Oncogenic role of microRNA-155 in mycosis fungoides: an in vitro and xenograft mouse model study.

Background: MicroRNA (miR)-155 contributes to the proliferation of mycosis fungoides (MF) in vitro and is upregulated in tumours of MF compared with early MF lesions.

Objectives: To investigate the contribution of miR-155 to the cancerous phenotype and drug resistance of MF/Sézary cell lines.

Methods: miR-155 was inhibited in MF cell lines (MyLa and MJ) by transduction of miRZip anti-miR-155, and overexpressed in Hut78 cells by transduction of miRVec-miR-155; empty plasmids served as controls.

Alopecia areata: Animal models illuminate autoimmune pathogenesis and novel immunotherapeutic strategies.

One of the most common human autoimmune diseases, alopecia areata (AA), is characterized by sudden, often persisting and psychologically devastating hair loss. Animal models have helped greatly to elucidate critical cellular and molecular immune pathways in AA. The two most prominent ones are inbred C3H/HeJ mice which develop an AA-like hair phenotype spontaneously or after experimental induction, and healthy human scalp skin xenotransplanted onto SCID mice, in which a phenocopy of human AA is induced by injecting IL-2-stimulated PBMCs enriched for CD56+/NKG2D+ cells intradermally.

Abnormal interactions between perifollicular mast cells and CD8+ T-cells may contribute to the pathogenesis of alopecia areata.

Alopecia areata (AA) is a CD8+ T-cell dependent autoimmune disease of the hair follicle (HF) in which the collapse of HF immune privilege (IP) plays a key role. Mast cells (MCs) are crucial immunomodulatory cells implicated in the regulation of T cell-dependent immunity, IP, and hair growth. Therefore, we explored the role of MCs in AA pathogenesis, focusing on MC interactions with CD8+ T-cells in vivo, in both human and mouse skin with AA lesions.

A new humanized mouse model for alopecia areata.

Although alopecia areata (AA) is not life threatening, it may lead to severe psychological disturbances, reducing the quality of life in all ages. Thus, a new animal model is needed for shedding more light onto the pathogenesis of this cell-mediated, organ-specific autoimmune disease to identify more effective therapeutic strategies. Recently, we succeeded in developing a new humanized mouse model of AA, which includes transplantation of healthy human scalp skin obtained from normal volunteers on to severe-combined immunodeficient mice.

The beneficial effect of blocking Kv1.3 in the psoriasiform SCID mouse model.

The Kv1.3 channel is important in the activation and function of effector memory T cells. Recently, specific blockers of the Kv1.

Lymphocytes, neuropeptides, and genes involved in alopecia areata.

Many lessons in autoimmunity - particularly relating to the role of immune privilege and the interplay between genetics and neuroimmunology - can be learned from the study of alopecia areata, the most common cause of inflammation-induced hair loss. Alopecia areata is now understood to represent an organ-restricted, T cell-mediated autoimmune disease of hair follicles. Disease induction is associated with collapse of hair follicle immune privilege in both humans and in animal models.

Aging of human epidermis: reversal of aging changes correlates with reversal of keratinocyte fas expression and apoptosis.

The goal of this study was to determine the role of Fas-mediated apoptosis in human epidermal aging. Epidermal Fas expression and apoptosis are increased in aged human skin. Aging changes of human epidermis, including decreased epidermal thickness and proliferation, are reversed following grafting of human skin to SCID (severe combined immunodeficiency) mice.

Transfer of alopecia areata in the human scalp graft/Prkdc(scid) (SCID) mouse system is characterized by a TH1 response.

Alopecia areata is an autoimmune condition directed at hair follicles, which results in loss of hair. We have previously demonstrated that it is possible to transfer hair loss, along with the immunohistologic findings of alopecia areata, to human scalp grafts on Prkdc(scid) (SCID) mice by injection of autologous activated lesional T-cells. This study examines the cytokine profile of T-cells and follicular epithelium following transfer of hair loss.

Psoriasis is mediated by a cutaneous defect triggered by activated immunocytes: induction of psoriasis by cells with natural killer receptors.

This study was performed to ask whether psoriasis is a unique pathologic response of epidermis of psoriatic patients, or cells with natural killer receptors can induce psoriatic changes in skin from nonpsoriatic donors. Human nonlesional skin from five psoriatics, as well as from seven nonpsoriatics was grafted on to beige-SCID mice. Lymphocyte lines with natural killer activity, and mixed natural killer, natural killer T cell phenotype, were generated by culture of peripheral blood mononuclear cells from both psoriatic, and normal donors, in 100 U interleukin-2 per ml for 14 d.

Mediation of alopecia areata by cooperation between CD4+ and CD8+ T lymphocytes: transfer to human scalp explants on Prkdc(scid) mice.

Objective: To determine the role of CD4+ and CD8+ T lymphocytes in the pathogenesis of alopecia areata.

Design: Relapse of alopecia areata was induced in autologous human scalp grafts on Prkdc(scid) mice by injection of activated T lymphocytes derived from lesional skin. CD4+ and CD8+ T cells were separated by magnetic beads before injection.

Melanocyte-associated T cell epitopes can function as autoantigens for transfer of alopecia areata to human scalp explants on Prkdc(scid) mice.

Alopecia areata is a tissue restricted autoimmune condition affecting the hair follicle, resulting in hair loss. The goal of this study was to test the hypothesis that the autoantigen of alopecia areata is melanocyte associated. Potential autoantigens were tested in the human scalp explant/Prkd(scid) CB-17 mouse transfer system.