Expression of leucocyte and lymphocyte adhesion molecules in the human kidney

Effect of Kidney Transplantation on Accelerated Immunosenescence and Vascular Changes Induced by Chronic Kidney Disease

Kidney transplantation is the best option for patients with end-stage renal disease. Despite the improvement in cardiovascular burden (leading cause of mortality among patients with chronic kidney disease), cardiovascular adverse outcomes related to the inflammatory process remain a problem. Thus, the aim of the present study was to characterize the immune profile and microvesicles of patients who underwent transplantation. We investigated the lymphocyte phenotype (CD3, CD4, CD8, CD19, and CD56) and monocyte phenotype (CD14, CD16, CD86, and CD54) in peripheral blood, and endothelium-derived microvesicles (annexin V+CD31+CD41–) in plasma of patients with advanced chronic kidney disease (n = 40), patients with transplantation (n = 40), and healthy subjects (n = 18) recruited from the University Hospital “12 de Octubre” (Madrid, Spain). Patients with kidney transplantation had B-cell lymphopenia, an impairment in co-stimulatory (CD86) and adhesion (CD54) molecules in monocytes, and a reduction in endothelium-derived microvesicles in plasma. The correlations between those parameters explained the modifications in the expression of co-stimulatory and adhesion molecules in monocytes caused by changes in lymphocyte populations, as well as the increase in the levels of endothelial-derived microvesicles in plasma caused by changes in lymphocyte and monocytes populations. Immunosuppressive treatment could directly or indirectly induce those changes. Nevertheless, the particular characteristics of these cells may partly explain the persistence of cardiovascular and renal alterations in patients who underwent transplantation, along with the decrease in arteriosclerotic events compared with advanced chronic kidney disease. In conclusion, the expression of adhesion molecules by monocytes and endothelial-derived microvesicles is related to lymphocyte alterations in patients with kidney transplantation.

The profiles of soluble adhesion molecules in the "great obstetrical syndromes". J Matern Fetal Neonatal Med 2018;32:2113-2136. [PMID: 29320948 DOI: 10.1080/14767058.2018.1427058]

OBJECTIVE

The objective of this study was to determine the profiles of maternal plasma soluble adhesion molecules in patients with preeclampsia, small-for-gestational-age (SGA) fetuses, acute pyelonephritis, preterm labor with intact membranes (PTL), preterm prelabor rupture of the membranes (preterm PROM), and fetal death.

MATERIALS AND METHODS

A cross-sectional study was conducted to determine maternal plasma concentrations of sE-selectin, sL-selectin, and sP-selectin as well as sICAM-1, sVCAM-1, and sPECAM-1 in patients with (1) an uncomplicated pregnancy (control, n = 100); (2) preeclampsia (n = 94); (3) SGA fetuses (in women without preeclampsia/hypertension, n = 45); (4) acute pyelonephritis (n = 25); (5) PTL (n = 53); (6) preterm PROM (n = 24); and (7) fetal death (n = 34). Concentrations of soluble adhesion molecules and inflammatory cytokines (tumor necrosis factor (TNF)-α and interleukin (IL)-8) were determined with sensitive and specific enzyme-linked immunoassays.

RESULTS

In comparison to women with a normal pregnancy, (1) women with preeclampsia had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1, and a lower concentration of sL-selectin (all p values < .001); (2) patients with SGA fetuses had higher median concentrations of sE-selectin, sP-selectin, and sVCAM-1 (all p values < .05); (3) patients with a fetal death had higher median concentrations of sE-selectin and sP-selectin (all p values < .05); (4) patients with acute pyelonephritis had higher median plasma concentrations of sE-selectin, sICAM-1, and sVCAM-1 (all p values < .001); (5) patients with preeclampsia and acute pyelonephritis, plasma concentrations of sVCAM-1, sE-selectin, and sP-selectin correlated with those of the proinflammatory cytokines TNF-α and interleukin (IL)-8 (all p values < .05); (6) patients with PTL had a higher median concentration of sP-selectin and a lower median concentration of VCAM-1 (all p values < .05); and (7) women with preterm PROM had lower median concentrations of sL-selectin and sVCAM-1 (all p values < .05).

CONCLUSIONS

The results of this study show that endothelial cell activation/dysfunction reflected by the plasma concentration of sE-selectin is not specific to preeclampsia but is present in pregnancies complicated by SGA fetuses, acute pyelonephritis, and fetal death. Collectively, we report that each obstetrical syndrome appears to have a stereotypical profile of soluble adhesion molecules in the peripheral circulation.

T Cells: Soldiers and Spies--The Surveillance and Control of Effector T Cells by Regulatory T Cells

Traditionally, T cells were CD4+ helper or CD8+ cytotoxic T cells, and with antibodies, they were the soldiers of immunity. Now, many functionally distinct subsets of activated CD4+ and CD8+ T cells have been described, each with distinct cytokine and transcription factor expression. For CD4+ T cells, these include Th1 cells expressing the transcription factor T-bet and cytokines IL-2, IFN-γ, and TNF-β; Th2 cells expressing GATA-3 and the cytokines IL-4, IL-5, and IL-13; and Th17 cells expressing RORγt and cytokines IL-17A, IL-17F, IL-21, and IL-22. The cytokines produced determine the immune inflammation that they mediate. T cells of the effector lineage can be naïve T cells, recently activated T cells, or memory T cells that can be distinguished by cell surface markers. T regulatory cells or spies were characterized as CD8+ T cells expressing I-J in the 1970s. In the 1980s, suppressor cells fell into disrepute when the gene for I-J was not present in the mouse MHC I region. At that time, a CD4+ T cell expressing CD25, the IL-2 receptor-α, was identified to transfer transplant tolerance. This was the same phenotype of activated CD4+ CD25+ T cells that mediated rejection. Thus, the cells that could induce tolerance and undermine rejection had similar badges and uniforms as the cells effecting rejection. Later, FOXP3, a transcription factor that confers suppressor function, was described and distinguishes T regulatory cells from effector T cells. Many subtypes of T regulatory cells can be characterized by different expressions of cytokines and receptors for cytokines or chemokines. In intense immune inflammation, T regulatory cells express cytokines characteristic of effector cells; for example, Th1-like T regulatory cells express T-bet, and IFN-γ-like Th1 cells and effector T cells can change sides by converting to T regulatory cells. Effector T cells and T regulatory cells use similar molecules to be activated and mediate their function, and thus, it can be very difficult to distinguish soldiers from spies.

Results of life-supporting galactosyltransferase knockout kidneys in cynomolgus monkeys using two different sources of galactosyltransferase knockout Swine

BACKGROUND

Various durations of survival have been observed in the xenotransplantation of life-supporting α-1,3-galactosyltransferase knockout (GalT-KO) porcine kidneys into nonhuman primates. Although others have demonstrated loss of GalT-KO-transplanted kidneys within 2 weeks, we have reported an average survival of 51 days with the cotransplantation of the kidney and vascularized thymus and an average of 29 days with the kidney alone. To determine the factors responsible for this difference in survival time, we performed xenogeneic kidney transplantations into cynomolgus monkeys with an anti-CD40L-based regimen using two different strains of GalT-KO swine, one derived from MGH miniature swine and the other obtained from Meji University.

MATERIALS AND METHODS

Eight cynomolgus moneys received GalT-KO kidneys. Three kidney grafts were from Massachusetts General Hospital (MGH)-Nippon Institute for Biological Science (NIBS) GalT-KO pigs and five GalT-KO grafts were from MEIJI GalT-KO swine. All cynomolgus recipients were treated identically.

RESULTS

Recipients of kidneys from the MGH GalT-KO kidneys swine, produced by nuclear transfer in Japan, survived an average of 28.7 days, whereas recipients of MEIJI GalT-KO kidneys swine survived an average of 9.2 days. Among the differences between these two groups, one potentially revealing disparity was that the MEIJI swine were positive for porcine cytomegalovirus, whereas the MGH-derived swine were negative.

CONCLUSION

This is the first study comparing renal xenotransplantation from two different sources of GalT-KO swine into nonhuman primates at a single center. The results demonstrate that porcine cytomegalovirus may be responsible for early loss of GalT-KO swine kidney xenografts.

Podocytes regulate neutrophil recruitment by glomerular endothelial cells via IL-6-mediated crosstalk

Stromal cells actively modulate the inflammatory process, in part by influencing the ability of neighboring endothelial cells to support the recruitment of circulating leukocytes. We hypothesized that podocytes influence the ability of glomerular endothelial cells (GEnCs) to recruit neutrophils during inflammation. To address this, human podocytes and human GEnCs were cultured on opposite sides of porous inserts and then treated with or without increasing concentrations of TNF-α prior to addition of neutrophils. The presence of podocytes significantly reduced neutrophil recruitment to GEnCs by up to 50% when cultures were treated with high-dose TNF-α (100 U/ml), when compared with GEnC monocultures. Importantly, this phenomenon was dependent on paracrine actions of soluble IL-6, predominantly released by podocytes. A similar response was absent when HUVECs were cocultured with podocytes, indicating a tissue-specific phenomenon. Suppressor of cytokine signaling 3 elicited the immunosuppressive actions of IL-6 in a process that disrupted the presentation of chemokines on GEnCs by altering the expression of the duffy Ag receptor for chemokines. Interestingly, suppressor of cytokine signaling 3 knockdown in GEnCs upregulated duffy Ag receptor for chemokines and CXCL5 expression, thereby restoring the neutrophil recruitment. In summary, these studies reveal that podocytes can negatively regulate neutrophil recruitment to inflamed GEnCs by modulating IL-6 signaling, identifying a potential novel anti-inflammatory role of IL-6 in renal glomeruli.

Correlation between ICAM1 and VCAM1 gene polymorphisms and histopathological changes in kidney allograft biopsies

INTRODUCTION

The immunoglobulin-like molecules intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) are responsible for endothelial cell-leukocyte adhesion followed by transmigration of leukocytes through the endothelial cell lining. The aim of this study was to examine the correlation between polymorphisms in ICAM1 and VCAM1 genes and histopathological changes in transplanted kidney biopsies.

MATERIAL AND METHODS

The study enrolled 82 Caucasian renal transplant recipients (48 males, 34 females). Genotyping of the rs5498 ICAM1 and the rs1041163 and rs3170794 VCAM1 gene polymorphisms was performed using real-time polymerase chain reaction (PCR). Biopsies were performed in 82 patients and were reviewed by a renal pathologist and the Banff working classification criteria were used.

RESULTS

There were no significant associations between VCAM gene polymorphisms and histopathological changes in kidney allograft biopsies. ICAM1 gene polymorphism was associated with the grade of interstitial fibrosis. Interstitial fibrosis was more severe among individuals with the G allele than those with the A allele (AA vs. GG+AG, p = 0.017). There were no statistically significant associations between ICAM1 gene polymorphism and other histopathological changes in kidney allograft biopsies.

CONCLUSIONS

The results of our study suggest that rs5498 ICAM1 gene polymorphism is associated with the grade of interstitial fibrosis in kidney recipients and the changes are more severe in patients with the G allele.

Circulating adhesion molecules and purine nucleotides during kidney allograft reperfusion

The impairment of organ function due to ischemia-reperfusion injury is still an important problem in solid organ transplantation. Numerous experimental and clinical studies of native organs have shown that ischemia-reperfusion constitutes an acute inflammatory process involving cell surface adhesion molecule expression. These markers are crucial for the recruitment and infiltration of effector cells into the postischemic tissue. Purines released by the postischemic tissue as the products of the degradation of high-energy nucleotides can be regarded as markers of disturbed energy metabolism. The aim of this study was to examine the correlation between circulating adhesion molecules and purine metabolites in graft renal vein plasma during 49 cases of kidney reperfusion. E-selectin, ICAM-1, and VCAM-1 concentrations correlated positively with hypoxanthine concentrations during reperfusion, whereas the concentrations of ICAM-1 correlated negatively with xanthine concentrations. The results of the present study suggested that the concentrations of adhesion molecules in the renal vein during reperfusion correlated with purine metabolites, reflecting metabolic changes in renal tissue.

Inhibition of connective tissue growth factor by small interfering RNA prevents renal fibrosis in rats undergoing chronic allograft nephropathy

AIM

Connective tissue growth factor (CTGF) is a highly profibrogenic molecule implicated in renal fibrogenesis. Small interfering RNA (siRNA) is an effective tool to silence gene expression. This study determined whether caudal vein injection of siRNA targeting CTGF inhibited its expression in rat kidneys in vivo, and furthermore whether it protected the kidney from renal fibrosis in chronic allograft nephropathy (CAN).

METHODS

Male inbred Fischer (F344, RT1(lv1)) rat renal grafts were orthotopically transplanted into Lewis (LEW, RT1(1)) rats following the procedure of Kamada with our modification. At 6 weeks, recipients were divided into siRNA, normal saline (NS), and control siRNA groups, using daily siRNA-targeting CTGF (0.1 mg/kg), or NS, or a control siRNA via caudal vein injection for 14 days. At 4, 6, and 8 weeks, we observed the pathologic changes, expression of CTGF, E-cadherin, collagen I and IV, and anti-smooth muscle actin (alpha-SMA).

RESULTS

Serum creatinine level, Banff score, and the expression of CTGF were significantly lower among the siRNA than the NS or the control siRNA groups at 8 weeks (P < .05). The expressions of collagen I and IV, and alpha-SMA were also significantly downregulated and E-cadherin was lost in the siRNA versus the NS and control siRNA groups at 8 weeks.

CONCLUSIONS

This study showed that delivery of CTGF siRNA via the caudal vein significantly inhibited expression of CTGF in rat kidneys, effectively preventing fibrosis in CAN. The results suggest that siRNA-targeting of CTGF has the potential to be a novel strategy for amelioration of CAN.

Circulating adhesion molecules during kidney allograft reperfusion

Adhesion molecule expression is an important event during early transplant failure. The aim of the present study was to examine the release of adhesion molecules during the first minutes of kidney allograft reperfusion in relation to delayed graft function and acute graft rejection. We enrolled 49 renal transplant recipients, including 13 cases of delayed graft function (DGF) and 11 cases of acute graft rejection (AR). Plasma concentrations of E-selectin, VCAM-1 and ICAM-1 after 3 min of reperfusion were significantly higher than in the iliac vein before reperfusion. There was no statistically significant difference between patients with and without DGF as regards E-selectin, VCAM-1 and ICAM-1 concentrations in the iliac vein before and in the renal vein after 3 min of reperfusion. Concentrations of adhesion molecules in the iliac vein before reperfusion and in the renal vein after 3 min of reperfusion did not differ significantly between patients with and without AR except for ICAM-1 iliac vein concentration which was significantly increased in AR patients. Plasma levels of E-selectin, ICAM-1 and VCAM-1 were increased after kidney allograft reperfusion. Moreover, elevated serum levels of ICAM-1 before transplantation correlated with subsequent acute kidney allograft rejection. The results suggest that elevated ICAM-1 levels may be implicated in acute graft rejection.

Effect of antibodies to intercellular adhesion molecule type 1 on the protection of distant organs during reperfusion syndrome in rats

We investigated kidney and lung alterations caused by intercellular adhesion molecule type 1 (ICAM-1) blockade after ischemia and reperfusion of hind limb skeletal muscles. Rats were submitted to ligature of the infrarenal aorta for 6 h. The animals were randomized into three groups of 6 rats each: group I, sacrificed after ischemia; group II, reperfusion for 24 h, and group III, reperfusion for 24 h after receiving monoclonal anti-ICAM-1 antibodies. At the end of the experiment, blood samples were collected for creatinine, lactate dehydrogenase, creatine phosphokinase, potassium, pH and leukocyte counts. Samples were taken from the muscles of the hind limbs and from the kidneys and lungs for histological analysis and measurement of the neutrophil infiltrate by myeloperoxidase staining. The groups did not differ significantly with regard to the laboratory tests. There were no major histological alterations in the kidneys. An intense neutrophil infiltrate in the lungs, similar in all groups, was detected. Myeloperoxidase determination showed that after reperfusion there was significantly less retention of polymorphonuclear neutrophils in the muscles (352 +/- 70 vs 1451 +/- 235 x 10(2) neutrophils/mg; P<0.01) and in the kidneys (526 +/- 89 vs 852 +/- 73 10(2) neutrophils/mg; P<0.01) of the animals that received anti-ICAM-1 before perfusion compared to the group that did not. The use of anti-ICAM-1 antibodies in this experimental model minimized neutrophil influx, thus reducing the inflammatory process, in the muscles and kidneys after ischemia and reperfusion of the hind limbs.

Plasma and urinary soluble adhesion molecule expression is increased during first documented acute pyelonephritis

BACKGROUND

The degree of inflammatory reaction and leucocyte trafficking during acute pyelonephritis has been related to the risk of developing renal parenchymal scarring. Adhesion molecules play a central role in leucocyte recruitment during inflammation.

AIMS

(1) To determine whether circulating and urinary concentrations of E-selectin and intercellular adhesion molecule 1 (ICAM-1) were abnormal during first documented acute pyelonephritis; (2) to investigate whether circulating or urinary concentrations were predictive for the development of abnormalities on DMSA imaging.

METHODS

Plasma and urine samples were collected from 40 children with a first episode of acute pyelonephritis within one week of infection (acute sample) and at six weeks (late sample). Control samples were collected from 21 healthy age matched controls and 18 age matched controls with febrile illness not secondary to urinary tract infection.

RESULTS

Plasma and urinary sE-selectin were higher in acute samples (median 176.3 ng/ml and 0.12 ng/mmol respectively) compared with late (97.8 ng/ml and 0.029 ng/mmol) and both control (65.6 ng/ml and 0 ng/mmol) and febrile control (urine 0 ng/mmol) samples. Plasma sICAM-1 was higher in acute samples (428 ng/ml) than controls (365.2 ng/ml), and acute sICAM-1 urine concentrations were higher than febrile control concentrations (3.2 v 0.7 ng/mmol). No correlations were detected between sE-selectin or sICAM-1 and acute or late DMSA scan changes.

CONCLUSION

Plasma and urinary sE-selectin and sICAM-1 are significantly increased during acute pyelonephritis, though no correlation exists between the presence of high plasma or urine concentrations and DMSA scan changes, both during acute infection and six weeks post-infection.

Expression of intercellular adhesion molecule-1 in the cortex of preserved rat kidneys

BACKGROUND

Prolonged cold ischemia has been shown to be an important factor in the development of posttransplant renal dysfunction. The exact mechanisms have not been completely defined. The expression of intercellular adhesion molecule-1 (ICAM-1) (CD 54) in rat kidneys stored in University of Wisconsin (UW) solution was studied in an attempt to correlate ischemia time with immunogenicity of the graft.

METHODS

Kidneys from male Lewis rats were perfused with UW solution, removed, and bathed in UW solution at 4 degrees C for 4, 12, 24, and 48 h. For the evaluation of expression of ICAM-1, immunohistochemical staining, Western blotting, and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) were performed.

RESULTS

Immunohistochemical staining in normal, nonischemic kidneys revealed that glomerular capillaries expressed ICAM-1 but that tubular cells did not. The preserved kidneys were analyzed by immunohistochemistry, Western blotting, and semiquantitative RT-PCR and showed increased transcription and expression of ICAM-1 in the cortex of the kidney. Expression reached a maximum at 24 h and declined at 48 h. The ICAM-1 protein expression in the preserved kidney cortex relative to control kidneys was increased at 4 h (1.68 +/- 0.60-fold of control kidneys, P = 0.06), 12 h (2.38 +/- 0.90-fold, P = 0.02), 24 h (3.70 +/- 1.29-fold, P = 0.01), and 48 h (2.00 +/- 0.54-fold, P = 0.01). The messenger RNA expression (the ratio of ICAM-1 to glyceraldehyde-3-phosphate dehydrogenase) in preserved kidneys cortex relative to control kidneys was increased at 4 h (1.19 +/- 0.14-fold of control kidneys), 12 h (1.38 +/- 0.16-fold), 24 h (1.77 +/- 0.29-fold), and 48 h (1.19 +/- 0.12-fold) (P < 0.05 for all time points).

CONCLUSIONS

We conclude that cold preservation of rat kidneys in UW solution induces increasing levels of ICAM-1 cell surface expression and gene transcription. Further study is necessary to determine if this increase in adhesion molecule expression increases the immunogenicity of the allograft and contributes to the development of posttransplant renal dysfunction.

Soluble intercellular adhesion molecule-1 (sICAM-1) after kidney transplantation: the origin and role of urinary sICAM-1?

BACKGROUND

Intercellular adhesion molecule-1 (ICAM-1) binds to leukocyte adhesion receptors LFA-1 and MAC-1, and mediates leukocyte adhesion to target structures. During acute rejection there is increased expression of ICAM-1 in vascular and tubulointestial cells, and consequently accumulation of inflammatory leukocytes. Soluble ICAM-1 (sICAM-1) is released from ICAM-1 expressing cells and excreted into the surrounding fluid. Increased serum sICAM-1 levels are found in patients with acute rejections of various allografts, and high urinary levels in steroid resistant acute kidney allograft rejection.

METHODS

Urinary excretion of sICAM-1 was measured by EIA in 136 kidney allograft recipients during the first 1-6 post transplant weeks: 30 patients developed acute rejection, and 106 patients had stable graft function. The molecular weight, binding to hyaluronan, and the origin of urinary sICAM-1 were studied.

RESULTS

We show that urinary sICAM-1 circulates as a monomer with a molecular weight between 50 and 100 kD. It binds to immobilized, but not to circulating hyaluronan. About one week after transplantation the mean sICAM-1/creatinine ratio (306 ng/mmol) in transplanted patients was higher than in the healthy controls (167 ng/mmol, P<0.01), and remained basically unchanged during the follow-up in patients with stable graft function, whereas it increased in patients developing rejection, being about 2.5-fold above the initial level a few days before rejection (P<0.01). Urinary sICAM-1 did not correlate with the urinary albumin, whereas in patients developing rejection it correlated with urinary IL-2R (r=0.5146, P<0.001), a marker of lymphocyte activation. In the urinary sediment of rejecting patients ICAM-1 was demonstrated in the tubular epithelial cells, and in the macrophages.

CONCLUSIONS

Increased urinary excretion of sICAM-1 was demonstrated in kidney transplanted patients a few days before acute rejection. It seems to originate from activated macrophages and/or from the tubular epithelial cells. The fact that urinary sICAM-1 is not bound to hyaluronan or to leukocytes suggests that it is not able to compete with membrane-bound ICAM-1 for these bindings, but may do so for the binding of activated macrophages.

The contribution of adhesion molecule expression in donor kidney biopsies to early allograft dysfunction

BACKGROUND

Renal allograft rejection is associated with the expression of adhesion molecules on vascular endothelial and tubular epithelial cells.

METHODS

To assess whether the number of cell adhesion molecules expressed in donor kidneys can predict early rejection or delayed graft function, kidney biopsies from 20 living and 53 cadaveric kidney donors were obtained before engraftment into the recipients and the expression of the cell adhesion molecules intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), and endothelial leukocyte adhesion molecule (E-selectin) were determined by immunohistochemistry.

RESULTS

All biopsies from living donors showed significantly lower expression of ICAM-1 and VCAM-1 compared to biopsies from cadaveric donors. There was no difference in the expression of adhesion molecules on tubular cells between transplants with primary function compared to allografts with early rejection in living donated kidneys (ICAM-1: 2+/-8 vs. 3+/-8%; VCAM-1: 9+/-7 vs. 1+/-1%), as well as in cadaveric kidneys (ICAM-1: 38+/-29 vs. 39+/-38%; VCAM-1: 55+/-27 vs. 48+/-29%). The expression of ICAM-1 molecules on tubular cells was determined to be a predictor for the occurrence of delayed graft function in cadaveric kidneys (ICAM-1: 65+/-24* vs. 38+/-29% delayed graft versus primary graft function). No delayed graft function occurred in recipients of living donated kidneys.

CONCLUSIONS

These data suggest that adhesion molecule expression in donor biopsies is not a predictor for early allograft rejection, but can be used as a marker for the development of postischemic acute renal allograft failure.

Expression of ICAM-1 and HLA class II in acute cellular and vascular rejection of human kidney allografts

We studied the relationship between ICAM-1 and class II expression on graft tubular cells and the relationship with graft inflammation in 50 kidney transplants monitored with serial aspiration biopsies after transplantation. Of the 50 grafts, 26 had an acute rejection 17 +/- 10 days after transplantation, 5 also had acute vascular rejection (AVR) and 24 had no rejection. The initial post-transplant ICAM-1 and class II expression was low in all grafts. All 21 grafts with acute cellular rejection (ACR) displayed ICAM-1 induction, with a peak at the beginning of acute blastogenic rejection and declining over 20 days to prerejection levels. Class II expression reached a peak later and also declined later to prerejection levels. In the grafts with irreversible AVR both ICAM-1 and class II expression remained elevated. The 24 grafts with no rejection displayed no ICAM-1 or class II induction on tubular cells during the follow-up. The differences between ICAM-1 and classs II expression in biopsies with rejection and with no rejection were statistically significant. The results demonstrate that ICAM-1 was induced early during ACR on the graft tubular cells and that it disappeared rapidly in reversible rejections. The induction of class II antigens was slightly slower but quantitatively greater. In the irreversible rejections with a combination of ACR and AVR both ICAM-1 and class II expression remained elevated.

mRNA expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in acute renal allograft rejection

BACKGROUND

The intercellular adhesion molecule-1 (ICAM-1) and the vascular cell adhesion molecule-1 (VCAM-1) show a form of complementary distribution in normal and grafted kidneys. The molecular mechanism by which ICAM-1 and VCAM-1 are increased or induced on vascular cells during acute renal allograft rejection has not been clearly defined.

METHODS

We examined ICAM-1 and VCAM-1 mRNA expression in 17 renal allograft biopsies with (n=12) and without (n=5) features of acute rejection, and four control renal biopsies with no detectable abnormalities by RNA in situ hybridization. The expression of ICAM-1 and VCAM-1 protein was also assessed by immunohistochemical staining of frozen sections.

RESULTS

In controls and nonrejecting graft biopsies, the signals of the ICAM-1 and VCAM-1 transcripts in vascular cells were almost negligible. Specific signals of ICAM-1 and VCAM-1 mRNAs were detected on the endothelial cells of small muscular arteries in most cases with acute renal allograft rejection. The messages for ICAM-1 and VCAM-1 were also detected on arterial smooth muscle cells in all the five cases with severe type III rejection.

CONCLUSIONS

These results suggest that the induced appearance of ICAM-1 and VCAM-1 on the vascular cells of acutely rejecting renal transplants was related to actual cellular synthesis and that both adhesion molecules could act together in the rejection process. They also suggest that the expression of ICAM-1 and VCAM-1 genes by arterial smooth muscle cells may be an important cause of transmural arteritis in severe acute renal allograft rejection.

TGF-beta(1) down-regulates inflammatory cytokine-induced VCAM-1 expression in cultured human glomerular endothelial cells

BACKGROUND

Endothelial cells are active participants in the processes controlling coagulation, inflammation and the immune response. Variations are recognized between endothelia isolated from different vascular beds as well as from different species. Though transforming growth factor-beta(1) (TGF-beta(1)) has been known to have an anti-inflammatory action, little is known about its effect on expression of cellular adhesion molecules during the inflammatory process in human glomerular endothelial cells. The aim of this study was to determine the effect of TGF-beta(1) on the inflammatory cytokine-induced expression of vascular cell adhesion molecule-1 (VCAM-1) in cultured human glomerular endothelial cells.

METHODS

The culture of human glomerular endothelial cells was established using the normal portion of nephrectomized renal tissues and identified by factor VIII staining and cellular uptake of fluorescent-labelled acetylated low-density lipoprotein (LDL). The endothelial cells were stimulated by interleukin-1beta (IL-1beta), tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) with or without TGF-beta(1). Cellular expression of VCAM-1 was measured by enzyme-linked immunosorbent assay (ELISA) and flow cytometry, and VCAM-1 mRNA was measured by Northern blot analysis.

RESULTS

TGF-beta(1) (1, 10 and 25 ng/ml) blunted IL-1beta- (5 ng/ml) induced VCAM-1 expression significantly (OD=1.08+/-0.14, 1. 10+/-1.16 and 1.05+/-0.14 vs IL-1beta=1.97+/-0.29, n=6, P<0.05) in ELISA. The addition of TGF-beta(1) (1, 10 and 25 ng/ml) also suppressed TNF-alpha- (10 ng/ml) induced VCAM-1 expression (OD=1. 14+/-0.15, 1.17+/-0.17 and 1.18+/-0.16 vs TNF-alpha=1.96+/-0.26, n=6, P<0.05). The same results were obtained by flow cytometry. TGF-beta(1) (10 ng/ml) inhibited both IL-1beta- (5 ng/ml) and TNF-alpha-(10 ng/ml) induced expression of VCAM-1 (MFI: IL-1beta=90. 8+/- 17.6, IL-1beta+TGF-beta(1)=37.8+/-14.9, TNF-alpha=113.6+/- 12.4, TNF-alpha+TGF-beta(1)=64.3+/-13.8, mean+/-SD, n=3, P<0.05). By Northern blot analysis, TGF-beta(1) (10 ng/ml) significantly suppressed the stimulatory effect of IL-1beta and TNF-alpha.

CONCLUSIONS

These results show that TGF-beta(1) down-regulates the inflammatory cytokine-induced expression of VCAM-1 in human glomerular endothelial cells, which could be a novel mechanism for the anti-inflammatory action of TGF-beta(1) during the inflammatory processes in human glomerular diseases.

Immunomodulatory effect of pentoxifylline during human allograft rejection: involvement of tumor necrosis factor-alpha and adhesion molecules

BACKGROUND

Pentoxifylline (PTX), a methylxanthine phosphodiesterase inhibitor, is poorly active as an immunosuppressant but prevents the synthesis of proinflammatory cytokines. In a randomized double-blind study comparing PTX versus placebo in 140 patients receiving cadaveric kidney grafts under cyclosporine and prednisone, we have shown that PTX weakened the consequences of rejection on graft survival. To assess the mechanism underlying the beneficial effect recorded during this trial, we analyzed the impact of PTX on tumor necrosis factor (TNF-alpha) production and expression of cell adhesion molecules.

METHODS

Plasma levels of TNF-alpha and its soluble receptors (sTNF-RI, sTNF-RII) and of soluble vascular cell adhesion molecule 1 (sVCAM-1) were monitored over the 6 months postgraft period when PTX or placebo were administered. Expression of VCAM-1 and intercellular cell adhesion molecule 1 was scored by immunohistochemical staining of biopsy specimens from patients who underwent rejection crisis. Lymphocyte subset composition was analyzed longitudinally during cytomegalovirus (CMV) infections.

RESULTS

Plasma TNF-alpha levels were significantly reduced in the PTX-treated group over the 6 months of administration, and specifically during isolated rejection episodes and during CMV infections. Plasma levels of sTNFR-I, sTNFR-II, and sVCAM-1 did not differ between the two groups of patients, but a decrease in renal tubular VCAM-1 expression was observed in the PTX group. During CMV infections, CD8 lymphocytosis and expansion of CD57+ (CD28-) CD8+ T cells were similar in the two groups.

CONCLUSION

The data collected during this double-blind study point to an immunomodulatory role of PTX, the beneficial effect on graft survival resulting from a restraining effect of the drug on the inflammatory conditions involved in acute graft rejection.

Effects of ICAM-1 antisense oligonucleotide on the tubulointerstitium in mice with unilateral ureteral obstruction

Effects of ICAM-1 antisense oligonucleotide on the renal tubulointerstitium in mice with unilateral ureteral obstruction.

BACKGROUND

To extend our previous study of the therapy of the renal lesions of unilateral ureteral obstruction (UUO) in mice by an inhibitor of intercellular adhesion molecule-1 (ICAM-1), we investigated the blocking effects of ICAM-1 antisense oligonucleotides (ASONs) on the ICAM-1 expression in mouse kidney.

METHODS

First, ICAM-1 ASON was transducted into mouse renal tubular epithelial cells to investigate the effects of ICAM-1 ASON in vitro. Second, fluorescein isothiocyanate (FITC)-labeled ICAM-1 ASON was injected intravenously to determine the distribution of the ASON in vivo. Third, the expression of ICAM-1 in kidney and the changes of renal morphology were observed to investigate the therapeutic effects of ICAM-1 ASON on the UUO mice in vivo.

RESULTS

The expressions of ICAM-1 in the epithelial cells induced by interleukin-1beta were inhibited by ICAM-1 ASON at the dosages of 100 and 200 nmol/L. Twenty-four hours after an introvenous injection with FITC-labeled ICAM-1 ASON, the highest level of fluorescein was detected within the proximal tubules in mouse kidney. Results of immunohistology and Northern blot showed that the ICAM-1 expression was markedly reduced in the obstructed kidney after treatment with ICAM-1 ASON. The ASON also alleviated the infiltration of inflammatory cells and accumulation of the extracellular matrix in the tubulointerstitium of UUO mice without apparent side effects.

CONCLUSION

Our data demonstrate that ICAM-1 ASON is taken up primarily by the proximal tubular cells of mouse kidney. ICAM-1 ASON can selectively inhibit the ICAM-1 expression of the renal tubular cells both in vitro and in vivo.

Cadaver versus living donor kidneys: impact of donor factors on antigen induction before transplantation

BACKGROUND

It is widely recognized that living-related donor (LRD) renal allografts have a higher overall graft survival than cadaver donor transplants. We tested the hypothesis that part of this is attributable to LRD kidneys being obtained under optimal conditions from healthy donors, whereas cadaveric kidneys may have experienced injury as a result of inflammatory events around the time of brain death.

METHODS

We have performed a comparative immunohistochemical analysis of pretransplant donor biopsies from cadaveric (N = 65) and LRD (N = 29) kidneys to determine any differences that may predispose them to subsequent damage. Cryostat sections were stained with antibodies to leukocytes, adhesion molecules, and human leukocyte antigen (HLA)-DR antigens, and the expression was assessed semiquantitatively.

RESULTS

High levels of endothelial E-selectin and proximal tubular expression of HLA-DR antigens, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 were detected in biopsies from cadaveric kidneys, whereas expression of these markers was markedly reduced in LRD kidneys. High levels of tubular antigen expression were significantly associated with traumatic death, prolonged ventilation, and episodes of infection in cadaver donors. Furthermore, the expression of pretransplant tubular antigens in cadaver donor kidneys was significantly associated with early acute rejection following transplantation, suggesting that such kidneys are predisposed to subsequent immune-mediated attack following transplantation.

CONCLUSIONS

These results may explain, in part, the superior outcome of LRD allografts compared with cadaver renal allografts.

T lymphocyte adhesion mechanisms within inflamed human kidney: studies with a Stamper-Woodruff assay

Renal inflammatory conditions are characterized by mononuclear cell recruitment to sites of inflammation. We have developed a modified Stamper-Woodruff assay system to analyze mechanisms of functional T cell adhesion to cryostat sections of renal biopsy material from patients with vasculitic glomerulonephritis (GN) and acute allograft rejection. Peripheral blood T cells adhered to intraglomerular, periglomerular, and tubulointerstitial regions of the cortex. Blocking monoclonal antibodies against tissue expressed ICAM-1, VCAM-1, and the CS-1 domain of fibronectin (CS-1Fn) differentially attenuated T cell adhesion. Glomerular adhesion in vasculitic GN and tubulointerstitial adhesion in acute rejection were particularly sensitive to both anti-ICAM-1 and anti-VCAM-1 antibodies, indicating a prominent role for ICAM-1 and VCAM-1 at glomerular sites in vasculitis and at tubulointerstitial sites in rejection. Furthermore, using KL/4 cells (LFA-1 expressing) and Jurkat cells (VLA-4 expressing), we demonstrated specific LFA-1/ICAM-1- and VLA-4/VCAM-1-mediated interactions within glomerular and tubulointerstitial compartments. Jurkat cells also adhered to VCAM-1-free sites, and binding was inhibitable by anti-CS-1Fn antibody, thereby demonstrating a role for VLA-4/fibronectin interactions especially at intraglomerular sites in acute rejection where VCAM-1 is notably absent. We therefore propose a prominent functional role for ICAM-1, VCAM-1, and CS-1 domain fibronectin in T cell recruitment to the inflamed kidney.

The Role of Adhesion Molecules in Human Leukocyte Attachment to Porcine Vascular Endothelium: Implications for Xenotransplantation

Many obstacles still prevent successful xenotransplantation of porcine donor organs. When hyperacute rejection is averted, transplanted pig organs are subject to acute vascular and cellular rejection. In autologous systems, leukocyte recruitment into inflamed tissues involves selectins, integrins, and Ig family members. To determine whether these mechanisms allow human leukocytes to effectively enter porcine grafts, the pathways by which human leukocytes adhere to TNF-α-stimulated porcine aortic endothelium were examined under static and physiologic flow conditions. L-selectin and E-selectin had overlapping functions in neutrophil capture and rolling, whereas Ab blockade of E-selectin and the β2 integrins inhibited firm arrest of rolling neutrophils. Combined blockade of selectins and β2 integrins resulted in negligible human neutrophil attachment to pig endothelium. Lymphocyte attachment to porcine endothelium was primarily L-selectin mediated, whereas β2 integrin and VCAM-1/very late Ag-4 (VLA-4) interactions promoted static adhesion. Concurrent β2 integrin, VLA-4, VCAM-1, and L-selectin blockade completely inhibited lymphocyte attachment. Thus, interactions between leukocyte-endothelial cell adhesion receptor pairs remained remarkably intact across the human-porcine species barrier. Moreover, disrupting the adhesion cascade may impair the ability of human leukocytes to infiltrate a transplanted porcine organ during rejection.

Sulfation-dependent down-regulation of interferon-gamma-induced major histocompatibility complex class I and II and intercellular adhesion molecule-1 expression on tubular and endothelial cells by glycosaminoglycans

BACKGROUND

Previously, it has been demonstrated that heparin inhibits major histocompatibility complex (MHC) class II and intercellular adhesion molecule-1 (ICAM-1) expression on interferon-gamma (IFN-gamma)-stimulated human umbilical vein endothelial cells (HUVECs). Inasmuch as proximal tubular epithelial cells (PTECs) are prime targets in acute renal allograft rejection, we investigated whether there is a difference in the ability of heparin to influence MHC and ICAM-1 expression on PTECs as compared to HUVECs. We also studied whether the degree of sulfation of heparin is of relevance for the binding to IFN-gamma and inhibition of MHC and ICAM-1 expression after IFN-gamma stimulation.

METHODS

Cultured HUVECs and PTECs were stimulated with IFN-gamma for 72 hr in the presence or absence of various heparinoids. MHC and ICAM-1 expression were thereafter determined by fluorescence-activated cell sorting.

RESULTS

Heparin was able to inhibit the up-regulation of MHC and ICAM-1 in a dose-dependent fashion on both IFN-gamma-stimulated HUVECs and PTECs. In PTEC cultures, higher concentrations of heparin were required for the inhibition of MHC class I. Heparin and supersulfated glycosaminoglycans (GAGs) were able to bind to IFN-gamma, whereas N-desulfated N-acetylated GAGs with a low amount of sulfate were not. Inhibition of cell-bound heparan sulfate proteoglycan sulfation with NaClO3 resulted in an impaired MHC and ICAM-1 expression after IFN-gamma stimulation.

CONCLUSION

We postulate that IFN-gamma binds to cell-bound heparan sulfate proteoglycan in a sulfation-dependent fashion. This binding may facilitate the interaction of IFN-gamma with its receptor. Supersulfated GAGs with low anti-coagulant activity could be used therapeutically to decrease MHC and ICAM-1 expression on organ grafts.

Major histocompatibility complex class II expression by intrinsic renal cells is required for crescentic glomerulonephritis

The requirement for major histocompatibility complex class II (MHC II) to initiate immune renal injury was studied in a murine model of CD4(+) T cell-dependent crescentic glomerulonephritis (GN). C57BL/6 (MHC II+/+) mice developed crescentic GN with glomerular CD4(+) T cell infiltration and renal injury, in response to a nephritogenic antigen (sheep globulin) planted on their glomerular basement membrane. MHC II-deficient C57BL/6 mice (MHC II-/-) did not develop crescentic GN, CD4(+) T cell infiltration, or injury, indicating that this form of immune glomerular injury is MHC II dependent. The requirement for MHC II expression by intrinsic renal cells was studied in chimeric mice, which expressed MHC II on bone marrow-derived cells and in the thymus, but not in the kidneys. These chimeric mice had normal T and B cell populations and MHC II expression in their spleens and lymph nodes and developed an immune response to systemically and cutaneously administered sheep globulin. However, they did not develop crescentic GN, CD4(+) T cell infiltration, or renal injury in response to the sheep globulin planted in their glomeruli. These studies demonstrate that interaction of CD4(+) T cells with intrinsic renal cells expressing MHC II is required for development of cell-mediated immune renal injury.

In situ analysis of adhesion molecule expression in kidneys infected with murine malaria

The expression of intercellular adhesion molecule-1 (ICAM-1), the ligand leucocyte function antigen-1 (LFA-1, CD11a), and complement receptor type 3 (CR3, or Mac-1, CD11b) has been studied in murine kidneys acutely infected with the fatal malaria parasite Plasmodium berghei ANKA. Thirty-six kidney sections from five groups of C57BL/6J mice on day 5, 10, 15, and 20 post-infection, and normal controls, were stained with monoclonal antibodies against ICAM-1, LFA-1, and Mac-1. There was markedly enhanced expression of ICAM-1 in the glomerular mesangium and the endothelium of blood vessels from day 10 post-infection. ICAM-1 was also found in the proximal tubular epithelial cells in an apical location, with a linear pattern. In addition, the glomeruli showed positive staining for LFA-1 and Mac-1 on day 10 post-infection, mainly in the infiltrating inflammatory cells. Mesangial cells and inflammatory cells in the cortical tubulointerstitium showed positive staining for ICAM-1, LFA-1, and Mac-1 at the later stages of infection. There were strong correlations between ICAM-1 expression on endothelial cells of glomerular/peritubular capillaries with inflammatory cells positive for LFA-1 and Mac-1, which correlated with proteinuria. These findings show that several adhesion molecules are up-regulated in murine malaria-associated nephritis. The expression of ICAM-1 on endothelial cells correlated with the severity of inflammatory responses, indicating the relationship between the expression of adhesion molecules and cell-mediated immune renal injury. It is suggested that adhesion molecules play an important role in the pathogenesis of murine nephritis. Better knowledge of the function of these molecules in malaria infection may open new approaches to antimalarial therapy.

Adhesion molecules and urinary tumor necrosis factor-alpha in idiopathic membranous glomerulonephritis

Adhesion molecules are required in several physiological processes, but their altered function/expression is associated with the pathogenesis of inflammatory diseases. In the present study on idiopathic membranous glomerulonephritis (MGN) the expression of adhesion molecules (ICAM-1, VCAM-1, PECAM-1, E-selectin, LFA-1, Mac-1) was analyzed in different cellular compartments of the kidney using an indirect immunoperoxidase technique and monoclonal antibodies. Relationships between the expression of these molecules and the clinical and morphological activity of the disease and the urinary excretion of tumor necrosis factor alpha (TNF-alpha) were studied in 20 patients. The results were compared with the findings in ten normal kidneys and urinary TNF-alpha in 17 healthy subjects. The expression of adhesion molecules in glomeruli and tubules was unchanged apart from a diminished expression of VCAM-1 (P = 0.014) in glomerular parietal epithelial cells and PECAM-1 in glomerular endothelial cells (P < 0.01). Interstitial peritubular capillaries expressed significantly (P = 0.009) more E-selectin compared with the controls. The interstitial compartment had a highly increased number of cells expressing ICAM-1 in MGN (32.4 +/- 4.6 cells/high power field) compared with the controls (9.4 +/- 1.2; P < 0.001). Also, cells expressing VCAM-1 (10.2 +/- 1.6 vs. 2.8 +/- 1.9; P = 0.005). PECAM-1 (25.9 +/- 5.3 vs. 7.4 +/- 2.1; P = 0.006), and LFA-1 (20.4 +/- 3.6 vs. 8.3 +/- 1.5; P = 0.041) were increased in the interstitium. Proteinuria correlated particularly with the expression of E-selectin in peritubular capillaries (r = 0.63, P = 0.004). The number of LFA-1 expressing inflammatory cells in the interstitium correlated with peritubular capillary E-selectin (r = 0.8, P < 0.001) and interstitial ICAM-1 (r = 0.61, P = 0.009) expression, but histological alterations did not correlate with the expression of adhesion molecules. Tumor necrosis factor-alpha excretion was significantly increased in MGN (41 +/- 8 pg/mg creatinine) compared with the controls (13 +/- 2; P = 0.001), and in particular, it correlated with the interstitial expression of LFA-1 (r = 0.71, P = 0.002). This study suggests that active MGN leads not only to proteinuria but also to increased urinary TNF-alpha excretion. These may serve as triggers for the up-regulation of adhesion molecules in the peritubular capillaries and interstitial cells thus enhancing the development of the interstitial injury.

Intercellular adhesion molecule-1 (ICAM-1), leucocyte function-associated antigen-1 (LFA-1) and leucocyte infiltration in proliferative human glomerulonephritis

The expression of the intercellular adhesion molecule-1 (ICAM-1), infiltrating cells positive for its ligand leucocyte adhesion molecule-1(LFA-1), and the markers of total leucocytes (CD45RB), T cells (CD45RO), and monocytes/macrophages (CD68) were examined by an indirect immunoperoxidase method on renal biopsy specimens from 20 patients with mesangial proliferative glomerulonephritis-IgA negative (MesProGN) and 20 with IgA nephropathy (IgAN). Histologically, normal portions of the kidney tissue (n = 15) obtained from patients with renal trauma or renal tumours were used as controls. The expression of ICAM-1 was evident and extended in mesangium, on endothelial cells of peritubular capillaries, interstitial cells, several infiltrating immune cells and on tubular epithelial cells, particularly on atrophic tubuli in renal biopsies of MesProGN and IgAN. In both types of glomerulopathies a significant increase in the number of glomerular and interstitial LFA-1-positive cells correlated positively with the expression of ICAM-1. The number of glomerular and interstitial LFA-1-positive cells correlated positively with the number of monocytes/macrophages in glomeruli and interstitium. The strong correlation between expression of ICAM-1 and LFA-1 and between LFA-1-positive cells and immune cells makes these adhesion molecules useful markers of activity and suggest that they are involved in recruitment of leucocytes in the studied types of proliferative glomerulopathies.

Cell adhesion molecules in clinical renal transplantation

Leukocyte adhesion molecules are critically involved at a number of stages in immune and inflammatory responses, and their importance in the response to a renal allograft has been recognized for some years. They are involved in antigen presentation, in the cascade of events leading to extravasation of leukocytes into the allograft, in the subsequent migration of leukocytes through the extracellular matrix, and in the interactions between effector and target cells. Thus the adhesion molecules are highly attractive targets for therapeutic intervention in organ transplantation. Strategies have been explored to exploit the involvement of adhesion molecules in ischemia/reperfusion injury, allograft rejection, and the induction of immunological tolerance. Furthermore, the expression of a number of adhesion molecules is regulated by cytokines, and elevated levels may be detected both in transplant biopsies and as soluble forms measured in serum and urine. It has been proposed that these changes in levels might provide useful information in the diagnosis of allograft rejection and differentiation from other causes of graft dysfunction.

Engraftment of human kidney tissue in rat radiation chimera: II. Human fetal kidneys display reduced immunogenicity to adoptively transferred human peripheral blood mononuclear cells and exhibit rapid growth and development

BACKGROUND

Transplantation of human kidney tissue under the kidney capsule of immunodeficient animals (severe combined immunodeficiency [SCID]/Lewis and SCID/nude chimeric rats), and the subsequent intraperitoneal infusion of allogeneic human peripheral blood mononuclear cells (PBMC), results in a rapid and consistent human renal allograft rejection. We investigated the consequences of grafting human fetal kidney fragments instead of the adult tissue.

METHODS

The development of human fetal kidney tissue and its interaction with allogeneic human PBMC in chimeric rats were analyzed by histology, immunohistochemistry, and in situ hybridization.

RESULTS

We report successful establishment of human fetal kidney to SCID/Lewis and SCID/nude chimeric rats. The intrarenal human fetal renal implants displayed rapid growth and maintained numerous developing glomeruli and tubular structures up to 4 months after transplantation. In contrast to the adult human kidney, infusion of allogeneic human PBMC resulted in either minimal human T-cell infiltration or abundant nonrejecting T-cell infiltrates, characterized by a reduced number of T cells of the CD45RO+ or HLA-DR+ subsets, both leading to less tissue destruction as well as to continued growth of the human fetal renal tissue. This observation was found to be related to the reduced protein expression of tissue HLA class I and II, intercellular adhesion molecule 1, and vascular adhesion molecule 1 in the fetal grafts compared with the adult grafts. Lack of tissue expression of Fas ligand in the fetal grafts suggests that the latter does not contribute to the delayed rejection of human fetal kidneys.

CONCLUSIONS

Our model should be useful for the study of human fetal renal development and the human alloresponse against fetal tissue.

Glomerulointerstitial interaction of adhesion molecules in IgA nephropathy and membranoproliferative glomerulonephritis

The expression of two adhesion molecules, ICAM1 (CD54) and ICAM3 (CD50), infiltrating cells positive for their ligand, LFA1 (CD11a), and the markers of total leukocytes (CD45), T cells (CD3), granulocytes/monocytes (CD15), and macrophages (CD68) in renal interstitium were examined by an indirect immunoperoxidase method. The study was longitudinally performed on repeat renal biopsy specimens from 69 patients with two different proliferative glomerulonephritides: 43 with IgA nephropathy (IgAN) and 26 with membranoproliferative glomerulonephritis (MPGN). Interstitial ICAM1 (iICAM1) was mainly expressed on endothelium of peritubular venules and sometimes on tubular epithelium, and interstitial ICAM3 (iICAM3) on infiltrating immune cells. In IgAN, iICAM1 was significantly correlated with glomerular infiltration of LFA1+ cells (gLFA1) and CD68+ cells (gCD68) (r = 0.478/0.500; P < 0.0001) as well as CD3+ cells (gCD3) (r = 0.402; P < 0.002). In MPGN, iICAM1 was significantly correlated only with gCD68 (r = 0.382; P < 0.05). In both diseases, iICAM1 and iICAM3 were significantly correlated with interstitial infiltration of LFA1+ cells (iLFA1) and CD68+ cells (iCD68) (r = 0.616 to 0.815; P < 0.0001) and with interstitial infiltration of CD3+ cells (iCD3) (r = 0.474 to 0.816; P < 0.01). The iICAM3 was also significantly correlated with interstitial CD45+ cells (iCD45) (r = 0.672 in IgAN and 0.769 in MPGN; P < 0.00001). Interstitial infiltration of these immune cells was significantly correlated with the histologic parameters indicating renal injury, such as the index of glomerular lesion and the percent interstitial volume (r = 0.410 to 692; P < 0.05). Longitudinal analysis revealed that the parameters described above showed corresponding change with each other at the follow-up biopsy. These findings suggest that the glomeruler infiltration of T cells and macrophages influences the ICAM1/ICAM3 expression of the interstitial cells, especially In IgAN, and that ICAM1/LFA1 and ICAM3/LFA1 interactions contribute to the persistent infiltration of the interstitium by immune cells in both diseases.

Adhesion molecules and rejection of renal allografts

Despite an increasing amount of immunohistochemical and molecular biology data relating to the pathogenesis of kidney transplant rejection, the pathological diagnosis of this condition still rests on routine light microscopy. The detection of changes in expression and distribution of adhesion molecules in renal allograft biopsies may open a new era of increased accuracy of rejection diagnosis. Of the various adhesion molecule reactivities, peritubular capillary VCAM-1 staining appears to be the most specific finding for chronic rejection. This same staining reaction is seen in acute rejection, but may have less specificity in that setting.

Selective increase in CD4-positive graft-infiltrating mononuclear cells among the infiltrates in class I disparate kidney grafts undergoing rejection

Long-term tolerance to kidney allografts across a two-haplotype class I disparity is uniformly induced in miniature swine with a short course of cyclosporine (CsA). In the absence of CsA, all recipients acutely reject kidney allografts within 2 weeks. Previous experiments have shown that graft-infiltrating mononuclear cells (GIC) migrate to the allograft in both CsA-treated and untreated animals. To evaluate the correlation between GIC phenotype and the clinical status, infiltrating cells were examined by flow cytometry, using selective gating to distinguish them from other renal cells. GIC from tolerant and rejector animals were mostly mature T cells, with 84% CD8+ cells, which consisted of 68% CD8+/CD4- and 16% CD8+/ CD4+ cells. This cellular phenotype was, however, markedly different from that of peripheral blood lymphocytes, suggesting a selective migration of cells into the graft. This selective process counterselected the CD3+/CD2- subset of GIC, which was never found in the graft. The distribution of GIC subsets was initially comparable in tolerated and rejected kidneys, but the CD4 single-positive subset then increased specifically in the allograft destined to rejection. The absence of CD4 single-positive cells in tolerated grafts was unlikely to be due to a direct effect of the CsA, because long-term tolerant animals, which received a second kidney without further immunosuppression, also showed no increase in CD4 single-positive cells. The fact that CD4 single-positive cells appeared only within the rejected kidneys, strongly suggests that this cell subset may be important in mediating immune rejection and supports the hypothesis that the development of tolerance in this model depends on a relative deficit of T-cell help.

Interaction between proximal tubular cells and allogenic leukocytes mediated by interleukin-1 and prostaglandin

The present study investigates the interaction between proximal tubular cells (TC) and peripheral blood mononuclear cells (PBMC) with respect to interleukin-1 (Il-1) and prostaglandin E2 (PGE2) in co-culture experiments. Stimulator cells were proliferating human TC propagated in culture and characterized by expression of ICAM-1 and MHC-class II in response to cytokines. The presence of TC reduced spontaneous growth of PBMC by 42%, with a concomittant 50% reduction of Il-1 release and a 6-fold increase of PGE2 release in the growth medium. The growth reduction was partly counteracted by addition of II-1 and indomethacin. Addition of II-1 stimulated the PGE2 release from PBMC and TC by about 75% and 500%, respectively. Growth of TC cultured alone was inhibited by II-1 in a dose-dependent manner, with maximum effect at 10 U/ml, whereas PGE2 showed no effect. These results suggest that TC have the capacity to interact with PBMC, and this potentially tissue-protective mechanism induced by TC may have clinical implications.

Cell adhesion molecule expression within human glomerular and kidney organ culture

A glomerular and kidney organ culture method was developed to study cytokine inducibility of adhesion molecules and MHC antigen expression. Glomerular cells showed constitutive expression of intercellular cell adhesion molecule-1 (ICAM-1) and MHC class I and II antigens, but not vascular cell adhesion molecule-1 (VCAM-1), E-selectin, or P-selectin. Expression of E-selectin on glomerular endothelial cells (ECs) was induced by interleukin-1 (IL-1), tumour necrosis factor (TNF), interferon-gamma (IFN-gamma) and granulocyte/ macrophage-colony stimulating factor (GM-CSF); this induction was inhibited by transforming growth factor beta (TGF beta) and by IL-4. P-selectin expression was never seen within glomeruli. VCAM-1 was constitutively expressed by Bowman's capsule and proximal tubules and was weakly induced on glomerular ECs by TNF and IL-4 in combination. Glomerular endothelial ICAM-1 expression was increased by IL-1, TNF, IFN-gamma, and GM-CSF, while TGF beta inhibited induction by TNF and IL-1. Expression of MHC class I and II antigens by glomerular ECs was constitutive; further upregulation of MHC class II by IFN-gamma was observed. These studies suggest that leukocyte-endothelial cell interactions that occur within the kidney follow broadly similar principles as are proposed to occur elsewhere in the body but, in addition, there are subtle differences that reflect local conditions.

Expression of adhesion molecules in rat renal cortex during experimental hydronephrosis

Unilateral ureteral obstruction (UUO) is associated with an early and steadily increasing infiltration of macrophages into the renal cortical interstitium. As adhesion molecules may play an important role in macrophage recruitment following the mechanical disturbance after UUO, we delineated the time course of intercellular adhesion molecule (ICAM)-1 and vascular adhesion molecule (VCAM)-1 mRNA and protein expression. A significant 6.6- (P < 0.001), 2.6- (P < 0.025), 2.6- (P < 0.01), and 2.0-fold (P < 0.005) increase in ICAM-1 mRNA expression was observed at 12, 24, 48, and 96 hours after obstruction, respectively, in comparison to the contralateral unobstructed kidney (CUK). Despite an apparent relief of obstruction, four weeks following reversal of obstruction mRNA levels of ICAM-1 remained equivalent to the 96-hour obstructed kidney group. No significant difference in VCAM-1 mRNA expression was observed between the obstructed kidneys and CUK specimens. Immunohistochemistry revealed focal labeling of ICAM-1 on the apical and basolateral surface of the renal tubules, peritubular interstitium, and vessels of the renal cortex by 12 hours after UUO. In contrast, only faint staining for ICAM-1 protein was observed in the cortex from CUK specimens. The obstructed and CUK specimens exhibited diffuse immunolocalization of VCAM-1 in the cortical tubules and Bowman's capsular epithelium. In situ hybridization showed mRNA transcription for ICAM-1 localized in the peritubular interstitium and cortical tubules from obstructed kidneys. To lend mechanistic insight into the response of ICAM-1 to the mechanical disturbance after UUO, the expression of ICAM-1 mRNA was examined when freshly isolated proximal tubules were exposed to angiotensin II (1 to 100 microM) immediately after preparation. Levels of ICAM-1 mRNA were elevated 1.4-, 7.1-, and 3.7-fold when exposed to 10 microM, 100 microM, and 1000 microM of angiotensin II for one hour, respectively, when compared to control cultures. The addition of losartan to proximal tubules for one hour prior to angiotensin II stimulation decreased ICAM-1 levels to control values. In summary, this investigation demonstrates that ICAM-1 is important in the initiation of macrophage recruitment into the renal cortex of the obstructed kidney. These findings provide evidence that angiotensin II, produced after ureteral ligation as a result of tubular injury and dysfunction, may play a central role in the release of ICAM-1 from the proximal tubule epithelial cells.

Adhesion molecules in renal diseases

Different adhesion molecules are implicated in the pathogenesis in glomerulonephritis. Leukocyte adhesion molecules play a critical role in causing renal damage in a variety of glomerulonephritic conditions. In order to understand the mechanisms by which distinct adhesion molecules are involved in human glomerulonephritis, it is necessary to have an overview of their function in maintenance of tissue architecture, morphogenesis, immunosurveillance, inflammation, tumor growth, etc. Thus, this review addresses the role of cadherins, selectins, integrins, and members of the immunoglobulin supergene family in developing, normal, and diseased kidney with special attention to glomerulonephritis and possible new therapeutic approaches.

Adhesion molecules in human crescentic glomerulonephritis

The expression of the intercellular adhesion molecule-1 (ICAM-1) and its ligand lymphocyte function associated antigen-1 (LFA-1 or alpha L), the vascular cell adhesion molecule-1 (VCAM-1), endothelial leukocyte adhesion molecule-1 (ELAM-1), and the cellular receptors for extracellular matrix, alpha 1, alpha 2, alpha 3, alpha 5, alpha 6, alpha V, beta 1, and beta 3 integrin subunits, was studied in 28 patients with crescentic glomerulonephritis (GN) related to several mechanisms: four patients with anti-glomerular basement membrane antibodies or anti-GBM disease; 16 with immune complex mediated GN; and eight with pauci-immune GN, associated with vasculitis in four cases. A three-step immunoperoxidase technique was used on sections obtained from frozen renal biopsies. At the initial stage of evolution of the lesions, all the cells of the crescents expressed the beta 1, beta 3, alpha 1, alpha 3, and alpha V subunits of integrins, ICAM-1, and VCAM-1, and some cells expressed the alpha 2, alpha 5, alpha 6, and alpha L subunits of integrins along the plasma membrane. At a later stage, when the crescents were fibrocellular, alpha 3 and alpha 1 subunit expression was polarized, localized mainly in front of the extracellular matrix. In fibrotic crescents, the alpha 2, alpha 5, alpha 6, and alpha L chains were no longer detected, and VCAM-1 and ICAM-1 expression was decreased. VCAM-1 and ELAM-1 appeared on endothelial cells of peritubular capillaries in relation to the appearance of infiltrating inflammatory cells. The results of this study show that several adhesion molecules were expressed on cells forming crescents and were modified during crescent evolution; that these molecules were up-regulated on endothelial cells in relation to the severity of the inflammatory response; and that whatever the mechanism of the glomerulonephritis, adhesion molecule expression was identical. It can be postulated that adhesion molecules play a role in crescentic glomerulonephritis. Better knowledge of these molecules in human glomerulonephritis may open the way to a new therapeutic approach.