cloning, expression and characterization of recombinant human fc receptor like 1, 2 and 4 molecules

background: the fc receptor like (fcrl) molecules belong to the immunoglobulin (ig) superfamily with potentially immunoregulatoryfunction. among the fcrl family fcrl2 and 4 are predominantly expressed on memory b cells and fcrl1 is a pan- b cell marker. to date, noligand has been identifid for the human fcrl1, 2 and 4 molecules.objectives: cloning, expression, purifiation and structural analysis of the extracellular domain of human fcrl1, 2 and 4 proteins.materials and methods: in this study, the extracellular part of human fcrl1, 2 and 4 were subcloned into prokaryotic expression vectorspet-28b (+) and transformed into bl21-de3 e.coli strain. protein expression was optimized by fie adjustments such as induction time,incubation temperature and expression hosts. recombinant fcrl proteins were purifid by metal affity chromatography using ni-ntaresin. purifid fcrl proteins were further characterized by sds-page and immunoblotting using his-tag and fcrl specifi polyclonalantibodies.results: our results demonstrated that fcrl1, 2 and 4 were successfully expressed in pet-28b (+) vector. optimization of the expressionprocedure showed that iptg induction at od600 = 0.9 and overnight incubation at 37˚c resulted in the highest expression levels of fcrlproteins ranging from approximately 15% (fcrl1) to 25% (fcrl2 and 4) of the total bacterial lysate proteins.conclusions: these purifid recombinant proteins are potentially a valuable tool for investigating the immunoregulatory function offcrl molecules and the production of specifi mabs for immunotherapeutic interventions.