Toll-like receptor signalling induces the expression of serum amyloid A in epidermal keratinocytes and dermal fibroblasts.

BACKGROUND: Toll-like receptors (TLRs) play critical roles in innate immune response by sensing pathogen- or damage-associated molecular patterns. Epidermal keratinocytes and dermal fibroblasts also produce proinflammatory cytokines and chemokines under stimulation with TLR ligands. Serum amyloid A (SAA) is an essential factor in the pathogenesis of secondary amyloidosis, and also has immunomodulatory functions. SAA are produced mainly by hepatocytes but also by a variety of cells, including immune cells, endothelial cells, synoviocytes, and epidermal keratinocytes. However, SAA expression in human dermal fibroblasts has not been shown to date. AIM: To investigate the effect of TLR ligands on SAA expression in epidermal keratinocytes and dermal fibroblasts. METHODS: We investigated whether TLR ligands induce the expression of SAA in normal human epidermal keratinocytes (NHEKs) and normal human dermal fibroblasts (NHDFs) by real-time quantitative PCR and ELISA. The effect of SAA on its own expression in NHDFs was also studied. RESULTS: SAA expression was induced via nuclear factor-κB by TLR1/2, 3, 5 and 2/6 ligands in NHEKs. In NHDFs, TLR1/2 and TLR2/6 ligands increased SAA expression. SAA further induced its own expression via TLR1/2 and NF-κB in NHDFs, as previously reported for NHEKs. CONCLUSIONS: Our results provide new evidence that the skin's innate immune response contributes to the production of SAA, which might lead to an increased risk of systemic complications such as secondary amyloidosis of recessive dystrophic epidermolysis bullosa.

Expression of serine protease inhibitors in epidermal keratinocytes is increased by calcium but not 1,25-dihydroxyvitamin D3 or retinoic acid.

BACKGROUND: In human skin, the serine proteases kallikrein-related peptidase (KLK)5 and KLK7 degrade corneodesmosome proteins, leading to desquamation. Serine protease activity of the skin is tightly regulated by the interplay between such proteases and serine protease inhibitors, including lymphoepithelial Kazal-type related inhibitor (LEKTI), encoded by SPINK5; secretory leucocyte peptidase inhibitor (SLPI); and elafin. Expression of KLK5 and KLK7 is controlled and upregulated by stimulants such as calcium, 1,25-dihydroxyvitamin D3 [1,25(OH)2 VD3 ] and retinoic acid (RA). OBJECTIVES: To understand the effect of calcium, 1,25(OH)2 VD3 and RA on the expression of serine protease inhibitors in epidermal keratinocytes. METHODS: We stimulated normal human epidermal keratinocytes (NHEKs) with high calcium, 1,25(OH)2 VD3 or RA, and then analysed the expression of serine protease inhibitors using quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay and immunocytofluorescence. We also analysed trypsin- and chymotrypsin-like serine protease activities in stimulated NHEKs. RESULTS: High calcium, but not 1,25(OH)2 VD3 or RA, significantly induced the expression of LEKTI, SLPI and elafin at both transcript and protein levels in NHEKs. These inductions were time- and dose-dependent. The activities of trypsin- and chymotrypsin-like serine proteases were significantly up- and downregulated by high calcium, respectively, in NHEKs. CONCLUSIONS: High calcium, but not 1,25(OH)2 VD3 or RA, increases the expression of serine protease inhibitors in epidermal keratinocytes. Our findings contribute to the understanding of the mechanisms by which serine protease activities are regulated by serine proteases and related inhibitors in epidermal keratinocytes.

Survival rates and prognostic factors of Epstein-Barr virus-associated hydroa vacciniforme and hypersensitivity to mosquito bites.

BACKGROUND: Epstein-Barr virus (EBV)-associated T/natural-killer lymphoproliferative disorders form a group of diseases that includes classical and systemic hydroa vacciniforme (HV) and hypersensitivity to mosquito bites (HMB). Patients with systemic HV (sHV) and HMB often have a poor prognosis, although little is known about the prognostic factors. OBJECTIVES: To elucidate the prognostic factors of HV and HMB. METHODS: We studied clinicopathological manifestations, routine laboratory findings, anti-EBV titres, EBV DNA load and EBV-encoded gene expression, including expression of BZLF1, in 50 patients with classical HV (cHV), sHV, HMB only and HMB with HV (HMB + HV), and further analysed 30 patients who were available for follow-up. RESULTS: The median age of disease onset was 5 years (range 1-74). A follow-up study indicated that fatal outcomes were observed in three of eight patients with sHV, two of six patients with HMB only, and two of five patients with HMB + HV. The main causes of death were complications from haematopoietic stem-cell transplantation and multiorgan failure. There were no fatalities among the 11 patients with cHV. Univariate analysis revealed two poor prognostic indicators: (i) onset age > 9 years and (ii) the expression of an EBV-encoded immediate-early gene transcript, BZLF1 mRNA, in the skin lesions (P < 0·001 and P = 0·003, respectively). CONCLUSIONS: No prognostic correlation was observed in EBV-infected lymphocyte subsets, anti-EBV antibody titres or EBV DNA load. Late onset and EBV reactivation are both related to more severe phenotypes of the disease, and thus may predict a poor prognosis.

Initial evidence demonstrating the association between the vascular status in surgically resected renal parenchymal pathology and sexual function.

Our goal is to evaluate the association between histopathology of glomerulosclerosis (GS) and atherosclerosis (AS) in the nephrectomized normal parenchyma together with patients' background, and erectile dysfunction (ED) of patients treated with radical nephrectomy (RN) for renal cell carcinoma (RCC). ED was assessed with the International Index of Erectile Function in 65 patients who were less than age 70 years at the time of questionnaire. Glomeruli status was assessed by the extent of global GS. AS was graded based on lumen occlusion and frequency of involvement. Patients' backgrounds included any comorbidities, post-RN renal insufficiency, tumor pathology, demographics and social status. The presence of diabetes mellitus and lack of a spouse were independent predictors for severe ED, whereas G0/1 AS was an independent predictor for mild/no ED. The extent of global GS was significantly lower in patients with mild/no ED than in other patients. Our study represents the first report identifying healthy arterial status in the renal parenchyma as a significant indicator of favorable erectile function and that the evaluation of AS severity is not a superior indicator of severe ED in the presence of comorbidities or social status among patients treated with RN.

Cathelicidin antimicrobial peptide LL-37 augments interferon-ß expression and antiviral activity induced by double-stranded RNA in keratinocytes.

BACKGROUND: Cathelicidin antimicrobial peptide LL-37 has the capacity to kill a wide range of microbes and to modify host immunity. Recently, our group observed that the activation of keratinocytes by LL-37 and DNA greatly increases interferon (IFN)-ß through Toll-like receptor (TLR)9. However, the effect of LL-37 on the induction of IFN-ß through TLR3, a sensor of double-stranded (ds) RNA, in keratinocytes is not well known. OBJECTIVES: To investigate whether LL-37 could affect TLR3 signalling and antiviral activity in normal human epidermal keratinocytes (NHEKs). METHODS: We investigated the production of IFN-ß in NHEKs stimulated with a TLR3 ligand, poly (I:C), in the presence of LL-37. To examine the effect of LL-37 and poly (I:C) on antiviral activity, a virus plaque assay using herpes simplex (HS) virus type-1 was carried out. The uptake of poly (I:C) conjugated with fluorescein isothiocyanate (FITC) into the keratinocytes was observed in the presence of LL-37. Immunostaining for TLR3 and LL-37 was performed using skin samples from HS. RESULTS: LL-37 and poly (I:C) synergistically induced the expression of IFN-ß in NHEKs. Furthermore, co-stimulation with LL-37 and poly (I:C) significantly decreased the viral plaque numbers compared with poly (I:C) or LL-37 alone. LL-37 enhanced the uptake of FITC-conjugated poly (I:C) into cells. Immunohistochemical analysis demonstrated that the expression of TLR3 and LL-37 is upregulated in HS lesions. CONCLUSIONS: Our findings suggest that LL-37 augments the antiviral activity induced by dsRNA in keratinocytes, which may contribute to the innate immune response to cutaneous viral infections such as HS.

Detection of antibodies against the non-calcium-dependent epitopes of desmoglein 3 in pemphigus vulgaris and their pathogenic significance.

BACKGROUND: Antidesmoglein (anti-Dsg) 3 serum antibody titres are usually correlated with the disease activity of pemphigus vulgaris (PV), but some patients retain high titres even in remission. OBJECTIVES: The aim of our study was to determine whether anti-Dsg3 antibodies in PV sera recognized calcium (Ca(2+) )-dependent or non-Ca(2+) -dependent epitopes, and to evaluate their pathogenicity. METHODS: Dsg3 baculoprotein-coated enzyme-linked immunosorbent assay (ELISA) plates were treated with 0.5 mmol L(-1) ethylenediaminetetraacetic acid (EDTA). The binding ability of anti-Dsg3 monoclonal antibodies (mAbs) was analysed. Eight of the 83 patients with PV who were screened had elevated Dsg3 ELISA index values > 00 in remission. The binding ability of these PV sera was analysed. We evaluated the pathogenicity of anti-Dsg3 serum antibodies against the non-Ca(2+) -dependent epitopes using a dissociation assay. RESULTS: The reactivity of pathogenic anti-Dsg3 mAbs against the Ca(2+) -dependent epitopes diminished markedly in the EDTA-treated ELISA, whereas no such reduction was observed in mAbs against the non-Ca(2+) -dependent epitopes. The sera of all the patients contained antibodies against both Ca(2+) -dependent and non-Ca(2+) -dependent epitopes. In six out of the eight patients, the ratio of antibodies against Ca(2+) -dependent to non-Ca(2+) -dependent epitopes decreased in remission. EDTA-treated Dsg3 baculoproteins adsorbed anti-Dsg3 serum antibodies against the non-Ca(2+) -dependent epitopes, but the remnant PV antibodies retained the ability to induce acantholysis in the dissociation assay. CONCLUSIONS: We have established an assay to measure indirectly the titres of anti-Dsg3 serum antibodies against the Ca(2+) -dependent epitopes, based on the differences between EDTA-untreated and EDTA-treated ELISA index values, as a routine laboratory test to reflect the pathogenic anti-Dsg3 serum antibody titres more accurately.

Granulysin-producing cytotoxic T cells in the mucocutaneous lesions of Behçet disease: a distinct inflammatory response from erythema nodosum.

BACKGROUND: Cytotoxic T lymphocytes (CTLs) have been recognized as an important effector cell in Behçet disease (BD). Granulysin is a cytolytic granule protein expressed by CTLs and natural killer cells. AIM: To evaluate the involvement of granulysin-producing T cells in the pathogenesis of BD. METHODS: Using immunohistochemistry, lymphocyte subsets expressing granulysin were investigated in mucocutaneous lesions of BD. Serum granulysin levels were assayed by ELISA. RESULTS: Granulysin-positive cells were seen in specimens from oral ulcers, genital ulcers and acne-like eruptions, but not erythema nodosum-like lesions. Both CD4+ and CD8+ T cells expressed granulysin. Serum granulysin levels did not correlate with disease activity in BD. CONCLUSION: Immune reactions mediated by granulysin-positive CTLs may play an important role in the pathogenesis of acne-like eruptions, oral ulcers and genital ulcers in BD.

Ichthyosiform eruptions in association with primary cutaneous T-cell lymphomas.

BACKGROUND: Malignant lymphoma is occasionally complicated by ichthyosiform eruptions. OBJECTIVES: To analyse histopathologically the ichthyosiform eruptions associated with cutaneous lymphomas. METHODS: We reviewed the files of patients with malignant lymphoma seen in our dermatology department between January 2001 and May 2006 to search for patients with ichthyosiform eruptions. RESULTS: In our series, nine of 106 patients with malignant lymphomas had ichthyosiform eruptions during their clinical courses, including three (30%) of 10 patients with anaplastic large cell lymphoma (ALCL) and six (14%) of 44 patients with mycosis fungoides (MF). None of the 18 patients with cutaneous B-cell lymphoma had ichthyosiform eruptions. The three patients with ALCL had ichthyosiform eruptions histopathologically consistent with acquired ichthyosis (AI) in which packed horny layers and thin granular layers were present without lymphocytic infiltration. In contrast, four of the six patients with MF (stages Ib and IIb) had ichthyosiform eruptions with epidermotropic infiltration of atypical lymphocytes, as observed in ichthyosiform MF (IMF). Of the remaining two patients, one showed histopathological features overlapping AI and IMF, and the other had AI alone. These two patients (stages IVa and IIb) had tumours composed of CD30+ cells. Filaggrin expression was markedly diminished in both AI and IMF-like eruptions, similar to that of inherited ichthyosis vulgaris. CONCLUSIONS: Ichthyosiform eruptions are often associated with ALCL and MF and can be classified into three groups: AI associated with ALCL and MF expressing CD30, IMF, and their overlap.

The role of CD4 and CD8 cytotoxic T lymphocytes in the formation of viral vesicles.

BACKGROUND: Herpetic vesicles caused by herpes simplex virus and varicella zoster virus, and hydroa vacciniforme (HV) are characterized by umbilicated vesicule formation. OBJECTIVES: To understand the histogenesis of umbilicated vesicles in herpetic vesicles and HV, we demonstrated the presence of the virus-associated molecules in the lesions, and the pathogenic role of cytotoxic T-lymphocyte (CTL) immune responses. METHODS: Phenotyping of infiltrating cells was carried out in biopsy specimens from herpes simplex, varicella, herpes zoster and HV, and compared with nonviral contact dermatitis. Viral antigens and Epstein-Barr virus-encoded small nuclear RNA (EBER) were detected by immunostaining and by in situ hybridization, respectively. Infiltrating CTLs expressing granzyme B and granulysin were determined by double immunostaining using confocal laser scanning microscopy. RESULTS: In all herpetic vesicles, the corresponding viral antigens were observed in the cytopathic keratinocytes, and infiltration of lymphoid cells was present in the upper dermis and around the vessels. In all HV lesions studied, EBER+ T cells made up 5-10% of the dermal infiltrates and the dermal infiltrates contained almost no CD56 cells. CTLs expressing granzyme B and granulysin were present in both herpetic and HV lesions, in which they made up 10-30% of the total dermal infiltrates, whereas they comprised less than 5% of the infiltrates of biopsy specimens from nonviral contact dermatitis. Confocal laser microscopic examination demonstrated that both CD4+ and CD8+ T cells expressed granzyme B and granulysin. CONCLUSIONS: CD4+ and/or CD8+ CTLs reactive to the virus-infected cells might be responsible for the histogenesis of herpetic and HV lesions characterized by umbilicated vesicles.

Involvement of granulysin-producing T cells in the development of superficial microbial folliculitis.

BACKGROUND: Granulysin is a recently identified antimicrobial protein expressed on cytotoxic T cells, natural killer (NK) cells and NKT cells. It has been shown that granulysin contributes to the defence mechanisms against mycobacterial infection. Superficial microbial folliculitis is a common skin disease. In a previous report, we showed that, as a first line of defence, alpha-defensin, a human neutrophil peptide, and beta-defensin (human beta-defensin-2) were expressed in infiltrating neutrophils and in lesional epidermal keratinocytes, respectively, in superficial folliculitis. As we also observed many infiltrating lymphocytes in lesional dermis, we hypothesized that infiltrating lymphocytes may possess antimicrobial substances, such as granulysin, and play a role in the defence mechanism as a second line of defence. OBJECTIVES: Seven specimens of superficial microbial folliculitis diagnosed clinically and histologically were examined by means of immunohistochemistry. To identify the phenotype of cells expressing granulysin, confocal laser microscopic examination was performed. RESULTS: A dense lymphoid cell infiltrate was observed in pustules, in the perivascular regions. A large number of these lymphoid cells were positive for granulysin. Phenotypically, cells consisted of CD3+ T cells, CD8+ T cells and UCHL-1+ T cells. CD20+ cells and CD56+ cells were not observed. Microscopic examination with a confocal laser showed that the lymphocytes producing granulysin were CD3+ and CD4+ T cells but not CD8+ T cells. CONCLUSIONS: We showed that many granulysin-bearing T cells infiltrated affected follicles and perilesional dermis in superficial microbial folliculitis. However, few granulysin-positive lymphoid cells were observed in sterile pustular lesions. Our observations indicated that adaptive immunity such as granulysin, a lymphocyte-produced antimicrobial protein, may play an important role in the cutaneous defence mechanism.