Fucosylated clusterin present on human breast cancer modulates the function of DC-SIGN expressing macrophages

AMIGORENA, SEBASTIAN; MERLOTTI IPPÓLITO, ANTONELLA; GEFFNER, JORGE; LOPEZ MALIZZIA, ALVARO; SABATTE, J; CARREGAL, SOL

Congreso; Reunión Conjunta De Sociedades De Biociencias Lxv Reunión Anual De La Sociedad Argentina De Inmunología (SAI); 2017

SAI

Clusterin (CLU) is a ubiquitous glycoprotein up regulated in manytypes of cancer. We have previously described a novel fucosilatedclusterin glycoform, present in semen, able to bind to DC-SIGN, a Ctype lectin receptor present on dendritic cells (DCs) and macrophages.The interaction of fucosylated clusterin with dendritic cells promotesthe endocytosis of misfolded extracellular proteins and modulatesthe function of DCs favoring the acquisition of a tolerogenicprofile. Numerous studies have shown that glycosylation changesare associated with the development of cancer. The aim of this studywas to analyze properties of clusterin produced by breast cancer.We hypothesize that breast cancer clusterin might bear fucosylatedglycans and bind to DC-SIGN, inhibiting the immune response.The presence and properties of CLU were analyzed on humanluminal A breast cancer samples, and non-invaded breast tissuewas used as control. The concentration of total CLU didn´t showsignificant differences between tumor and ?healthy? tissues (n=21,p=0.3105). The presence of fucosylated clusterin was analyzed byan ELISA based assay, using the fucose binding lectin ulex europeaus.The amount of fucosylated clusterin was higher on tumorthan helthy-tissue (n=21 p=0.0071). Moreover, tumor-CLU wasshown to bind DC-SIGN when analyzed by western-blot while CLUfrom healthy tissue did not (n=5). We also demonstrate the presenceof DC-SIGN+ macrophages on tumor samples by either RNAseqand flow cytometry (n=9-5). Furthermore, we show that fucosylatedclusterin binds to monocyte derived macrophages and inhibits theupregulation of activation markers upon LPS stimulation (HLA-DRn=5 p