ABSTRACT
Tuberculosis (TB) is still an infectious disease that greatly threatens human health, and is always refractory to the current therapeutic modalities. Accumulated evidence revealed that microRNAs (miRNAs) are closely with various pathologies, such as TB. The possibilities of miRNAs as diagnostic biomarkers and therapeutic targets have been proved. However, it is still unknown if miRNA is implicated in the TB-associated immunity. This study revealed that miR-155, which has been shown to suppress the activation of natural killer (NK) cells associated with tumors, was downregulated in serum samples of TB patients (n=90), compared with healthy controls (n=31). Cytotoxicity assays indicated that NK cells, which have been demonstrated to promote TB progression, exhibited lower cytotoxicity in high serum miR-155 TB patients (n=37). There is an inverse relationship between serum miR-155 abundance and NK cell cytotoxicity (R=-0.659, P=0.000). Further studies demonstrated that miR-155 level is inversely associated with the concentration of TNFα secreted by NK cells from TB patients (n=37, R=-0.694, P=0.000). Collectively, serum miR-155 level was shown to be negatively associated with the TB-suppressing activity of NK cells, and this miRNA can be used as a potential therapeutic agent for TB treatment.
ABSTRACT
As a major health threat, tuberculosis (TB) is resistant against the current therapeutic strategies. Increasing evidence indicates that miRNAs are implicated in various disorders by affecting specific target genes. Recently, the association of miRNAs with TB has also been established by several studies, and their potentials in the prognosis and treatment of TB have also been verified. miR-183 is shown to promote the activation of macrophage through NF-κB pathway. However, it is still unclear if serum miR-183 can be used to assess the activity of TB-associated macrophage. This study was aimed to address this issue. We employed qPCR assay to detect the expression level of miR-183 in blood from TB patients and healthy individuals. miR-183 abundance was found to be increased in serum samples from TB patients, compared with healthy controls. Further analysis revealed that miR-183 level is positively associated with the activity of macrophages from TB patients, evidenced by their increased phagocytosis rates and enzyme activity in high serum miR-183 group. In conclusions, high level of serum miR-183 is associated with the activity of macrophage originating from TB patients.
