Detection of HIV resistance due to gene polymorphismin chemokine receptors in healthy individuals

Human immunodeficiency virus (HIV) causes acquired immunodeficiency syndrome (AIDS). It was first described in 1980 as a disease and now has become a world-wide pandemic. It was first identified in Sub-Saharan Africa. Nowadays, it is known that some individuals have an innate immunity to HIV because of the gene polymorphism occurring congenitally in the chemokine receptors. Under normal conditions, two chemokine receptors promoting the entry of HIV-1 into the target cell after the initial binding of gp120 protein to CD4 on lymphocytes and monocytes were defined, and these co-receptors are called CCR5 and CXCR4. In this study, the correlation between the polymorphism of the relevant genes, which are thought to create inborn resistance to HIV, and innate immunity to HIV was investigated in order to contribute to enlighten the genetic basis in the formation of innate immunity to HIV.The study included 50 previously diagnosed HIV/AIDS positive individuals as the control group and 50 HIV/AIDS negative individuals as the study group on a volunteer basis and within the framework of ethics rules by giving particular importance to individual privacy after their individual written consents were obtained. Peripheral blood samples were taken from a total of 100 individuals included in the study and control groups in EDTA and gel tubes along with their detailed medical history in Yeditepe University, Medical Faculty Hospital by signing consent form. HIV/AIDS positivity and negativity of all individuals in the study were redemonstrated by studying the serum samples obtained from gel tubes on immunoassay system (Siemens, Germany) using the ELISA method. Serums were separated from the blood samples of the individuals in other gel tubes and DNA isolation was performed from this serum portion. Using the appropriate primers from the isolated DNA samples, the target region was amplified by Classical Polymerase Chain Reaction (PCR), and in the next stage, using the the restriction enzymes and carrying out the cutting protocol, our target region was cut on a thermal cycler (Techne, England) device with restriction enzymes, and then processed with the agarose gel electrophoresis method, and the bands obtained were compared on a gel imaging device (Biorad, USA).The DNA band images we obtained as a result of this study revealed that there was no mutation in CXCR4 and CCR5 chemokine receptors of 50 HIV negative individuals in our study group. In other words, 50 individuals participated in our study did not have resistance to HIV infection subjects in CXCR4 and CCR5 chemokine receptors as a result of innate mutation. The agarose gel electrophoresis performed after the restriction stage showed that the resulting DNA bands of all cases were 236bp for CCR5 and 190bp for CXCR4, that is, all individuals had a wild type DNA molecule and they did not have any gene polymorphism in CXCR4 and CCR5 chemokine receptors, and accordingly indicating that the individuals had no resistance to HIV virus. If the band size that we obtained on the agarose gel for CXCR4 chemokine receptor was about 173 bp, we would have detected the presence of a mutation in this case. Likewise, if the band size that we obtained on the agarose gel for the CCR5 chemokine receptor was about 201 bp, we would have also mentioned a mutation, gene polymorphism. A limited number of people are resistant to HIV infection, because these people have a mutation in CCR5 and CXCR4 chemokine receptors, which are co-receptors. People who have homozygous deletions in CCR5 gene are resistant to the infection despite encountering the virus many times. It has been found that some of the infected individuals who are heterozygous for this deletion do not reach the AIDS stage for a long time.