Anti-Calnexin (D577) Antibody (A25463)

Cells release exosomes into extracellular medium. Although the important roles of exosomes in many physiological and pathological processes are being revealed, the mechanism of exosome-cell interaction remains unclear. In this article, employing real-time fluorescence microscopy, the motion of exosomes on the plasma membrane or in the cytoplasm of recipient PC12 cells was observed directly. In addition, several motion modes of exosomes were revealed by single particle tracking (SPT). The changes between motion modes were also detected, presenting the dynamic courses of exosome attachment onto plasma membrane and exosome uptake. Octadecyl rhodamine B chloride (R18) was found to be useful to distinguish endocytosis from fusion during exosome uptake. Colocalization with organelle markers showed exosomes were sorted to acidic vesicles after internalization. The results provide new sight into the exosome-cell interaction mode and the intercellular trafficking of exosomes. This study will help to understand the roles of exosomes at cell level.

STAT6 plays a prominent role in adaptive immunity by transducing signals from extracellular cytokines. We now show that STAT6 is required for innate immune signaling in response to virus infection. Viruses or cytoplasmic nucleic acids trigger STING (also named MITA/ERIS) to recruit STAT6 to the endoplasmic reticulum, leading to STAT6 phosphorylation on Ser(407) by TBK1 and Tyr(641), independent of JAKs. Phosphorylated STAT6 then dimerizes and translocates to the nucleus to induce specific target genes responsible for immune cell homing. Virus-induced STAT6 activation is detected in all cell-types tested, in contrast to the cell-type specific role of STAT6 in cytokine signaling, and Stat6(-/-) mice are susceptible to virus infection. Thus, STAT6 mediates immune signaling in response to both cytokines at the plasma membrane, and virus infection at the endoplasmic reticulum.