ABSTRACT
Objective To explore the role of dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) in the tubulointerstitial lesions of immune-mediated nephrotoxic nephritis (NTN) and the intervention regulation by anti-P-selectin lectin-EGF domain monoclonal antibody (PsL-EGFmAb). Methods WKY rats were randomly divided into control,NTN and PsL-EGFmAb-treated groups. The mrs in NTN group were injected with 1 ml nephrotoxic rabbit serum per kilogram of rat body weight; the ones in PsL-EGFmAb-treated group were injected with 2 mg PsL-EGFmAb per kilogram of rat body weight simultaneously and 2 h later after nephrotoxic rabbit serum injection; and those in control group were injected with equal volume of 0.9% saline. Renal function and pathology were observed at day 4, 7 and 14 after the induction of NTN. Distribution of DC-SIGN + dendritic cells (DCs) in renal tissues was measured by immunofluorescence. Real-time PCR was performed to examine the expression of P-selectin,RANTES, TNF-α, IL-10, IFN-γ and IL-4. Expression of MHC Ⅱ , CD80 and DC-SIGN on dendritic cells was analyzed by flow cytometry. Transendothelial migration was used to detect the ability of DCs migration. DCs ability to activate T cells was determined by mixed lymphocyte reaction (MLR). ELISA was used to detect the concentration of IFN-γ and IL-4 in the supernatant of MLR. Results At day 4, immature DC-SIGN+ DCs infiltrated the rat renal tubulointerstium of NTN group, matured at day 14, and enhanced the ability to migrate and activate T cells. The distribution of DC-SIGN + DCs was significantly related to the form of crescent, tubulointerstial lesions and renal function. In addition, expression of chemokine RANTES and proinflammatory cytokine TNF-α continuously augmented since day 4, while anti-inflammatory eytokine IL-10 decreased after markedly increased at day 4. At day 14, IFN-γ/IL-4 mRNA increased, which was obviously related to DCs maturation. The intervention of PsL-EGFmAb supressed the expression of DC-SIGN and CD80 on DCs, depressed DCs maturation, migration and ability to activate T cells,down-regulated proinflammatory cytokines and up-regulated anti-inflammatory cytokines in kidney,and thus regulated Th1/Th2 bias. At the same time, kidneys showed the decrease of crescents,improvement of tnbulointerstium damage and renal function. Conclusions DC-SIGN may mediate DCs tubulointerstitial infiltration. It may be also a potent regulator of local immune reaction imbalance and pathology of tubulointerstium. PsL-EGFmAb may depress DCs migration and downregulate DCs maturation and function through DC-SIGN, and thus having a role in prevention and treatment.
ABSTRACT
Objective To explore the distribution of dendritic cells (DCs) and the expression of adhesion molecules in rat kidney with unilateral ureteral obstruction (UUO),as well as the regulatory effect of anti-P-selectin lectin-EGF domain monoelonal antibody (PsL-EGFmAb) on adhesion,maturation and function of human DCs cultured in vitro.Methods UUO rat models were established,which were divided into sham group (n=6),untreated group (n=18)and treated group with PsL-EGFmAb(n=18).DCs were analyzed with Axioplan 2 microscopy,while P-selectin being observed by immunohistochemistry.CD34~+ stem cells were isolated from cord blood and cultured in 20%IMDM medium with SCF,GM-CSF,TGF-?1,Flt-3L and TNF-?in vitro.During development, PsL-EGFmAb was added and IL-10 served as control.FACS was performed to detect the expression of HLA-DR,CD1a,CD11c,CD54,CD83,CD80,CD86,CD209 (DC-SIGN) and CD62-P,-E,-L (P-,E-,L-selectin) on DCs.RT-PCR was performed to detect the expression of NF-_KB P50, P65 mRNA.MLR was performed to detect the stimulatory effect of DCs on T cell proliferation and ELISA to determine IL-12p70 amount.Results Comparing with Sham group,the expression of P- selectin was up-regulated among tubulointerstitium mainly on renal tubular epithelial cell after unilateral ureteral obstruction on day 1,while CD1a~+CD80~+DCs being also found in renal interstitium. The expression of P-seleetin and CD1a~+CD80~+DCs was increased evidently on day 7,and correlated with the degree of renal tubulointerstitial fibrosis closely.However,these changes became less conspicuous in rat treated with PsL-EGFmAb.In vitro experiment showed on day 5 after cultured with the induction of TNF-?,immature DCs highly expressed C-type lectin DC-SIGN of pattern recognition receptors;the expression of co-stimulatory molecules such as CD11c,CD83,CD80 and CD86 on mature DCs was up-regulated in paralleling with the mRNA level of NF-_KB;the secretion of IL-12 was enhanced,as well as displaying the features of antigen-presenting cells with a higher ability to induce proliferation of T lymphocytes in vitro.In addition,L-selectin expressed highly on immature DCs,but lowly on mature DCs,neither of two DCs expressed P- and E-selectin.Compared with the IL-10 treated group,PsL-EGFmAb had an inhibitory effect on DC-SIGN of DCs with down- regulating the mRNA level of NF-_KB.PsL-EGFmAb could also inhibited CD11c,CD83,CD80, CD86 expression,reduced secretion of IL-12,and inhibited T cell proliferation stimulated by DCs in vitro.Conclusion DCs may play a critical role on initiating the inflammatory injury of renal tubulointerstitium,and the inhibitory effect of PsL-EGFmAb on DC maturation and function correlated with the inhibition of DC-SIGN,which is mainly mediated through NF-_KB signaling pathway.