Yoshinori Aragane

Intravenous Infusion of Syngeneic Apoptotic Cells by Photopheresis Induces Antigen-Specific Regulatory T Cells

The basis of extracorporeal photopheresis is the reinfusion of leukocytes previously exposed to 8-methoxypsoralen (8-MOP) and UVA radiation. It has been approved for the palliative treatment of cutaneous T cell lymphoma and has reported benefits in autoimmune diseases, transplant rejection, and graft-vs-host disease. However, the underlying mechanism of photopheresis remains unresolved. Because UVB radiation can cause immune tolerance via induction of regulatory T cells, we studied whether photopheresis exerts a similar effect extracorporeally. Therefore, we established a model of photopheresis using a murine model of contact hypersensitivity. Splenocytes and lymph node cells of mice that were sensitized with dinitrofluorobenzene were exposed to 8-MOP plus UVA in vitro. Intravenous injection of these cells into naive mice caused inhibition of a hapten immune response, which was lost upon depletion of CD11c+ cells but not T cells. Mice that received untreated cells or cells exposed to UVA or 8-MOP alone were not affected. Inhibition was cell-mediated and Ag-specific as demonstrated by transfer of tolerance from the primary recipients into naive animals, which could, however, properly respond to the unrelated hapten oxazolone. Transfer activity was lost when cells were depleted of CD4+ or CD25+ subpopulations. These data suggest that photopheresis exerts its immunomodulatory effects via the induction of Ag-specific regulatory T cells.

Ultraviolet Radiation-Induced Regulatory T Cells Not Only Inhibit the Induction but Can Suppress the Effector Phase of Contact Hypersensitivity

Epicutaneous application of haptens to UV-exposed skin induces hapten-specific tolerance. This is mediated via regulatory T cells (Tr), as i.v. injection of T cells from UV-tolerized mice into naive animals renders the recipients unresponsive to the respective hapten. However, when UV-induced Tr are injected i.v. into sensitized mice, contact hypersensitivity (CHS) is not suppressed, suggesting that Tr inhibit the induction, but not the elicitation, of CHS and are inferior to T effector cells. As sensitization takes place in the lymph nodes, but elicitation occurs in the area of challenge, we postulated that Tr injected i.v. locate to the lymph nodes and not to the periphery and therefore only suppress the induction, not the elicitation, of CHS. Indeed, i.v. injection of Tr into sensitized mice did not inhibit CHS, although injection of Tr into the ears of sensitized mice suppressed the challenge. Inhibition was hapten specific, as injection of dinitrofluorobenzene (DNFB)-specific Tr into the ears of oxazolone (OXA)-sensitized mice did not affect challenge with OXA. However, when ears of OXA-sensitized mice were injected with DNFB-specific Tr and painted with DNFB before OXA challenge, CHS was suppressed. Inhibition correlated with the local expression of IL-10. Depletion studies and FACS analysis revealed that Tr express the lymph node-homing receptor L-selectin, but not the ligands for the skin-homing receptors E- and P-selectin, suggesting that UV-induced Tr, although able to inhibit T effector cells, do not suppress the elicitation of CHS upon i.v. injection, because they obviously do not migrate into the skin.

Acne phototherapy with a high-intensity, enhanced, narrow- band, blue light source: an open study and in vitro investigation

The purpose of this study was to investigate the efficacy of phototherapy with a newly-developed high-intensity, enhanced, narrow-band, blue light source in patients with mild to moderate acne. An open study was performed in acne patients who were treated twice a week up to 5 weeks. Acne lesions were reduced by 64%. Two patients experienced dryness. No patient discontinued treatment due to adverse effects. In vitro investigation revealed that irradiation from this light source reduced the number of Propionibacterium acnes (P. acnes), but not Staphylococcus epidermidis that were isolated from the acne patients. Phototherapy using this blue light source was effective and well tolerated in acne patients and had an ability to decrease numbers of P. acnes in vitro, suggesting that this phototherapy may be a new modality for the treatment of acne.

Involvement of dectin-2 in ultraviolet radiation-induced tolerance.

Hapten sensitization through UV-exposed skin induces hapten-specific tolerance which can be adoptively transferred by injecting T cells into naive recipients. The exact phenotype of the regulatory T cells responsible for inhibiting the immune response and their mode of action remain largely unclear. Dectin-2 is a C-type lectin receptor expressed on APCs. It was postulated that dectin-2 interacts with its putative ligands on T cells and that the interaction may deliver costimulatory signals in naive T cells. Using a soluble fusion protein of dectin-2 (sDec2) which should inhibit this interaction, we studied the effect on contact hypersensitivity (CHS) and its modulation by UV radiation. Injection of sDec2 affected neither the induction nor the elicitation phase of CHS. In contrast, UV-induced inhibition of the CHS induction was prevented upon injection of sDec2. In addition, hapten-specific tolerance did not develop. Even more importantly, injection of sDec2 into tolerized mice rendered the recipients susceptible to the specific hapten, indicating that sDec2 can break established tolerance. FACS analysis of spleen and lymph node cells revealed a significantly increased portion of sDec2-binding T cells in UV-tolerized mice. Furthermore, transfer of UV-mediated suppression was lost upon depletion of the sDec2-positive T cells. Taken together, these data indicate that dectin-2 and its yet unidentified ligand may play a crucial role in the mediation of UV-induced immunosuppression. Moreover, sDec2-reactive T cells appear to represent the regulatory T cells responsible for mediating UV-induced tolerance.

Immunohistochemical detection for nuclear β‐catenin in sporadic basal cell carcinoma

Background Despite the increasing incidence of basal cell carcinoma (BCC), its pathogenesis has remained largely unknown. Recently, it was reported that genes involved in tissue morphogenesis, such as sonic hedgehog or patched, were found to be mutated in BCC, suggesting the involvement of those molecules in the pathogenesis of this tumour. Furthermore, there is evidence that the Wnt‐mediated signalling pathway may be one of the downstream targets of sonic hedgehog‐mediated signalling, which has led us to focus on molecular events on the Wnt pathway in BCC. Among the signal transducers involved in the Wnt pathway, it is clear that β‐catenin plays a pivotal role in the promotion of morphogenesis and cell growth. In respect to this, it has been reported that, in particular circumstances, as in colorectal cancers, β‐catenin migrates to the nuclei, where it exerts an ability to activate the transcription of various genes.

Videomicroscopic and histopathological investigation of intense pulsed light therapy for solar lentigines.

A noncoherent, broadband, intense pulsed light source has been effective for symptoms of photoaging skin as a nonablative method. The purpose of this study was to investigate the mechanism of efficacy of intense pulsed light for solar lentigines, a symptom of photoaging skin, with videomicroscopy and histopathology. Skin lesions of patients with solar lentigines who received one treatment of intense pulsed light were examined. Sixteen of 20 patients showed tiny crusts clinically. These tiny crusts were confirmed to be micro-crust formation after epidermal injury with sequential observation using videomicroscope and histopathology. Drop-off of micro-crusts with ample melanin pigments lead to clinical improvement of skin lesions. Intense pulsed light with absorption spectrum for melanin induced injury of melanin-containing epidermal cells via photothermal effects, suggesting that intense pulsed light may be a new modality for solar lentigines.

Successful Treatment of Pulmonary Metastasis and Local Recurrence of Angiosarcoma with Docetaxel

Angiosarcoma of the face and scalp of the elderly frequently recurs locally, metastasizes early despite various treatments, and has a poor prognosis. We describe a patient who had angiosarcoma of the scalp with pulmonary metastasis. Local recurrence occurred after excision and local and arterial administration of IL‐2. A weekly administration method of docetaxel was therefore selected, resulting in complete remission of the pulmonary metastasis and a partial response of the local recurrence. This favorable clinical outcome in our case suggests that docetaxel therapy may be an option for the treatment of angiosarcoma of the scalp with pulmonary metastasis.

Levofloxacin is effective for inflammatory acne and achieves high levels in the lesions: an open study.

The oral antibiotics used to treat acne include tetracycline, doxycycline and minocycline as first-line therapy, while erythromycin, trimethoprim-sulfamethoxazole and ampicillin/amoxicillin are used as alternatives [1, 2]. The quinolones have a broad spectrum of action against gram-positive and gram-negative bacteria. Levofloxacin (LVFX) is an optically active isomer of racemic ofloxacin with an antibacterial activity twice that of the parent compound [3]. LVFX has been reported to be as effective and safe as ciprofloxacin for the treatment of uncomplicated infections of the skin and appendages [4]. In this investigation, we performed an open study of a new quinolone, LVFX, as oral therapy of acne vulgaris from August 2000 to April 2001. Thirty-five patients, 25 females and 10 males, with inflammatory acne lesions participated in this study. The average age was 24 years (range 14–45). Each patient had at least 15 superficial inflammatory lesions (papules and/or pustules) and fewer than 5 deep lesions (nodules and/or macrocysts) and had no past history of oral antibiotics for acne. Seven and 6 patients had received gentamicin and nadifloxacine creams in the last previous year, respectively. During the 4 weeks prior to the study, no medication was administered. The aims of the study were explained to the patients, and they gave informed consent. Each patient took LVFX at a dose of 100 mg three times a day for 4 weeks, during which time any other acne therapy was prohibited. Clinical assessment was performed 3 times during the trial period (0, 2 and 4 weeks). Two patients discontinued treatment for non-medical reasons. First, the number of inflammatory lesions was counted. Before the treatment, the number of papules, pustules and papules + pustules (mean B SD) was 23.4 B 14.4, 8.2 B 7.8 and 31.5 B 20.5, respectively. At 2 weeks, the numbers (means B SD) were 14.4 B 11.8, 4.0 B 5.1 and 18.4 B 16.0, respectively. At 4 weeks, the numbers (means B SD) were 9.8 B 9.2, 1.9 B 3.0 and 11.7 B 11.7, respectively. Thus, LVFX achieved a marked reduction of papules, pustules and papules + pustules by 38.5, 51.2 and 41.6% at 2 weeks, as well as by 58.1, 76.8 and 62.9% at 4 weeks, respectively. The secondary criterion was the investigator’s global improvement rating on a 5-point scale (–1 = worsened, 0 = unchanged, 1 = improved, 2 = markedly improved and 3 = resolved). Assessment of efficacy showed that 68.6 and 85.7% of the patients were improved by weeks 2 and 4, respectively (table 1). By week 4, 71.4% of the patients showed marked improvement or clearance of their acne lesions (table 1). No adverse effects were seen in any of the patients and no patient discontinued treatment due to adverse effects. Eleven strains of Propionibacterium acnes, 8 strains of Staphylococcus epidermidis and 1 strain of Enterobacter aerogenes were isolated, with P. acnes and S. epidermis being isolated simultaneously from 7 specimens. Ten of the 11 P. acnes strains had a minimum inhibitory concentration (MIC) of 0.12 Ìg/ml, while the MIC of the remaining strain was 0.25 Ìg/ml. The MIC80 of LVFX for P. acnes was 0.12 Ìg/ml. MIC values for S. epidermidis ranged from 0.25 to 4 Ìg/ml, with the MIC80 of LVFX being 4 Ìg/ml. The MIC for E. aerogenes was 0.12 Ìg/ml. The values of MIC80 of minocycline, tetracycline and erythromycin for P. acnes were 0.03, 0.12 and 0.03 Ìg/ml, respectively. The values of MIC80 of minocycline, tetracyline and erythromycin for S. epidermidis were 0.5, 1.0 and 16 Ìg/ml, respectively. The LVFX concentration of the content of comedones in 21 randomly selected patients at 2 weeks was measured with HPLC. The LVFX level ranged from 0.69 to 34.48 Ìg/g with a mean

Myoepithelioma possibly originating from the accessory parotid gland.

Myoepithelioma originates almost exclusively from myoepithelial cells of the salivary, prostate and mammary glands. The skin is a very rare site where myoepithelioma occurs. We describe a patient with a myoepithelioma on the right cheek seen as a subcutaneous nodule that was separated from the parotid gland at surgical resection. Histopathological findings were consistent with those of a myoepithelioma that had originated from the parotid gland, suggesting that this tumor may have developed from the accessory parotid gland.

Disseminated scleroderma of a Japanese patient successfully treated with bath PUVA photochemotherapy.

BackgroundLocalized scleroderma is known to be resistant to therapies. Recently, it has been reported that bath PUVA photochemotherapy is effective for treating this dermatosis.ObjectivesAlthough according in earlier reports mainly white populations have been treated successfully with bath PUVA therapy, there is little knowledge of whether it is effective in treating colored populations. We treated a 64-year-old Japanese woman suffering from disseminated scleroderma with bath PUVA photochemotherapy to see its effects.ConclusionAlthough rather high cumulative UVA doses were required for this patient compared with those needed in earlier reports, no adverse effects were observed. The lesions were markedly improved, suggesting that this therapeutic modality is well-tolerated and useful for colored patients such as the Japanese. Furthermore, it turns out that the thermographical assessment is useful to estimate clinical improvement of this sclerosing skin disorder.SommaireAntécédentsLa sclérodermie localisée s’est avérée résistante aux divers traitements. On a rapporté récemment que la PUVAthérapie est efficace dans le traitement de cette dermatose.ObjectifBien que, selon certains rapports antérieurs, la PUVAthérapie ait donné d’excellents résultats surtout chez les blancs, il existe peu de données indiquant si elle est efficace chez les gens de couleur. Toutefois, une Japonaise de 64 ans souffrant de sclérodermie disséminée a été traitée par PUVAthérapie.ConclusionBien que d’assez fortes doses cumulatives d’UV-A aient été nécessaires dans le cas de cette patiente comparativement aux sujets qui ont fait l’objet de rapports antérieurs, aucun effet indésirable n’a été observé. Les lésions étaient nettement atténuées, ce qui fait croire que ce mode de traitement est bien toléré et qu’il est également efficace chez les patients de couleur comme cette Japonaise. En outre, il s’est avéré que l’examen thermographique est utile pour évaluer l’amélioration clinique de cette affection sclérosante de la peau.