AOL-Conjugated Colloid Gold Immunochromatographic Strip For The Rapid Detection Of Core Fucosylation On IgG In The Serum Of SLE Patients

Core fucosylation catalyzed by ?1,6-fucosyltransferase(Fut8)is closely related to the pathogenesis of systemic lupus erythematosus(SLE).Detection of anti-nuclear antibodies(ANAs)is fundamental for the diagnosis of SLE.In the present study,we found that the core fucosylation level of Immunoglobulin G(Ig G)is markedly up-regulated in the sera of SLE patients detected by Aspergillus oryzae lectin(AOL)blot.In sandwich Dot enzyme-linked immunosorbent assay(Dot ELISA),the core fucosylation level was also found significantly increased in the sera of SLE patients with a higher ANA titer.In order to establish a laboratory assay which is rapid and convenient to diagnose SLE,we prokaryotically expressed the gene of AOL and C3 domain repeated protein G(Sp G3)and generate an AOL-conjugated colloid gold Immunochromatographic strips(ICS).The detection limit of core fucosylated Ig G was 10 ?g/ml for AOL-conjugated colloid gold ICS.As well as indirect immunofluorescence,the AOL-conjugated colloid gold ICS showed the reliable results in the sera of 39 SLE patients.Our results indicated that the AOL-conjugated colloid gold ICS can serve as a reliable rapid diagnostic test for suspected cases of SLE.Objective:In order to establish a novel method for the diagnosis SLE,which based on the core fucosylated modification,we studied the change of core fucosylation on Ig G between the serum of healthy people and the patients diagnosed SLE,which provides a reliable experimental basis for the diagnosis of SLE in clinic.Methods:(1)We detected the core fucosylation level of Ig G in SLE sera using Lectin Blot(LB)and Dot ELISA.(2)We redesigned the gene of Sp G3,which has a high affinity to bind Ig G and established the p ET21a-Sp G3 expression system.(3)We redesigned Fle A,and prokaryotic expression of AOL which has the specific binding capability to core fucose.(4)Based on the core fucosylated modification,we established the AOL-conjugated colloid gold immunochromatographic strip for the rapid detection of core fucosylation on Ig G in the serum of SLE patients.Results:(1)The level of core fucosylation was significantly increased in SLE serum and the core fucosylation level was also found significantly increased in the sera from SLE patients with a higher ANA titer.(2)Construct the p ET28a-Fle A expression system and successfully expressed AOL.(3)Construct the p ET21a-Sp G3 expression system and successfully expressed Sp G3.(4)Establishment of AOL-conjugated colloidal gold Dot-ELISA.(5)We established the AOL-conjugated colloid gold Immunochromatographic strips(ICS)and found the AOL-conjugated colloidal gold ICS for SLE sera showed positive results,but the group of the healthy control showed negative results.Conclusion:A key finding of our study is that the core fucosylated serum Ig G could serve as a useful biomarker for SLE detection in clinical practice.In the present study,both AOL and Sp G3 were prokaryotically expressed.Since the N-glycosylation pathways were lacked in bacteria,the sole glycosylation was Ig Gs from the sera.Therefore,the AOL-conjugated colloidal gold ICS showed the high specificity and sensitivity.Our data pave the way for the future development of an adequate screening test in epidemiologic surveillance for suspected SLE.