Inside-out integrin signaling in macrophages. Analysis of the role of the alpha 6A beta 1 and alpha 6B beta 1 integrin variants in laminin adhesion by cDNA expression in an alpha 6 integrin-deficient macrophage cell line.

摘要: Leukocytes use the alpha 6 beta 1 integrin to adhere laminin based on mAb inhibition and affinity chromatography studies. This adhesion requires leukocyte stimulation with either PMA or specific cytokines, a process that has been termed "inside-out" signaling. In present study, involvement of structural variants in this regulated was examined using mouse macrophages. The two known variants, 6A 6B, differ only their cytoplasmic domain sequences. Using reverse transcriptase-polymerase chain reaction, we observed macrophages express variant, contrast most cell types which both 6B variants. role subunit macrophage assessed by cDNA transfection P388D1 cells. We found line does not even response phorbol 12-myristate 13-acetate (PMA) stimulation, though it normally fibronectin tissue culture plastic. Subsequent analysis employing reaction immunoprecipitation surface labeled cells revealed expresses neither nor subunits. Stable chick human cDNAs into resulted chimeric expression. transfectants exhibited inside-out signaling because markedly increased ability but did increase Similar results were obtained after cDNA. Analysis facilitated generation monoclonal antibody, 2B7, is for subunit. These observations demonstrate can be pathways macrophages, type 1. data presented also clearly domains do PMA.