ESPN 51th Annual Meeting

ESPN 2018


 
Exosomes from idiopathic nephrotic syndrome patients exacerbates immune dysregulation
Fehime K. Eroglu 1 Muzaffer Yıldırım 1 Gökberk Kaya 1 Tulin Gungor 2 Gokce Gur Can 2 Evrim K. Cakici 2 Fatma Yazilitas 2 Mehmet Bulbul 2 Ihsan Gursel 1

1- Bilkent University, Department of Molecular Biology and Genetics, Ankara, Turkey
2- Dr Sami Ulus Maternity and Children Hospital, Department of Pediatric Nephrology , Ankara, Turkey
 
Introduction:

Exosomes are nanovesicles released by virtually all known cell types under healthy and pathological conditions. They play critical roles in intercellular communication and facilitate immune modulation. Pathogenesis of idiopathic nephrotic syndrome (INS) is still unclear; one or more circulating factors or immune mediators affecting glomerular filtration barrier permeability were suspected. In this study, we examined immunological properties of plasma-derived exosomes and aimed to characterize their effects on peripheral mononuclear cells (PBMC) in childhood INS.

Material and methods:

Exosomes were isolated from platelet depleted plasma using Exosome Isolation Kit. PBMC of 16 patients (11 MCD and 5 FSGS) on relapse (taking no or low dose steroids) and 8 healthy controls (HC) were isolated by density gradient separation and characterized by flow cytometry. Patient and healthy PBMCs were stimulated with 50 ug/ml patients’ own (isogenic) and healthy exosomes and IL10, IL17, IFNγ, IL4 levels were measured from supernatant by ELISA. 

Results:

 There was no significant difference of Th1, Th2, Th17 and Treg percentages between patients and controls. % of CD14+ mononuclear cell was significantly higher and % of CD19+ B-cells was significantly lower in MCD patients. PD-L1 expressing CD19B- cells were significantly higher in MCD and FSGS patients compared to HCs whereas PD-L1 expressing CD14+ mononuclear cells were indifferent among groups. Moreover, exosomes expressing PD-L1 were significantly higher in MCD and FSGS patients compared to HCs. MCD exosomes stimulated significantly higher IL10 and IL4 levels from healthy PBMCs compared to exosomes isolated from HCs but IP10 and IFNγ levels were indifferent. MCD patients’ own exosomes stimulated significantly higher IL17 from their isogenic PBMCs compared FSGS patients and HCs. 

Conclusions:

Our data implicated that immune dysregulation in relapse INS involved both T- and B-cells. Circulating exosomes of relapse INS patients act immune modulatory on healthy and isogenic PBMCs, which suggested that they may affecting podocyte biology due to immune modulatory nature. Our current extensive studies tackle on these issues and we are attempting to unravel the immunoregulatory roles of exosomes on podocyte functions.