members of a family in Spain who were suffering from type 1F limb-girdle muscular dystrophy.
But HIV researchers were interesting in the same gene because it playing a role in transporting the virus inside cells. They then got in touch with geneticists in Madrid; who took blood samples from those family members and infecting the blood with HIV revealing a welcome surprise. The lymphocytes white blood cells that are an important part of the immune system; of people with the rare muscular illness were naturally resistant to HIV.
Gene mutation linking
HIV is among the most studied viruses, adding however that much remaining to be learning; such as why five percent of patients who are infecting do not develop AIDS. There are mechanisms of resistance to infection that are very poorly understanding. TNPO3 has been described as a key factor in the infection by the human immunodeficiency virus (HIV-1), the causative agent of AIDS.
Viral entry depends on fusion of viral and cellular membranes through successive interactions with CD4 receptor combined with CXC chemokine receptor type 4 (CXCR4) or CC chemokine receptor type 5 (CCR5). Once the core is releasing into the cytosol; the reverse transcriptase converts the viral RNA genome into a double-stranded copy DNA (cDNA) and the capsid (CA) uncoating process is initiating.
Heterozygous single nucleotide
But LGMD1F patients show a heterozygous single nucleotide deletion in the TNPO3 gene that generating a TNPO3 mut protein. Our results demonstrate that cells from patients with this mutation; in TNPO3 are resistant to HIV-1 infection in vitro. We are facing with an in vivo situation in which the genetic defect; that causes this rare disease confers resistance to HIV infection.
Therefore, TNPO3mutation represents a natural model to understand the pathogenesis of both diseases. But cells from LGMD1F patients can be using to understand the mechanisms of action of TNPO3 in HIV infection; and to design new therapeutic strategies for the treatment of both diseases. The use of HIV-1 as a methodological tool will permit a better understanding of the physiopathological mechanisms derived from the mutation; in TNPO3 that causes the muscle disease.