Background: Polyomavirus BK is one of the life-threatening infections in kidney transplant recipients. The activation of this virus can eventually lead to the loss of the graft. There are very few studies on the expression level of BK virus microRNAs. Therefore, in this study, we investigated the function of BK virus microRNAs and their effect on host cell microRNAs’ expression level. BK virus encodes two microRNAs, namely miR-B1-3p and miR-B1-5p. Therefore, it is crucial to study these microRNAs as markers of viral infection and their regulation. So far, there is no approved drug or vaccine to treat BK virus infection. Consequently, understanding the relationship between BK virus and host cell microRNAs is integral to the control of infection in kidney transplant patients.
Materials and Methods: In this study, ten tissue samples from kidney transplant recipients with symptoms of BK virus nephropathy, ten urine samples from kidney transplant patients without active BK virus infection, and 20 healthy individuals were included. The expression level of the studied microRNAs was measured in all the samples using SYBR Green Real-time PCR.
Results: The results showed that the expression level of the studied microRNAs, including miR-B1-3p, miR-B1-5p, miR-155, miR-520, miR-10b, miR-30a in the tissue samples of kidney transplant patients with BK virus nephropathy symptoms were significantly increased compared to kidney transplant patients without active BK virus infection.
Conclusion: The assessment of some microRNAs, such as miR-520, miR-30a, and miR-B1-3p/5p, may assist in the prediction and prevention of BKPyV activation in KTRs, particularly in urine samples.