Domain fusion TLR2-4 enhances the autophagy-dependent clearance of <i>Staphylococcus aureus</i> in the genetic engineering goat.

Abstract

<i>Staphylococcus aureus</i> infections pose a potential threat to livestock production and public health. A novel strategy is needed to control <i>S. aureus</i> infections due to its adaptive evolution to antibiotics. Autophagy plays a key role in degrading bacteria for innate immune cells. In order to promote <i>S. aureus</i> clearance via Toll-like receptor (TLR)-induced autophagy pathway, the domain fusion TLR2-4 with the extracellular domain of TLR2, specific recognizing <i>S. aureus</i>, and transmembrane and intracellular domains of TLR4 is assembled, then the goat expressing <i>TLR2-4</i> is generated. TLR2-4 substantially augments the removal of <i>S. aureus</i> within macrophages by elevating autophagy level. Phosphorylated JNK and ERK1/2 promote LC3-puncta in TLR2-4 macrophages during <i>S. aureus</i>-induced autophagy via MyD88 mediated the TAK1 signaling cascade. Meantime, the TRIF-dependent TBK1-TFEB-OPTN signaling is involved in TLR2-4-triggered autophagy after <i>S. aureus</i> challenge. Moreover, the transcript of <i>ATG5</i> and <i>ATG12</i> is significantly increased via cAMP-PKA-NF-κB signaling, which facilitates <i>S. aureus</i>-induced autophagy in TLR2-4 macrophages. Overall, the novel receptor TLR2-4 enhances the autophagy-dependent clearance of <i>S. aureus</i> in macrophages via TAK1/TBK1-JNK/ERK, TBK1-TFEB-OPTN, and cAMP-PKA-NF-κB-ATGs signaling pathways, which provide an alternative approach for resistant against <i>S. aureus</i> infection.