Functional characterization of the signaling pathways induced by ligation of the EMR2 receptor on neutrophils

• Main Authors: Zih Ying Chen, 陳姿穎
• Other Authors: H. H. Lin
• Format: Others
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/12026904245326710466

碩士 === 長庚大學 === 生物醫學研究所 === 97 === The EGF-TM7 receptors belong to a subfamily of adhesion-GPCRs that are predominantly expressed on myeloid leukocytes. We have recently shown that ligation of EMR2, one of the EGF-TM7 members, by 2A1 mAb primes numerous neutrophil functions, including cell adhesion, migration, release of reactive oxygen species and degranulation. However, the precise signaling mechanism mediated by EMR2 remains elusive. Herein, we examined the activation status and kinetics of signalling molecules well known in neutrophil activation. First, Our results show rapid increased phosphorylation of mitogen-activated protein kinases (MAPK), p38 and JNK in neutrophils upon EMR2 ligation. Second, neutrophils stimulated with 2A1 did not induce an increase of intracellular calcium concentration and the cAMP level. In addition, ligation of EMR2 by 2A1 was shown to reduce the LPS-mediated inhibitory effect on spontaneous neutrophils apoptosis. Taken together, our results suggested that the function of EMR2 receptor in neutrophils is likely signaled via MAPKs.