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Background Langerhans cells (LCs) are one of the initial target cells for HIV following sexual exposure and they are productively infected by HIV. HIV-infected LCs migrate to the draining lymph nodes (dLNs) and transmit the virus to CD4+ T cells, leading to the dissemination of HIV. In contrast with the role of LCs in initial HIV acquisition, little is known about the modulation of immune responses by HIV-infected LCs. Objective We aimed to elucidate the induction of HIV-specific CD8+ T cells and regulatory T cells (Tregs), both of which play important roles in regulating the progression of HIV infection. Methods We examined the inducibility of HLA-A*0201 restricted HIV-specific CD8+ T cells and Tregs by HIV-primed LCs or HIV-primed dendritic cells (DCs) as a control. Results The number of HIV-specific CD8+ T cells induced by HIV-primed monocyte-derived LCs (mLCs) was significantly higher than that by HIV-primed monocyte-derived DCs (mDCs). Additionally, HIV-specific CD8+ T cells induced by HIV-primed mLCs produced more IFN-γ than HIV-nonspecific CD8+ T cells. HIV-primed human epidermal LCs also induced IFN-γ-producing HIV-specific CD8+ T cells. As for the induction of Tregs, HIV-primed mLCs and human epidermal LCs significantly impaired the induction of FoxP3hiCD45RA− effector Tregs than HIV-unprimed mLCs and human epidermal LCs. Conclusions HIV-primed LCs trigger beneficial immune responses against HIV infection through the increased induction of HIV-specific CD8+ T cells and the decreased induction of effector Tregs in the initial phase of HIV infection, thereby contributing to the prolonged onset of AIDS.

Three-dimensional (3D) epidermal models reconstructed from human skin-derived keratinocytes have been utilized as an alternative to animal testing and models, not only in toxicology, but also in skin biology. Although there are currently several reconstructed human epidermis (RHE) models commercially available, the donors of the keratinocytes are not identified in these models. A tailor-made system is needed to investigate the individual differences in RHE derived from each donor.It is possible to make an individual RHE using each donor's keratinocytes, which are usually obtained by invasive procedures such as skin excision or biopsy. To overcome this drawback, we established an RHE model using keratinocytes derived from plucked hair follicles as a less invasive procedure under conditions without feeder cells, serum, or matrix proteins. In this chapter, we provide a method of isolation and two-dimensional (2D) culture of keratinocytes derived from adult human plucked hair follicles including the outer root sheath (ORS). We also provide a detailed protocol for establishing an RHE model by culturing the keratinocytes under a 3D culture condition. We believe that our less invasive technique will provide a useful tool for investigating individual RHE in both normal and disease settings.

Three-dimensional (3D) epidermal models reconstructed from human skin-derived keratinocytes have been utilized as an alternative to animal testing and models, not only in toxicology, but also in skin biology. Although there are currently several reconstructed human epidermis (RHE) models commercially available, the donors of the keratinocytes are not identified in these models. A tailor-made system is needed to investigate the individual differences in RHE derived from each donor.It is possible to make an individual RHE using each donor's keratinocytes, which are usually obtained by invasive procedures such as skin excision or biopsy. To overcome this drawback, we established an RHE model using keratinocytes derived from plucked hair follicles as a less invasive procedure under conditions without feeder cells, serum, or matrix proteins. In this chapter, we provide a method of isolation and two-dimensional (2D) culture of keratinocytes derived from adult human plucked hair follicles including the outer root sheath (ORS). We also provide a detailed protocol for establishing an RHE model by culturing the keratinocytes under a 3D culture condition. We believe that our less invasive technique will provide a useful tool for investigating individual RHE in both normal and disease settings.

We report a case of an 88-year-old woman with a decalvant, erythematous, ulcerated tumor extending from the right temporal to occipital region. Histopathological analysis revealed a dense infiltration of medium-to-large-sized atypical cells throughout the entire dermis. The result of immunohistochemical analysis showed that the infiltrating T cells expressed programmed death-1 (PD-1), Bcl-6 and CXCL13. Flow cytometry analysis showed that CD4(+) PD-1(hi) T cells also expressed CD10, inducible T-cell co-stimulator and CXCR5. On the basis of the clinical appearance and the histopathological findings, we diagnosed the patient with primary cutaneous peripheral T-cell lymphoma, not otherwise specified. Recently, the concept of primary cutaneous follicular helper T (TFH)-cell lymphoma was proposed, and in this case, tumor cells clearly expressed TFH-cell markers. Therefore, we considered this case to be a variant of the entity. Although this entity is still provisional, this case supports the new concept.

From a clinicopathological conference on nine elderly patients with Epstein-Barr virus (EBV)-associated T/natural killer (NK)-cell lymphoma, we have addressed the patients' backgrounds, clinical manifestations, histopathological findings, cytogenesis, complications and prognoses. Among these elderly patients (>65 years old), seven patients had extranodal NK/T-cell lymphoma, nasal type (ENKL) with an NK-cell phenotype, and two patients had EBV(+) T-cell lymphomas or lymphoproliferative disorders (LPD) with cutaneous lesions mimicking pityriasis lichenoides et varioliformis acuta (PLEVA) or hydroa vacciniforme (HV). No patients had a previous episode of EBV-related symptoms such as infectious mononucleosis, chronic active EBV infection, HV or hypersensitivity to mosquito bites. Elderly patients with ENKL may show the centroblastoid variant. EBV(+) CD8(+) CD56(+/-) lymphocytes may be responsible for the development of PLEVA or HV-like cutaneous lesions in the elderly.

ejd.2012.1737 Auteur(s) : Youichi Ogawa youichi73027@hotmail.com, Rui Aoki, Kazutoshi. Harada, Takamitsu Matsuzawa, Takashi Inozume, Naotaka Shibagaki, Tatsuyoshi Kawamura, Shinji Shimada Department of Dermatology, Faculty of Medicine, University of Yamanashi, 1110 Shimokato Chuo, Yamanashi 409-3898, Japan Crohn's disease (CD) is an ulcerative granulomatous inflammatory disorder and accompanies numerous dermatologic complications, such as disease-associated skin findings (metastatic CD, contiguous perianal [...]

Pellagra is caused by niacin deficiency and characterized by hotosensitive dermatitis, diarrhea, dementia, however, the exact athomechanism of these symptoms is not yet known. Since the athological and clinical anomalies of pellagre aremostly common o those of zinc defiency,we suspected the alteration of Langerhans ells might be the clue of pellagra lesion, whose disappearance is lso noted in acrodermatitis enteropathica recently. We analysed he presence of various cells in pellagra patients, and confirmed he selective disappearance of dendritic cells componens assumed y the immunohistochemical staining for langerin, HLA-DR, CD1a nd S100 at lesiona skin. Mast cells, merkel cells and melanocytes id not largely change their numbers compared with normal skin. e relvealed that the degeneration of kerationcytes in the upper pinous layer is not by the pure apoptotic pathway represenred y the expresion of cleaved caspase 3 and TUNEL method. We furher analyzed the temporal change of the dendritic cells at skin and ntestines using the pellagra model treated with niacin antagonist, AN, or the niacin defient diet. From the observations,we supposed hat losses of the cutaneous dendritic cells are the commonandpriary pathophysiological mechanism of the trophic skin diseased ncluding pellagra and acrodermatitis enteropathica.

SummaryHerpes simplex virus (HSV)-2 shedding is associated with increased risk for sexually acquiring HIV. Because Langerhans cells (LCs), the mucosal epithelium resident dendritic cells, are suspected to be one of the initial target cell types infected by HIV following sexual exposure, we examined whether and how HSV-2 affects HIV infection of LCs. Although relatively few HSV-2/HIV-coinfected LCs were detected, HSV-2 dramatically enhanced the HIV susceptibility of LCs within skin explants. HSV-2 stimulated epithelial cell production of antimicrobial peptides (AMPs), including human β defensins and LL-37. LL-37 strongly upregulated the expression of HIV receptors in monocyte-derived LCs (mLCs), thereby enhancing their HIV susceptibility. Culture supernatants of epithelial cells infected with HSV-2 enhanced HIV susceptibility in mLCs, and this effect was abrogated by blocking LL-37 production. These data suggest that HSV-2 enhances sexual transmission of HIV by increasing HIV susceptibility of LCs via epithelial cell production of LL-37.