Kinetics and characterization of intercellular adhesion molecule-1 (ICAM-1) expression on keratinocytes in various inflammatory skin lesions and malignant cutaneous lymphomas

Gut-tropic T cells and extra-intestinal autoimmune diseases

Gut-tropic T cells primarily originate from gut-associated lymphoid tissue (GALT), and gut-tropic integrins mediate the trafficking of the T cells to the gastrointestinal tract, where their interplay with local hormones dictates the residence of the immune cells in both normal and compromised gastrointestinal tissues. Targeting gut-tropic integrins is an effective therapy for inflammatory bowel disease (IBD). Gut-tropic T cells are further capable of entering the peripheral circulatory system and relocating to multiple organs. There is mounting evidence indicating a correlation between gut-tropic T cells and extra-intestinal autoimmune disorders. This review aims to systematically discuss the origin, migration, and residence of gut-tropic T cells and their association with extra-intestinal autoimmune-related diseases. These discoveries are expected to offer new understandings into the development of a range of autoimmune disorders, as well as innovative approaches for preventing and treating the diseases.

Gene regulation of intracellular adhesion molecule-1 (ICAM-1): A molecule with multiple functions

Intracellular adhesion molecule 1 (ICAM-1) is one of the most extensively studied inducible cell adhesion molecules which is responsible for several immune functions like T cell activation, extravasation, inflammation, etc. The molecule is constitutively expressed over the cell surface and is regulated up / down in response to inflammatory mediators like cellular stress, proinflammatory cytokines, viral infection. These stimuli modulate the expression of ICAM-1 primarily through regulating the ICAM-1 gene transcription. On account of the presence of various binding sites for NF-κB, AP-1, SP-1, and many other transcription factors, the architecture of the ICAM-1 promoter become complex. Transcription factors in union with other transcription factors, coactivators, and suppressors promote their assembly in a stereospecific manner on ICAM-1 promoter which mediates ICAM-1 regulation in response to different stimuli. Along with transcriptional regulation, epigenetic modifications also play a pivotal role in controlling ICAM-1 expression on different cell types. In this review, we summarize the regulation of ICAM-1 expression both at the transcriptional as well as post-transcriptional level with an emphasis on transcription factors and signaling pathways involved.

Increased sHLA-G Is Associated with Improved COVID-19 Outcome and Reduced Neutrophil Adhesion

Human leukocyte antigen (HLA) is a group of molecules involved in inflammatory and infective responses. We evaluated blood sHLA-E and sHLA-G levels in hospitalized COVID-19 patients with respiratory failure and their relationship with clinical evolution, changes in endothelial activation biomarker profile, and neutrophil adhesion. sHLA-E, sHLA-G, and endothelial activation biomarkers were quantified by ELISA assay in plasma samples. Neutrophil adhesion to endothelium was assessed in the presence/absence of patients' plasma samples. At admission, plasma levels of sHLA-G and sHLA-E were significantly higher in COVID-19 patients with respiratory failure compared to controls. COVID-19 clinical improvement was associated with increased sHLA-G plasma levels. In COVID-19, but not in control patients, an inverse correlation was found between serum sICAM-1 and E-selectin levels and plasma sHLA-G values. The in vitro analysis of activated endothelial cells confirmed the ability of HLA-G molecules to control sICAM-1 and sE-selectin expression via CD160 interaction and FGF2 induction and consequently neutrophil adhesion. We suggest a potential role for sHLA-G in improving COVID-19 patients' clinical condition related to the control of neutrophil adhesion to activated endothelium.

Anti-Inflammatory Effects of Compounds from Cudrania tricuspidata in HaCaT Human Keratinocytes

The root bark of Cudrania tricuspidata has been reported to have anti-sclerotic, anti-inflammatory, antioxidant, neuroprotective, hepatoprotective, and cytotoxic activities. In the present study, the effect of 16 compounds from C. tricuspidata on tumor necrosis factor-α+interferon-γ-treated HaCaT cells were investigated. Among these 16 compounds, 11 decreased IL-6 production and 15 decreased IL-8 production. The six most effective compounds, namely, steppogenin (2), cudraflavone C (6), macluraxanthone B (12), 1,6,7-trihydroxy-2-(1,1-dimethyl-2-propenyl)-3- methoxyxanthone (13), cudraflavanone B (4), and cudratricusxanthone L (14), were selected for further experiments. These six compounds decreased the expression levels of chemokines, such as regulated on activation, normal T cell expressed and secreted (RANTES) and thymus and activation-regulated chemokine (TARC), and downregulated the protein expression levels of intercellular adhesion molecule-1. Compounds 2, 6, 12, 4, and 14 inhibited nuclear factor-kappa B p65 translocation to the nucleus; however, compound 13 showed no significant effects. In addition, extracellular signal regulatory kinase-1/2 phosphorylation was only inhibited by compound 14, whereas p38 phosphorylation was inhibited by compounds 13 and 4. Taken together, the compounds from C. tricuspidata showed potential to be further developed as therapeutic agents to suppress inflammation in skin cells.

Current advances in the nano-delivery of celastrol for treating inflammation-associated diseases

Inflammation is ubiquitous in the body, and uncontrolled inflammation often contributes to various diseases. Celastrol, a compound isolated from a Chinese medicinal herb, holds great potential in treating multiple inflammation-associated diseases. However, its further clinical use is limited by its poor solubility, bioavailability, and high organ toxicity. With the advancement of nanotechnology, the nano-delivery of celastrol can effectively improve its oral bioavailability, maximize its efficacy and minimize its side effects. Here, we summarize the roles of celastrol in the treatment of various inflammation-associated diseases, with a special emphasis on its role in modulating immune cell signaling or non-immune cell signaling within the inflammatory microenvironment, and we highlight the latest advances in nano-delivery strategies for celastrol to treat diseases associated with inflammation.

ICAM-1 in HIV infection and underlying mechanisms

Intercellular adhesion molecule 1 (ICAM-1) is a glycoprotein that participates in inflammatory and immune responses. Both cell surface and soluble ICAM-1 are significantly increased during human immunodeficiency virus (HIV) infection, and ICAM-1 has important functions in promoting inflammatory responses and enhancing HIV infectivity; however, a comprehensive summary these roles has yet to be elaborated. In this review we describe the general biological characteristics of ICAM-1, its association with HIV disease progression and promotion of HIV production, mechanisms inducing upregulation of ICAM-1, and possible intervention strategies, representing important insights in the context of HIV treatment.

Carpinus turczaninowii extract modulates arterial inflammatory response: a potential therapeutic use for atherosclerosis

BACKGROUND/OBJECTIVES

Vascular inflammation is an important feature in the atherosclerotic process. Recent studies report that leaves and branches of Carpinus turczaninowii (C. turczaninowii) have antioxidant capacity and exert anti-inflammatory effects. However, no study has reported the regulatory effect of C. turczaninowii extract on the arterial inflammatory response. This study therefore investigated modulation of the arterial inflammatory response after exposure to C. turczaninowii extract, using human aortic vascular smooth muscle cells (HAoSMCs).

MATERIALS/METHODS

Scavenging activity of free radicals, total phenolic content (TPC), cell viability, mRNA expressions, and secreted levels of cytokines were measured in LPS-stimulated (10 ng/mL) HAoSMCs treated with the C. turczaninowii extract.

RESULTS

C. turczaninowii extract contains high amounts of TPC (225.6 ± 21.0 mg of gallic acid equivalents/g of the extract), as well as exerts time-and dose-dependent increases in strongly scavenged free radicals (average 14.8 ± 1.97 µg/mL IC₅₀ at 40 min). Cell viabilities after exposure to the extracts (1 and 10 µg/mL) were similar to the viability of non-treated cells. Cytokine mRNA expressions were significantly suppressed by the extracts (1 and 10 µg/mL) at 6 hours (h) after exposure. Interleukin-6 secretion was dose-dependently suppressed 2 h after incubation with the extract, at 1–10 µg/mL in non-stimulated cells, and at 5 and 10 µg/mL in LPS-stimulated cells. Similar patterns were also observed at 24 h after incubation with the extract (at 1–10 µg/mL in non-stimulated cells, and at 10 µg/mL in the LPS-stimulated cells). Soluble intracellular vascular adhesion molecules (sICAM-1) secreted from non-stimulated cells and LPS-stimulated cells were similarly suppressed in a dose-dependent manner after 24 h exposure to the extracts, but not after 2 h. In addition, sICAM-1 concentration after 24 h treatment was positively related to IL-6 levels after 2 h and 24 h exposure (r = 0.418, P = 0.003, and r = 0.524, P < 0.001, respectively).

CONCLUSIONS

This study demonstrates that C. turczaninowii modulates the arterial inflammatory response, and indicates the potential to be applied as a therapeutic use for atherosclerosis.

Potent laminin-inspired antioxidant regenerative dressing accelerates wound healing in diabetes

The successful treatment of chronic dermal wounds, such as diabetic foot ulcers (DFU), depends on the development of safe, effective, and affordable regenerative tools that the surgeon can rely on to promote wound closure. Although promising, strategies that involve cell-based therapies and the local release of exogenous growth factors are costly, require very long development times, and result in modest improvements in patient outcome. We describe the development of an antioxidant shape-conforming regenerative wound dressing that uses the laminin-derived dodecapeptide A5G81 as a potent tethered cell adhesion-, proliferation-, and haptokinesis-inducing ligand to locally promote wound closure. A5G81 immobilized within a thermoresponsive citrate-based hydrogel facilitates integrin-mediated spreading, migration, and proliferation of dermal and epidermal cells, resulting in faster tissue regeneration in diabetic wounds. This peptide-hydrogel system represents a paradigm shift in dermoconductive and dermoinductive strategies for treating DFU without the need for soluble biological or pharmacological factors.

Ectoine-containing cream in the treatment of mild to moderate atopic dermatitis: a randomised, comparator-controlled, intra-individual double-blind, multi-center trial

INTRODUCTION

The natural cyclic tetrahydropyrimidine, ectoine, is a low-molecular, water-binding, organic osmolyte. Previously, topical application of ectoine to healthy human skin was shown to improve skin hydration as well as skin barrier function.

OBJECTIVES

We therefore speculated that topical application of ectoine would be beneficial for patients with atopic dermatitis (AD), in which a genetically defined defect in skin barrier function is of major pathogenetic relevance. We assessed the efficacy of an ectoine-containing cream (EHK02-01) in the management of 65 patients with mild to moderate AD in a randomized, intra-individual, double-blind, multi-center trial, in which the efficacy of ectoine was compared to a nonsteroidal anti-inflammatory cream previously found to primarily act on skin barrier function and therefore with a comparable mode of action.

METHODS

Sixty-five patients with mild to moderate AD aged 18-65 years were enrolled. The patients applied EHK02-01 and the control cream on two symmetrical lesions twice daily for 28 days. At the beginning, after 7 and after 28 days, treated skin areas were assessed by modified, objective local SCORAD (Scoring Atopic Dermatitis) and IGA (Investigator's Global Assessment) as well as the patients' judgment of efficacy and their assessment of pruritus.

RESULTS

EHK02-01 was found to be very well tolerated. Even more important, efficacy of EHK02-01 treatment was equivalent to that achieved with the reference product.

CONCLUSION

These results indicate that topical treatment with EHK02-01 may represent a novel option for the treatment of patients with AD.

Circulating ICAM-1 levels in serum of uveitis patients

Intercellular Adhesion Molecule-1 (ICAM-1) is a cytokine-inducible adhesion molecule expressed on cells of multiple lineages at sites of inflammation. Recently a truncated form of ICAM-1 has been discovered to be circulating in serum. This study reports on circulating serum (cICAM-1) levels in 132 uveitis patients (HLA-B 27 pos. acute anterior uveitis (AAU); HLA-B27 neg. anterior uveitis (AU); intermediate uveitis (IU); heterochromic cyclitis Fuchs (HCF); sarcoidosis; Toxoplasmosis). Measurement of circulating ICAM-1 serum levels was performed using a monoclonal antibody based ELISA, with healthy blood donors serving as the control group. Applying multiple variance analysis and the Student Newmann-Keuls test we found a statistically significant elevation of serum cICAM-1 level in the HLA-B 27 neg. AU group (n:31), in the IU group (n:25) and in patients with sarcoidosis (n:18). Serum levels of HLA-B27 pos. AAU patients, patients with HCF and patients suffering from ocular toxoplasmosis did not differ significantly from levels of the control group.

Treatment of inflammatory diseases with a monoclonal antibody to intercellular adhesion molecule 1

A mouse monoclonal antibody to intercellular adhesion molecule 1 (ICAM-1) has been evaluated in multiple animal models of inflammation as well as in the clinic. Anti-ICAM-1 has been found to protect against allograft rejection and ischaemia/reperfusion injury in non-human primates and rabbits. In open-label phase I-II studies, anti-ICAM-1 appears to have prolonged kidney allograft survival when used as induction therapy in conjunction with traditional triple immunosuppressive therapy. Anti-ICAM-1 has shown beneficial effects in the treatment of rheumatoid arthritis when given for five days. Most patients receiving anti-ICAM-1 made antibodies to the mouse immunoglobulin.

alpha-Melanocyte stimulating hormone, inflammation and human melanoma

Alpha-melanocyte stimulating hormone (alpha-MSH) arises from the proteolytic cleavage of proopiomelanocortin (POMC) and is the most potent naturally occurring melanotropic peptide. The biological effects of alpha-MSH are mediated via melanocortin receptors (MCRs), which are expressed in virtually every cutaneous cell type. alpha-MSH has pleiotrophic functions including the modulation of a wide range of inflammatory stimuli such as proinflammatory cytokines, adhesion molecules and inflammatory transcription factors. All of the former would be consistent with a cytoprotective role for this hormone in protecting skin cells from exogenous stress, as would occur following UV exposure or exposure to agents inducing inflammation or oxidative stress. In addition to actions on normal skin cells it also modulates both cutaneous and uveal melanoma cell behavior. With respect to melanoma, alpha-MSH is intriguing as studies have shown that while alpha-MSH has the potential to retard metastatic spread (by reducing cell migration and invasion) it is also capable of reducing the ability of the immune system to detect tumor cells (by down regulating adhesion molecules that would normally assist in immune cell interaction with melanoma cells). This review considers the evolving biology of alpha-MSH and discusses its role in man that extend far beyond pigmentation of skin melanocytes, suggesting that the detoxifying role of alpha-MSH in inducing melanogenesis is only one aspect of the stress-coping role of this hormone. Indeed melanoma cells may owe at least some of their success to the 'protective' role of alpha-MSH.

Second messenger pathways in pulmonary host defense

The alveolar macrophage responds to bacterial infection with the production of inflammatory mediators that include TNFalpha. Early production of TNFalpha results in increased bacterial clearance, whereas too much TNFalpha results in many of the hallmarks of bacterial sepsis. TNFalpha production is regulated at many levels, including multiple signaling pathways, that lead to transcription, translation, and release of functional TNFalpha. Interactions of mitogen-activated protein (MAP) kinases, lipid signaling pathways, and oxidant-mediated mechanisms regulate the response of alveolar macrophages to infection. Animal models of sepsis support the central role played by macrophage-derived TNFalpha in sepsis.

The relevance of peripheral blood T-helper 1 and 2 cytokine pattern in the evaluation of patients with mycosis fungoides and Sézary syndrome

BACKGROUND

There is evidence that a T-helper (Th) 2 cytokine pattern dominates in the peripheral blood as well as in tissue of patients with Sézary syndrome (SS), and that the malignant clone is of Th2 phenotype. However, there are conflicting studies on the cytokine pattern in the peripheral blood in different stages of cutaneous T-cell lymphoma (CTCL).

OBJECTIVES

To examine, by means of flow cytometry (FC), the Th1/Th2 cytokine profile [cytoplasmic interferon (IFN)-gamma/interleukin (IL)-4] in peripheral blood T cells from patients with mycosis fungoides (MF) and SS, the most common forms of CTCL, and to correlate their expression with clinical stage, clonality and T-cell immunophenotype changes in order to evaluate their relevance in CTCL progression.

METHODS

We investigated by FC the percentage of CD3+ T cells expressing cytoplasmic IFN-gamma and IL-4 after stimulation in blood specimens of 43 CTCL patients (32 stage I-II and 11 stage III-IV), eight of whom were erythrodermic. Next, we compared cytoplasmic IFN-gamma and IL-4 expression between patients of different stages and controls, and correlated our findings to T-cell receptor (TCR)-gamma gene rearrangement, used as a marker of clonality, and changes in T-cell immunophenotype (CD4+, CD8+, CD4+/CD7-, CD4+/CD25+) and natural killer cells. Polymerase chain reaction amplification of the TCR-gamma gene was performed in 41 blood and 26 skin specimens. We also examined the cytokine expression pattern in patients with erythrodermic MF and SS.

RESULTS

A significantly higher frequency of CD3+/IL-4+ T cells was found in late (III-IV) compared with early (I-II) CTCL patients (P = 0.002) or controls (P < 0.001). There were significant positive correlations between the percentages of CD3+/IL-4+ and the percentages of CD3+/CD4+ T cells (r = 0.385, P = 0.05), CD4+/CD7- T cells (r = 0.335, P < 0.05) and CD4+/CD25+ T cells (r = 0.433, P = 0.01); there was a negative correlation between the percentages of CD3+/IL-4+ and CD3+/CD8+ T cells (r = -0.463, P = 0.005) and a positive correlation between the percentages of CD3+/IFN-gamma+ and CD3+/CD8+ T cells (r = 0.368, P = 0.02). Increased percentages of CD3+/IL-4+, CD3+/CD4+ and CD4+/CD7- T lymphocytes were associated with the presence of clonality (P = 0.025, P < 0.001 and P = 0.0031, respectively). All independent variables showed a statistically significant difference between SS and erythrodermic MF patients, or controls, apart from cytoplasmic IL-4, which was high both in erythrodermic MF and SS patients compared with controls (P = 0.003 and P = 0.008, respectively). In multiple regression logistic analysis, the probability of belonging to advanced CTCL stages was associated only with increased cytoplasmic IL-4 (P = 0.007, odds ratio 1.13, 95% confidence interval 1.033-1.229).

CONCLUSIONS

Increased T-cell cytoplasmic IL-4 is more frequent in late CTCL stages, correlates with T-cell immunophenotype changes found in advanced disease and is associated with clonality. Increased cytoplasmic IL-4 is frequent both in erythrodermic MF and SS patients, in contrast to other variables found increased only in SS, suggesting that IL-4 may be an early indicator of disease progression. Moreover, our results show that increased cytoplasmic IL-4 is the sole predictor of advanced CTCL disease and confirm the relevance of FC determination of IL-4 in the routine evaluation of CTCL cases.

Upregulation of epidermal surface molecule expression in primary and ultraviolet-induced lesions of lupus erythematosus tumidus

BACKGROUND

Lupus erythematosus tumidus (LET), a photosensitive skin disorder with characteristic clinical and histological features, has not been generally accepted as a subset of cutaneous lupus erythematosus (CLE).

OBJECTIVES

To analyse the expression of epidermal surface molecules in skin biopsy specimens from patients with LET and to relate the results to other variants of CLE, such as discoid lupus erythematosus (DLE) and subacute CLE (SCLE).

METHODS

In total, 45 patients with different subtypes of CLE were included in the study, and cryostat sections from primary and ultraviolet (UV) A- and UVB-induced skin lesions were investigated using immunohistochemical methods.

RESULTS

In contrast to healthy controls, skin lesions of LET showed upregulation of intercellular adhesion molecule-1 (ICAM-1) and histocompatibility class II molecules (HLA-DR), with an expression pattern resembling that seen in DLE and SCLE. Furthermore, staining with a monoclonal antibody against 27E10, a distinct marker for cell activation and differentiation, revealed intense focal or band-like labelling of all epidermal layers independent of the type of lesion.

CONCLUSIONS

Expression of epidermal surface molecules such as ICAM-1, HLA-DR and 27E10 is equally upregulated in primary and UV-induced lesions of patients with LET, DLE and SCLE. These results support our recent clinical findings that LET represents a distinct subset of CLE with a similar immunopathomechanism rather than a different disease.

The CXCR3 activating chemokines IP-10, Mig, and IP-9 are expressed in allergic but not in irritant patch test reactions

Differentiation between allergic and irritant contact dermatitis reactions is difficult, as both inflammatory diseases are clinically, histologically, and immunohistologically very similar. Previous studies in mice revealed that the chemokine IP-10 is exclusively expressed in allergic contact dermatitis reactions. In the present study, we investigated whether the mRNA expression of IP-10 and the related CXCR3 activating chemokines, Mig and IP-9 are also differentially expressed in human allergic contact dermatitis and irritant contact dermatitis reactions. Skin biopsies from allergic (13 cases) and sodium lauryl sulfate-induced irritant patch test reactions (13 cases), obtained 1-72 h after patch testing, were studied by means of an in situ hybridization technique. Results of chemokine mRNA expression were correlated with clinical scoring, histology, and immunohistochemical data including the proportion of inflammatory cells expressing CXCR3, the receptor for IP-10, Mig, and IP-9, and ICAM-1 and HLA-DR expression on keratinocytes. IP-10, Mig, and IP-9 mRNA were detected in seven of nine allergic contact dermatitis reactions after 24-72 h, but not in sodium lauryl sulfate-induced irritant contact dermatitis reactions. ICAM-1 expression by keratinocytes was only found in allergic contact dermatitis reactions and correlated with chemokine expression. Moreover, up to 50% of the infiltrating cells in allergic contact dermatitis expressed CXCR3, in contrast to only 20% in irritant contact dermatitis reactions. In conclusion, we have demonstrated differences in chemokine expression between allergic contact dermatitis and irritant contact dermatitis reactions, which might reflect different regulatory mechanisms operating in these diseases and may be an important clue for differentiation between allergic contact dermatitis and irritant contact dermatitis reactions.

Nicotine- and arecoline-induced interleukin-1 secretion and intercellular adhesion molecular-1 expression in human oral epidermoid carcinoma cells in vitro

The purpose was to examine interleukin (IL)-1 concentrations and intercellular adhesion molecule (ICAM)-1 expression in nicotine/arecoline-exposed oral KB CCL17 cultures. Enzyme-linked immunosorbent assay was used to quantify IL-1 concentrations in culture supernatants. A repeated-measures analysis of variance was used to identify differences among the groups. IL-1 beta concentrations increased by 2.6, 2.7 and 7.5 times those of the control in groups treated with 1 microM nicotine, arecoline or with both, respectively. IL-1 beta concentrations were more dramatically increased when the agents tested were at 100 microM concentration. Similar, although less dramatic, alterations in IL-1 alpha concentrations were observed. The fluorescence intensity of ICAM-1 (CD54) analysed by flow cytometry was also significantly increased in a dose-dependent manner when the cells were treated with nicotine and/or arecoline. Nicotine and arecoline therefore significantly increased IL-1 alpha and -1 beta secretions and the surface expression of ICAM-1 in KB CCL17 cells.

Follicular cutaneous T-cell lymphoma: a clinicopathological study of nine cases

Nine patients with follicular cutaneous T-cell lymphoma (CTCL), a recently described variant of lymphoma, are presented. On the basis of clinical manifestations and disease course, three groups of patients were distinguished: (i) two patients with follicular CTCL not associated with conventional lesions of mycosis fungoides (MF) and showing no evolution towards MF in follow-up periods of 3 and 6 years; (ii) one patient with follicular CTCL that evolved into conventional MF within 3 years; (iii) six patients showing conventional MF lesions either before or concurrently with the follicular lesions and thus representing follicular CTCL of the true MF type. The follicular lesions included hair-devoid patches or plaques with spiky hyperkeratotic papules (four patients), keratosis pilaris-like lesions (four), comedo-like lesions (four), follicular papules with alopecia (three) and milia-like lesions (three). Histopathological examination showed perifollicular and intrafollicular lymphocytes, without mucin deposition and with minimal or no involvement of the overlying epidermis. Significant syringotropism was also observed in three cases. Immunohistochemical analysis showed the predominance of CD4 + T cells, deletion of CD7 in some cases, Ki-67 + lymphocytes confined mainly to the follicular epithelium, and expression of keratinocyte intercellular adhesion molecule-1 exclusively in the hair follicle. T-cell receptor gamma gene rearrangement was positive in the one case studied from each group. Different treatment modalities were employed, the most commonly used as monotherapy being phototherapy: psoralen ultraviolet A in four patients, two of whom showed a complete clinical and histopathological remission, and ultraviolet B in one patient, who showed a complete remission (both clinical and histopathological). This study indicates that follicular CTCL is more common than reflected in the literature, has heterogeneous clinical manifestations, and is either an expression of or closely related to MF. The influence of the follicular involvement on the therapeutic response remains to be clarified. However, our therapeutic experience clearly suggests that some patients with follicular CTCL can benefit from phototherapy.

Differentiation of normal human keratinocytes influences hexavalent chromium uptake and distribution and the ability of cells to withstand Cr(VI) cytotoxicity

The degree of differentiation of normal human keratinocytes determines the biology of the cells to a large extent. We have previously documented that keratinocytes from different donors differ significantly in their ability to withstand hexavalent chromium [Cr(VI)]-induced cytotoxicity. Several factors may contribute to this differing donor sensitivity to Cr(VI). The aims of this study were to investigate to what extent keratinocyte differentiation might influence Cr(VI) uptake and the ability of cells to withstand Cr(VI)-induced cytotoxicity. Keratinocytes from different donors were cultured under identical conditions and exposed to Cr(VI) (as potassium dichromate) at different points during their maturation process. The degree of differentiation of the cells was assessed using a quantitative assay for involucrin and related to the Cr(VI) cytotoxicity experienced by the cells. Chromium content was measured in whole cell, cytosolic and particulate fractions. While proliferative keratinocytes exposed to Cr(VI) showed a high degree of cytotoxicity to dichromate exposure, the more differentiated cells showed significantly less cytotoxicity but a higher uptake of the metal ion into the cells. The relative percentage of cytosolic chromium was high in the proliferative cells and decreased as the cells matured, suggesting that differentiated cultures were binding most of the chromium to the particulate fraction. Total chromium also increased during differentiation. The use of the channel-blocking agent 4, 4'-diisothiocyanate-2-2'-stilbenedisulphonic acid confirmed the spatial differences of chromium accumulation in the phenotypically different cultures, in that it prevented Cr(VI) entry into the proliferative cells and attenuated dichromate cytotoxicity in these cultures, but had no effect on the Cr(VI) uptake in differentiated cells, nor did it reduce its cytotoxicity. These data support the hypothesis that the upper differentiated layers of the epidermis are able to offer considerable physical protection to the lower proliferative layers from chemical pro-oxidants.

Follicular mycosis fungoides

We describe a patient with follicular mycosis fungoides (MF), a rare folliculotropic variant of cutaneous T-cell lymphoma (CTCL). Follicular involvement in CTCL usually presents clinically as alopecia mucinosa associated histologically with follicular mucinosis. Follicular MF differs from alopecia mucinosa/follicular mucinosis associated with MF with regard to its clinical presentation, histology and, presumably, prognosis. Our patient presented with the characteristic findings of follicular MF, i.e. infiltrated plaques showing numerous enlarged, comedo-like follicular infundibula; histology was dominated by exclusive folliculotropism of atypical lymphocytes sometimes forming follicular Pautrier's microabscesses, and by lack of epidermotropism and follicular mucinosis. Despite photochemotherapy and treatment with oral retinoids and interferon alpha, the patient's follicular MF rapidly developed into a progressive CTCL with large tumorous lesions, but responded to electron beam therapy. The course of our patient's disease confirms the notion that follicular MF may be associated with a worse prognosis than classical MF. However, electron beam irradiation induced remission of follicular MF that was maintained by a combination therapy consisting of extracorporeal photopheresis and interferon alfa.

The epidermal phenotype during initiation of the psoriatic lesion in the symptomless margin of relapsing psoriasis

BACKGROUND

The mature psoriatic lesion does not necessarily demonstrate changes relevant to early phases of the lesion.

OBJECTIVE

In a model for relapsing psoriasis we examined the epidermal phenotype by means of a panel of immunohistochemical parameters: keratins 14 and 16, epidermal growth factor receptor (EGFR), Ki-67 antigen, and Tdt-mediated Unscheduled Nick End Labeling to detect apoptosis.

METHODS

In 9 patients, we cleared psoriatic plaques by topical treatment with clobetasol-17-propionate under hydrocolloid occlusion. Relapse (defined as a clinical sum score > or = 6) was awaited. Biopsy specimens of the psoriatic lesion, the cleared skin, the relapsed plaque, and its clinically normal margin were assessed.

RESULTS

Psoriasis recurred after 19+/-6 weeks (mean +/- SEM). During treatment all parameters improved considerably; however, the number of apoptotic cells was not affected. Ki-67 values decreased well below the normal range. At initial relapse, the symptomless skin adjacent to the relapsing lesion (margin) showed a marked expression of keratin 16 and EGFR. Ki-67 expression was increasing in the margin but was below values of the mature lesion. The localization of cycling cells in the first suprabasal layers was a remarkable feature. Keratin 14 expression was increased in the recurrent lesion itself, but not in the symptomless margin.

CONCLUSION

Keratin 16 and EGFR expression are early phenomena in the evolution of the lesion, and they anticipate epidermal proliferation. The expression of keratin 14 follows overt epidermal hyperproliferation. The present observation in incipient psoriasis lends support to the hypothesis that the basal cell compartment does not have a primary involvement in the initiation of epidermal abnormalities in psoriasis, but that a coordinated sequence of events involving proliferation and differentiation markers in the first suprabasal layers of the epidermis could be the key to the pathogenesis of this puzzling disease.

Humanized antibodies as potential therapeutic drugs

BACKGROUND

Antibodies have been used therapeutically to treat a variety of clinical conditions. The introduction of monoclonal antibodies and more recently, engineered humanized antibodies has greatly refined and expanded the therapeutic potential of this modality of treatment.

LEARNING OBJECTIVES

To reinforce the reader's knowledge of the therapeutic application of antibody in the treatment for different diseases. More specifically, to enhance reader's understanding of basic methods employed in the production and clinical use of humanized antibodies.

DATA SOURCE

The MEDLINE database was used to review the humanized antibody related literature.

CONCLUSION

Humanized antibodies provide a novel approach for the treatment of a broad range of diseases. Expanded use will depend on improvement in their efficacy (avidity and specificity), demonstration of their safety, and reduction of their immunogenicity.

The participation of proliferative keratinocytes in the preimmune response to sensitizing agents

The aims of this study were to investigate whether keratinocytes are capable of playing a direct preimmune role in the pathophysiology of allergic contact dermatitis (ACD) and to examine to what extent the degree of differentiation might influence this. We measured the ability of sensitizing agents to up-regulate intercellular adhesion molecule 1 (ICAM-1) expression in cultured normal human keratinocytes (NHK) and in the transformed human keratinocyte HaCaT cell line. In proliferative HaCaT cells, following a 24 h exposure, nickel compounds, para-phenylenediamine (pPD) and 1-chloro-2,4-dinitrobenzene produced a concentration-dependent up-regulation of ICAM-1 expression without reducing cell viability, while K2Cr2O7 led to ICAM-1 up-regulation at cytotoxic concentrations, and CrCl3 was without effect. In NHK, NiSO4 and pPD induced ICAM-1 expression to a significantly greater extent in proliferative cells than in differentiated cells, where involucrin expression was measured to assess the differentiation state. NiSO4- or pPD-pretreatment of proliferative HaCaT cells enhanced T-cell binding, which was abolished by neutralizing antibodies to ICAM-1 or CD18. Our investigations concerning the involvement of oxidative stress in the induction of ICAM-1 expression in response to sensitizing agents were inconclusive. The oxidizing agents FeCl3 and H2O2 up-regulated ICAM-1 expression in HaCaT cells but there was no clear relationship between the ability of agents to induce ICAM-1 expression and their ability to alter the levels of reduced glutathione. Although pPD increased interleukin-1 alpha release from NHK, this cytokine was not capable of inducing ICAM-1 expression in NHK. Tumour necrosis factor-alpha, which does induce ICAM-1 expression in NHK, was not detected in response to pPD, arguing against an autocrine pathway of ICAM-1 induction in response to pPD. In summary, we report the direct interaction of sensitizing agents with keratinocytes leading to the generation of immune signals, particularly by proliferative keratinocytes, suggesting an active role for the proliferative keratinocyte in the pathophysiology of ACD.

Adhesion molecules in vernal keratoconjunctivitis

AIMS/BACKGROUND

Adhesion molecules play a key role in the selective recruitment of different leucocyte population to inflammatory sites. The purpose of the present study was to investigate the presence and distribution of adhesion molecules in the conjunctiva of patients with vernal keratoconjunctivitis (VKC).

METHODS

The presence and distribution of adhesion molecules were studied in 14 conjunctival biopsy specimens from seven patients with active VKC and in four normal conjunctival biopsy specimens. We used a panel of specific monoclonal antibodies (mAbs) directed against intercellular adhesion molecule-1 (ICAM-1), intercellular adhesion molecule-3 (ICAM-3), lymphocyte function associated antigen-1 (LFA-1), very late activation antigen-4 (VLA-4), vascular cell adhesion molecule-1 (VCAM-1), and endothelial leucocyte adhesion molecule-1 (ELAM-1) In addition, a panel of mAbs were used to characterise the composition of the inflammatory infiltrate.

RESULTS

In the normal conjunctiva, ICAM-1 was expressed on the vascular endothelium only, LFA-1 and ICAM-3 on epithelial and stromal mononuclear cells, and VLA-4 on stromal mononuclear cells. The expression of VCAM-1 and ELAM-1 was absent. The number of cells expressing adhesion molecules was found to be markedly increased in all VKC specimens. This was concurrent with a heavy inflammatory infiltrate. Strong ICAM-1 expression was induced on the basal epithelial cells, and vascular endothelial cells. Furthermore, ICAM-I was expressed on stromal mononuclear cells. LFA-1 and ICAM-3 were expressed on the majority of epithelial and stromal infiltrating mononuclear cells. VLA-4 expression was noted on stromal mononuclear cells. Compared with controls, VKC specimens showed significantly more ICAM-3+, LFA-3+, LFA-1+, and VLA-4+ cells. VCAM-1 and ELAM-1 were induced on the vascular endothelial cells.

CONCLUSIONS

Increased expression of adhesion molecules may play an important role in the pathogenesis of VKC.

Immunopathogenesis of oral lichen planus and recurrent aphthous stomatitis

Oral mucosal bullous/desquamative/ulcerative diseases involve immunopathological mechanisms that account for loss of adhesion between contiguous keratinocytes or to structures within the basal lamina. Some are antibody mediated, in which specific adhesion molecules of the desmosome, hemidesmosome, and basement membrane become antigenic targets. Oral lichen planus and recurrent apthous ulcers, although manifesting disparate clinical appearances and natural history, share immunopathological features that involve T cell-mediated immunity. Although the antigens, haptens, or autoantigens are not usually apparent, current research poses the hypothesis that both of these common oral mucosal diseases are a delayed-type hypersensitivity or cell-mediated response to an antigenic stimulus residing within the epithelium. This article reviews the research evidence for this hypothesis.

Characterization of T-cell subsets infiltrating post-burn hypertrophic scar tissues

In this study, skin-infiltrating cells were characterized in both the active and remission phases of post-burn hypertrophic scar biopsies. Immunohistochemistry examination of active phase samples showed an abundant presence of Langerhans cells, T cells, macrophages, a low presence of natural killer cells and the lack of B lymphocytes. In active hypertrophic scars T lymphocytes infiltrate deep into the superficial dermis and are also observed in the epidermis: CD3+ cells were present at about 222 +/- 107 per 0.25 mm2. In particular the analysis of lymphocyte subpopulations showed that CD4+ T cells predominate in the dermis as well as in the epidermis of active hypertrophic scars whereas CD8+ cells were less well represented (CD4/CD8 ratio is 2.06). This distribution was also shown in remission phase samples and in normotrophic scar specimens, although the lymphocyte number was significantly lower. Approximately 70 per cent of T lymphocytes present in the tissue involved in active phase hypertrophic scar samples were activated (positive with anti-HLA-DR and IL-2 receptor antibodies) which is significantly higher than remission phase hypertrophic and normotrophic scars, in which positivity was 40 and 38 per cent, respectively. Upon activation, the lesional lymphocytes release several cytokines, locally and transiently, that interact with specific receptors in response to different stimulation. Central to the immune hypothesis of hypertrophic scars is that some of the T-cell lymphokines act on keratinocytes, fibroblasts and other cell types to induce changes characteristic of these scars. The presence and close proximity of activated T lymphocytes and antigen-presenting cells of various phenotypes in both the epidermis and dermis of hypertrophic tissues provides strong circumstantial evidence of a local immune response. However, the manner in which T cells achieve and maintain their activated state in hypertrophic tissues is not yet known, and both antigen-dependent and independent mechanisms may contribute.

Zinc-induced suppression of inflammation in the respiratory tract, caused by infection with human rhinovirus and other irritants

Free ionic zinc (Zn2+) in saliva shortens duration and severity of common cold (CC) symptoms. It is proposed that Zn2+ complexes with proteins of critical nerve endings and surface proteins of human rhinovirus (HRV) (a) interrupt nerve impulses and (b) block docking of HRV on intercellular adhesion molecule-1 (ICAM-1) on somatic cells, thereby interrupting HRV infection. Since leukocyte function associated antigen-1 (LFA-1) binds leukocytes to cells through ICAM-1, initiating inflammation, Zn2+ is expected to block LFA-1/ICAM-1 binding and thereby suppress inflammation. This could explain reduction of inflammation experienced by persons taking zinc gluconate/glycine (ZGG) lozenges for CC. Allergic rhinitis (AR) and CC share many common symptoms, and ZGG also mitigates AR symptoms. Focal irritation, increased ICAM-1 expression, and recruitment of leukocytes to epithelial foci are the common elements. Zinc ions may be an important anti-inflammatory factor because they can block docking of both HRV and LFA-1 with ICAM-1.

Serum levels of soluble intercellular adhesion molecule-1 (ICAM-1) and the expression of ICAM-1 mRNA in uterine cervical cancer

The purpose of this investigation was to evaluate the serum level of soluble intercellular adhesion molecule-1 (sICAM-1) in patients with squamous cell carcinoma of the cervix. Serum levels of sICAM-1 were measured by enzyme-linked immunosorbent assay in patients with cervical cancer (stage 0 through IV). Expression of mRNA in tumor tissues was evaluated by reverse transcriptase-polymerase chain reaction. Serum level of sICAM-1 in patients with advanced-stage (II-IV) or recurrent cervical cancer was found to be increased significantly. Expression of ICAM-1 mRNA was observed in most tumor tissues. Results suggest that sICAM-1 is shed from the cancerous tissue in patients with squamous cell carcinoma of the cervix.

Follicular mycosis fungoides: a clinicohistopathologic study

BACKGROUND

Follicular mycosis fungoides (FMF) is a recently described variant of cutaneous T-cell lymphoma, histopathologically characterized by infiltrates of atypical CD4+ T lymphocytes around and within the epithelium of the hair follicles (folliculotropism). To date, only four cases of FMF have been reported.

OBJECTIVE

Our goal was to identify cases of FMF and compare them with those previously reported.

METHODS

The clinical and histopathologic features of three cases of FMF were analyzed. In addition, in one case immunohistochemical analysis in paraffin-embedded and frozen tissue as well as genotypic studies were performed.

RESULTS

The three reported cases showed typical histologic findings of FMF, namely, perifollicular and intrafollicular infiltrates of atypical lymphocytes, in the absence of either epidermotropism or follicular mucinosis. Clinically, the lesions were similar to classic MF, but also contained follicular papules. Immunohistochemistry and gene rearrangement studies showed findings similar to classic MF.

CONCLUSION

FMF is a rare variant of cutaneous T-cell lymphoma. Including our three cases, only seven patients have been reported. We hypothesize that the follicular epithelium in patients with FMF may express increased levels of skin-selective homing receptors and adhesion molecules. These may be involved in the induction of the folliculotropism of atypical lymphocytes.

Pervanadate mimics IFNgamma-mediated induction of ICAM-1 expression via activation of STAT proteins

Differential expression of intercellular adhesion molecule-1 (ICAM-1) in the epidermis plays a critical role in the regulation of cutaneous inflammation, immunologic reactions, and tissue repair. Transcriptional upregulation of ICAM-1 in response to interferon-gamma (IFNgamma) occurs through a palindromic response element pIgammaRE. pIgammaRE is homologous to IFNgamma-activated sequences, which bind to tyrosine phosphorylated members of the transcription factor family known as signal transducers and activators of transcription (STAT). The importance of tyrosine phosphorylation events in the STAT pathway led us to investigate the effect of the protein tyrosine phosphatase inhibitor, pervanadate, on ICAM-1 expression. We show that treatment of A431 cells and human keratinocytes with pervanadate stimulates protein complex formation on pIgammaRE in a time- and concentration-dependent manner. As demonstrated by mobility supershift assays, the pervanadate-stimulated complex is similar to the IFNgamma-stimulated complex and contains Stat1. Pervanadate treatment also led to an increase in overall protein tyrosine phosphorylation and phosphorylation of Stat1, as well as the subsequent increase in ICAM-1 mRNA and cell surface protein levels. These data show that pervanadate can mimic each step in the IFNgamma-mediated pathway leading to ICAM-1 expression, demonstrate the ability of a pharmacologic agent to bypass the standard cytokine-receptor interaction required for increased ICAM-1 expression, and emphasize the importance of protein tyrosine phosphatases and protein tyrosine kinases in mediating inflammatory responses in the skin.

Folliculotropic mycosis fungoides with large-cell transformation presenting as dissecting cellulitis of the scalp

Follicular mycosis fungoides (MF) is a rare variant of cutaneous T-cell lymphoma (CTCL) in which malignant lymphocytes preferentially infiltrate hair follicles. This report describes a patient with follicular mycosis fungoides presenting in a manner similar to dissecting cellulitis of the scalp with nonhealing, draining nodular lesions. Follicular mucinosis associated with folliculotropic mycosis fungoides resulted in follicular disruption and deep dissecting cellulitis. Large-cell transformation of CTCL was present in the initial diagnostic scalp and axillary lymph node specimens. The patient died from progressive CTCL 9 months following initial diagnosis despite electron beam radiation, topical mechlorethamine, interferon-alpha, and systemic chemotherapy. This case indicates that large-cell transformation of folliculotropic mycosis fungoides is an aggressive form of CTCL, and that folliculotropic mycosis fungoides can give rise to lesions which resemble dissecting cellulitis of the scalp. Upregulation of intercellular adhesion molecule-1 (ICAM-1) on follicular epithelium adjacent to lymphocyte function-associated antigen-1 (LFA-1)-positive folliculotropic lymphoma cells in this report provides insight into lymphocyte homing mechanisms in folliculotropic MF.

ICAM-1 expression on keratinocytes in mechanically-injured skin of a patient with atopic dermatitis

The expression of intercellular adhesion molecule-1 (ICAM-1) on keratinocytes was studied in skin specimens of patch- or scratch-test using Dermatophagoides farinae (DF) antigen in atopic dermatitis (AD). Positive patch test reaction showed exocytosis of lymphocytes and focal expression of ICAM-1 on keratinocytes. Similar lymphocyte infiltration and keratinocyte expression of ICAM-1 were observed in tape-stripped skin which was subjected as the control. In addition, focal ICAM-1 expression on keratinocytes was also observed without exocytosis of lymphocytes. By scratch-test with DF antigen, ICAM-1 expression on keratinocytes was observed in eight out of eleven patients. One specimen showed ICAM-1 expression in spite of the absence of exocytosis of lymphocytes. Two out of three specimens from negative scratch-test sites with control liquid (mixture of equal amount of saline and glycerine) showed ICAM-1 expression in a similar manner to that of the positive scratch tests. In normal control skin, patch-test sites showed focal and weak expression of ICAM-1. Normal appearing skin of AD also showed no ICAM-1 expression. Therefore, in patients with atopic dermatitis, keratinocytes may express ICAM-1 prior to infiltration of lymphocytes into the epidermis and this expression might be induced not only by cytokines produced by lymphocytes but also by mechanically injured (tape-stripped or scratched) epidermal cells.

The role of alpha E beta 7 integrin (CD103) and E-cadherin in epidermotropism in cutaneous T-cell lymphoma

Adhesion molecules such as integrins and cadherins are thought to play a critical role in T-cell migration and localization within the epidermis (epidermotropism). The purpose of this study was to correlate T-cell expression of the integrin CD103 and E-cadherin in cutaneous T-cell lymphoma (CTCL). Serial sections of skin biopsies from 22 patients with CTCL and 13 with benign reactive dermatitis were stained with antibodies to CD4, CD103, and E-cadherin by the avidin-biotin peroxidase technique. CD103 was expressed on single epidermotropic CD4+ T-cells in 9/9 early stage (patch/plaque) CTCL and 6/10 reactive dermatitis biopsies. Less than 30% of dermal T-cells expressed CD103. All 4/4 late stage (tumor) CTCL were CD103-. Epidermal aggregates of CD4+ T-cells (Pautrier's microabscesses) were CD103-. E-cadherin was expressed on epidermal keratinocytes and follicular and sweat gland epithelia but not on T-cells. We conclude that CD103 expression on cutaneous T-cells parallels the degree of epidermotropism exhibited in both neoplastic and inflammatory disorders of the skin. E-cadherin is not expressed on T-cells infiltrating the skin. Further investigation is necessary to further elucidate the interaction between CD103 and E-cadherin in facilitating trafficking of T-cells into the epidermis.

Expression of the adhesion molecules ICAM-1, VCAM-1, and E-selectin and their ligands VLA-4 and LFA-1 in chronic venous leg ulcers

BACKGROUND

Leukocyte binding to endothelial cells (ECs) is thought to contribute to the pathogenesis of leg ulcers caused by chronic venous insufficiency. In other systems, such binding is mediated by the interaction of adhesion molecules such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule- (VCAM-1) and E-selectin (on ECs), and leukocyte function-associated antigen-1(LFA-1) and very late activated antigen-4 (VLA-4) (on Leukocytes).

OBJECTIVE

Our purpose was to determine whether an increased expression of these adhesion molecules contributes to the pathogenesis of chronic venous insufficiency.

METHODS

Twenty-seven biopsy specimens of inflamed dermatoliposclerotic skin adjacent to venous leg ulcers were stained immunohistochemically with monoclonal antibodies against ICAM-1, VCAM-1, LFA-1, VLA-4, and E-selectin. Staining intensity was compared with that of normal skin.

RESULTS

Specimens of leg ulcers caused by chronic venous insufficiency showed increased expression of ICAM-1 and VCAM-1 but not of E-selectin on The expression of LFA-1 and VLA-4 on perivascular leukocytes was increased dramatically in comparison to healthy skin.

CONCLUSION

Upregulation of ICAM-1 and VCAM-1 on ECs may contribute to the increased adherence and extravasation of LFA-1 and VLA-4-positive leukocytes in chronic venous insufficiency.