A novel role for ?2-microglobulin: a precursor of antibacterial chemokine in respiratory epithelial cells.

ABSTRACT: We analyzed a panel of cationic molecules secreted in the culture medium of human respiratory epithelial cells (REC) upon activation by IL-1? and different pathogen-associated molecular patterns. A 9?kDa fragment derived from ?2-microglobulin (B2M) was identified and named shed 9?kDa B2M (sB2M-9). The primary structure of sB2M-9 was revealed to increase its pI value that potentially could play an important role in innate defense. sB2M-9 exhibits antibacterial activity against Gram positive Staphylococcus aureus (SA) but not against Gram negative Klebsiella pneumonia (KP). Upon its binding to SA, sB2M-9 induces clumps, a phenomenon not observed with B2M. Migration of THP-1 monocytes exposed to SA clumps was significantly greater than that to SA without clumps. sB2M-9 binds to SA, more likely as a chemokine, to facilitate THP-1 migration. As a whole, we demonstrated that REC release a novel chemokine with antibacterial activity that is shed from B2M to facilitate THP-1 migration.

SUBMITTER: Chiou SJ 

PROVIDER: S-EPMC4977529 | biostudies-literature | 2016 Aug

REPOSITORIES: biostudies-literature