*3.3.2 tsRNA and inflammation*

Little research has been carried out on the involvement of tsRNA in the immune system; however, the expression of 5′tiRNA and tRF5 has been reported in mouse leukocytes and human monocytes respectively [69]. It is possible that tsRNAs play a regulatory role in the cellular response to inflammatory signals. In human chondrocytes, the pro-inflammatory cytokine IL-1β was shown to increase the expression of specific tRF-3s [70]. These fragments downregulated the cytokine signaling molecule JAK3 in an Ago-dependent manner. Furthermore, tsRNA may possess the ability to stimulate the immune response with reports demonstrating that tsRNA bind directly to Toll-like receptors on T-helper 1 and cytotoxic T cells [71].
