Tax-1 protein of Human T-cell Leukemia Virus type 1(HTLV-1) serves as a key transcriptional regulatory gene product and has a crucial role in transactivating genes of infected cells by employing their transcriptional factors. This modulation includes induction of genes which encode CC-chemokines and their receptors. In this study, a recombinant vector containing Tax-1 gene was made and tested for its ability to induce CCR5 (CC chemokine receptor 5) expression in K562 cell line.
In order to perform this research, two blood samples of HTLV-1 positive were obtained from Urmia blood transfusion center. After DNA extraction, a complete sequence of Tax-1 gene was amplified by specific primers. Recombinant vectors carrying Tax-1 gene were synthesized and transformed into Escherichia coli (E. coli). After bacteria transformation, bacteria containing recombinant plasmid were selected and purified. Then, the recombinant shuttle vectors, pCDNA3.1-TAX, were transfected into the cell culture (K562 cell line). Expression of CCR5 was measured after 72 hr by Syber Green Real-Time PCR method compared to control cell culture. Normalization was done with GAPDH as a standard gene.
Cloning of Tax-1 gene in the vector, pCDNA3.1 was confirmed by colony PCR, restriction digestion, and sequencing methods. Expression of Tax-1 and CCR5 genes were confirmed by real time PCR and also, expression of CCR5 gene showed an 8-fold increase in comparison to mock-treated controls (p<0.05).