Increased prevalence of dysplastic and malignant lip lesions in renal-transplant recipients

BACKGROUND

Renal-transplant recipients are known to have increased rates of skin cancer associated with exposure to the sun. Little is known, however, about the prevalence and histologic features of lesions of the lips in these patients, or about risk factors for such lesions.

METHODS

We examined the lips of 160 renal-transplant recipients (105 men and 55 women; mean [+/- SD] age, 48 +/- 13 years) and 160 normal subjects matched with the transplant recipients for age, sex, and skin type. The mean length of time between transplantation and the examination was 69 +/- 52 months; 58 percent of the recipients had received their grafts more than 60 months earlier.

RESULTS

Among the 160 renal-transplant recipients, 21 (13 percent) had leukoplakia; in 2 (1.2 percent) the leukoplakia contained squamous-cell carcinoma. In contrast, only one normal subject (0.6 percent) had leukoplakia. Histologically, 13 of the 21 leukoplakias (62 percent) in the renal-transplant recipients who underwent biopsy were dysplastic, and 2 (10 percent) contained squamous-cell carcinoma. Actinic change was evident in 91 percent of the dysplastic lesions but not in the nondysplastic lesions (P < 0.001). Exposure to the sun and smoking were risk factors for dysplastic and malignant lip lesions in the renal-transplant recipients (P < 0.001 and P = 0.003, respectively). Among these recipients, only men had dysplastic or malignant lip lesions (P = 0.006); lipstick was used frequently by 73 percent of the women. The clinical appearance of lip lesions did not predict the presence of dysplasia or cancer.

CONCLUSIONS

Renal-transplant recipients have an increased prevalence of leukoplakia, dysplasia, and cancer of the lip.

An association between recurrent oro-genital ulceration and non-steroidal anti-inflammatory drugs

Recurrent oro-genital ulceration is a common condition of unknown aetiology. This paper describes a patient who had severe recurrent oro-genital ulceration which was unresponsive to conventional therapy. The patient was taking non-steroidal anti-inflammatory drugs (NSAIDs) prescribed for osteoarthritis. When she stopped this medication, she had no further genital ulceration and the pattern of her oral ulceration was dramatically improved. There have been no previously reported cases of recurrent oro-genital ulceration associated with NSAIDs.

Prevalence and risk factors associated with leukoplakia, hairy leukoplakia, erythematous candidiasis, and gingival hyperplasia in renal transplant recipients

The aims of this study were to determine the prevalence of intraoral lesions in renal transplant recipients and to identify possible risk factors. The oral mucosa of 159 renal transplant recipients and 160 control patients was examined. The most common lesion in renal transplant recipients was cyclosporin-induced gingival hyperplasia (prevalence 22%) and patients with gingival hyperplasia were found to be taking significantly more cyclosporin-A than those without (p < 0.001). The prevalence of hairy leukoplakia and leukoplakia in renal transplant recipients was 11.3% and 10.7%, respectively, compared with 0% and 5.6% in the controls. Oral candidiasis was observed in 9.4% of renal transplant recipients compared with 2.5% of the controls; 3.8% of renal transplant recipients exhibited erythematous candidiasis, but this was not seen in the controls. Renal transplant recipients had a significantly increased risk of developing gingival hyperplasia (p < 0.0001), oral candidiasis (p < 0.0005), and two other conditions that have a well-established association with the immune suppression accompanying HIV infection, hairy leukoplakia (p < 0.0001) and erythematous candidiasis (p < 0.01).

Pyostomatitis vegetans and associated systemic disease. A review and two case reports

In this article two case reports of pyostomatitis vegetans are presented. Both cases were associated with inflammatory bowel disease and one case was also associated with liver dysfunction. It has recently been reported that there may be a link between liver dysfunction and pyostomatitis vegetans. The management of the condition is illustrated and the literature on the subject is reviewed.

VCAM-1 and ICAM-1 are expressed by Langerhans cells, macrophages and endothelial cells in oral lichen planus

Expression of intercellular adhesion molecule-1 (ICAM-1, CD54) and vascular cell adhesion molecule-1 (VCAM-1, CD106) was examined in oral lichen planus (OLP) and normal oral mucosa (NOM). Immunoperoxidase staining showed ICAM-1 expression by vascular endothelium in all biopsies of OLP and NOM whereas endothelial VCAM-1 staining was found in 2/7 NOM and 8/9 OLP. In the lamina propria of NOM occasional cells were ICAM-1 or VCAM-1 positive, and virtually no staining of intraepithelial dendritic cells was seen for either marker. Intraepithelial dendritic cells stained for ICAM-1 in 7/9 and VCAM-1 in 4/9 OLP biopsies. Double immunofluorescence showed dual labelling of Langerhans cells (LC) with CD1a and VCAM-1 in a further 5/12 cases of OLP, but there was no such staining in four NOM. This is the first report of LC staining with VCAM-1. Induction of ICAM-1 and VCAM-1 on LC and macrophages in OLP suggests these cells are activated and may contribute to the pathogenesis of OLP by presenting antigen to infiltrating lymphocytes.

Leucocyte endothelial cell adhesion: a study comparing human umbilical vein endothelial cells and the endothelial cell line EA-hy-926

EA-hy-926 is a cell line produced by hybridizing human umbilical vein endothelial cells (HUVEC) and the epithelial cell line A549. To establish whether EA-hy-926 could be used as a model for endothelial cells (EC) in leucocyte-EC adhesion interactions, the effect of interleukin-4 (IL-4), tumour necrosis factor (TNF) or interferon-gamma (IFN) stimulation on their adhesiveness and expression of E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) was compared with that of HUVEC and A549. Although HUVEC exhibited increased adhesiveness and adhesion molecule expression with IL-4, TNF or IFN, EA-hy-926 exhibited these responses only with TNF. CD11/CD18-dependent binding accounted for a significant component of basal binding to HUVEC and EA-hy-926, but did not account for the increased binding of T cells, JY, J6, ICH-BJ or ICH-KM cell lines to TNF-stimulated monolayers. At least part of the CD11/CD18-independent adhesion was attributable to VCAM-1 induction on HUVEC and EA-hy-926. TNF-stimulation also induced E-selectin expression on EA-hy-926 and HUVEC and an accompanying increase in neutrophil (PMN) binding. The EA-hy-926 cells used in this study, therefore, showed responses similar to HUVEC when stimulated with TNF but not when stimulated with IL-4 or IFN.

Endothelial cell leukocyte adhesion molecule-1 (ELAM-1) and intercellular adhesion molecule-1 (ICAM-1) expression in gingival tissue during health and experimentally-induced gingivitis

The changes in vascular adhesion molecule expression and numbers of infiltrating leukocytes during a 21-day experimental gingivitis episode were investigated immunohistochemically. Monoclonal antibodies to ELAM-1 (1.2B6), ICAM-1 (6.5B5), CD3 (OKT3-pan-T cell) and neutrophils (PMN-elastase) were used to identify positive vessels and leukocytes within gingival biopsies taken on d 0, 7, 14 and 21. Vascular endothelium expressed ELAM-1 and ICAM-1 both in clinically 'healthy' tissue (d 0) and in experimentally inflamed tissue (d 7 to 21). Positive vessels were found mainly in the connective tissue subjacent to the junctional epithelium where the highest numbers of T cells and neutrophils were also seen. Although T cells were found in all tissue areas studied, neutrophils were largely concentrated in the junctional epithelium and the subjacent connective tissue but were absent from the oral epithelial region. As the experimental gingivitis developed, the number of T cells or neutrophils in the different tissue regions did not change significantly although the most intense vascular ICAM-1 and ELAM-1 staining redistributed to the CT adjacent to the junctional epithelium. A prominent feature was the intense ICAM-1 positive staining of the junctional epithelium and its absence in the closely adjacent oral epithelium, in both clinically 'healthy' and inflamed tissue. The gradient of ICAM-1 in junctional epithelium, with the strongest staining on the crevicular aspect plus the vascular expression of ELAM-1 and ICAM-1 in both clinically 'healthy' and inflamed tissue may be crucial processes which direct leukocyte migration towards the gingival crevice.

Pyostomatitis vegetans: report of three cases and review of the literature

Pyostomatitis vegetans is a rare condition of the mouth frequently associated with chronic inflammatory bowel disease. It is characterized by miliary abscesses and superficial erosions affecting a hyperplastic, soft and friable oral mucosa. Three cases are presented here and used as a basis for reviewing the literature and discussing the differential diagnosis, etiology and treatment of this unusual condition.

Endothelial leukocyte adhesion molecule-1 and intercellular adhesion molecule-1 mediate the adhesion of eosinophils to endothelial cells in vitro and are expressed by endothelium in allergic cutaneous inflammation in vivo

We have compared the adhesion of 51Cr-labeled eosinophils and neutrophils to cultured human umbilical vein endothelial cell (EC) monolayers that have been stimulated with IL-1, TNF, or LPS. Each agent stimulated the adhesion to EC of both eosinophils and neutrophils in a similar dose- and time-dependent manner. F(ab')2 fragments of mAb 1.2B6 (anti-endothelial leukocyte adhesion molecule (ELAM)-1) and mAb 6.5B5 (anti-intercellular adhesion molecule (ICAM)-1) each inhibited partially, and to a similar extent, eosinophil and neutrophil adhesion to EC monolayers prestimulated with TNF (10 ng/ml) for 6 h. Greater inhibition of both eosinophil and neutrophil adhesion was achieved by combining the effects of mAb 1.2B6 with either mAb 6.5B5 or mAb TS1/18 (anti-CD18). These observations indicate that both ELAM-1 and ICAM-1 are involved in the adhesion of eosinophils and neutrophils to EC stimulated with TNF. In order to determine whether these molecules are expressed in vivo during allergen-induced late phase allergic responses in the skin, human skin biopsies were examined at 6 h after Ag or saline challenge with the use of an alkaline phosphatase-staining technique. Both ELAM-1 and ICAM-1 were expressed with greater intensities in Ag-challenged biopsies, suggesting that these molecules may be involved in granulocyte recruitment in vivo. The similarities we have established between mechanisms of eosinophil and neutrophil adhesion to cytokine-stimulated EC suggests that factors other than differential leukocyte-EC adhesion may be responsible for the selective accumulation of eosinophils at sites of allergic inflammation.

Tumor necrosis factor combines with IL-4 or IFN-gamma to selectively enhance endothelial cell adhesiveness for T cells. The contribution of vascular cell adhesion molecule-1-dependent and -independent binding mechanisms

The adhesion of lymphocytes to vascular endothelium is the first step in their passage from the blood into inflammatory tissues. By modulating endothelial cell (EC) adhesiveness for lymphocytes, cytokines may regulate lymphocyte accumulation and hence the nature and progression of inflammatory responses. IL-1, TNF, IFN-gamma, and IL-4 each increase EC adhesiveness for T cells when used alone in adhesion assays in vitro. As cytokines are more likely to act in combination at sites of inflammation in vivo, we have studied the stimulating effect of different combinations of cytokines on EC adhesiveness for T cells and polymorphonuclear leukocytes (PMN). Acting alone IL-1, TNF, IFN-gamma, and IL-4 each significantly enhanced EC adhesiveness for T cells (p less than 0.005), whereas only IL-1 (p less than 0.005) and TNF (p less than 0.005) but not IFN-gamma or IL-4 significantly enhanced adhesiveness for PMN. When EC were stimulated with optimal concentrations of TNF in combination with IL-4 or IFN-gamma, there was a significant further increase in adhesiveness for T cells (p less than 0.003), but not PMN, over that seen with TNF alone. The additive effect of TNF and IL-4 was more marked than that of TNF and IFN-gamma. Although approximately equal proportions of T cells and PMN bound to TNF-stimulated EC, nearly double the proportion of T cells compared with PMN bound EC preincubated with TNF and IL-4 together. A similar interaction with IL-4 or IFN-gamma was exhibited by lymphotoxin. mAb-inhibition studies indicated that the extra increase in binding caused by stimulating EC with TNF and IL-4 in combination was mediated by VCAM-1 whereas that caused by stimulating with TNF and IFN-gamma in combination was substantially mediated through leukocyte function-associated Ag-1- and VCAM-1-independent mechanisms. These observations suggest that whereas IL-1 and TNF alone are unselective in terms of leukocyte adhesion to EC, the combination of TNF (or LT) with IL-4 or IFN-gamma may be of key importance in determining the recruitment of a lymphocyte-predominant infiltrate in immune mediated inflammation, and in initiating the transition from acute to chronic inflammation.

Tumor necrosis factor combines with IL-4 or IFN-gamma to selectively enhance endothelial cell adhesiveness for T cells. The contribution of vascular cell adhesion molecule-1-dependent and -independent binding mechanisms

The adhesion of lymphocytes to vascular endothelium is the first step in their passage from the blood into inflammatory tissues. By modulating endothelial cell (EC) adhesiveness for lymphocytes, cytokines may regulate lymphocyte accumulation and hence the nature and progression of inflammatory responses. IL-1, TNF, IFN-gamma, and IL-4 each increase EC adhesiveness for T cells when used alone in adhesion assays in vitro. As cytokines are more likely to act in combination at sites of inflammation in vivo, we have studied the stimulating effect of different combinations of cytokines on EC adhesiveness for T cells and polymorphonuclear leukocytes (PMN). Acting alone IL-1, TNF, IFN-gamma, and IL-4 each significantly enhanced EC adhesiveness for T cells (p less than 0.005), whereas only IL-1 (p less than 0.005) and TNF (p less than 0.005) but not IFN-gamma or IL-4 significantly enhanced adhesiveness for PMN. When EC were stimulated with optimal concentrations of TNF in combination with IL-4 or IFN-gamma, there was a significant further increase in adhesiveness for T cells (p less than 0.003), but not PMN, over that seen with TNF alone. The additive effect of TNF and IL-4 was more marked than that of TNF and IFN-gamma. Although approximately equal proportions of T cells and PMN bound to TNF-stimulated EC, nearly double the proportion of T cells compared with PMN bound EC preincubated with TNF and IL-4 together. A similar interaction with IL-4 or IFN-gamma was exhibited by lymphotoxin. mAb-inhibition studies indicated that the extra increase in binding caused by stimulating EC with TNF and IL-4 in combination was mediated by VCAM-1 whereas that caused by stimulating with TNF and IFN-gamma in combination was substantially mediated through leukocyte function-associated Ag-1- and VCAM-1-independent mechanisms. These observations suggest that whereas IL-1 and TNF alone are unselective in terms of leukocyte adhesion to EC, the combination of TNF (or LT) with IL-4 or IFN-gamma may be of key importance in determining the recruitment of a lymphocyte-predominant infiltrate in immune mediated inflammation, and in initiating the transition from acute to chronic inflammation.

Endothelial leukocyte adhesion molecule-1 and intercellular adhesion molecule-1 mediate the adhesion of eosinophils to endothelial cells in vitro and are expressed by endothelium in allergic cutaneous inflammation in vivo

We have compared the adhesion of 51Cr-labeled eosinophils and neutrophils to cultured human umbilical vein endothelial cell (EC) monolayers that have been stimulated with IL-1, TNF, or LPS. Each agent stimulated the adhesion to EC of both eosinophils and neutrophils in a similar dose- and time-dependent manner. F(ab')2 fragments of mAb 1.2B6 (anti-endothelial leukocyte adhesion molecule (ELAM)-1) and mAb 6.5B5 (anti-intercellular adhesion molecule (ICAM)-1) each inhibited partially, and to a similar extent, eosinophil and neutrophil adhesion to EC monolayers prestimulated with TNF (10 ng/ml) for 6 h. Greater inhibition of both eosinophil and neutrophil adhesion was achieved by combining the effects of mAb 1.2B6 with either mAb 6.5B5 or mAb TS1/18 (anti-CD18). These observations indicate that both ELAM-1 and ICAM-1 are involved in the adhesion of eosinophils and neutrophils to EC stimulated with TNF. In order to determine whether these molecules are expressed in vivo during allergen-induced late phase allergic responses in the skin, human skin biopsies were examined at 6 h after Ag or saline challenge with the use of an alkaline phosphatase-staining technique. Both ELAM-1 and ICAM-1 were expressed with greater intensities in Ag-challenged biopsies, suggesting that these molecules may be involved in granulocyte recruitment in vivo. The similarities we have established between mechanisms of eosinophil and neutrophil adhesion to cytokine-stimulated EC suggests that factors other than differential leukocyte-EC adhesion may be responsible for the selective accumulation of eosinophils at sites of allergic inflammation.

IL-4 regulates endothelial cell activation by IL-1, tumor necrosis factor, or IFN-gamma

Alteration in the surface membrane of endothelial cells (EC) is a feature of endothelial activation both at sites of inflammation in vivo and after stimulation with cytokines in vitro. The effects of stimulating EC with IL-1 or TNF include enhanced adhesiveness for polymorphonuclear leukocytes (PMN) and T cells, the induction of EC leukocyte adhesion molecule-1 (ELAM-1) expression, and the increased expression of intercellular adhesion molecule-1 (ICAM-1) and the 1.4C3 Ag. In contrast, IFN-gamma stimulation increases EC binding of T cells but not PMN and enhances ICAM-1 expression but not ELAM-1 or 1.4C3 Ag expression. Recently we have reported that the T cell-derived cytokine IL-4 also increases EC adhesiveness for T cells but not PMN. In this study we have examined the effect of IL-4 on the expression of several cytokine-inducible EC activation Ag, by using a previously described ELISA technique. IL-4 modulation of activation Ag expression was concentration dependent, optimal at around 100 U/ml, and exhibited a unique pattern compared to that seen with the other cytokines. Although, IL-4 stimulation increased 1.4C3 Ag expression (p less than 0.001), it significantly inhibited constitutive ICAM-1 expression (p less than 0.01) and did not induce ELAM-1. Furthermore, IL-4 exhibited significant synergy with IL-1 or TNF in inducing 1.4C3 Ag expression (p less than 0.001) but inhibited the increased expression of ICAM-1 produced by IL-1, TNF, or IFN-gamma (p less than 0.01) and inhibited the induction of ELAM-1 by IL-1 and TNF (p less than 0.001). In contrast, IL-4 had no effect on the expression of EC HLA-class I, -DR, -DP, or -DQ and neither enhanced nor inhibited the effect of IFN-gamma on the expression of these molecules. Finally, although IL-4 alone caused little if any shape change in EC monolayers, it strongly synergized with TNF or IFN-gamma in causing a change in shape to a more fibroblastic morphology. These observations indicate that IL-4 increases EC adhesiveness for T cells by the induction of a different adhesion molecule to ICAM-1. Furthermore, the ability of IL-4 to both enhance and inhibit the expression of activation Ag on EC already activated by IL-1, TNF, or IFN-gamma suggests that it may be important in altering the quality of inflammatory responses such as may occur during the development and maintenance of chronic or immune-mediated inflammation.

IL-4 regulates endothelial cell activation by IL-1, tumor necrosis factor, or IFN-gamma

Alteration in the surface membrane of endothelial cells (EC) is a feature of endothelial activation both at sites of inflammation in vivo and after stimulation with cytokines in vitro. The effects of stimulating EC with IL-1 or TNF include enhanced adhesiveness for polymorphonuclear leukocytes (PMN) and T cells, the induction of EC leukocyte adhesion molecule-1 (ELAM-1) expression, and the increased expression of intercellular adhesion molecule-1 (ICAM-1) and the 1.4C3 Ag. In contrast, IFN-gamma stimulation increases EC binding of T cells but not PMN and enhances ICAM-1 expression but not ELAM-1 or 1.4C3 Ag expression. Recently we have reported that the T cell-derived cytokine IL-4 also increases EC adhesiveness for T cells but not PMN. In this study we have examined the effect of IL-4 on the expression of several cytokine-inducible EC activation Ag, by using a previously described ELISA technique. IL-4 modulation of activation Ag expression was concentration dependent, optimal at around 100 U/ml, and exhibited a unique pattern compared to that seen with the other cytokines. Although, IL-4 stimulation increased 1.4C3 Ag expression (p less than 0.001), it significantly inhibited constitutive ICAM-1 expression (p less than 0.01) and did not induce ELAM-1. Furthermore, IL-4 exhibited significant synergy with IL-1 or TNF in inducing 1.4C3 Ag expression (p less than 0.001) but inhibited the increased expression of ICAM-1 produced by IL-1, TNF, or IFN-gamma (p less than 0.01) and inhibited the induction of ELAM-1 by IL-1 and TNF (p less than 0.001). In contrast, IL-4 had no effect on the expression of EC HLA-class I, -DR, -DP, or -DQ and neither enhanced nor inhibited the effect of IFN-gamma on the expression of these molecules. Finally, although IL-4 alone caused little if any shape change in EC monolayers, it strongly synergized with TNF or IFN-gamma in causing a change in shape to a more fibroblastic morphology. These observations indicate that IL-4 increases EC adhesiveness for T cells by the induction of a different adhesion molecule to ICAM-1. Furthermore, the ability of IL-4 to both enhance and inhibit the expression of activation Ag on EC already activated by IL-1, TNF, or IFN-gamma suggests that it may be important in altering the quality of inflammatory responses such as may occur during the development and maintenance of chronic or immune-mediated inflammation.

IL-4 increases human endothelial cell adhesiveness for T cells but not for neutrophils

The adhesion of leukocytes to vascular endothelium is the first step in their passage from the blood into inflammatory tissues. By modulating endothelial cell (EC) adhesiveness for leukocytes, cytokines may regulate leukocyte accumulation and hence the nature and progression of inflammatory responses. We have found that the T cell cytokine IL-4 increases the adhesion of T cells, but not neutrophils, to human umbilical vein EC monolayers. The increase in T cell adhesion induced by IL-4 was dose dependent (ED50 = 5 U/ml) and peaked around 33 U/ml. No increase in adhesion of neutrophils was observed at concentrations of IL-4 up to 1000 U/ml. The kinetic of the increase in T cell adhesion exhibited a steady rise peaking between 18 and 24 h before returning to basal levels by 72 h. The IL-4 specificity of the effect was confirmed by the ability of neutralizing anti-IL-4, but not anti-TNF, antibodies to abolish the effect. The increase in T cell-EC adhesion was due to an effect of IL-4 on EC inasmuch as preincubation of the T cells with IL-4 did not increase T cell binding. Furthermore, preincubation of A549 epithelial cell line monolayers with IL-4 caused no increase in T cell binding whereas A549 cells and EC showed a similarly enhanced adhesiveness for T cells after preincubation with IL-1, TNF, or IFN-gamma. EC treated with IL-4 retained their increased adhesiveness for T cells after light fixation, suggesting that IL-4 up-regulates binding by increasing the expression or accessibility of EC surface receptors for lymphocytes. Although antibodies to intercellular adhesion molecule-1 (CD54) and the beta-chain (CD18) of lymphocyte function-associated Ag-1 (CD11a/CD18) partially inhibited T cell adhesion to unstimulated EC, they did not affect the increase in adhesion due to IL-4 stimulation, indicating that the increased binding resulted from the generation of an alternative binding receptor(s) on the EC membrane. These findings suggest that IL-4 may play a role in the selective recruitment of T cells into sites of immune-mediated chronic inflammation.

IL-4 increases human endothelial cell adhesiveness for T cells but not for neutrophils

The adhesion of leukocytes to vascular endothelium is the first step in their passage from the blood into inflammatory tissues. By modulating endothelial cell (EC) adhesiveness for leukocytes, cytokines may regulate leukocyte accumulation and hence the nature and progression of inflammatory responses. We have found that the T cell cytokine IL-4 increases the adhesion of T cells, but not neutrophils, to human umbilical vein EC monolayers. The increase in T cell adhesion induced by IL-4 was dose dependent (ED50 = 5 U/ml) and peaked around 33 U/ml. No increase in adhesion of neutrophils was observed at concentrations of IL-4 up to 1000 U/ml. The kinetic of the increase in T cell adhesion exhibited a steady rise peaking between 18 and 24 h before returning to basal levels by 72 h. The IL-4 specificity of the effect was confirmed by the ability of neutralizing anti-IL-4, but not anti-TNF, antibodies to abolish the effect. The increase in T cell-EC adhesion was due to an effect of IL-4 on EC inasmuch as preincubation of the T cells with IL-4 did not increase T cell binding. Furthermore, preincubation of A549 epithelial cell line monolayers with IL-4 caused no increase in T cell binding whereas A549 cells and EC showed a similarly enhanced adhesiveness for T cells after preincubation with IL-1, TNF, or IFN-gamma. EC treated with IL-4 retained their increased adhesiveness for T cells after light fixation, suggesting that IL-4 up-regulates binding by increasing the expression or accessibility of EC surface receptors for lymphocytes. Although antibodies to intercellular adhesion molecule-1 (CD54) and the beta-chain (CD18) of lymphocyte function-associated Ag-1 (CD11a/CD18) partially inhibited T cell adhesion to unstimulated EC, they did not affect the increase in adhesion due to IL-4 stimulation, indicating that the increased binding resulted from the generation of an alternative binding receptor(s) on the EC membrane. These findings suggest that IL-4 may play a role in the selective recruitment of T cells into sites of immune-mediated chronic inflammation.

A monoclonal antibody that detects a novel antigen on endothelial cells that is induced by tumor necrosis factor, IL-1, or lipopolysaccharide

The alteration in the surface of endothelial cells (EC) in response to cytokines is likely to be of great importance to the regulation of cell migration and thereby to the evolution of inflammatory processes. We have generated three mAb against cytokine inducible Ag on EC. Whereas mAb 1.2B6 and 6.5B5 were found to react with ELAM-1 and ICAM-1, respectively, mAb 1.4C3 reacted with a novel molecule that showed a different pattern of expression from ELAM-1 or ICAM-1 after stimulation of EC by TNF, IL-1, or LPS. Like ELAM-1, the 1.4C3 Ag was minimally expressed on resting EC, whereas ICAM-1 was moderately expressed. After stimulation with IL-1, TNF, or LPS, ELAM-1 expression was maximal after 4 to 6 h, 1.4C3 Ag after 6 to 10 h, and ICAM-1 after 10 to 24 h. The duration of 1.4C3 expression was intermediate between ELAM-1 and ICAM-1, and was more prolonged in response to TNF than IL-1 or LPS. Whereas the expression of the three Ag showed a similar dose response to varying concentrations of IL-1 or LPS, EC required a 10-fold higher concentration of TNF for half maximal expression of ELAM-1 than for half maximal expression of 1.4C3 Ag or ICAM-1 (5 ng/ml compared to 0.5 ng/ml). Of the three Ag, only ICAM-1 was enhanced by IFN-gamma. SDS-PAGE under reducing conditions showed the 1.4C3 Ag to migrate as a single band with a relative molecular mass of approximately 95 kDa. mAb 1.4C3 adds to our understanding of the kinetics of the EC response to different cytokines and will be useful in studying the regulation of EC activation. Furthermore, the 1.4C3 molecule may have an important role in leukocyte-EC interactions.

A monoclonal antibody that detects a novel antigen on endothelial cells that is induced by tumor necrosis factor, IL-1, or lipopolysaccharide

The alteration in the surface of endothelial cells (EC) in response to cytokines is likely to be of great importance to the regulation of cell migration and thereby to the evolution of inflammatory processes. We have generated three mAb against cytokine inducible Ag on EC. Whereas mAb 1.2B6 and 6.5B5 were found to react with ELAM-1 and ICAM-1, respectively, mAb 1.4C3 reacted with a novel molecule that showed a different pattern of expression from ELAM-1 or ICAM-1 after stimulation of EC by TNF, IL-1, or LPS. Like ELAM-1, the 1.4C3 Ag was minimally expressed on resting EC, whereas ICAM-1 was moderately expressed. After stimulation with IL-1, TNF, or LPS, ELAM-1 expression was maximal after 4 to 6 h, 1.4C3 Ag after 6 to 10 h, and ICAM-1 after 10 to 24 h. The duration of 1.4C3 expression was intermediate between ELAM-1 and ICAM-1, and was more prolonged in response to TNF than IL-1 or LPS. Whereas the expression of the three Ag showed a similar dose response to varying concentrations of IL-1 or LPS, EC required a 10-fold higher concentration of TNF for half maximal expression of ELAM-1 than for half maximal expression of 1.4C3 Ag or ICAM-1 (5 ng/ml compared to 0.5 ng/ml). Of the three Ag, only ICAM-1 was enhanced by IFN-gamma. SDS-PAGE under reducing conditions showed the 1.4C3 Ag to migrate as a single band with a relative molecular mass of approximately 95 kDa. mAb 1.4C3 adds to our understanding of the kinetics of the EC response to different cytokines and will be useful in studying the regulation of EC activation. Furthermore, the 1.4C3 molecule may have an important role in leukocyte-EC interactions.

T cells and neutrophils exhibit differential adhesion to cytokine-stimulated endothelial cells

In vitro adhesion assays were used to directly compare the adhesion of polymorphonuclear leucocytes (PMN) and T cells to endothelial cells (EC). PMN exhibited lower binding to unstimulated EC than T cells. When EC were stimulated with interleukin-1 (IL-1), tumour necrosis factor (TNF) or bacterial lipopolysaccharide (LPS) there was a large and rapid increase in adhesiveness for PMN which peaked at 4 hr. This had fallen significantly by 24 hr and by 72 hr was not significantly elevated above unstimulated adhesion. The increase in adhesiveness of cytokine-stimulated EC for T cells was smaller and more gradual than for PMN, with adhesion peaking around 8 hr and remaining significantly elevated at 72 hr. In contrast, interferon-gamma (IFN-gamma) enhanced EC adhesiveness for T cells but not for PMN, with maximal T cell EC adhesiveness occurring 24 hr after stimulation. As leucocyte adhesion to vascular endothelium is the first step in diapedesis, differences in PMN and T-cell adhesion to EC may be important in determining the timing and composition of inflammatory infiltrates.

Enhanced adhesion of autologous lymphocytes to gamma-interferon-treated human endothelial cells in vitro

An adhesion assay was developed using human umbilical vein endothelial cell cultures and autologous and allogeneic lymphocytes separated from cord blood. Endothelial monolayers cultured in plain or gamma-interferon (IFN gamma)-supplemented medium were cocultured with lymphocytes for 1 h and non-adherent lymphocytes removed by washing. Autologous and allogeneic lymphocytes exhibited significantly increased adhesion with IFN gamma-treated cells compared with untreated controls. The increased adhesion to IFN gamma-treated endothelial cells was significantly inhibited when autologous or allogeneic lymphocytes were pre-treated with saturating amounts of an anti-CD4 monoclonal antibody. The results indicate that IFN gamma enhances lymphocyte binding to endothelium and that the CD4 molecule may be involved in this process. This could be an important mechanism in targetting the migrating of T-helper (Th) cells to areas of chronic inflammation and in antigen presentation by endothelial cells.